Kimber A. Geving

Assist. t Counsel

Division of Legal Counsel

IN THE MATTER OF:

PROPOSED AMENDMENTS TO

GROUNDWATER QUALITY

STANDARDS

(35 Ill. Adm. Code 620)

CLEINK'S

eceivEcto

OFFICE

JUL 1 1 2008

STATE

OF

ILLINOIS

R08-18

Pollution Control Board

(Rulemaking-Public Water Supplies)

BEFORE THE ILLINOIS POLLUTION CONTROL BOARD

NOTICE OF FILING

Dorothy. Gunn, Clerk

Illinois Pollution Control Board

James R. Thompson Center

100 W. Randolph, Suite 11-500

Chicago, Illinois 60601

(Via Federal Express)

Matt Dunn

Environmental Bureau Chief

Office of the Attorney General

James R. Thompson Center

100 W. Randolph, 12

th

Floor

Chicago, Illinois 60601

(Via First Class Mail)

(Service List-Via First Class Mail)

Bill Richardson

Chief Legal Counsel

Illinois Dept. of Natural Resources

One Natural Resources Way

Springfield, Illinois 62702-1271

(Via First Class Mail)

Richard R. McGill, Jr.

Hearing Officer

Illinois Pollution Control Board

James R. Thompson Center

100 W. Randolph, Suite 11-500

Chicago, Illinois 60601

(Via Federal Express)

PLEASE TAKE NOTICE that I have today filed with the Office of the Clerk of the

Illinois Pollution Control Board the Illinois Environmental Protection Agency's

MOTION TO CORRECT THE TRANSCRIPT, ERRATA SHEET NUMBER 3, AND

SUPPLEMENTAL TESTIMONY OF THE ILLINOIS EPA

a copy of each of which is

herewith served upon you.

ILLINOIS EVIRONMENTAL

PROTECTION AGENCY

---

DATED: July 10, 2008

1021 North Grand Ave. East

P.O. Box 19276

Springfield,' Illinois 62794-9276

(217) 782-5544

---

BEFORE THE ILLINOIS POLLUTION CONTROL BOARD

"

C

IE

LER

C

K'S

E

OFFICE

V

FFICE

E D

JUL 1 1 2008

R08-18

?

STATE OF ILLINOIS

(Rulemaking-Public 'eaVtgaPiLr

g

jol

Board

MOTION TO CORRECT THE TRANSCRIPT

NOW COMES the Illinois Environmental Protection Agency ("Illinois EPA") by

one of its attorneys, Kimberly A. Geving, and pursuant to 35 Ill. Adm. Code 101.604

moves the hearing officer in this matter to correct the transcript of June 18, 2008 as

follows:

Page?Line?Correction

10?4?Change "Standard" to "Standards"

10

?

12-13

?

Change "upgraded subject to" to "updated for"

10?23?Change "RECRA" to "RCRA"

11?11?Change "incorporation" to "incorporations"

11?13?Change "changes" to "references"

13?1?Change "contaminant" to "contaminants"

14

?6?

Change "Innovated" to "Integrated"

14?

14?Same change as in line 6 on this page

15

?

2

?

Change "Review" to "Reviewed"

15?14

?Change "stop" to "stopped"

15?

22

?Add and "and" after "Substances"

16?5?

Change "bioda" to "biota"

16?

13?Change "Tier" to "Tiered"

17

?

18?Change "self' to "soil"

19?

21?Mr. Davis' first name is Alec, not Alex

24?

21

?

Change "R89149(b)" to "R89-14(B)"

27

?8?Change "35I1Ad.620.410(e)" to "35 Ill. Adm. Code

620.410(e)"

28?14

?Change "mailable" to "malleable"

28?17?

Delete "proposed and then"

28?

18?After "of' add "cations and anions"

28?

18

?Replace "already put the" with "are composed of

28?

18?Make the last "cation" plural

IN THE MATTER OF:

PROPOSED AMENDMENTS TO

GROUNDWATER QUALITY

STANDARDS

(35 Ill. Adm. Code 620)

---

28

19

28

21

31

9

31

32 •

32

34

34

36

37

40

40

41

42

42

42

42

43

51

51

51

51

56

58

62

5

17

6

13

23

24

2

12

23

3

14

14

14

21

2

3

19

24

20

19

18

Kimberl A. Geving

Assist. t Counsel

Division of Legal Counsel

Make "anion" plural

Delete "and those"

The reference to "THE COURT" is incorrect

The reference to "Dave" is incorrect. There was no Dave

present at the hearing

Change "instigation" to "removal efficiency of

Change "not" to "none"

Change "carcinogenic" to "carcinogen"

Change "620.10(b)" to "620.410(b)"

Change "043" to ".043"

Change "Qualities" to "Quality's"

Change "contents" to "constants"

Change "rule" to "Board"

Change "R8914(b)" to "R89-14(B)"

Change "basis" to "bases"

Change "to" to "and"

Change "confirm" to "confirmed"

Replace "by the" with "in"

Change "35E.Ad.611" to "35 Ill. Adm. Code 611"

Change "mount" to "melt"

Change "go" to "going"

Change "R914(b)" to "R89-14(B)"

We believe the hearing officer said "R08-18"

Add "addition" after "in" •

Change "prescribes" to "subscribes"

Change "1-dichloroethane" to "1,1,dichloroethane"

Respectfully submitted,

ILLINOIS ENVIRONMENTAL

PROTECTION AGENCY

Dated: July 10, 2008

1021 N. Grand Ave

P.O. Box 19276

Springfield, Illinois

(217) 782-5544

. East

62794-9276

---

BEFORE THE ILLINOIS POLLUTION CONTROL BOARD

IN THE MATTER OF:

)

)

PROPOSED AMENDMENTS TO

)

R08-18

GROUNDWATER QUALITY

)

(Rulemaking-Public W

elsVE

STANDARDS

S OFFICE

D

)

(35 Ill. Adm. Code 620)

)

)

JUL 1 1 2008

ERRATA SHEET NUMBER 3

Pollution

STATE OF

Control

ILLINOIS

B

oard

NOW COMES

the Illinois Environmental Protection Agency through one of its

attorneys, Kimberly Geving, and.submits this ERRATA SHEET NUMBER 3 to the

Illinois Pollution Control Board and the participants on the Service List. Please note that

the errata changes reflect amendments to our original proposal as submitted to the Board

on February 15, 2008 and not to the existing rule or any changes made in Errata Sheets 1

and 2.

Tom Hornshaw, Rick Cobb, and Gary King will provide testimony in support of

these changes at the hearing on July 16, 2008.

Section

620.410(b)

Anthracene

2.10,0434

Chloroform

0.07

0.0002

Chrysene

0.012

07004-6

Di-n-octyl phthalate

0.28 0.02

Fluoranthene

0.28

0.206

Indeno(1,2,3-cd)pyrene

0.00043

620.420(b)

Anthracene

10.5

0.0434

Benzo(k)fluoranthene

0.006

0.0008

Benzo(a)pyrene

0.002

0.00162

Chloroform

0.35 0:004-

Chrysene

0.06 0,004-6

Di-n-octyl phthalate

1.4

0.02

Fluoranthene

1.4 0406

Indeno(1,2,3-cd)pyrene

0.0022

0.00043

Methoxychlor

0.2

---

Kimberl A. Ge mg

Assist. Counsel

Division of Legal Counsel

620.605(c)

Remove this from the proposal.

Respectfully submitted,

ILLINOIS ENVIRONMENTAL

PROTECTION AGENCY

DATED: July 10, 2008

1021 North Grand Avenue East

P.O. Box 19276

Springfield, Illinois 62794-9276

(217) 782-5544

2

---

BEFORE THE ILLINOIS POLLUTION CONTROL BOARD

IN THE MATTER OF:

R08-018

Receive()

(Rulemaking-Public Water Supp

ol7

utio

E

n

R:

OFFICE

STATE OF

SUPPLEMENTAL TESTIMONY OF THE ILLINOIS EPAP

jUL

/ 1 2008

C

ontrol

trol

I

Board

This testimony responds to additional questions and requests provided in an Illinois

Pollution Control Board Hearing Officer Order issued on June 20, 2008. The testimony is

intended to answer the following questions asked in the Illinois Pollution Control Board ("Board")

Hearing Officer Order. Additionally, the Illinois EPA is adding Gary King to the panel of

witnesses, and this supplemental testimony is a joint effort of Richard P. Cobb, Thomas C.

Hornshaw, and Gary King. All three witnesses will be available to answer questions regarding this

written testimony.

I.

?

BOARD QUESTIONS/REQUESTS AND ILLINOIS EPA RESPONSES

Board questions/requests are followed by emboldened Illinois EPA responses.

Question 1 -

At page 11 of Mr. Cobb's pre-filed testimony, he states that the proposed

standards are based on a United States Environmental Protection Agency ("USEPA") Maximum

Contaminant Level ("MCL") or Board MCL, a reference dose ("RfD") in USEPA's Integrated

Risk Information System (IRIS), USEPA Health Effects Assessment Summary Table

("HEAST") RfD, Provisional Peer Reviewed Toxicity Values ("PPRTV") RfD, and IRIS

Slope Factor ("Sfo").

a.

Please clarify whether USEPA's MCLs are the same as the Board's MCLs. If not,

please explain any differences.

b.

The proposed standards for several inorganic and organic chemical constituents

are based on RfDs and Sfos obtained from the various USEPA databases. Please

explain how the Agency used the RfDs and Sfos to derive the proposed standards

for

various chemical constituents

i. Would the Agency be able to update the tables on pages 12 and 13 of Mr.

Cobb's pre-filed testimony to include the appropriate RfD values used to

determine the proposed standards?

PROPOSED AMENDMENTS TO

GROUNDWATER QUALITY

STANDARDS

(35 Ill. Adm. Code 620)

---

ii.?

Also, would the Agency be able to submit pertinent documentation from

the USEPA databases concerning the RfDs and Sfos used to derive the

proposed standards?

c.?

Please clarify whether any of the proposed Class I standards are based on the

RfDs from USEPA's HEAST database. If so, please submit documentation

concerning the relevant RfDs/Sfos used to derive the proposed standards.

Response to Question (1)(a) – Yes. The U.S. EPA MCL is the same as the Board's

drinking water standards at 35 Ill. Adm. Code 611.

Response to Request (1)(b)(i) and (1)(b)(ii) and (1)(c) – In response to these requests,

we reviewed the basis for all the proposed changes to the groundwater standards.

The accompanying Table 1 (below) lists the basis for each change. This review has

resulted in a few additional changes to the proposed standards, which are explained

as follows:

•

Chloroform- The values originally proposed, 0.0002 mg/1 for Class I and 0.001 mg/1

for Class II, were from the TACO groundwater objectives. These values were

developed from the lowest PQL, the only option for developing a Health Advisory

concentration for a carcinogen pursuant to Subpart F at the time this chemical was

entered into TACO. However, our review found both a cancer Sfo (from California

EPA) and a non-cancer RfD (from IRIS), and since we are proposing to amend the

Subpart F procedures for carcinogens to also consider the 1-in-1,000,000 cancer risk

level, we now need to compare the 1-in-1,000,000 risk (0.0027 mg/1) and PQL (0.0002

mg/1) values as potential groundwater standards. Also, the IRIS RfD has been used

by EPA as the basis for promulgating a final Maximum Contaminant Level Goal

(MCLG) of 0.07 mg/1 in the Stage 2 Disinfectants and Disinfectants Byproducts Rule,

which they state as being protective for both cancer and non-cancer effects. This

information presents a dilemma in that Subpart F, while specifying procedures for

developing Health Advisories for carcinogens and non-carcinogens, does not provide

guidance as to which takes precedence if both values can be developed. In most cases,

we would recommend the lower of the two, but in this case we prefer the MCLG, even

though it is the higher of the two values (0.07 vs. 0.0027 mg/1), since it is taken from a

promulgated federal rule and is found to be protective against cancer. We welcome

the Board's review of this issue.

•

Solubility- All references to the use of solubility as a basis for groundwater standards

have been removed (discussed in depth in response to Request 8).

•

Benzo(a)pyrene (BaP) and Methoxychlor- Our proposal calls for replacing the

existing Class II groundwater standards for BaP (0.002 mg/I) and Methoxychlor (0.2

mg/1) with values based on solubility, but since solubility is no longer considered in

developing standards, the proposed solubility-based standards of 0.0016 mg/1 and

0.045 mg/1, respectively, should be dropped and these two chemicals should be

removed from the proposal.

2

---

Response to Question (1)(c)- The reference to HEAST should be dropped. HEAST

was used to derive some of the TACO objectives. However, we are now listing the

TACO objective as the basis for some of the proposed new groundwater standards.

TABLE 1: Toxicology Values Used To Develop Proposed 620 Standards

Inorganic Chemicals

Proposed

Class I

Standard

(mg/L)

Basis for

Class I

Standard

Proposed

Class II

Standard

(mg/L)

Basis for

Class

II

Standard

Reference

Dose (RfD)

Oral Slope

Factor

(SFo)

Arsenic*

0.010

Board

and

U.S.EPA MCL

0.20

Irrigation

-

-

Molybdenum

0.035

IRIS RID

0.035

1X Class I

0.005

-

Perchlorate

0.0049

IRIS RfD

0.0049

Treatment

Factor

0.0007

-

Vanadium

0.049

TACO /H

EAST

RfD

0.1

•

Irrigation

0.007

•

-

Volatile Organic

Compounds

Proposed

Class I

Standard

(mg/L)

Basis for

Class I

Standard

Proposed

Class II

Standard

(mg/L)

Basis for

Class II

Standard

Reference

Dose (RfD)

Oral Slope

Factor

(SFo)

Acetone

6.3

TACO/IRI S

RfD

6.3

1X Class I

0.9

-

2-Butanone (MEK)

4.2

IRIS RfD

4.2

1X Class I

0.6

-

Carbon disulfide

0.7

TACO/IRIS

RfD

3.5

5X Class I

0.1

-

Chloroform* (risk-based)

0.0027

10

-6

cancer

risk/CalEPA

SFo

0.014

5X Class I

-

0.031

Chloroform* (criteria-based)

0.07

U.S.EPA

MCLG

0.35

5X Class I

-

-

Dichlorodifluoromethane

1.4

IRIS RID

7.0

5X Class I

0.2

-

1,1-Dichloroethane

1.4

PPRTV RID

7.0

5X Class I

0.2

-

Isopropylbenzene (Cumene)

0.7

IRIS RfD

3.5

5X Class I

0.1

-

Trichlorofluoromethane

2.1

IRIS RfD

10.5

5X Class I

0.3

-

Semivolatile Organic

Compounds

Proposed

Class I

Standard

(mg/L)

Basis for

Class I

Standard

Proposed

Class II

Standard

(mg/L)

Basis for

Class II

Standard

Reference

Dose (RfD)

Oral Slope

Factor

(SFo)

Acenaphthene

0.42

TACO/IRI S

RID

2.1

5X Class I

0.06

-

Anthracene

2.1

TACO/IRI S

RfD

10.5

5X Class I

0.3

-

Benzo(a)anthracene*

0.00013

TACO/ADL

0.00065

5X Class I

-

-

Benzo(b)fluoranthene*

0.00018

TACO/ADL

0.0009

5X Class I

-

-

Benzo(k)fluoranthene*

0.0012

10-6 cancer

risk/IRIS

risk/IRISSFo

0.006

5X Class I

-

0.073

Benzoic acid

28.0

TACO/IRI S

RfD

28.0

1X Class I

4.0

-

Chrysene*

0.012

1 0-6 cancer

0.06

5X Class I

-

0.0073

3

---

risk/IRIS SFo

Dibenzo(a,h,)anthracene*

0.0003

TACO/ADL

0.0015

5X Class I

-

-

Diethyl phthalate

5.6

TACO/IRIS

RID

5.6

1X Class I

0.8

-

Semivolatile Organic

Compounds (continued)

Proposed

Class I

Standard

(mg/L)

Basis for

Class I

Standard

Proposed

Class

I

Standard

(mg/L)

Basis for

Class H

Standard

Reference

Dose (RfD)

Oral Slope

Factor

(SFo)

Di-n-butyl phthalate

0.7

TACO/IRI S

RID

3.5

5X Class I

0.1

-

Di-n-octyl phthalate

0.28

TACO/

PPRTV RID

1.4

5X Class I

0.04

-

Fluoranthene

0.28

TACO/IRIS

RfD

1.4

5X Class I

0.04

-

Fluorene

0.28

TACO/IRIS

RID

1.4

5X Class I

0.04

-

Indeno(1,2,3-cd)pyrene*

0.00043

TACO/ADL

0.0022

5X Class I

-

.

-

2-Methylnaphthalene

0.028

IRIS RfD

0.14

5X Class I

0.004

-?

.

2-Methylphenol

0.35

TACO/IRI S

RfD

0.35

1X Class I

0.05

Naphthalene

0.14

TACO/IRIS

RID

0.22

TACO/IRIS

RfD

0.02

-

p-Dioxane*

0.0077

10?

-6 cancer

risk/IRIS SFo

0.0077

1X Class I

-

0.011

Pyrene

0.21

TACO/IRIS

RfD

1.05

5X Class I

0.03

-

Pesticide Compounds

Proposed

Class I

Standard

(mg/L)

Basis for

Class

I

Standard

Proposed

Class

II

Standard

(mg/L)

Basis for

Class

H

Standard

Reference

Dose

(RfD)

Oral Slope

Factor

(SFo)

alpha-BHC*

0.00011

TACO/ADL

0.00055

5X Class I

-

Dicamba

0.21

IRIS RID

0.21

1X Class I

0.03

-

MCPP (Mecoprop)

0.007

IRIS RfD

0.035

5X Class I

0.001

-

Explosive Compounds

Proposed

Class I

Standard

(mg/L)

. Basis for

Class I

Standard

Proposed

Class II

Standard

(mga)

Basis for

Class H

Standard

Reference

Dose (RfD)

Oral

Slope

Factor

(SFo)

1,3-Dinitrobenzene

0.0007

IRIS RID

0.0007

1X Class I

0.0001

-

2,4-Dinitrotoluene*

0.0001

l

e cancer

risk/IRIS SFo

0.0001

1X Class I

-

0.68

2,6-Dinitrotoluene*

0.00031

TACO/ADL

0.00031

1X Class I

-

-

HMX•

1.4

IRIS RfD

1.4

1X Class I

0.05

Nitrobenzene

0.0035

TACO/IRIS

RID

0.0035

1X Class I

0.0005

-

RDX

0.084

IRIS RID

0.084

1X Class I

0.003

0.84

-

1,3,5-Trinitrobenzene

IRIS RID

0.84

1X Class I

0.03

-

2,4,6-Trinitrotoluene

0.014

IRIS RID

0.014

1X Class I

0.0005

-

* Denotes a carcinogen.

- Denotes no data or not applicable.

4

---

Question 2 - On page 11 of Mr. Cobb's pre-filed testimony, he states that some of the

proposed standards are based on Method Detection Limits ("MDLs") used to derive the Part 620,

Subpart F, Appendix A: Human Threshold Toxicant Advisory Concentration for Tiered

Approach to Corrective Action Objectives ("TACO") groundwater objectives under Part

742.

a.

Please clarify whether all of the proposed standards based on TACO groundwater

objectives are based on MDLs.

b.

Also, please explain how MDLs were used to derive the proposed standards for

which TACO groundwater objectives are listed as the basis for the standard.

Response to Question (2)(a) – Referencing the MDL was incorrect. The practical

quantitation limit ("PQL") should have been referenced.

Response to Question (2)(b) - Some of the TACO objectives were based on PQLs (not

MDLs) where the health based numbers were below the PQL.

Question 3 - Also on page 11 of Mr. Cobb's pre-filed testimony, he notes that carcinogens

are denoted in the proposed Class I standard by an asterisk. Please clarify whether

dibenzo(a,h)anthracene should be listed under Section 620.410(b) with an asterisk to

indicate that it is a carcinogen.

Response to Question 3 – Dibenzo (a,h) anthracene is a carcinogen, and should be so

noted.

Request 4 - The proposal lists the acronyms for several chemical constituents in Section

620.410. Please provide the chemical names for alpha-BHC, MCPP, HMX and RDX.

Response to Request 4 – The following provides the chemical, common and

abbreviated names:

Chemical.Naine

onithon Name

Abbreviated

-

'Name

1,2,3,4,5,6-hexachlorocyclohexane

Alpha-Benzene

hexachloride

alpha-BHC

2-(2-Methyl-4-chlorophenoxy)

propionic acid

Mecoprop

MCPP

Octahydro-1,3,5,7-Tetranitro-

1,3,5,7-Tetrazocine

High Melting

Explosive, Octogen

HMX

Hexahydro-1,3,5-trinitro-1,3,5-

triazine

Royal Demolition

Explosive, Cyclonite

RDX

Request 5 - On page 14 of Mr. Cobb's pre-filed testimony, he states that the proposed Class

II standards for inorganic constituents are based on irrigation and livestock watering from a

5

---

1972 report published by the National Academy of Sciences entitled "Water Quality

Criteria." Would the Agency be able to submit a copy of the NAS report or the relevant

pages of the report?

Response to Request 5 – Per your request a copy of the NAS report is attached.

Question 6 -

On page 14 of Mr. Cobb's pre-filed testimony, the groundwater standards

table lists the basis for the proposed Class II standard for molybdenum as the Class I standard, but

it is

also noted that the irrigation criterion is 10. Please explain the rationale for proposing the

Class II standard for molybdenum at the same level as Class I standard instead of the

irrigation criterion.

Response to Question 6 – The note should have been that the irrigation criterion is

0.01 milligrams per liter ("mg/1"). Therefore, since the magnitude of the proposed

Class I standard at 0.035 mg/1 is not significantly different from 0.01 mg/1, the Illinois

EPA proposed the 0.035 mg/1 as the Class II standard.

Question 7 - On

page 16 of Mr. Cobb's pre-filed testimony, he states that a five-fold

treatment factor was used to derive a Class II standard for organic compounds with a Koc value

greater than that of ethylbenzene or a Henry's Law constant greater than that of methylene

chloride. Please comment on whether the same factors were considered in deriving the

TACO Class II groundwater objectives, which are also being proposed as the Class II

. standards in the Agency's proposal.

Response to Question 7 – Yes.

Request 8 -

Mr. Cobb lists water solubility as the basis for several Class I and Class II

standards. Please provide citations to the publications from which the Agency obtained the water

solubility values to develop the standards.

Response to Request 8 - There has been considerable dialogue recently between the

Agency and the Illinois Environmental Regulatory Group (IERG) regarding the use

of solubility as a limitation on the Class I and Class II groundwater standards. Some

of this dialogue is reflected in a line of questioning initiated by Mr. Davis in the first

hearing in Chicago, and the Agency and IERG continued this dialogue in a July 8

meeting at the Agency. Several key issues were discussed at this meeting.

The Illinois EPA has been administering 35 Ill. Adm. Code 742 "Tiered Approach to

Corrective Action Objectives" ("TACO") since 1998. TACO has proven to be a

complex, but flexible approach to the remediation of contaminated sites in Illinois and

has been a model for the development of similar approaches in several other States.

There are a number of principles that underlie the successes of TACO. Two of those

principles are pertinent to the discussion of water solubility as a basis for

groundwater quality standards in this proceeding: (1) the risk-based principles

6

---

embodied in Tiers 1,2, and 3 of Part 742 and (2) the "speed bump" principles in

Subpart C. The risk-based methodology allows the development of remediation

objectives that are tailored to the specific contaminant risks pertinent to a site. The

speed bump principles provide a methodology such that the contaminant source

materials are removed from a site. As an example, groundwater cannot be excluded

as a pathway of concern until free product is removed.

There is a close nexus between TACO and the Part 620 standards. The groundwater

remediation objectives in TACO (Appendix B, Table E) were generally either taken

from Part 620 or were developed using Part 620 methodologies to protect

groundwater users. TACO has been updated as the Part 620 standards have changed

over the years. Since the Part 620 standards are primarily health based in origin,

TACO evaluations of the groundwater ingestion exposure route have likewise been

health based in evaluating risk from the site contamination.

The current regulatory proceeding will result in changes to the Part 620 standards.

In due course, TACO will be amended to reflect the Part 620 standards. Currently,

Illinois EPA is working on a significant amendatory proposal to TACO that is

intended to be filed with the Board later this summer. This proposal will incorporate

a new pathway (indoor inhalation) and many changes to the Tier 1 remediation

objectives based on more current toxicological information. We also intend the

proposal to reflect the ongoing changes in this Part 620 proceeding.

As part of Illinois EPA's consultation with the Site Remediation Advisory Committee

("SRAC") with regards to our draft TACO proposal, it was brought to our attention

that some of the proposed changes to the Part 620 standards, namely those based on

solubility of contaminants, would have unintended, but potentially significant

consequences for cleanups under TACO. The concern is that where groundwater

quality standards are based on contaminant solubility rather than contaminant health

risks the TACO groundwater and soil remediation objectives for those contaminants

will no longer have a risk-based approach.

After reviewing the concerns raised by SRAC, we concur that the existing Agency

proposal would have unintended consequences on TACO cleanups and should be

modified. For example, for the contaminant anthracene, the existing Tier 1 soil

remediation objective ("RO") for residential properties for the soil component of the

groundwater ingestion exposure route is 12,000 mg/1, which would protect drinking

water uses in Class I groundwater. If the groundwater quality standard is based on

solubility (.043 mg/I) instead of risk to drinking water users (2.1 mg/1), then the

calculated Tier 1 soil RO would drop two orders of magnitude from 12,000 mg/kg to

43 mg/kg. Illinois EPA believes that TACO should continue the risk-based approach

it has followed to date.

Thus, as a result of the Agency dropping the solubility limitation, this request is now

moot and no citations are provided. Note that where solubility had been listed in Mr.

Cobb's testimony as the basis for a groundwater standard, the standard has been

7

---

replaced by the appropriate risk-based value in the attached Table 1 for Anthracene,

Benzo(k)fluoranthene, Chrysene, Di-n-octyl phthalate, Fluoranthene, and

Indeno(1,2,3-c,d)pyrene. Note also that for Benzo(a)pyrene and Methoxychlor, which

already have existing standards, Mr. Cobb's testimony on page 17 states that the

Class II standards should be changed to reflect water solubility; since solubility is no

longer a basis for standards, these chemicals' existing Class II standards should not

be changed, and these two chemicals should be removed from the proposal.

Question 9 - All of the proposed Class II standards, which are based on water solubility, are

set at the same level as the Class I standards, except for benzo(a)pyrene, benzo(k)fluoranthene and

methoxychlor. Please explain the Agency's intent.

Response to Question 9 –

The question is now moot, as discussed above.

Question 10 - According to the table on page 16 of Mr. Cobb's pre-filed testimony and

errata

sheet No. 2, the proposed Class II standard for benzo(a)pyrene is 0.0016 mg/L. Further, on

page 17 of Mr. Cobb's pre-filed testimony, he states that the existing Class II standard should be

amended to 0.0002 mg/L based on its water solubility. Please clarify which value

represents the limit based on water solubility of benzo(a)pyrene, 0.0016 mg/L or 0.0002

mg/L.

Response to Question 10 –

The question is now moot, as discussed above.

Question 11 - The proposed Class II standards for explosive

.

compounds at Section

620.420(c) are set at the same levels proposed for Class I groundwater. Please clarify whether the

Koc values or the Henry's Law constants for these compounds are below threshold values

considered by the Agency for setting standards based on treatability.

Response to Question 11 –

The aforementioned thresholds are used when data is

available on best available treatment ("BAT") technology research. Unfortunately no

BAT studies were available for these contaminants. Thus, the proposed Class II

standards were based on a

lx

treatability factor.?

-

Question 12 - On page 18 of Mr. Cobb's pre-filed testimony, regarding the proposed

changes to the Class IV groundwater quality standards pertaining to explosive contaminants, he

states that the designation of a previously mined area is being proposed because it moves the

compliance point from the pit of the mine to the boundary of the permitted area in order

to establish off-site contamination. Please clarify whether the proposed changes are

intended to apply only to a "previously mined area" as defined in Section 620.110, which

limits such area to land disturbed or affected by coal mining operations prior to February

1, 1983.

Response to Question

12 –

Yes, the Illinois EPA intended for the proposed

amendment to Subsection 620.440(d) to apply to a "previously mined area" as defined

in Section 620.110, which limits such area to land disturbed or affected by coal mining

operations prior to Februaryl, 1983. This clarification is needed to reverse part of

8

---

what I provided in my testimony concerning the boundary of the permitted area.

Since this mining was done pre-1983, there was no permit boundary.

Request 13 - On page 2 of Dr. Hornshaw's pre-filed testimony, he refers to a USEPA

memorandum dated December 5, 2003, concerning Human Health Toxicity Values in Superfund

Risk Assessments. Would the Agency be able to submit a copy of the memorandum?

Response to Request 13 —

See the attached.

Question 14 - On page 3 of Dr. Hornshaw's pre-filed testimony, he notes that one of the

issues concerning the new hierarchy of toxicity values pertains to the retirement of PPRTV by

USEPA.

a.

Please clarify whether retirement of a PPRTV for a chemical means that

USEPA has established a permanent RID for the chemical or just dropped

the value from its database.

b.

Also, does USEPA provide any explanation for retiring a PPRTV?

Response to Question 14(a)—

It is the Toxicity Assessment Unit's understanding that

entries into the PPRTV database have a 6-month time limit, after which the entry is

retired and removed from the database. Since these retirements are not based on the

quality of the data, we have decided to continue using the toxicity information. We

are not aware of EPA's timetable for developing permanent RfDs and Sfos in IRIS or

for "un-retiring" values and adding them back into the PPRTV database.

Response to Question 14(b)-

We have not been provided with any explanations for

retiring chemicals from the PPRTV database other than that there is a 6-month time

limit.

Question 15 - On page 4 of Dr. Hornshaw's pre-filed testimony, regarding subchronic

exposures, he states that the Agency used the IRIS values with the Uncertainty Factor removed for

some of the chemical constituents as the first tier when available. Please identify the chemical

constituents for which this procedure was used to develop the proposed standards.

Response to Question 15 —

None. This was included in testimony only as an example

of the issues that the Toxicity Assessment Unit had to resolve regarding the EPA

hierarchy of toxicity information sources. Subchronic toxicity values are only used in

conjunction with the construction worker soil ingestion exposure route in

.

TACO, so

no subchronic values were used to develop the proposed standards.

Question 16 - Also on page 4 of Dr. Hornshaw's pre-filed testimony, he states that changes

needed in TACO because of the new hierarchy will be addressed when the next revision to the

TACO rules are proposed to the Board. Please clarify whether the TACO groundwater

9

---

objective for 1,1-Dichloroethane of 0.7 mg/L, which is lower than the proposed Class I

standard of 1.4 mg/L, is one of the needed revisions.

Response to Question 16 – Yes.

Question 17 -

On page 5 of Dr. Hornshaw's pre-filed testimony, he states that the Toxicity

Assessment Unit decided to include in the proposal any chemical from the Bureau of Land's

master list that had a toxicity value in the IRIS database. Please explain the rationale for limiting

the chemicals to only those with IRIS toxicity values instead of considering the USEPA's

three-tier hierarchy.

Response to Question 17 –

As

stated in Dr. Hornshaw's oral testimony in response to

a similar question, the Toxicity Assessment Unit decided to include in the proposal

any of the "new" chemicals (those not already in TACO) for which toxicity data were

available in the IRIS and PPRTV databases. It was reasoned that these two sources

provide nationally-accepted and peer-reviewed criteria as the basis for developing the

new standards.

Question 18 -

On page 7 of Dr. Hornshaw's pre-filed testimony, he states that additional

corrections are necessary for several reasons, including the revision of the selection criteria for

groundwater standards for carcinogenic chemicals. Dr. Hornshaw notes that the revised

criteria require a comparison of each carcinogenic constituent's health based

concentration (1 in million risk level) with its corresponding analytical MDL, the greater

of which is compared with the constituent's reported water solubility.

a.

Please clarify whether the analytical detection limit represents the carcinogenic

constituent's MDL or its lowest Practical Quantitation Limit (PQL).

b.

If the detection limit represents the MDL, should Part 620, Subpart F continue to

refer to PQLs or should it be amended to state MDLs?

Response to Question 18(a)– As discussed above, all references to MDLs should

be

changed to PQLs.

Response to Question 18(b)- Continue to refer to PQLs.

II. CONCLUSION

This concludes the supplemental testimony of the Illinois EPA witnesses. We will be

available to answer any questions.

10

---

MIV

GueeTO

F;

A Report of the

Committee on Water Quality Criteria

Environmental Studies Board

National Academy of Sciences

National Academy of Engineering

Washington, D.C., 1972

At the request of

and funded by

The Environmental Protection Agency

Washington, D.C., 1972

---

---

,••••••,

•

GENERAL TABLE OF CONTENTS

NOTICE ?

LETTER OF TRANSMITTAL

?

?

vi

MEMBERS OF THE ENVIRONMENTAL STUDIES BOARD

?

vii

?

MEMBERS OF THE WATER QUALITY CRITERIA COMMITTEE,

NAS STAFF, AND PANEL MEMBERS, ADVISORS, AND CON-

TRIBUTORS

??

viii

PREFACE

?

xv

?

ACKNOWLEDGMENTS

?

xvii

GENERAL INTRODUCTION

?

?

1

SECTION I RECREATION AND AESTHETICS ?

6

?

SECTION II PUBLIC WATER SUPPLIES

?

48

SECTION III FRESHWATER AQUATIC LIFE AND WILDLIFE

?

106

SECTION IV MARINE AQUATIC LIFE AND WILDLIFE

?

214

SECTION

V

AGRICULTURAL USES OF WATER

?

298

SECTION VI INDUSTRIAL WATER SUPPLIES ?

? 368

APPENDIX I (RECREATION AND AESTHETICS) ?

398

APPENDIX II (FRESHWATER AQUATIC LIFE AND WILDLIFE)

?

402

APPENDIX III (MARINE AQUATIC LIFE AND WILDLIFE)

?

448

GLOSSARY ?

519

CONVERSION" FACTORS

?

524

BIOGRAPHICAL NOTES ON THE WATER QUALITY CRITERIA

COMMITTEE AND THE PANEL MEMBERS

?

? 528

AUTHOR INDEX

?

535

SUBJECT INDEX

?

562

---

---

WATER FOR LIVESTOCK ENTERPRISES

Domestic animals represent an important segment of

agriculture and arc a vital source of food. Like man and

many other life forms. they are affected by pollutants in

their environment. This section is concerned primarily

‘vith considerations of livestock water qualit

y and factors

affectin

g

. it. These include the presence of ions causing ex-

cessive salinit

y

, elements and ions which are toxic, bio-

logically produced toxins, radionuclides, pesticide residues,

and pathogenic and parasitic organisms.

Of importance in determining recommendations for these

substances in livestock water supplies are the quantity of

water an animal consumes per day and the concentration

of the mineral elements in the water supply from which he

consumes it. Water is universally needed and consumed by

farm animals, but it does not account for their entire daily

intake of a particular substance. Consequently, tolerance

levels established for many substances in livestock feed do

not accuratel

y take into consideration the tolerance levels

for those substances in water. Concentrations of nutrients

and toxic substances in water affect an animal nn the basis

of the total amount consumed. Because of this. some assess-

ment of the amounts of water consumed b

y live-stock on a

daily basis and a knowledge of the probable quantity of ele-

ments in water and how they satisfy daily nutritional re-

quirements are needed for determining possible toxicity

levels.

WATER REQUIREMENTS FOR LIVESTOCK

The water content of animal bodies is relativel y constant :

68 per cent to 72 per cent of the total weight on a fat-free

basis. The level of water in the body usually cannot change

appreciably without dire consequences to the animal;

therefore, the minimal requirement for water is a reflection

of water excreted from the body plus a component for

growth in young animals (Robinson and McCance 1952,"

Mitchell 196246).

Water is excreted from the body in urine and feces. in

evaporation from the lungs and skin, in sweat, and in pro-

ductive secretions such as milk and eggs. Anything that

influences any of these modes of water loss affects the mini-

mal water requirement of the animal.

The urine contains the soluble products of metaboli

that must be eliminated. The amount of urine excret

dail

y varies with the feed. work, external temperature, wa

consumption. and other factors. The hormone vasopres.

antidiuretic hormone) controls the amount of urine

affecting the reabsorption of water from the kidne

y

tubu

and ducts. Under conditions of water scarcity, an anirr.

may concentrate its urine to some extent by reabsorbing

greater amount of water than usual, thereby lowering t.

animal's requirement for water. This capacity for conce.

tration, however, is usuall y limited. If an animal consum

excess salt or a high protein diet, the excretion of urine

increased to eliminate the salt 'or the end products of pr,

tein metabolism, and the water requirement is theret

increased.

The amount of water lost in the feces varies dependin

upon diet and species. Cattle, for instance, excrete feet

with a high moisture content while sheep, horses, an

chickens excrete relatively dr

y feces. Substances in the die

that have a diuretic effect will increase water loss by thi

route.

Water lost by evaporation from the skin and lungs (in

sensible water loss) may account for a large part of th(

body's water loss approaching, and in some cases exceeding

that lost in the urine. If the environmental temperature i.

increased, the water lost by this route is also increased

Water lost through sweating may be considerable, especiall\

in the case of horses, depending on the environmental tem-

perature and the activity of the animal.

All these factors and their interrelation make a minimal

water requirement difficult to assess. There is also the ad-

ditional complication that a minimal water requirement

does not have to be supplied entirely by drinking water.

The animal has available to it the water contained in

feeds, the metabolic water formed from the oxidation of

nutrients, water liberated by polymerization, dehydration,

or synthesis within the bod y

, and preformed water associ-

ated with nutrients undergoing oxidation when the energy

balance is negative. All of these may vary. The water

available from the feed will vary with the kind of feed and

with the amount consumed. The metabolic water formed

304

---

Water for Livestock Enterprises/305

from the oxidation'of nutrients may be calculated by the use

of factors obtained from equations of oxidation of typical

proteins, fats, and carboh

ydrates. There are 41. 107, and

60 grams (g) of water formed per 100 g of protein, fat. and

carbohydrate oxidized. respectivel

y

. In fasting animals, or

those subsisting on a

p

rotein deficient diet. water may be

formed from the destruction of tissue protein. In general. it

is assumed that tissue protein is associated with three times

its weight of water, so that per gram of tissue protein

metabolized, three

g

rams of water are released.

It has been found b

y

careful water balance trials that the

water requirement of various species is a function of body

surface area rather than weight. This implies that the re-

quirements are a function of energy metabolism. and

Adolph (19331" found that a convenient liberal standard of

total water intake is 1 milliliter i ml) per calorie (cal) of heat

produced. This method automaticall

y

included the in-

creased requirement associated with activit

y

. Cattle require

somewhat higher amounts of water (1.29 to 2.05 g. cal) than

other animals. However, when cattle's large excretion of

water in the feces is taken into account, the values are ap-

proximately a gram per calorie.

For practical purposes, water requirements can be meas-

ured as the amount of water consumed voluntarily under

specified conditions. This implies that thirst is a result of

need.

Water Consumption of Animals

In dry roughage and concentrate feeding programs the

water present in the feed is so small relative to the animal's

needs that it may be ignored (Winchester and Morris

1956)."

Beef Cattle.

Data calculated b

y

Winchester and Mor-

ris (1956)

55

indicated that values for water intake vary

widely depending primarily on ambient temperature and

dry matter intake. European breeds consumed approxi-

mately 3.5, 5.3, 7.0, and 17 liters of water daily per kilo-

gram (kg) dry matter ingested at 40, 70, 90, 100 F, respec-

tively. Thus at an atmospheric temperature of 21 C (70 F),

a 450 kg steer on a 9.4 kg dail

y dry matter ration would

consume approximatel

y

50 liters of water per day, while at

32 C (90 F) the expected dail

y

water intake would be 66

liters.

Dairy Cattle.

The calculations of Winchester and

Morris (1956)" showed how water requirements varied

with weight of cow, fat content of milk, ambient tempera-

ture, and amount needed per kilogram of milk daily. These

investigations indicated that at 21 C (70 F) a cow weighing

approximately 450 kg would consume about 4.5 liters of

water per kilogram dry feed plus 2.7 1/kg of milk produced.

Dairy heifers fed alfalfa and silage obtained about 20 per

cent of their water requirements in the feed. Dairy cattle

suffer more quickly from a lack of water than from a

shortage of any other nutrient and will drink 3.0 to 4.0 kg of

water per kilogram of dr

y matter consumed (National Re-

search Council, Committee

on

Animal Nutrition, hereafter

referred to as NRC 1971a)." Cows producing 40 kg of milk

per day ma

y

drink up to 110 kg of water when fed dry

feeds.

Sheep.

Generally water consumption by sheep amounts

to two times the weight of dry matter feed intake (NRC

1968b)." But many factors may alter this value, e.g.,

ambient temperature, activity, age, stage of production,

plane of nutrition, composition of feed, and type of pasture.

Ewes on dry feed in winter require four liters per head

daily

before lambing and six or more liters per da

y when

nursing lambs (Morrison 1959).4s

Swine.

Pigs require 2 to 2.5 kg of water per kilogram

of dry

feed, but voluntary consumption ma

y

be as much as

4 to 4.5 kg in high ambient temperature (NRC 1968a)."

Mount et al. (1971)

4

' reported the mean water:feed ratios

were between 2.1 and 2.7 at temperatures between 7 .and

22 C. and between 2.8 and 5.0 at 30 and 33 C. The range

of mean water consumption extended from 0.092 to 0.184

l'kg bod

y

weight per day. Leitch and Thomson 09441"

cited studies that demonstrated that a water-to-mash ratio

of 3:1 gave the best results.

Horses.

Leitch and Thomson (19441" cited data that

horses needed two to three liters of water per kg dry ration.

Morrison (1936) 47

obtained data of a horse going at a trot

that gave off 9.4 kg of water vapor. This amount was

nearly twice that given off when walking with the same

load, and more than three times as much as when resting

during the same period.

Poultry.

James and Wheeler (1949)" observed that

more water was consumed by poultry when protein was

increased in the diet; and more water was consumed with

meat scrap, fish meal, and dried whey diets than with an

all-plant diet. Poultry generally consumed

.

2 to 3 kg of

water per kilogram of dry feed. Sunde (1967)" observed

that when laying hens, at 67 percent production, were de-

prived of water for approximately 36 hours. production

dropped to eight per cent within five days and did not re-

turn to the production of the controlled hens until 25-30

days later. Sunde

(personal communication

19711" prepared a

table that showed that broilers increased on daily water

consumption from 6.4 to 211 liters per 1,000 birds between

two and 35 days of age, respectively. Corresponding water

intake values for replacement pullets were 5.7 to 88.5 liters.

RELATION OF NUTRIENT ELEMENTS IN WATER

TO TOTAL DIET

All the mineral elements essential as dietary nutrients

occur to some extent in water (Shirley 1970).

66 Generally

the elements are in solution, but some may be present in

suspended materials. Lawrence (1968)" sampled the Chat-

tahoochee River system at six different reservoirs and river

and creek inlets and found about 1, 3, 22, 39. 61, and 68

per cent of the total calcium, magnesium, zinc, manganese,

---

306/Section

V-Agricultural Uses of Water

copper, and iron present in suspended materials, respec-

tively. Any given water supply requires analysis if dietary

decisions are to be most effective.

In the Systems for Technical Data (STORET) .of the

Water Programs Office of the Environmental Protection

Agenc

y

, data (1971)" were accumulated from surface

water analyses obtained in the United States during the

period 1957-1969. These data included values for the

mean, maximum, and minimum concentrations of the

nutrient elements (see Table V-I ). These values obviously

include many samples from calcium-magnesium, sulfate-

chloride and sodium-potassium, sulfate-chloride type of

water as well as the more common calcium-magnesium,

carbonate-bicarbonate type. For this reason the mean

values for sodium, chloride, and sulfate may appear some-

what high.

Table V-2 gives the estimated average intake of drinking

water of selected categories of various species of farm ani-

mals expressed as liters per da

y

. Three values for each of

calcium and salt are given for illustrative purposes. One

column expresses the National Academy of Sciences value

for daily requirement of the nutrient per day; the second

gives the amount of the element contributed by the average

concentration of the element (calculated from data in

Table V-1) in the average quantity of water consumed

daily: 'the third column gives the approximate percentage

of the daily requirements contributed by

. the water drunk

each day for each species of animal.

Magnesium, calculated as in Table V-2, was found to be

present in quantities that would provide 4 to 11 per cent of

the requirements for beef and dairy cattle, sheep, swine,

horses, chickens, and turkeys.

Cobalt (Co) concentrations obtained by Durum et al.

(1971)

58

were calculated, as they were more typical of water

available to livestock than current values reported in

STORET (1971)." A sufficient amount of Co was present

at the median level to supply approximately three to 13

TABLE V-1--Water Composition, United States, 1957-69

(STORET) (Collected at 140 stations)

Substance

Man

Maximum

Minimum

No Dens.

Phoselsours. mg/I

?

0.017

5.0

0.001

1.121

Calcium, mg/1

?

57.1

173.0

11.0

510

Mammies. iog/1

?

14.3

131.0

8.5

1,143

Sodie■, Ing/I

?

55.1

7.500.0

0.2

1,131

Polasies,

mgil ?

4.3

370.0

0.06

1,104

Chloride, mg/I.

??

471.0

19.000.0

0.000

37.355

Sulfite, m1(1

?

13.5.9

3.311.0

0.000

30,229

C

Me

i Ai

l

?

13.1

210.0.

0.1

1,1171

Iron.4/1 ?

43.9

4.600.0

0.10

1,836

Marmaraa,r4/1

?

29.4

3, 230.0

0.20

1,811

Iim.;

4

1/1

?

51.1

1.113.0

1.0

1,883

Salemens.4,1

?

0.016

1.0

0.01

234

Iodine, Ail ?

46.1

3.36.0

4.0

IS

Coksal0.4/1

?

1.0

5.0

0.800

720

• tholmsu

mad &Send (1970)".

Duren

et al. (1971)".

TABLE V-2-Daily Requirements of Average Concentra

of Calcium and Salt

in

Water for Various Animals

Calcium?

Sand

Daily. ?

Animal

?

rata?Average.

?

Approt?

AmL iA• Pi

intake. I Required' amt in?

percentage Required •

drinking o.

daily gm?

drinking?

of Req. in daily gm water. gm

water,

gm?

water

Beal

cattle 450 kg body wt.

Nursing cow

?

60

28

3.4

12

25

8.5

Finishing steer ?

60

21

3.4

16

24

8.5

Dairy

cattle 450 kg body wt.

Lactating cow

?

90

76

5.1

7

66

12.7

Growing heifer ?

60

15

3.4

22

21

8.5

Maintarunca cow ?

60

12

3.4

28

21

8.5

Sheep

Lactating

nee,

64 kg ?6

6.8

0.3

5

73

?

.

0.9

Fattening lamb, 45 kg

?4

3.1

0.2

7

10

0.6

Swine

Growing, 30 kg

?

6

10.7

0.31

3

4.3

0.84

Fattening. GO to 100 kg

?

it

16.5

0.46

3

4.3

1.12

Lactating

sows. 200-250 kg ?

14

33.0

0.80

2

21.0

1.96

Horses 450 kg body era

Medium work ?

40

14

2.3

16

90

5.6

Lactating

?

50

30

2.9

10

90

7.1

Poultry

Chickens. 1

weal

old ?0.2

1.0

0.011

1

0.31

0.03

Win hen

?

0.3

3.4

0.011

<I

0.44

0.03

Turkey ?

0.2

1.2

0.011

I

0.31

0.03

•

See disunion on Water

Consumption in text for sources of these vellum

o

Sources ml values are

the National

Academy of Sciences. NRC Bulletins on Nutrient requirements.

Cab:skated Irons Table

1.

Bawd en sodium in water.

per cent of the dietary requirements of beef and dairy cat

sheep, and horses. The NRC (1971a," 196813

6

9 does

state what the cobalt requirements were for poultry

a

swine.

Sulfur values demonstrated that approximately 29

cent of beef cattle requirements were met at average

cc

centrations: dairy cattle 21 to 45 per cent: sheep 10 to

per cent : and horses 18 to 23 per cent of their requiremer.

The NRC (1971a," 1968b

61

) do not give sulfur requiremer

for poultry and swine.

Iodine was not among the elements in the STORI

accumulation, but values obtained by Dantzman a:

Breland (1970)" for 15 rivers and lakes in Florida can

used as illustrative values. Iodine was present in sufficie

amounts to exceed the requirements of beef cattle ar

nonlactating horses and to meet 8 to 10 per cent of t:

requirements of sheep and 24 to 26 per cent of those of her

Phosphorus, potassium, copper, iron, zinc, manganese, ar

selenium, when present at mean concentrations (Table V-1

would supply daily only one to four per cent or less of th,

recommended by the NRC (1966,

60

1968a," 1968b,

62

1970,

1971a,

64

1971b

65

) for beef and dairy cattle, sheep, swim

horses, and poultry at normal water consumption levels.

If the maximum values shown in Table V-1 are presen

some water would contain the dietary requirements of som

species in the case of sodium chloride, sulfur, and iodine

Appreciable amounts of calcium, copper, cobalt, iror

---

Water for Livestock Enterprises; 307

manganese, zinc, and selenium would be present, if water sodium chloride in the drinking water greatly delayed the

were supplied with the maximum levels present. On the onset of egg production, but 15,000 mg/I or more were re-

other hand, if the water has only the minimum concentra-

quired to affect growth over a 10-week period. In swine,

tion of any of the elements present. it would supply very 15,000 mg/I of sodium chloride in the drinking water

thc.- daL iequitements.

caused death in the smaller animals, some leg stiffness in

It is generally believed that elements in water solution the larger, but 10,000 mg/1 did not appear particularl

y

in-

are available to the animal that consumes the water, at jurious once they became accustomed to it. Sheep existed

least as much as when present in solid feeds or dry salt on water containing 25,000 mg

.

/I of sodium or calcium

mixes. This was indicated when Shirle

y et al. (1951,67 chloride or 30,000 mg/1 of magnesium sulfate but not with-

1957

68 ) found that P" and Ca", dissolved in aqueous solu-

out some deleterious effects. Cattle were somewhat less re-

tion as salts and administered as a drench, were absorbed at sistant, and it was concluded that 10,000 mg ,

1 of total salts

equivalent levels to the isotopes, when the

y were incor- should be considered the upper limit under which their

porated in forage as fertilizer and fed to steers, respectively. maintenance could be expected. A lower limit was suggested

Many isotope studies have demonstrated that minerals in for lactating animals. It was further observed that the ani-

water consumed by animals are readil y

absorbed, deposited mals would not drink highly saline solutions if water of low

in their tissues, and excreted.

salt content was available, and that animals showing ef-

fects of saline waters returned quickly to normal when al-

EFFECT OF SALINITY ON LIVESTOCK

?

lowed a water of low salt content.

Frens (1946)

72

reported that 10,000 mg/1 of sodium

It is well known that excessivel

y

saline waters can cause chloride in the drinkin

g water

of

dairy cattle produced no

physiolczical upset or death of livestock. The ions most s y

mptoms of toxicity, while 15.000 mg; I caused a loss of

commonly involved in causing excessive salinity are calcium, appetite, decreased milk production, and increased water

magnesium, sodium, sulfate, bicarbonate, and chloride. consumption with symptoms of salt poisoning in 12 days.

Others may contribute significantl

y

in unusual situations, In studies with beef heifers, Embry et al. (1959) 7 ' re-

and these may also exert specific toxicities separate from the ported that the addition of 10,000 mg11 of sodium sulfate

osmotic effects of excessive salinity. (See Toxic Elements to the drinking water caused severe reduction in its con-

and Ions below.)

sumption, loss of weight, and 'symptoms of dehydration.

Early in this centur

y

, Larsen and Bailey (1913)

80

re-

Either 4,000 or 7,000 mg/I of added sodium sulfate increased

ported that a natural water varying from 4,546 to 7,369 water intake but had no effect on rate of gain or general

mg/1 of total salts, with sodium and sulfate ions predomi-

health. Similar observations were made using waters with

nating, caused mild diarrhea but no symptoms of toxicity in added sodium chloride or a mixture of salts, except that

dairy cattle over a two-year period. Later, Ramsa

y

(1924)8' symptoms of dehydration were noted, and the mixed salts

reported from his observations that cattle could thrive on caused no increase in water consumption. Levels of up to

water containing 11,400 mg/1 of total salts. that they could 6,300 mg/1 of added mixed salts increased water consump-

live under certain conditions on water containing 17,120 tion in weanling pigs, but no harmful effects were observed

mg/1, and that horses thrived on water with 5,720 mg;1 over a three-month period.

and were sustained when not worked too hard on water

In Australia, Peirce (1957,

63

1959," 1960,

85

1962,86

with 9,140 mg/I.

1963,

87

1966,

38 1968a, 89

1968b

90

) conducted a number of

The first extensive studies of saline water effects on rats experiments on the salt tolerance of Merino wethers. Only

and on livestock were made in Oklahoma (Heller and Lar-

minor harmful effects were observed in these sheep when

wood 1930,

76 Heller 1932, 7 ' 1933).

7

' Rats were fed waters they were confined to waters containing 13,000 mg/1 or

of various sodium chloride concentrations, and it was found less of various salt mixtures.

among other things that (a) water consumption increased Nevada workers have reported several studies on the ef-

with salt concentration but only to a point after which the fects of saline waters on beef heifers. They found that

animals finally refused to drink until thirst drove them to it, 20,000 mg/1 of sodium chloride caused severe anorexia,

at which time they drank a large amount at one time and weight loss, anhydremia, collapse, and certain other symp-

then died; (b) older animals were more_ resistant to the ef-

toms, while 10,000 mg/1 had no effects over a 30-day period

fects of the salt than were the young; (c) the effects of salin-

other than to increase water consumption and decrease

ity were osmotic rather than related to any specific ion; blood urea (Weeth et al. 1960)." Additional experiments

(d) reproduction and lactation were affected before growth (Weeth and Haverland 1961)

98 again showed 10,000 mg/I

effects were noted; (e) there appeared. in time, to be a to cause no symptoms of toxicity: while at 12.000 mg/1

physiological adjustment to saline waters; and (f) 15,000-

adverse effects were noted, and these intensified with in-

17,000 mg/I of total salts seemed the maximum that could creasing salt concentration in the drinking water. At a con-

be tolerated, some adverse effects being noted at concen-

centration of 15,000 mg/1, sodium chloride increased the

trations lower than this. With laying hens, 10,000 mg/1 of ratio of urine excretion to water intake (Weeth and

---

308/Section V—Agricultural Uses of Water

Lesperance 1965),

100

and a prompt and distinct diuresis

occurred when the heifers consumed water containing 5.000

or 6,000 mgt1 following water deprivation (Weeth et al.

1968).

101

While with waters containing about 5,000 mg

I

(Weeth and Hunter 1971)" or even less Weeth and Capps

1971)" of sodium sulfate no specific ion effects were noted,

heifers drank less, lost weight, and had increased methemo-

globin and sulfhemoglobin levels. A later study (Weeth and

Capps 1972)

96 gave similar results. but

in addition suggested

that the sulfate ion itself, at concentrations as low as 2150

m

g

71 had adverse effects.

In addition to the Oklahoma work, several studies on the

effects of saline water on poultry have been reported.

Selve (1943)" found that chicks 19 days old when placed

on experiment had diarrhea, edema, weakness, and respira-

tory problems during the first 10 days on water containing

9,000 mg.I of sodium chloride. Later, the edema disap-

peared, but nephrosclerotic changes were noted. Water

containing 3,000 mg '1 of sodium chloride was not toxic

to

four-week-old chicks.

Others (hare and Bielv 19481" observed that with two-

day-old chicks on water containing 9,000 mg:1 of added

sodium chloride there were a few deaths, some edema, and

certain other symptoms of toxicity. A solution with 18,000

mg/I of the salt was not toxic; however, when replaced on

alternate days by fresh water, neither was it readily con-

sumed.

Scrivner (1946)" found that sodium chloride in the drink-

ing water of day-old poults at a concentration of 5,000 mg I

caused death and varying degrees of edema and ascites in

over half of the birds in about two weeks. Sodium bicarbo-

nate at a concentration of 1.000 mgil was not toxic, at

3,000 mg caused some deaths and edema: and as the con-

centration increased above this, the effects were more pro-

nounced. A solution containing 1,000 mg 1 of sodium hy-

droxide caused death in two of 31 poults b

y 13 da y s, but the

remainder survived without effects, and 7,500 mgrl of

sodium citrate, iodide, carbonate, or sulfate each caused

edema and many deaths.

South Dakota workers (Krista et al. 1961)" studied the

effects of sodium chloride in water on laying hens, turkey

poults, and ducklings. At 4,000 mgil, the salt caused some

increased water consumption, watery droppings, decreased

feed consumption and growth, and increased mortality.

These effects were more pronounced at a higher concentra-

tion, 10,000 mgil, causing death in all of the turkey poults

at

two

weeks, some symptons of deh y

dration in the chicks,

and decreased egg production in the hens. Experiments with

laying hens restricted to water containing 10,000 mg/1 of

sodium or magnesium sulfate gave results similar to those

for sodium chloride.

In addition to the experimental work, there have been

reports in the literature of field observations relating to the

effects of excessively saline water (Ballantvne 1957,"

Gastler and Olson 1957," Spafford 1941"), and a number

TABLE V-3—Guide to the Use of Saline

Waters

for

Livestock and Poultry

Total soluble salts

content of waters

?

Comment

Less than 1.000.

?

Relatively

low

level of salinity. Excellent for all classes of livestock and poultry.

1.000-2.999

?

?

Very satisfactory for

311

classes of livestock and poultry. May cause temporary and

diarrhea in livestock not accustomed to them or watery droppings in poultry.

3.000-4.999..

?Satisfactory for livestock, but may cause temporary diarrhea or be Mused at first

mals not Accustomed to them. Poor waters for poultry, often causing water feces, two

mortality. and decreased growth. especially in turkeys.

0,000-6.999

?

Can be used with reasonable safety tor dairy and beef cattle, for sheep, swine, and he

Avoid use for pregnant or lactating animals. Not acceptable for poultry.

1.000-10.000 . Unfit for poultry and probably Its swine. Considerable risk

ill using

for pregnant

or

tact.

cows. horses. or sheep, or lot the vouch ol these species. In pineal. use should be arc

although older ruminants. horses. poultry. and swine may subsist on them under re

conditions.

Over 10,000

?

.?

Risks with these highly saline waters are so great that they cannot be recommended for

under any conditions.

of guides to the use of these waters for livestock have be,

published (Ballantyne 1957," Embr y

et al. 1959,

71

Kris

et al. 1962," McKee and Wolf. 1963,

b

' Ofhcers of tl

Department of Agriculture and the Government Chemic.

Laboratories 1950.'2

Spafford, 1941"), Table V-3 is base

on the available published information. Among other thing

the following items are suggested for consideration in usin

this table:

•

Animals drink little, if any, highly saline water

water of low salt content is available to them.

• Unless they have been previously deprived of water

animals can consume moderate amounts of highl

saline water for a few days without being harmed.

•

Abrupt changes from water of low salinity to high]•

saline water cause more problems than a gradua

change.

• Depressed water intake is very likely to he accom

panicd by depressed feed intake.

Table V-3 was developed because in arid or semiarie

regions the use of highly saline waters may often be neces-

sary. It has built into it a very small margin of safety, anc

its use probably does not eliminate all risk of economic loss.

Criteria for desirability of a livestock water are a some-

what different matter. These should probably be such that

the risk of economic loss from using the water for any species

or age of animals, lactating or not, on any normal feeding

program, and regardless of climatic conditions, is almost

nonexistent. On the other hand, they should be made no

more severe than necessary to insure this small risk.

Recommendation

From the standpoint of salinity

and its osmotic

effects, waters containing 3,000 mg of soluble salts

per liter or less should be satisfactory for livestock

under almost any circumstance. While some minor

physiological upset resulting from waters with

---

Iroter

for Livestock Enterprises '309

salinities near this limit may be observed, eco-

nomic losses or serious physiological disturbances

should rarely, if ever, result from their use.

TOXIC

SUBSTANCES IN LIVESTOCK WATERS

There are many substances dissolved or suspended in

waters that may be toxic. These include inorganic elements

and their salts, certain organic wastes from man's activities,

pathogens and parasitic organisms, herbicide and pesticide

•residues, some biologicall

y

produced toxins, and radio-

nuclides.

For any of the above, the concentrations at which they

render a water undesirable for use for livestock is subject

to a number of variables. These include age, sex, species.

and physiological state of the animals: water intake, diet

and its composition, the chemical form of any .toxic element

present, and the temperature of the environment. Naturally,

if feeds and waters both contain a toxic substance, this must

he taken into account. Both short and long term effects and

interactions with other ions or compounds must also be con-

sidered.

The development of recommendations for safe concentra-

tions of toxic substances in water for livestock is extremely

difficult. Careful attention must be given to the discussion

that follows as well as the recommendations and to any ad-

ditional experimental findings that may develop. Based on

available research, an appropriate margin of safet

y

, under

almost all conditions, of specific toxic substances harmful

to livestock that drink the waters and to man who consumes

the livestock or their products, is reviewed below. Although

the margin of safet

y

recommended is usually large, the cri-

teria suggested cannot be used as a guide in diagnosing

livestock losses, since they are well below toxic levels for

domestic animals.

Toxic Elements and Ions

Those ions largely responsible for salinity in water

(sodium, calcium, magnesium, chloride, sulfate. and bi-

carbonate) are in themselves not very toxic. There are,

however, a number of others that occur naturally or as the

result of man's activities at troublesome concentrations. If

feeds and water both contain a toxic ion, both must be con-

sidered. Interactions with other ions, if known, must be

taken into account. Elements or ions become objectionable

in water when they are at levels toxic to animals, where they

seriously reduce the palatabilit y of the water, or when they

accumulate excessively in tissues or bod

y

fluids, rendering

the meat, milk, eggs, or other edible product unsafe or unfit

for human use.

Aluminum

Soluble aluminum has been found in surface waters of

the United States in amounts to 3 mg/I, but its occurrence

at such concentrations is rare because it readily precipitates

as the hydroxide (Kopp and Kroner 1970).

182

Most edible grasses contain about 15-20 mg: kg of the

element. However, there is no evidence that it is essential

for animal growth, and very little is found deposited in ani-

mal tissues (Underwood 19711.

2

" It is not highl

y

toxic

(McKee and Wolf 1963,"

3

Underwood 19711,

2

" but Deo-

bald and Elvehjem (1935)'" found that a level of 4.000 mg

aluminum per kilogram of diet caused phosphorus de-

ficienc

y

in chicks. Its occurrence in water should not cause

problems for livestock, except under unusual conditions

and with acid waters.

Recommendation.

Livestock

should be protected where natural

drinking waters contain

no more

than 5

mg/1

aluminum.

Arsenic

Arsenic has lon

g been notorious as a poison. Nevertheless.

it is present in all livin

g

tissues in the inorganic and in

certain organic forms. It has also been used Medicinally.

It is accepted as a safe feed additive for certain domestic.

animals. It has not been shown to he a required nutrient

for animals, possibly because its ubiquity has precluded t

hp

compounding of deficient diets (Frost 1967).'"

The toxicity of arsenic can depend on its chemical form.

its inorganic oxides being considerably more toxic than

organic forms occurring in living tissues or used as feed

additives. Differences in toxicities of the various forms are.

clearly related to the rate of their excretion, the least toxic.

being the most rapidly eliminated (Frost 1967, 1

" Under-

wood 1971).

2 " Except in unusual cases. this element should

occur in waters lar

gely as inorganic oxides. In waters carr

y

-ing or in contact with natural colloidal material. the soluble

arsenic content may be decreased to a very low level by ad-

sorption.

Wadsworth (1952)

26

" gave the acute toxicit y of inorganic

arsenic for farm animals as follows: poultry, 0.05-0.10 g per

animal: swine. 0.5-1.0 g per animal; sheep, goats, and

horses, 10.0-15.0 g per animal: and cattle, 15-30 g per

animal. Franke and Moxon (1936) 146 concluded that the

minimum dose 'required to kill 75 per cent of rats given

intraperitoneal injections of arsenate was 14-18 mg arsenic

per kilogram, while for arsenite it was 4.25-4.75 mg; kg of

bod

y

weight.

When mice were given drinking water containing 5 mg/1

of arsenic as arsenite from weaning to natural death, there

was some accumulation of the element in the tissues of

several organs, a somewhat shortened life span, but no

carcinogenic effect (Schroeder and Balassa 1967).

2 " In a

similar study with rats (Schroeder et al. 1968b),

236 neither

toxicit

y

nor carcinogenic effects were observed, but large

amounts accumulated in the tissues.

Peoples (1964)

220 fed arsenic acid at levels up to 1.25 mg/

kg of bod

y

weight per day for eight weeks to lactating

cows. This is equivalent to an intake of 60 liters of water

---

310,

Section 1

:

—.4gricultural Des of

Water

containing 5.5 mgil of arsenic (10.4 mg of arsenic acid)

daily b

y

a 500 kg animal. His results indicated that this

form of arsenic is absorbed and rapidl y

.

excreted in the

urine. Thus there was little tissue storage of the element:

at no level of the added arsenic was there an increased

arsenic content of the milk. and no toxicit

y

was observed.

According to Frost (19671,

1

" there is no. evidence that

10 parts per million (ppm) of arsenic in the diet is toxic to

any animal.

Arsenicals have been accused of bein

g carcinogenic. This

matter has been thoroughly reviewed b y Frost 119671,149

who concluded that they appear remarkably free of this

property.

Most human foods contain less than 0.5 ppm of arsenic,

but certain marine animals used as human food may con-

centrate it and may contain over 100 ppm (Frost 196711°

Underwood 1971 2

"). Permissible levels of the element in

muscle meats is 0.5 ppm: in edible meat by-products. 1.0

ppm: and in e

g

gs. 0.5 ppm (U.S. Dept. of Health. Educa

tion, and Welfare. Food and Dru

g

Administration 1963.2'5

1964 256

). Federal Drinking Water Standards list 0.05 mg; I as

the upper allowable limit to humans for arsenic, but McKee

and Wolf (19631

1

" suggested 1.0

me I

as the upper limit

for livestock drinking water. The possible role of biological

meth

ylation in increasing the toxicit

y (Chemical Engineer-

ing News 1971)'

2

" suggested added caution, however, and

natural Nvaters seldom contain more than 0.2 mg •1 (Durum

et al. 1971).11'

Recommendation

To provide the necessary caution, and in view of

available data, an upper limit of 0.2 mg/I of

arsenic

in water is recommended.

Beryllium

Bery

llium was found to occur in natural surface waters

only

at ver

y low levels, usually below 1 pg

, 1 (Kopp and

Kroner 1970)." Conceivably, however, it could enter

waters in effluents from certain metallurgical plants. Its

salts are not hi

g

hl

y

toxic, laborator

y

rats having survived

for two

y

ears on a diet that supplied the element at a level

of about 18 mg

, kg of bod y

weight daily. Pomelee (1953) '3

calculated that a cow could drink almost 1.000 liters of

water containing 6,000 mg,

s

l without harm, if these data

for rats are transposable to cattle. This type of extrapolation

must, however, be used with caution, and the paucity of

additional data on the toxicit

y

of beryllium to livestock

precludes recommending at this time a limit for its concen-

tration in livestock waters.

Boron

The toxicit

y of boron, its occurrence in foods and feeds,

and its role in animal nutrition have been reviewed by

McClure (1949),

1

" McKee and Wolf (1963),

m and

Underwood (1971). 254 Although essential for plants, there

is no evidence that boron is required by animals. It h.

relatively low order of toxicity. In the dair

y cow,

of boric acid per day for 40 days produced no ill en

(McKee and Wolf 19631.1"

There is no evidence that boron accumulates Hatt

extent in body tissues. Apparently, most n

waters could be expected to contain concentrations

below the level of 5.0 mg 1. This was the maximum amo

found in 1,546 samples of river and lake waters ft

various parts of the United States, the mean value bc

0.1 mgrl (Kopp and Kroner 1970). 182

Ground waters cc

contain substantiall

y

more than this at certain places.

Recommendation

Experimental evidence concerning the

toxic

of this element is meager. Therefore, to offer

large margin of safety,

an upper limit of 5.0 m

of boron in livestock waters is recommended.

Cadmium

Cadmium (C:d1 is normall

y found in natural

w

aters

ver

y low levels. A nationwide reconnaissance of surf

waters of the United States (Durum et al. 19711

11 ' revea.

that of over 720 samples, about four per cent contained o,

10 pgil of this element, and the highest level was

110

gr,

Ground water on Long Island, New York, contained .

mg•I as the result of contamination by waste from the el,

troplating industr y

, and mine waters in Missouri contain

1,000 mull (McKee and Wolf 1963).1"

Research to date suggests that cadmium is not an essent

element. It is, on the other hand, quite toxic. Man has be

sickened by about 15 ppm in popsicles. 67 ppm in punt

300 ppm in a cold drink. 530 ppm in gelatin, and 14.5 r

taken orall

y

: although a famil

y of four whose drinki:

water was reported to contain 47 ppm had no histor

y of

effects (McKee and Wolf 19631.19'

Extensive tests have been made on the effects of vario

levels of cadmium in the drinking water on rats and do

(McKee and Wolf 19631. 1

" Because of the accumlatic

and retention of the element in the liver and kidne

y

, it w;

recommended that a limit of 100 pgil, or preferably less. i

used for drinkin

g waters.

Parizek (1960)

219

found that a single dose of 4.5 mg Cd k

of body weight produced permanent sterility in male rat

At a level of 5 mgil in the drinking water of rats (Schroede

et al. 1963a)

2

" or mice (Schroeder et al. 1963b),

2 " reduce

longevity was observed. Intravenous injection of cadmiur

sulfate into pregnant hamsters at a level of 2 mg Cd k

of body weight on da

y

ei

g

ht of gestation caused malforma

tions in the fetuses (Mulvihill et al. 1970).21'"

Miller (1971) 1

" studied cadmium absorption and distri

bution in ruminants. He found that only a small part o

ingested cadmium was absorbed, and that most of what Nva

went to the kidne

y

s and liver. Once absorbed, its turnover

rate was ver

y

slow. The cow is very efficient in keeping

---

Water for Livestock Enterprises; 311

cadmium out of its milk, and Miller concluded that most

major animal products, including meat and milk, seemed

quite well protected a

g

ainst cadmium accumulation.

Interactions of cadmium several_ other trace ele-

ments (Hill et al. 1963, 1

" Gunn and Gould 1967, 159

Mason

and Young 19671

1

" somewhat confuse the matter of estab-

lishing criteria.

Recommendation

From the available data on the occurrence of

cadmium in natural waters, its toxicity, and its

accumulation in body tissues, an upper limit of

50 b

ig/1 allows an adequate margin of safety for

livestock and is recommended.

Chromium

In a five-

y

ear survey of lake and river waters of the

United States (Kopp and Kroner l9701,

15

" the hi

g hest level

found in over 1,500 samples was about 0.1 mg; I. the average

being about 0.001 mg. 1. In another similar surve

y (Durum

et al. 1971)

141

of 700 samples, none contained over 0.05 mg/1

of chromium VI and only 11 contained more than 0.005

mg/l. A number of industrial processes however use the

element, which then ma

y

be discharged as waste into sur-

face waters, possibly at rather high levels.

Even in its most soluble forms, the element is not readily

absorbed by animals, being largely excreted in the feces;

and it does not appear to concentrate in any particular

mammalian tissue or to increase in these tissues with age

(Mertz 1967, 1

" Underwood 197125x).

Hexavalent chromium is generall

y considered more toxic

than the trivalent form (Mertz 1967).

1

" However, in their

review of this element, McKee and Wolf (1963)'" suggested

_that it has a rather low order of toxicit

y

. Further. Gross and

Heller (1946)'" found that for rats the maximum nontoxic

level, based on growth, for chromium VI in the drinking

water was 500 mg I. The

y

also found that this concentration

of the element in the water did not affect feed utilization by

rabbits. Romoser et al. (1961)

2" found that 100 ppm of

chromium VI in chick diets had no effect on the perform-

ance of the birds over a 21-day period.

In a series of experiments. Schroeder et al. (1963a,238

1963b, 2 " 1964, 234

1965

23

') administered water containing

5 mg/1 of chromium III to rats and mice on low-chromium

diets over a life span. At this level, the element was not

toxic, but instead it had some beneficial effects. Tissue levels

did not increase significantly with age.

As a result of their review of chromium toxicity, McKee

and Wolf (1963)

193

suggested that up to 5 mgil of chromium

III or VI in livestock drinking water should not be harm-

ful. While this may be reasonable, it maybe unnecessarily

high when the usual concentrations of the element in nat-

ural waters is considered.

Recommendation

An upper allowable limit of 1.0 mg/1 for livestock

drinking waters is recommended. This provides a

suitable margin of safety.

Cobalt

In a recent survey of surface waters in the United States

(Durum et al. 1971)'" 63 per cent of over 720 samples were

found to contain less than 0.001

m

g/1 of cobalt. One sample

contained 4.5 mg: I, one contained 0.11 mg rl, and three

contained 0.05-0.10 mg; 1.

Underwood (1971)

2

" reviewed the role of cobalt in

animal nutrition. This element is part of the vitamin

B12

molecule. and as such it is an essential nutrient. Ruminants

s

y

nthesized their own vitamin I3

12

if they were given oral

cobalt. For cattle and sheep a diet containing about 0.1 ppm

of the element seemed nutritionally adequate. A wide

margin of safety existed between the required and toxic

levels for sheep and cattle, which were levels of 100 times

those usuall

y

found in adequate diets being well tolerated.

Nonruminants required preformed vitamin

B /2 .

When

administered to these animals in amounts well be

y

ond those

present in foods and feeds, cobalt induced polvcvthemia

(Underwood 1971).

2 " This was also true in calves prior to

rumen development: about 1.1 mg of the element per kg

of body \\Tight administered daily caused depression of ap-

petite and loss of weight.

Cobalt toxicity was also summarized by McKee and

Wolf (1963).'"

Recommendation

In view of the

data available on the occurrence

and toxicity of cobalt, an upper limit for cobalt in

livestock waters of 1.0 mg/I offers a satisfactory

margin of safety, and should be met by most

natural waters.

Copper

The examination of over 1,500 river and lake waters in

the United States (Kopp and Kroner 1970)

1

" yielded, at

the highest. 0.28 mgil of copper and an average value of

0.015 mg 1. These rather low values were probabl

y

due in

part to the relative insolubility of the copper ion in alkaline

medium and to its read y

adsorbability on colloids (McKee

and Wolf 1963).

1 " Where higher values than those reported

above are found, pollution from industrial sources or mines

can be suspected.

Copper is an essential trace element. The requirement for

chicks and turkey poults from zero to eight weeks of age is

4 ppm in the diet (NRC 19716).

206

For beef cattle on

rations low in molybdenum and sulfur, 4 ppm in the diet

is adequate: but when these elements are high, the copper

requirement is doubled or tripled (NRC 1970).

2° 4 A dietary

level of 5 ppm in the forage is suggested for pregnant and

---

312/Section 1

7

—Agricultural Uses of Mater

lactating ewes and their lambs (NRC 1968b

201 ). A level of

6 ppm in the diet is considered ade

q

uate for swine (NRC

1968a).202

Swine are apparently very tolerant of high leveis of

copper, and 250 ppm or more in the diet have been used

to improve livewei

g

.ht gains and feed efficiency (Nutrition

Reviews 1966a

2 n NRC I 968a).

2 " On the other hand, sheep

were very susceptible to copper poisoning (Underwood

1971),

254

and for these animals a diet containin

g 25 ppm

was considered toxic. About 9 mg per animal per day was

considered the safe tolerance level (NRC 1968b).'"

Several reviews of copper requirements and toxicity have

been presented (McKee and Wolf I963,'" Nutrition Re-

views 1966a.

21 ° Underwood

1971).

2

'

4 There is very little

ex-

perimental data on the effects of copper in the water supply

on animals. and its toxicity

must

be judged largely from the

results of trials where copper was fed. The element does not

appear to accumulate at excessive levels in muscle tissues,

and it is very readil

y

eliminated once its administration is

stopped. While most livestock tolerate rather high levels,

sheep do not (NRC 1968b).="

Recommendation

It is recommended that the upper limit for cop-

per in livestock waters be 0.5 mg/l. Very few natural

waters should fail

to meet this.

Fluorine

-

The role of fluorine as a nutrient and as a toxin has been

thoroughly reviewed

by Underwood (1971).

2

" (Unless

otherwise indicated, the following discussion, exclusive of

the recommendation, is based upon this review.) While

there is no doubt that dietar

y fluoride in appropriate

amounts improved the caries resistance of teeth. the element

has not yet been found essential to animals. If it is a dietary

essential, its requirement must be very low.

Its

ubiquity

probably insures a continuously adequate intake by ani-

mals.

Chronic fluoride poisoning of livestock has, on the other

hand, been observed in several areas of the world, resulting

in some cases from the consumption of waters of high fluoride

content. These waters come from wells in rock from which

the element has been leached, and they often contain

10-15 mg/l. Surface waters, on the other hand, usually con-

tain considerably less than 1 mgil.

Concentrations of 30-50 ppm of fluoride in the total

ration of dairy cows is considered the upper safe limit,

higher values being suggested for other animals (NRC

1971a).2

" Maximum levels of the element in waters that are

tolerated by livestock are difficult to define from available

experimental work. The species, volume, and continuity of

water consumption, other dietar

y

fluoride, and

age of the

animals, all have an effect. It appears, however, that as little

as 2 mg/1 may cause tooth mottling under some circum-

stances. At least a several-fold increase in its concentrat.

seems, however, required to produce other injurious effei

Fluoride from waters apparently does not accumulate

soft tissues to a significant degree. It is transferred to a v,

small extent into the milk and to a somewhat greater deg:

into eggs.

McKee and Wolf (1963) 1

" have also reviewed the mat

of livestock poisoning by fluoride, concluding that 1.0

TM

of the element in their drinking water did not harm th(

animals. Other more recent reports presented data

sugge

ina that even considerably higher concentrations of fluori

in the water may, with the exception of tooth mottlin

caused no animal health problems (Harris et al. 1963,

Shupe et al. 1964,

246

Nutrition Reviews 1966b,"' Savii

1967,

23

' Schroeder et al. 1968a237).

Recommendation

An upper limit

for fluorides in livestock drink in

waters of 2.0 mg/I is recommended. Although thi

level may result in some tooth mottling it shoul

not be excessive from the standpoint of anima

health or the deposition of the element in meat

milk, or eggs.

Iron

It is well known that iron (Fe) is essential to animal life

Further, it has a low order of toxicity. Deobald and Elveh

jem (1935) 138

found that iron salts added at a level o.

9,000 mg Fe/kg of diet caused a phosphorus deficiency ir.

chicks. This could be overcome by adding phosphate to the

diet. Campbell (1961) 124

found that soluble iron salt ad-

ministered to baby pigs by stomach tube at a level of 600 mu

Fe/kg of body weight caused death within siX hours. O'Don-

ovan et al. (1963) 212

found very high levels of iron in the

diet (4,000 and 5,000 mg/kg) to cause phosphorus deficiency

and to be toxic to weanling pigs. Lower levels (3,000

M9:

kg)

apparently were not toxic. The intake of water by livestock

may be inhibited by high levels of this element (Taylor

1935).

25

° However, this should not be a common or a serious

problem. While iron occurs in natural waters as ferrous

salts which are very soluble, on contact with air it is

oxi-

dized

and it precipitates as ferric oxide, rendering it essen-

tially harmless to animal health.

It is not considered necessary to set an upper limit of ac-

ceptability for iron in water. It should be noted, however,

that even a few parts per million of iron can cause clogging

of lines to stock watering equipment or an undesirable stain-

ing and deposit on the equipment itself.

Lead

Lake and river waters of the United States usually contain

less than'0.05 mg/1 of lead (Pb), although concentrations in

excess of this have been reported (Durum et al. 1971.141

Kopp and Kroner 1970).

182

Some natural waters in areas

where galena is found have had as much as 0.8 mg/I of the

---

Water for Livestock Enterprises,1313

element. It may also be introduced into waters in the ef-

fluents from various industries, as the result of action of the

water on lead pipes (McKee and Wolf 19631, 1

" or by

dennsition from pollt ted air (NRC 1972).2°7

A nutritional need for lead by animals has not been

demonstrated, but its toxicit

y is well known. A rather com-

plete review of the matter of lead poisoning by McKee and

Wolf (19631

1

" suggested that for livestock the toxicit y of

the element had not been clearly established from a quanti-

tative standpoint. Even with more recent data (Donawick

1966,

1

" Link and Pensinger 1966, 186

Harbourne et al.

1968,

160 Damron et al. 1969,

13 ' Hatch and Funneil 1969,1"

Egan and O'Cuill 1970,'" Aronson 1971), 1 " it is difficult to

establish clearl y

at

\chat

level of intake lead becomes toxic,

although a dail

y

intake of 6-7 mg Pb/k, of body weight has

been suggested as the minimum that eventually

g

ave rise

to signs of poisoning in cattle (Hammond and Aronson

1964).

16

' Apparentl

y

. cattle and sheep are considerably

more

resistant to lead toxicosis than are horses, being remarkably

tolerant to"the continuous intake of relativel

y large amounts

of the element ( Hammond and Aronson 1964. 1 " Garner

1967,

1

" Aronson 1971'

1

: NRC 1972 2 ° 7 ). However: there is

some tendency for it to accumulate in tissues and to be

transferred to the milk at levels that could be toxic to man

(Hammond and Aronson 1964).1

64

There is some agreement that 0.5 mg/I of lead in the

drinking water of livestock is a safe level (McKee and Wolf

1963);

193

and the findings of Schroeder and his associates

with laborator

y

animals are in agreement with this (1963a,2"

1963b,

239

1964,2

" 1965

235

). Using 10 times this level, or

5 mgll, of lead in the drinking water of rats and mice over

their life spans, these authors observed no obvious direct

toxic effects but did find an increase in death rates in the

older animals, especiall

y in the males. Schroeder et al.

(1965) 2

", observed that

. the increased mortalit y

was not

caused by overt lead poisoning, but rather by an increased

susceptibility to spontaneous infections. Hemphill et al.

(1971)

171

later reported that mice treated with subclinical

doses of lead nitrate were more susceptible to challenge with

Salmonella typhimurium.

Recommendation

In view of the lack of information concerning

the chronic toxicity of lead, its apparent role in

reducing disease resistance, and the very low inci-

dence in natural waters of lead contents exceeding

the 0.05 mg/I level, an upper

limit of

0.1 mg/1 for

lead in livestock waters is recommended.

Manganese

Like iron. manganese is a required trace element, occurs

in natural waters at only low levels as manganous salts, and

is precipitated in the presence of air as manganic oxide.

While it can be toxic when administered in the feed at high

levels (Underwood l971),

254 it is improbable' that it would

be found at toxic levels in waters.

It is doubtful that setting an upper limit of acceptability

is necessar

y for m ,,

r.garlese, but af: with iron, fc •.v milli-

grams per liter in water can cause objectionable deposits

on stock watering equipment.

Mercury

Natural waters may contain mercur

y originating from

the activities of man or from naturally occurring geological

stores (Wershaw 1970,

262

White et al. 1970).

263

The element

tends to sorb readily on a variety of materials, including the

bottom sediments of streams, greatly reducing the levels

that might otherwise remain in solution (Hem 1970) 17°

Thus, surface waters in the United States have usually

been found to contain much less than 5 A

O

of mercury

(Durum et al. 1971).

1 " In areas harboring mercur

y de-

posits, their biological methvlation occurs in bottom sedi-

ments ( Jensen and Jernelov 1969)

176

resulting in a con-

tinuous presence of the element in solution ( Greeson 1970).156

In comparison to the relative instability of organic com-

pounds such as salts of phenyl mercury and methoxyethyl

mercury (Gage and Swan 1961,

151

Miller et al. 1961,1"

Daniel and Gage 1969,

132

Daniel et al. 1971

1

") alkyl

mercury compounds including methyl mercury (CH3Hg+)

have a high` degree of stabilit

y in the bod

y

(Gage 1964,"°

Miller et al. 1961)' resulting in an accumulative effect.

This relatiVe stability, together with efficient absorption from

the gut, contributes to the somewhat greater toxicity of

orally administered methyl mercury as compared to poorly

absorbed inorganic mercury salts (Swensson et al. 1959).249

The biological half-life of meth y

l mercury varies from

about 20 to 70 da

y

s in most species (Bergrund and Berlin

1969).

1

" Brain, liver, and kidney were the or

g

ans that ac-

cumulated the highest levels of the element, with the distri-

bution of methyl and other alk

y

l mercury compounds favor-

ing nerve tissue and inorganic mercury favoring the kidney

(Malishe

y

skava et al. 1966,'" Platonow 1968,

222 Aberg et al.

1969)."2

Transfer of methyl mercury (Curley et al. 1971),

13

° but

not mercuric mercury (Berlin and Ullberg 1963),

114

to the

fetus has been observed. The element also appeared in the

eggs of poultr

y

(Kiwimae et al. 1969)

1° and wild birds

(Borg et al. 1969, 118

Dustman et al. 1970) 1

" but did not seem

to concentrate there much above levels found in the tissues

of the adult. Data concerning levels of mercury that may be

detrimental to hatchability of eggs are too meager to sup-

port conclusions at this time. Also, data concerning transfer

of mercury

to milk is lacking.

The animal organs representing the principal tissues for

mercury concentration are brain, liver. and kidney. It is

desirable that the maximum allowable limit

,

for mercury in

livestock waters should result in less than 0.5 ppm of ac-

cumulated mercury in these tissues. This is the level now in

---

3141Section

V—Agricultural Uses of Woier

use as the maximum allowable in fish used for human con-

sumption.

Few data are available quantitatively relating dietary

mercur y

levels with accumulation in animal tissues. The

ratios between blood and brain levels of meth y l mercury

appeared to range from 10 for rats to 0.2 for monkeys and

dogs t International Committee on Maximum Allowable

Concentrations of Mercury Compounds 19691. 1

" In addi-

tion, blood levels of mercury appeared to increase approxi-

matel

y in proportion to increases in dietar

y intake (Birke

ec al. 1967''': Tejning 1967251).

Assuming a 0.2 or more blood-to-tissue (brain or other tis-

sue) ratio for mercury in livestock. the maintenance of less

than 0.5 ppm mercur

y

in all tissues necessitates maintaining

blood mercur

y

levels below 0.1 ppm. This would indicate a

maximum daily intake of 2.3

I

.Lg of mercury per kilogram

body weight: Based upon daily water consumption by meat

animals in the range of up to about eight per cent of body

weight. it is estimated that water rimy contain almost 30

µg • I

of mercury as meth

y

l mercury without the limits of

these criteria being exceeded. Support for this approxima-

tion was provided in part by the calculations of Aber

g, et al.

(1969) lir= showing that after "infinite" time the body burden

of mercury in man will approximate 15.2 times the weekly

intake of methyl mercury. Applying these data to meat ani-

mals consuming water equivalent to eight per cent of body

weight and containing 30

A

O

of mercury would result in

an average of 0.25 ppm mercury in the whole animal body.

Recommendation

Until specific data become available for the vari-

ous species. adherence to an upper limit of

10

of mercury in water for livestock is recommended,

and this limit provides an adequate margin of

safety to humans who will subsequently not be

exposed to as much as 0.5 ppm of mercury through

the consumption of animal tissue.

Molybdenum

Underwood (1971)

254

reviewed the matter of molyb-

denum's role in animal nutrition. While the evidence that

it is an essential element is good, the amount of molybdenum

required has not been established. For cattle, for instance,

no minimum requirement has been set, but it is believed to

be low, possibly less than 0.01 ppm of the dry diet (NRC

1970).20'

McKee and Wolf (1963) 193

reviewed the matter of toxicity

of molybdenum to animals, but Underwood (1971)254

pointed out that many of the studies on its toxicity are of

limited value because a number of factors known to influence

its metabolism were not taken into account in making these

studies. These factors included the chemical form of

molybdenum, the copper status and intake of the animal,

the form and amount of sulfur in the diet, and other less

well defined matters. In spite of these, there are data to

support real species differences in terms of tolerance to

element. Cattle seem the least tolerant, sheep a little m

so, and horses and swine considerably more tolerant.

While Shirley et al. (1950)

245

found that drenching

Ste

daily with sodium molvbdate in an amount equialent

about 200 ppm of molybdenum in the diet for a period

seven months resulted in no marked symptoms of toxici

cattle on pastures where the herbage contained 20-100 p:

of molybdenum on a dry basis developed a toxicosis kno

as teart. Copper additions to the diet have been used

contrn1 this (Underwood 1971)."4

Cox et al. (1960) 127

reported that rats fed diets containi

500 and 800 ppm of added mol

y

bdenum showed toxic

symptoms and had increased levels of the element in th

livers. Some effects of the mol

y bdenum in the diets on li

\

enz

y

mes in the rats were not observed in calves that h

been maintained on diets containing up to 400 ppm of t

element.

Apparently, natural surface waters very rarel

y

contain

levels of this element of over 1 mg.1 (Kopp and Kror

I970),

1

" which seemed to offer no problem.

Conclusion

Because there are many factors influencing to:

icity of molybdenum, setting an upper allowab

limit for its concentration in livestock waters

not possible at this time.

Nitrates and Nitrites

Livestock poisoning by nitrates or nitrites is depende:

upon the intake of these ions from all sources. Thus, wat.

or forage may independently or together contain levels th.

are toxic. Of the two, nitrite is considerabl

y more toxi

Usually it is formed throu

g

h the biological reduction •

nitrate in the rumen of cattle or sheep. in freshly choppe

forage, in moistened feeds, or in waters contaminated wit

organic matter to the extent that they are capable of sul

porting microbial grow t

h. While natural waters often col

tain high levels of nitrate, their nitrite content is usuali

very low.

While some nitrate was transferred to the milk, Daviso

and his associates (1964)"

5

found that for dairy cattle fe

150 mg NO

3

N/kg of body weight the milk contained abou

3 ppm of NO

3

N. They concluded that nitrates in cattl

feeds did not appear to constitute a hazard to huma

health, and that animals fed nitrate continuously developer

some degree of adaptation to it.

The LD50 of nitrate nitro

g

en for ruminants was fount

to be

about

75 mg NO

3 N/k

g

, of body weight when ad

ministered as a drench (Bradley et al. 1940) 119 and abou

255 mg/kg of body weight when spra y

ed on forage ant

feed (Crawford and Kennedy 1960). 1 " Levels of 60 me

NO3 N/kg of body weight as a drench (Sapiro et al. 1949)23

and 150 mg NO

3

N/kg of body weig

ht in the diet (Prewit:

and Merilan 1958;

2'

4

Davison et al. 1964

135

) had no de-

---

Water for Livestock Enterprises/315

leterious effects. Lewis (1951) 1

" found that 60 per cent con-

version of hemoglobin to methemoglobin occurred in

mature sheep from 4.0 g of NO

3

N or 2.0 g of NO

2

N placed

in the rumen, or 0.4 g NO

2

N injected intravenously. As an

oral drench, 90 mg NO

3

N/kg of body weight gave peak

methemo

g

lobin levels of 5-6 000 ml of blood in sheep,

while intravenous injection of 6 mg NO.,N

.

; kg of body weight

gave similar results (Emerick et al. 1965))44

Nitrate-induced abortions in cattle and sheep have

generally required amounts approaching lethal levels

(Simon et al.. 1959,

247

Davison et al. 1962, 1

" Winter and

Hokanson 1964, 2

" Davison et al. 1965'").

Some experiments have demonstrated reductions in

plasma or liver vitamin A values resulting from the feeding

of nitrate to ruminants ( Jordan et al. 1961,

1

" Goodrich

et al. 1964, 153

Newland

.

and Deans 1964, 2

" Hoar et al.

1968 173

). The destructive effect of nitrites on carotene

(Olson et al. 1963 213

) and vitamin' A (Pugh and Garner

1963 225

) under acid conditions that existed in silage or in

the gastric stomach have also been noted. On the other

hand, nitrate levels of about 0.15 per cent in the feed

(equivalent to about I per cent of potassium nitrate) have

not been shown to influence liver vitamin A levels (Hale

et al. 1962, 161

Weichenthal et al. 1963,

261

Mitchell et al.

1967

197

) nor to have other deleterious effects in controlled

experiments, except for a possible slight decrease in produc-

tion.

Assuming a maximum water consumption in dairy cat-

tle of 3 to 4 times the dry matter intake (NRC 1971a205),

the concentration of nitrate to be tolerated in the water

should be about one-fourth of that tolerated in the feed.

This would be about 300 mgil of NO3N.

Gwatkin and Plummer (1946)

160

drenched pigs with

potassium nitrate solutions. finding that it required in ex-

cess of 300 mg NO 3 N

,

.. kg of bod

y

weight to cause erosion

and hemorrhage of the gastric mucosa and subsequent

death. Lower levels of this salt had no effect when ad-

ministered daily for 30 da

y

s. Losses in swine due to metho-

globinemia have occurred only with the consumption of

preformed nitrite and not with nitrate (McIntosh et al.

1943,

192

Gwatkin and Plummer 1946, 16

° Winks et al.

1950

265

). Nitrate administered orall

y

as a single dose was

found to be acutely toxic at 13 mg NO

2

N/kg of body weight,

8:7 mg/kg of body weight producing moderate methemo-

globinemia (Winks et al. 1950).

2

" Emerick et al. (1965)1"

produced moderate methemoglobinemia in pi

g

s with intra-

venous injections of 6.0 mg NO

2

N, kg of body weight and

found that the animals under one week of age were no more

Susceptible to poisoning than older ones.

Drinking water containing 330 mg/1 NO

3

N fed continu-

ously to growing pigs and to gilts from weaning through two

farrowing seasons had no adverse effects (Seerley et al.

1965). 2

" Further, 100 mg/I of NO

2 N in drinking water

had no effect on performance or liver vitamin A values of

pigs over a 105-day experimental period, and methemo-

globin values remained low. This level of nitrite greatly

exceeded the maximum of 13 mg/1 NO

2

N found to form

in waters in galvanized watering equipment and in the

presence of considerable organic matter containing up to

300 mg/1 NO3N.

In special situations involving the presence of high levels

of nitrates in aqueous slurries of plant or animal tissues,

nitrite accumulation reached a peak of about one-fourth to

one-half the initial nitrate concentration (McIntosh et al.

1943, 192 Winks et al. 1950,

265

Barnett 1952). 109

This situation

was unusual, but since wet mixtures are sometimes used for

swine, it must be considered in establishing criteria for

water.

Levels of nitrate up to 300 mg/1 NO

3

N or of nitrite up to

200 mg/1 of NO

2 N were added to drinking waters without

adverse effects on the growth of chicks or production of

laying hens (Adams et al. 1966).'" At 200 mg/1 NO2N,

nitrite decreased growth in turkey poults and reduced the

liver storage of vitamin A in chicks, laying hens, and

turkeys. At 50 mgt NO

2

N; no effects were observed on any

of the birds. Kienholz et al. (1966)

179

found that 150 mg '1

of NO3 N in the drinking water or in the feed of chicks or

poults had no detrimental effect on growth, feed efficiency,

methemoglobin level, or thyroid weight, while Sell and

Roberts (1963)

243

found that 0.12 per cent (1,200 ppm) of

NO

2

N in chick diets lowered vitamin A stores in the liver

and caused hypertrophy of the thyroid. Other studies have

shown poultry to tolerate levels of nitrate or nitrite similar

to or greater than those mentioned above (Adams et al.

1967,

1 " Crawford et al. 1969

129

). Up to 450 mg/1 of NO3N

in the drinking water of turkeys did not significantly affect

meat color (Mugler et al. 1970).199

Some have suggested that nitrate or nitrite can cause a

chronic or subclinical toxicity (Simon et al. 1959,2"

McLwain and Schipper 1963,'" Pander 1961,

221

Beeson

I964,

11

' Case 1957

1 "). Some degree of thyroid hypertrophy

ma

y

occur in some species with the consumption of subtoxic

levels of nitrate or nitrite (Bloomfield et al. 1961, 11

' Sell and

Roberts 1963),

2

" hut possibly not in all ( Jainudeen et al.

1965))" In the human newborn, a chronic type of methe-

globinemia may result from feeding waters of low NO3N

content (Armstrong et al. 1958).

1 °' It appears, however,

that all classes of livestock and poultry that have been studied

under controlled experimental conditions can tolerate the

continued ingestion of waters containing up to 300 mg .1 of

NO3

N or 100 mg-;1 of NO2N.

Recommendation

In order to provide a reasonable margin of safety

to allow for unusual situations such as extremely

high water intake or nitrite formation in slurries,

the NO3 N plus NO

2

N content in drinking waters

for livestock and poultry should be limited to 100

ppm or less, and the NO 2

N content alone be limited

to 10 ppm or less.

---

316: Section

1 ---Agricultural Uses of Water

Selenium

Rosenfeld and Beath (1964)

222

have reviewed the prob-

lems of selenium poisoning in livestock. Of the three types

of this poisonin g

; described, the "alkali disease" syndrome

required the lowest level of the element in the feed for its

causation. Moxon (1937)

193

placed this level at about 5 ppm,

and subsequent research confirmed this figure. Later work

established that the toxicity of selenium was very similar

when the element \Yas fed as it occurs in plants, as

. seleno-

methionine or selenocystine. or as inorganic selenite or

selenatc (Halverson et al. 1-962. 162 Rosenfeld and Beath

1964, 227 Halverson et al. 1966

15

'). Ruminant animals may

tolerate more as inorganic salts than do monogastric ani-

mals because of the salts' reduction to insoluble elemental

form by rumen microorganisms (Butler and Peterson

19611.121

.A study with rats (Schroeder 1967)

222

revealed that sele-

nite, but not selenate. in the drinking water caused. deaths

at a level of 2 mg 1 and was somewhat more toxic than

selenite administered in the diet. However, the results of

drenching studies with cattle and sheep (Maag and Glenn

1967)

107

indicated that selenium concentration in the water

should be slight, if it is any more toxic in the same chemical

form administered in the feed. If there arc differences with

respect to the effect of mode of ingestion on toxicity, they are

probably small.

To date, no substantiated cases of selenium poisoning in

livestock by waters have been reported, although some

spring and irrigation waters- have been found to contain

over I mg:1 of the element (B

y

ers 1935,

1 " Williams and

Byers 1935, 2

" Beath 1943

11

"). As a rule, well, surface, and

ocean waters appeared to contain less than 0.05 mg, 1,

usually. considerably less. B yers et al. (19381'

2 " explained

the low selenium content as a result of precipitation of the

selenite ion with ferric h

y

droxide. Microbial activity, how-

ever. removed either selenite or selenatc from water

(Abu-Erreish 19671;

1 " this ma

y

be another explanation.

In addition to its toxicit

y

, the essential role of selenium

in animal nutrition (Thompson and Scott 1970)"

2 must be

considered. Between 0.1 and 0.2 ppm in the diet have been

recommended as necessar

y

to insure against a deiiciency

in

•

poultry (Scott and Thompson 19691,

241 against white

muscle disease in ruminants (Muth 1963),"

1

- and other

diseases in other animals (Hartle

y

and Grant 1961).187

Selenium therapy suggests it as a requirement for livestock

in general. Inorganic selenium was not incorporated into

tissues to the same extent as it occurred in plant tissue

(Halverson et al. 1962,

1

" 1966,

163

Rosenfeld and Beath

1964227

)-. It is doubtful that 0.2 ppm or less of added inor-

ganic selenium appreciabl

y

increased the amount found in

the tissue of animals ingesting it. The data of Kubota et al.

(1967)

183

regarding the occurrence of selenium poisoning

suggested that over a good part of the United States live-

stock were receiving as much as 0.5 ppm or even more of

naturally occurring selenium in their diets continuous

without harm to them and without accumulating levels

the element in their tissues that make meats or livestc

products unfit for human use.

Recommendation

It is recommended

that the

upper limit f

selenium in livestock

waters be

0.05 mg/l.

Vanadium

Vanadium has been present in surface waters in t

United States in concentrations up to 0.3 mg/1, althouE

most of the analyses showed less than 0.05 mg/1 (Kopp at

Kroner 19701.1"

Recently, vanadium was determined essential for ti

growing rat, physiologically required levels appearing

be at or below 0.1 ppm of the diet (Schwarz and Mill

1971).

2

" It became toxic to chicks when incorporated in

the diet as ammonium meta

y

ahadate at concentratiol

over about 10 ppm of the element (Romoser et al. 1961.:

Nelson et al. 1962. 202 Berg 1963,

n2 Hathcock et al. 1964160

Schroeder and Balassa (1967)

233

found that when mice wet

allowed drinking xy

ater containing 5 of vanadium

vanadyl sulfate over a life span, no toxic effects were of

served, but the element did accumulate to some extent i

certain organs.

Recommendation

It

is

recommended that the upper limit fo

vanadium in drinking water- for livestock be

0.

mg

/l.

Zinc

There are many opportunities for the contamination c

waters by zinc. In some areas where it is mined, this meta

has been found in natural waters in concentrations as higl

as 50 mg. 1. It occurs in si

g

nificant amounts in effluent

from certain industries. Galvanized pipes and tanks ma\

also contribute zinc to acidic waters. In a recent survey o.

surface waters, most contained less than 0:05 mg/1 but some

exceeded 5.0 mg: 1, the highest value being 42 mg/1 (Durum

et al. 1971)."

Zinc is relativel

y

nontoxic for animals. Swine have

tolerated 1.000 ppm of dietary zinc (Grimmet et al. 1937,1"

Sampson et al. 1942.

2

" Lewis et al. 1957,

185

Brink et al.

1959 1

"), while 2,000 ppm or more have been found to be

toxic (Brink et al. 1959). 1

" Similar findings have been re-

ported for poultry (Klussendorf and Pensack 1958,

181

John-

son et al. 1962,

1 " Vohra and Kratzer 1968 239 ) where zinc

was added to the feed. Adding 2,320 mg

.

/1 of the element

to water for chickens reduced water consumption, egg pro-

duction, and body weight. After zinc withdrawal there were

no symptoms of toxicit

y in chickens (Sturkie 1956).

2

'8

In a

number of studies with ruminants. Ott et al. (1966a,215

---

Water for Livestock Enterprises/ 31 7

b

,

216 c,217

d218)

)

found zinc added to diets as the oxide to be

toxic, but at levels over 500 mg, kg of diet.

While an increased zinc intake reflected an increase in

level of the element in the bod

y

tissues, the tendency for its

accumulation was not great (Drinker et al. 1927,

140

Thomp-

son et al. 1927,

2

" Sadasivan 1951,

2's

Lewis et al. 19571.1"

and tissue levels fell rapidl

y

after zinc dosing was stopped

(Drinker et al. 1927,

1

" Johnson et al. 1962177).

Zinc is a dietary requirement of all poultry and livestock.

National Research Council recommendation for poults up

to eight weeks was 7

.

0 me kg of diet; for chicks up to eight

weeks, it was 50 mg/kg of diet (NRC 1971b):

2206

for swine.

50 mg/kg

•

of diet (NRC 1968a).

202

There is no established

requirement for ruminants, but zinc deficiencies were re-

ported in cattle grazing fora

g

e with zinc contents ranging

between 18 and 83 ppm (Underwood 1971).

2

" There is

also no established requirement for sheep, but lambs fed a

purified diet containing 3 ppm of the clement developed

symptoms of a deficiency that were prevented by adding 15

ppm of zinc to the diet: 30 ppm was required to give max-

imum growth (Ott et al. 1965).2'4

Cereal grains contained on the average 30-40 ppm and

protein concentrates from 20 to over 100 ppm (Davis

1966). 134

In view of this, and in view of the low order of

toxicity of zinc and its requirement by animals, a limit in

livestock waters of 25 mg zinc; I would have a very large

margin of safety. A higher limit does not seem necessary,

since there would be few instances where natural waters

would carry in excess of this.

Recommendation

It is recommended that the upper limit for zinc

in livestock waters be 25 mg/l.

Toxic Algae

The term "water bloom" refers to heavy scums of blue-

green algae that form on waters under certain conditions.

Perhaps the first report of livestock poisoning by toxic algae

was that of Francis (18781

1

" who described the problem in

southern Australia. Fitch et al. (1934)

146

reviewed a number

of cases of algal poisoning in farm animals in Minnesota

between 1882 and 1933. All were associated with certain

blue-green algae often concentrated by the wind at one end

of the lake. Losses in cattle. sheep, and poultry were re-

ported. The algae were found toxic to laboratory animals

on ingestion or intraperitoneal injection.

According to Gorham (1964)

1

" six species of blue-green

algae have been incriminated, as follows:

Nodularia spumigena

Micros

y

stis aeruginosa

Coelosphaerium Kuetzingianum

Gloeotrichia echinulata

Anabaena flos-aquae

Aphanizomenon flos-aquae

Of the above, Gorham states that

Microcystis

and

Ana-

baena

have most often been blamed for serious poisonings

and algal blooms consisting of one or more of these species

vary considerabl

y

in their toxicity

(Gorham

1

C

)41:) .155

According to Gorham (1960),'" this variability seems to

depend upon a number of factors, e.g., species and strains

of

algae that are predominant, types and numbers of bac-

terial associates, the conditions of growth, collection and

decomposition, the degree of animal starvation and sus-

ceptibilit

y

, and the amount consumed. To date, onl

y

one

toxin from blue-green algae has been isolated and identified,

onl y

from a few species and streams. This Was a cyclic pol

y

-peptide containing 10 amino acid residues, one of which

was the unnatural amino acid D-serine (Bishop et al.

1959)." This is also referred to as FDF (fast-death factor),

since it causes death more quickly than SDI

?

(slow-death

factor) toxins produced in water blooms.

Shilo (1967)

244 pointed out that the sudden decomposition

of algal blooms often preceded mass mortalit

y

of fish, and

similar observations were made with livestock poisonings.

This suggests that the Isis of the algae may be important

in the release of the toxins, but it also suggests that in some

circumstances botulism may be involved. The lack of oxy-

gen ma

y

have caused the fish kill and must also be con-

sidered.

Predeath symptoms in livestock have not been carefully

observed and described. Post-mortem examination is ap-

parently of no help in diagnosis (Fitch et al. 1934).1"

Feeding or injecting algal suspensions or water from suspect

waters have been used

,

to some extent, but the occasional

fleeting toxicity of these materials makes this procedure of

limited value. Identification of any of the toxic blue-green

algae species in suspect waters does no more than suggest

the possibility that they caused livestock deaths.

In view of the many unknowns and unresolved problems

relating blooms of toxic algae, it is impossible to suggest

an y

recommendations insuring against the occurrence of

toxic algae in livestock waters.

Recommendation

The use for livestock of waters bearing heavy

growths

of blue green algae should be avoided.

Radionuclides

Surface and groundwaters acquire radioactivity from

natural sources, from fallout resulting from atmospheric

nuclear detonations, from mining or processing uranium,

or as the result of the use of isotopes in medicine, scientific

research, or industry.

All radiation is regarded as harmful, and an

y

unnecessary

exposure to it should be avoided. Experimental work on the

biological half-lives of radionuclides and their somatic and

genetic effects on animals have been briefly reviewed by

McKee and Wolf (1963).

1 " Because the rate of decay of a

radionuclide is a physical constant that cannot be changed,

---

318 /Section

V

—

Agricultural Uses of rFater

radioactive isotopes must be disposed of by dilution or by

storage and natural decay. In view of the variabilit

y in half-

lives of the many radioisotopes, the nature of their radioac-

tive emissions. and the differences in metabolism of various

elements by different animals, the results of animal experi-

mentation do not lend themselves easily to the development

of recommendations.

Based on the recommendations of the U. S. Federal

Radiation 'Council (1960,

2

" 1961"'), the Environmental

Protection Agenc

y

will set drinking water standards for

radionuciidcs (1972)."' to establish the intake of radioac-

tivit

y

from waters that when added to the amount from all

ocher sources

\

611 not likel y

be harmful to man.

Recommendation

In view of the limited knowledge of the effect of

radionuclides in water on domestic animals, it is

recommended that the Federal Drinking Water

Standards he used for farm animals as well as for

man.

PESTICIDES (IN WATER FOR LIVESTOCK)

Pesticides include a large number of organic and inorganic

compounds. The United States production of synthetic

organic pesticides in

1970

was 1,060 million pounds con-

sisting almost entirel y of insecticides (501 million pounds),

herbicides (391 million pounds), and fungicides (168 million

pounds). Production data for inorganic pesticides was

limited. Based on production, acreage treated, and use

patterns, insecticides and herbicides comprise the major

agricultural pesticides. (Fowler 1972).

27

' Of these. some can

be detrimental to livestock. Some have low solubility in

water, but all cause problems if accidental spillage pro-

duces high concentrations in water, or if the

y become ad-

sorbed on- colloidal particles subsequently dispersed in

wa ter.

Insecticides are subdivided into three major classes of

compounds including metbylcarbamates. organopliospha tcs

and chlorinated h ydrocarbons. Nlany of these substances

produce no serious pollution hazards, because they are non-

persistent. Others, such as the chlorinated hydrocarbons,

are quite persistent in the environment and are the pesti-

cides most frequentl

y

encountered in water.

Entry of

Pesticides into Water

Pesticides enter water from soil runoff. direct application,

drift, rainfall, spills, or fault y waste disposal techniques.

Movement by erosion of soil particles with adsorbed pesti-

cides is one of the principal means of entry into water. The

amount carried in runoff water is influenced by rates of ap-

plication, soil type, vegetation, topography, and other

factors. Because of strong binding of some pesticides on soil

particles, water pollution b

y

pesticides is thought to occur

largely through the transport of chemicals adsorbed to soil

particles (Lichtenstein et al. 1966).

281

This mechanism r

not always be a major route. Bradle

y

et al. (1972)269

served that when 13.4 kg/hectare DDT and 26.8 kgthec.

toxophene were applied to cotton fields, only 1.3 and

per cent, respectively, of the amounts applied were detec

in natural runoff water over an 8-month period.

Pesticides can also enter the aquatic environment by di:

application to surface waters. Generally. this use is to c

trol mosquito larvae, nuisance aquatic weeds, and, as

several southern states, to control selected aquatic fat

such as snails (Chesters and Konrad 1971).

27

.

1

Both of th

pathways generall

y result in contamination of surface wa:

rather than groundwaters.

Precipitation. accidental spills. and fault

y

waste dispc

are less important entry routes. Pesticides detected in ra

water include DDT,

DDI),

DDE, dieldrin, alpha-BHC

gamma-RHO in extremel

y

minute concentrations 'i.e..

the order of 10- 12

parts or the nanograms per liter le%

(Weibel et 1966."" Cohen and Pinkerton 1966,

27 ' T

rant and Tatton 1968'"). Spills and fault

y

waste dispo

techniques arc usually responsible for short-term,

high -

le

contamination.

The amount of pesticide actually in solution, howev

is governed be a number of factors, the most importa

probabl y

being the solubility of the molecule. Chlorinat

h

y

drocarbon insecticides, for example, have low solubil:

in water (Freshwater Appendix II-D). Cationic pesticic

(i.e., paraquat and diquat) are rapidl

y and tightly both

to soil particles and are inactivated (Weed Society

America 1970).

2

" Most arsenical pesticides form insoluL

salts and arc inactivated (Woolson et al. 19711."

7

A sure.

of the water and soil la y

ers in farm ponds indicates high

concentrates of pesticides are associated with the soil lave

that interface with water than in the water

per se.

In an c

tensive surve

y

of farm water sources (U. S. Dept. of Agi

culture, Agricultural Research Service 1969a,"

2 hercaft,

referred to as Agriculture. Research Service 1969a"'

anal ysis of sediment showed residues in the magnitude

decimal fractions of a microgram per gram (pg

'g.)

a his

of 4.90 pg g DDT and its DDE and DDD degradatio

compounds. These were the principal pesticides found i

sediment. Dieldrin and endrin were also detected in sed:

ment in two stud

y

areas where surface drainage Ovate

entered farm ponds from an adjacent field.

Pesticides Occurrence in Water

Chlorinated h y

drocarbon insecticides are the pesticide

most frequently encountered in water. The

y include DUI

and its de

g

radation products DDE and DDD, dieldrin.

endrin. chlordane, aldrin, and lindane. In a pesticide moni-

toring program conducted from 1957 to 1965, Breidenbach

et al. (1967) 270

concluded that dieldrin was present in all

sampled river basins at levels from 1 to 22 nanograms

(ng)diter. DDT and its metabolites were found to occur in

most surface waters, while levels of endrin in the lower

---

Water for Livestock Enterprises/319

Mississippi decreased from a high of 214 ngil in 1963 to a

ran

g

e of 15 to 116 ngil in 1965. Results of monitoring

studies conducted by the U. S. Department of Agriculture

(Agri

,.

.ultural Research Service 1969a) 267 from 1965 to

1967 indicated that only very small amounts of pesticides

were present in any of the sources sampled. The most preva-

lent pesticides in water were DDT, its metabolites DDD and

DDE, and dieldrin. Levels detected were usuall

y

below

one part per billion. The DDT family, dieldrin, endrin,

chlordane, linclane, heptachlor epoxide, trifluralin. and

,4-D, were detected in the range of 0.1 to 0.01 In a

major survey of surface waters in the United States con-

ducted from 1965 to 1968 for chlorinated hydrocarbon pesti-

cides (Lichtenberg et al. 1969),

232 dieldrin and DDT (in-

cludin

g

DDE and DDD) were the compounds most fre-

quently detected throughout the 5-year period. After reach-

ing a peak in 1966. the total number of occurrences of all

chlorinated hydrocarbon pesticides decreased sharpl

y

in

1967 and 1968.

A list of pesticides most likel

y to occur in the environ-

ment and. consequently, recommended for inclusion in

monitoring studies. was developed by the former Federal

Committee on Pesticide Control (now Working Group .on

Pesticides). This list was revised (Schechter 1971)

290 and

expanded to include those compounds (1) whose persistence

is, of relatively lone-term duration; (2) whose use patterns

is large scale in terms of acreage; or (3) whose inherent

toxicity is hazardous enough to merit close surveillance.

The primary list includes 32 pesticides or classes of pesticides

(i.e. arsenical pesticides, mercurial pesticides, and several

dithiocarbamate fungicides) recommended to be monitored

in water. .A secondar

y

list of 17 compounds was developed

for consideration, if monitoring activities are expanded in

the future. The pesticides found on the primar

y list would

be those most likely to be encountered in farm water sup-

plies (see Freshwater Appendix II-D).

Toxicological Effects of Pesticides on Livestock

Mammals generall

y

have a greater tolerance to pesticides

than birds and fish. However, the increased use of pesticides

in agriculture, particularly the insecticides, presents a poten-

tial hazard to livestock. Some compounds such as the or-

g

anophosphorous insecticides can be extremely dangerous,

especially when mishandled or wrongly used. To date, how-

ever, there actually have been very few verified cases of

livestock poisoning from pesticides (Papworth 1967).

2 " In

the few instances reported, the cause of livestock poisoning

usually has been attributed to human negligence. For live-

stock, pesticide classes that may pose possible hazards are

the acaricides, fungicides, herbicides, insecticides, mollus-

cides, and rodenticides (Papworth 1967).287

Acaricides intended for use on crops and trees usually

have low toxicity to livestock. Some, such as technical

chlorobenzilate, have significant toxicity for mammals. The

acute oral LD50 in rats is 0.7 gjkg of body weight (Pap-

worth 1967).287

With fungicides, the main hazard to live-

stock apparentl y

is not from the water route, but from their

use as seed dressings for grain. Of the types used, the organo-

mercur

y

CC.'n

-I

po

r

a

rl

potentially the most

dangerous (McEntee 1950,

2

" Weibel et al. 1966295 ). The

use of all organomercur

y

fungicides is restricted b y the

Environmental Protection Agency (Office of Pesticides,

Pesticides Regulation Division 1972).

277 Consequentl

y, the

possible hazard to livestock from these compounds has, for

most purposes, been eliminated.

Of the herbicides in current use, the dinitro compounds

pose the greatest hazard to livestock. Dinitroorthocresol

(DNC or DNOC) is probably the most used member of

this group. In ruminants, however, DNC is destroyed

rapidl

y

by the rumen organisms (Papworth 1967). 2 " These

compounds are very persistent, up to two years, and for

livestock the greatest hazard is from spilla

ges, contamina-

tion of vegetation. or water. In contrast, the phenoXyacetic

acid derivatives (2 .4-D, MCPA) are comparativel

y

harm-

less. Fertig (19531"

S

states that suspected poisoning of

livestock or wildlife by phenoxy herbicides could not be

substantiated in all cases carefull

y surve

y

ed. The hazards

to livestock from hormone weed killers are discussed by

Rowe and Hymas (1955),

2

" and dinitrocompounds by

McGirr and Papworth (1953)"

4 and Edson (1954).27'

The possible hazards from other herbicides are 'reviewed by

Papworth (1967)

2

" and Radeleff (1970).2"

Of the classes of insecticides in use, some pose a potential

hazard to livestock, while others do not. Insecticides of

vegetable origin such as pyrethrins and rotenones. are prac-

tically non-toxic to livestock. Most chlorinated hydrocarbons

are not highly toxic to livestock, and none is known to ac-

cumulate in vital organs. DDT, DDD, dilan. methoxvchlor,

and perthane are not highly toxic to mammals. but some

other chlorinated h

y

drocarbons are quite toxic (Papworth

1967,

2

" Radeleff 1970283

). The insecticides that are poten-

tiall y

the most hazardous are the organophosphorus com-

pounds causing chlorinesterase inhibition. Some. such as

mipafax, induce pathological changes not directly related

to cholinesterase inhibition (Barnes and Denz 1953).268

Liquid organophosphorus insecticides are absorbed by all

routes, and the lethal dose for most of these compounds is

low (Papworth 1967,

287

Radeleff 1970288).

Pesticides in Drinking Water for Livestock

The subgroup on contamination in the Report of the

Secretary's Commission on Pesticides and Their Relation-

ship to Environmental Health (U.S. Dept. of Health, Edu-

cation, and Welfare 1969)

29

' examined the present knowl-

edge

.on mechanisms for dissemination of pesticides in the

environment, including the water route. There have been

no reported cases of livestock toxicity resulting from pesti-

cides in water. However, they conclude that the possibility

of contamination and toxicit

y

from pesticides is real because

of indiscriminate, uncontrolled and excessive use.

---

320/Section 17

—Agricultural Uses of Water

Pesticide residues in farm water supplies for livestock and

related enterprises are undesirable and must be reduced or

eliminated whenever possible. The primary problem of

reducing levels of pesticides iri water iS 'to' locate the source

of contamination. Once located, appropriate steps should

be taken to eliminate the source.

Some of the properties and concentrations of pesticides

found in water are shown in Table V-4. Although many

pesticides are readily broken down and eliminated b

y live-

stock with no subsequent toxicological effect, the inherent

problems associated with pesticide use include the accumu-

lation and secretion of either the parent compound or its

degradation products in edible tissues and milk (Butches

et al. 1970). 2

" Consequently, pesticides consumed b

y

live-

stock through drinking water ma

y

result in residues in fat

and certain produce (milk, eggs, wool). depending on the

level of exposure and the nature of the pesticide. There is

also a possibility of interactions between insecticides and

drugs. especially in animal feeds (Connev

.

and Hitchings

1969).2"

Nonpolar lipophilic pesticides such as the chlorinated

hydrocarbon insecticides (DDT, linciane, endrin. and

others) tend to accumulate in fatt

y tissue and ma y re-

sult in measurable residues. Polar, water soluble pesticides

and their metabolic derivatives are generally excreted in

the urine soon after ingestion. Examples of this class would

include most of the phosphate insecticides and the acid

herbicides (2 ,4-D: 2 ,4 ,5-T: and others). Approximately

96 per cent of a dose of 2 ,4-D fed to sheep was excreted

unchanged in the urine and 1.4 per cent in the feces in 72

hours (Clark et al. 1964). 2

" Feeding studies (Claborn et al.

1960) 2

" have shown that when insecticides were fed to beef

cattle and sheep as a contaminant in their feed at dosages

that occur as residues on forage crops, all except methoxy-

chlor were stored in the fat. The levels of these insecticides

in fat decreased after the insecticides were removed from the

animals' diets. When poultr y

were exposed to pesticides

either by ingestion of contaminated food or through the use

of pesticides in poultry houses. Whitehead (1971)

2 " ob-

TABLE V-4—Some Properties, Criteria, and Concentrations

of Pesticides Found in Water

Solubility

A

y/liter?

Toxicity

L050

myike?

Maximum concentration.

AI

aldrin ?

?

38

? 0.015

dieldrin ?

110

?

?

46

? 0.401

endrin

?

160

?

?

10

? 0.133

heptachlor ?

?

56?

130?

0.041

heptachlor Inside ?

350

?

?

0.067

DDT ?

?

1.2

?

113?

0.316

DOE ?

?

0.050

DOD ?

?

0.140

2,4 . 06 ? ?

60,000?300-1000

• Maximum concentratioa 14 pesticide found in surface waters in the United States, from Lichttnbert et al.

(1969r ".

b

Retest to the herbicide family

2,440; 2,4,5•T;

and 2,4,5-TP.

served that the toxicities to birds of the substance

varied greatly. However, nonlethal doses may affect g

rate, feed conversion efficiency, egg production, eg

shell thickness, and viability

of the young. Although

fects of large doses may be considerable. Whitehear

eluded that little is known about the impairment of p

tion at low rates commonly used in agricultural bra(

Elimination of fat soluble pesticides from contam

animals is slow. Urinary excretion is insignifican

elimination

in

feces is slow. The primary route of exc

in a lactating animal is through milk. The lowest cone

Lions of pesticides in feeds that lead to detectable resit

animal tissues or products exceed the amounts fou

\cater by a factor of 10,000. However, at the compar

high dosage rates given in feeds, certain trends are app

Cows fed DDT in their diet at rates of 0.5, 1.0, 2.0, 3.

5.0 mg 'kg exhibited residues in milk at all feeding

except at 0.5 mg: kg. As the DDT feed levels incr

contamination increased (Zweig et al. 1961). 298 \4/her

were removed from contaminated feeds, the amot

time required for several pesticides to reach the non-c

able level was recorded (Moubr y et al. 1968). 2 " Di

had the longest retention time in milk, approximate:

days. DDT and its analogs, BHC, lindane, endrin

methoxychlor followed in that order. It should be er

sized that levels found in farm water supplies do not rr

significant contribution to animal body burdens of pest

compared to amounts accumulated in feeds.

Table V-4 shows the toxicity of some important

cides. Assuming the average concentration of any pes

in water is 0.1

A g/1, and the average daily consumpt

water by dairy or beef cattle is 60 liters per day, the

average dail y intake of DDT would be 0.006 mg. Fu

assumin

g that the avera

g e body weight for dairy or bet

tle is 450 kg and the LD50 for DDT is 113 mg kg

- -4),

then 50 grams would have to he consumed to app

the dose that would be lethal to 50 per cent of the anim

a steer were maintained on this water for 1,000 days, t

would have ingested about I 10.000 of the reported I

For endrin (LD50 10 mg kg), cattle would ingest 1

of the established LD50. The safety margin is pro

greater than indicated, because the calculations assum

all of the insecticide is retained unaltered during the

ingestion period. DDT is known to be degraded to a

HI

extent by bovine rumen fluid and by rumen microo

isms. For sheep, swine, horses, and poultry, the av

daily water intake in liters is about 5, 10, 40, and 0.

spectivelv. Consequently, their intake would be substan

less.

Fish as Indicators of Water Safety

The presence of fish may be an excellent monito

toxic levels of pesticides in livestock water supplies.

are numerous and well documented examples in the li

ture of the biological magnification of persistent pesti

---

Water for Livestock Enterprises/321

TABLE 17

-5—Examples of Fish as Indicators of Water

Safety for Livestock

Material

Tosic•lerels mg

, ' for fish

Toxic

aliens on animals

Aldrin

0.02?

?

3

mg!kg food (poultry).

Chlordane

1.0

(sunfish)

.

91

mrkg body weight in food (cattle).

Dieldrin

0.025

(Trout).......

25 mgikg food (rats).

.

Dirsteret

10.0 mg 'kg body weight in food (calves).

Endrin

0.003 (bass) .

3.5

nuke body weight in food (chicks).

Ferban. fermate

1.0 )o 4.0

Methorychlor

0.2

(bats)

14 mg allalla hay. not toxic (cattle).

Parathion

2.0 (go)dfishl..

75 mg 'kg body weight in food (cattle).

PenUchloroblunol

0.35

(bloegill) 60

mg

1

drinking water not toxic (cattle).

Pyrethrum (allethrin): .

2.0

to

10.0_?

?

1.400

to

2.800

mg kg body weight in food (rats).

Silver

5.0

?500

to

2.000

mg lc body weight in food (chicks).

Touohene

•

?

0.1

(bass)..

3510 110

mg 'kg body weig

h t in

loon

(cattle).

McKee and

Wol1.196310.

by fish and other aquatic organisms (Sec Sections III and

IV.on Freshwater and Marine Aquatic Life and Wildlife.)

Because of the lower tolerance levels of these aquatic

or

g

anisms for persistent pesticides such as chlorinated hy-

drocarbon insecticides, mercurial compounds, and heavy

metal fun

g

icides. the presence of hying fish in agricultural

water supplies would indicate their safety for livestock

(McKee and Wolf 1963)."' Some examples of individual

effects of pesticides upon fish compared to animal species

are shown in Table V-5. These data indicate that fish gen-

erall

y

.-have much lower tolerance for commonly used pesti-

cides than do livestock and poultry.

Recommendation

Feeding studies

indicate no deleterious effects of

reported pesticide residues in livestock drinking

water on animal health. To prevent unacceptable

residues in animal products, the maximum levels

proposed in the pesticide section of the Panel of

Public Water Supplies are recommended for farm

animal wafer supplies.

PATHOGENS AND PARASITIC ORGANISMS

Microbial Pathogens

One of the most significant factors in the spread of infec-

tious diseases of domesticated animals is the quality of

water which they consume. In man y instances the only

water available to livestock is from surface sources such as

ponds, waterholes, lakes, rivers and creeks. Not infrequently

these sources are contaminated by animals which wade to

drink or stand in them seeking refuge from pests. Con-

tamination with potential disease-producing organisms

comes from surface drainage originating in corrals, feed

lots, or pastures in which either sick or carrier animals are

kept.

Direct evidence relating the occurence of animal patho-

gens in surface waters and disease outbreaks is limited.

However, water ma

y

be a source for listeriosis caused by

Listeria monocytogenes

(Larsen 1964)

3

" and erysipelas caused

by

Erysipelothrix ritusiopalhiae

(Wood and Packer in press

1972)."° Tularemia of animals is not normally waterborne,

but the )i-ganism

Pasteurella tularensis

has been isolated from

waters in the United States (Parker et al. 1951. 3°' Seghetti

19521.

3 °' Enteric microorganisms, including the vibrios

(Wilson and Miles 1966)

309

and amoebae, have a long

record as water polluting agents.

The

Escherichia-Enterobacter-Klebscilla

group of enterics

are widel

y distributed in feed, water, and the general en-

vironment (Breed et al. 1957)."9 They

sometimes cause

urinary

disease. abscesses, and mastitis in livestock.

Sal-

monella

are very invasive and the carrier state is easil

y pro-

duced and persistent, often without any general evidence of

disease. Spread of the enterics outside the

y

ards, pens, or

pastures of infected livestock is a possibility, but the epi-

demiolog y

and ecology of this problem are not clear.

'In the United States, leptospirosis is probabl

y

the most

intimatel

y

water-related disease problem (Gillespie et al.

1957,

3°' C.:rawford et al. (969

3 °0

). The patho

g

enic leptospira

leave the infected host through urine and lack protection

.against dry

ing. Direct animal-to-animal spread can occur

through urine splashed to the eyes and nostrils of another

animal.

Infection by

leptospirosis from water often is direct: that

is, contaminated water infects animals that consume it or

come into contact with it.

Van Thiel (1948)

3 ° s and Gillespie et al. (1957)" 0

pointed

out that mineral composition and pH of water are factors

affecting continued mobilit

y

of voided leptospira. Most

episodes of leptospirosis can he traced to ponds. ricefields,

and natural waters of suitable pH and mineral composition.

For leptospira control, livestock must not be allowed to

wade in contaminated water. Indirect contamination of

water through sewage is unlikely, although free-living

leptospira ma y

occur in such an environment.

The Genus

Clostridium

is comprised of many species

(Breed et al. 1957),2

" some of which have no pathogenic

characteristics. Some such as

Clostridium perfrigens

and

Cl.

tetani

may become adapted to an enteric existence in ani-

mals. Almost all of them are soil adapted. Water has a vital

role in environments favorable for anaerobic infections

caused by

Clostridia.

Management of water to avoid oxygen depletion serves

to control the anaerobic problem. Temporary or permanent

areas of anaerobic water environment are dangerous to

livestock. Domestic animals should be prevented from con-

suming water not adequately oxygenated.

One of the best examples of water-related disease is bacil-

lary hemoglobinuria, caused by an organism

Cl. hemolvticum

found in western areas of North and South America. It has

been linked with liver fluke injury, but is not dependent on

the presence of flukes. Of particular concern has been the

spread of this disease to new areas in the western states. As

described by Van Ness and Erickson (1964)," each new

---

322/Section V—Agricultural Uses of Water

premise is an endemic area which has an alkaline, anaerobic

soil-water environment suitable for the organism. This

disease has made its appearance in new areas of the West

when these areas are cleared of brush and irrigated. To

avoid this problem, western irri

g

ation waters should be

'mana

ged to avoid cattail marshes. hummock grasses, and

other environments of prolon g

ed saturation.

Anthrax in livestock is a disease of considerable concern.

The organism causing anthrax,

Bacillus anthrocis,

may occur

in soils with pH above 6.0. The organism forms spores

which, in the presence of adeouate soil nutrients, vege-

tate and grow. The spread of disease b

y

drinking water

containing spores has never been

D roved. Bits of hide and

hair waste may be floated by

water downstream from manu-

facturin

g

plants. but very

few outbreaks have been reported

from these sources. The disease is associated with the water

from pastures where the grass has been killed (Van Ness

1971).

3

" The killed grass is brown rather than blackened. a

si g nificant difference from •water drowned vegetation in

general.

The epidemiology of virus infections tends to incriminate

direct contact: e.g., fomites. mechanical. and biological

vectors, but seldom water supplies. Water used to wash

away manure prior to the use of disinfectants or other bio-

logical control procedure ma

y carr

y viruses to the general

environment.

Viruses are classified by size, t

y

pe of nucleic acid, struc-

ture, ether sensitivity, tissue effects (which includes viruses

long known to cause recognizable diseases, such as pox and

hog cholera), and by other criteria. Onl y the ether-resistant

viruses, such as those causing polio and foot and mouth

disease in cattle, appear to present problems in natural

water (Prier

I

966).3"

Parasitic Organisms

Parasitic protozoa include numerous forms which are

capable of causing serious livestock losses. Most

.

outbreaks

follow direct spread among animals. Water contaminated

with these organisms or their cysts becomes an indirect

factor in spread of infection.

Some of the most important parasitic forms are the various

flukes which develop as adult forms in man and livestock.

Important ecological factors include presence of snails and

vegetation in the water, or ve

g

etation covered b

y

intermit-

tent overflow. This problem is very serious in irrigated at

but only when snails or other intermediate hosts are a•

able for the complete life cycle. Fluke eggs passed by

host, usually in the manure (some species, in the ur

enter the water and hatch into

miracidia.

These seek o

snail or other invertebrate host where they develop

sporocvsts.

These transform into redia which in turn

form other redia or several

cercariar.

The cercariae leave

snail and swim about the water where they may find

final host. or ma

y

encvst on vegetation to be eaten h

The life cycle is completed by maturing

in

a suitable

and establishment of an exit for eggs from the site of th(

tachment.

Roundworms include numerous species which may

water pathways in their life c y

cle. Free-living nemat,

can sometimes be found in a piped water supply, but

probabl y of little health -significance. Moisture is art -

portant factor in the life cy cle of many parasitic roundwc

and livestock are maintained in an environment where (

tamina non of water supplies frequentl y

occurs.

1

t is usu

thought that roundworm eggs arc eaten but water-sa

tut-,

environments provideideal conditions for maintaining pc

lations of these organisms and their eggs.

Parasitic roundworms probably evolved through ey

tionar

y

cycles exemplified' by the behavior of the gc

Strongvloides.Stronfvloides

spread along draina

g

,eways thro

the washdown of concrete feeding platforms and o

housing facilities for livestock.

The Guinea worm,

Dracunculus.

is dependent upon wa

because the adult la

y s e

gg

s only when the host come.

contact with water. Man. dogs. cats, or various wild m.

mals ma

y

harbor the adult, and the larvae develoi

C•cloN.

The life c

y

cle is thus maintained in a water envi,

ment when the

&clops

is swallowed by another suitable

Eggs of "horsehair worms" arc laid b

y

the adult in w

or moist soil. The larvae enc y

st and if eaten by an a ppro

ate insect Will continue development to the adult st;

Worms do not leave the insect unless they can enter wa

The prevention of water-borne diseases and parasiti

in domestic animals depends on interruption of the of

nisms' life c

ycle. The most effective means is to keep 1

stock out of contaminated \vater. Treatment for the rem(

of the pathogen or parasite from the host and destructio

the intermediate host are measures of control.

---

WATER FOR IRRIGATION

Irrigation farming increases productivity of croplands

and provides flexibilit

y

in alternating crops to meet market

demands. Earl y

irrigation developments in the arid and

semiarid West were lar

gel

y

along streams where onl

y

a

small part of the total annual flow was put to use. Such

streams contained dissolved solids accumulated through the

normal leachint-4 and weatherin g

processes with onl

y

slight

additions or increases in concentrations resulting from man's

activities. Additional uses of water resources have in many

cases concentrated the existing dissolved solids, added new

salts, contributed toxic elements, microbiologically polluted

the streams, or in some other way degraded the quality of

the water for irrigation. Water qualit

y criteria for irrigation

has become increasingly significant as new developments in

water resources occur.

Soil, plant. and climate variables and interactions must be

considered in developing criteria for evaluation of irriga--

tion water quality. A wide range of suitable water charac-

teristics is possible even when onl

y

a few variables are con-

sidered. These variables are important in determining the

quality

of water that can be used for irrigation under

specific conditions.

The physicochemical properties of a soil determine the

root environment that a plant encounters following irriga-

tion. The soil consists of an organo-mineral complex that

has the ability to react both physically and chemically with

constituents present in irrigation water. The degree to

which these added constituents will leach out of a soil, re-

main available to plants in the soil, or become fixed and

unavailable to plants, depends largely on the soil charac-

teristics.

Evapotranspiration by plants removes water from the

soil leavin

g

the salts behind. Since uptake b

y

plants is

negligible, salts accumulate in the soil in arid and semiarid

areas. A favorable salt balance in the root zone can be main-

tained by leaching, through the use of irrigation water in

excess of plant needs. Good draina

g

e is essential to prevent

a rising water table and salt accumulation in the soil surface

and to maintain adequate soil aeration.

In irrigated areas, a water frequently exists at some depth

below the

g

round surface, with an unsaturated condition

existin

g

above it. During and immediately following periods

of precipitation or irrigation, water moves downward

through the soil to

the water

table. At other times, water is

lost through evaporation from the soil surface, and trans-

piration from plants (evapotranspiration) ma

y

reverse the

direction of flow in the soil, so that water moves upward

from the water table by capillary Eow. The rate of move-

ment is dependent upon water content, soil texture, and

structure. In humid and subhumid regions, this capillary

rise of water in the soil is a valuable water source for use by

crops during periods of drought.

Even under favorable conditions of soil, drainage, and

environmental factors, too sparing applications of high

quality water with total dissolved solids of less than 100 mg/1

would ultimately damage sensitive crops such as citrus fruit;

whereas with adequate leaching, waters containing 500 to

1.000 mg/1 might be used safely. Under the same conditions,

certain salt-tolerant field crops mi g

ht produce economic re-

turns using water with more than 4,000 mg/l. Criteria for

judging water quality must take these factors into account.

The need for irrigation for optimum plant growth is de-

termined also by rainfall and snow distribution; and by

temperature, radiation, and humidit

y

. Irrigation must be

used for intensive crop production in arid and semiarid

areas and must supplement rainfall in humid areas. (See

Specific Irrig

ation Water Considerations below.)

The effects of water quality characteristics on soils and on

plant growth are directly related to the frequency and

amount of irrigation water applied. The rate at which water

is lost from soils through evapotranspiration is a direct

function of temperature, solar radiation, wind, and humid-

ity. Soil and plant characteristics also influence this water

loss. Aside from water loss considerations, water stress in a

plant, as affected by the rate of evapotranspiration, will

determine the plant's reaction to a given soil condition. For

example. in a saline soil at a given water content, a plant

will usuall

y

suffer more in a hot, dry climate than in a cool,

humid one. Considering the wide variation in the climatic

and soil variables over the United States, it is apparent that

water quality requirements also vary considerably.

Successful sustained irrigated agriculture, whether in arid

323

---

324/Section V—Agricultural Uses of Water

regions or in subhumid regions, or other areas, requires

skillful water application based upon the characteristics of

the land, water, and the requirements of the crop. Through

proper timing and adjustment of frequenc

y and volumes of

water applied, detrimental effects of poor quality water may

often be mitigated.

WATER QUALITY CONSIDERATIONS

FOR IRRIGATION

Effects on Plant Growth

Plants may be adversel

y

affected directlY b

y

either the

development of high osmotic conditions in the plant sub-

strate or by the presence of a phvtotoxic constituent in the

water. In g

eneral, plants are more susceptible to injury from

dissolved constituents during germination and early growth

than at maturity (Bernstein and Hao.

:

ward 1958).

3

''' Plants

affected during earl

y

growth ma

y result

in

complete crop

failure or severe y

ield reductions. Effects of undesirable

constituents may be manifested in suppressed vegetative

growth, reduced fruit development. impaired qualit

y of the

marketable product, or a combination of these factors.

The presence of sediment. pesticides, or pathogenic or-

ganisms in irrigation water, which may not specifically

affect plant growth, can affect the acceptability of the

product. Another aspect to be considered is the presence of

elements in irrigation water that are not detrimental to

crop production but ma

y

accumulate in crops to levels that

may be harmful to animals or humans.

Where sprinkler irrigation is used, foliar absorption or

adsorption of constituents in the water may be detrimental

to plant growth or to the consumption of affected plants by

man or animals. Where surface or sprinkler irrigation is

practiced, the effect of a

g

iven water quality on plant

growth is determined b

y

the composition of the soil solu-

tion. This is the growth medium available to roots after soil

and water have reacted.

Plant growth may be affected indirectl

y

through the in-

fluence of water qualit

y

on soil. For example, the absorption

by the soil of sodium from water will result in a dispersion

of the clay fraction. The degree of dispersion will depend

on the clay minerals present. This decreases soil permeabil-

ity and often results in a surface crust formation that deters

seed germination and emer

g

ence. Soils irrigated With

highly saline water will tend to be flocculated and have

relatively high infiltration rates (Bower and Wilcox 1965).315

A change to waters of sufficientl

y

lower salt content reduces

soil permeability and rates of infiltration by dispersion of the

clay fraction in the soil. This hazard increases when com-

bined with high sodium content in the water. Much de-

pends upon whether a given irrigation water is used con-

tinuously or occasionally.

Crop Tolerance to Salinity

The effect of salinity, or total dissolved solids, on the os-

motic pressure of the soil solution is one of the most im-

portant water quality considerations. This relates t

availability of water for plant consumption. Plants

been observed to wilt in fields apparentl

y

having ade

water content. This is usually the result of high soil sz

creating a physiological drought condition. Specificall

abilit

y

of a plant to extract water from a soil is deterr

by

the following relationship:

TSS=MS+SS

In this equation. (U.S. Department of Agriculture.

Sa

Laborator

y

Staff 1954

37

hereafter referred to as Sa.

Laboratory 1954 3 ''') the total soil suction (TSS) repro

the force with which water in the soil is withheld from

uptake. In simplified form, this factor is the sum c

matric suction (MS) or the physical attraction of so

water, and the solute suction (SS) or the osmotic pre

of the soil water.

As the water content of the soil decreases due to e

t

ranspiration. the water film surroundin

g the soil par

becomes thinner and the remaining water is held wit

creasingly greater force (NIS). Since only

.

pure Neat

lost to the atmosphere during evapotranspiration, th(

concentration of soil solution increases rapidly cit

the drying process. Since the matric suction of a soi

creases exponentially on drying, the combined effec

these two factors can produce critical conditions wit(

Bard to soil \•ater availability.

In assessing the problem of plant growth, the sal

level of the soil solution must be evaluated. It is diflicu

extract the soil solution from a moist soil within the rant

water content available to plants. It has been demonstra

however, that salinity levels of the soil solution and

resultant effects upon plant growth ma

y

be correlated

salinit

y

levels of soil moisture at saturation. The quantii

water held in the soil between field capacit

y and the "wi

point varies considerably from relativel

y low values

sand

y

soils to high values for soils high in cla

y

content

The U.S. Salinit

y

Laboratory Staff (l954) 3 " clevelo

the technique of using a saturation extract to meet

need. Demineralized water is added to a soil sample

point at which the soil paste glistens as it reflects light .

flows slightly when the container is tipped. The amoun

water added is reasonabl

y

related to the soil texture.

many soils; the water content of the soil paste is roue

twice that of the soil at field capacit

y and four times tha

the wilting point. This water content is called the saturat

percentage. When the saturated paste is filtered, the rest

ant solution is referred to as the saturation extract. The

content of the saturation extract does not give an ex

indication of salinit

y

in the soil solution under field con

dons, because soil structure has been destro

y

ed; nor doe

give a true picture of salinity gradients within the soil rest

ing from water extraction by roots. Although not truly

pitting salinit

y

in the immediate root environment, it d(

give a usable parameter that represents a soil salinit

y

vai

that can be correlated with plant growth.

---

Water for Irrigation/325

TABLE V-6—Relative Tolerance of

Crop

Plants to Salt,

(Listed in Decreasing Order of Tolerance)

High salt tolerance

?

Medium salt tolerance

?Low salt tolerance

VEGETABLE CROPS

tc..xiv=

12

?

Ec,.xioi= 10

?

EC.X1P=4

Garden beets?

Tomato

?

Radish

Ki'e?

Broccoli?

Cutup

Asparagus

?

Cablute?

Green beans

Spinach Bell pepper

Cauliflower

Lettuce

Sweet corn

Potatoes (White Rose)

Carrot

Onion

Peas

Squash

Cucumber

EC X10s

=f0

?

tc,.x10r=4?

EC,X10` = 3

FIELD CROPS

EC..xl(P= 16?

Ec,.xio3--

?

EC x101.-

-I

.

Barley (train)

?

Rye (grain)

?

Field beans

Sugar beet

?

Wheat (grain)

Rape?

Oats (train)

Colton?

Rice

Sorghum (grain)

Corn (field)

Flu

Sunflower

Castorbeans

EC >,;10,=10

FRUIT CROPS

Date palm

?

Pomegranate

?

Pear •

Fit

?

Apple

Olive

?

Orange

Grape

?

Grapefruit

Cantaloupe Prune

Plum

Almond

Apricot

Peach

Strawberry

Lemon

Avocado

FORAGE CROPS (in decreasing order tolerance)

Ecoow= It?

Ec.x io=

12

?

Eii,XICR=

Alkali salon

?

White sweet clover?

White Dutch clover

Bermuda grass

?

Mountain brome

?

Red clover

Rhodes gnu

?

Strawberry clover

?

Ladino clover

Rescue grass?

Oaths grass?

Burnet

Canada wildrye?

Sudan Fuss

Western whatgrass

?

Holum clover

Barley (hay)?

Alfalfa (California common)

Bridsloot trefoil

?

Tall fescue

Rye (hay)

Wheat (hay)

Oats (hay)

Orchardgrass

Blue grime

Meadow fescue

Reed canary

Big trefoil

Smooth brome

Tall meadow colgrass

Cicer milk vetch

Sours' over

Sickle milkatch

Ec,x10'-12?

EC,X10'..1

?

EG,X10,= 2

• The

numbers

hallowing EC,X10

3

are the electrical conductivity aloes of the saturation triad in rnillimhos pep

centimeter at 25 C associated

with

50•per

ant decease

in yield.

Salinity Laboratory Stahl

1454°s.

Salinity is most

readily measured by determining the

electrical conductivity

(EC) of a solution. This method re-

lates to the ability of salts in solution to conduct electricity

and results are expressed as milimhos (mhos X10-

3

) per

centimeter (cm) at 25 C. Salinit

y

of irrigation water

is

ex-

pressed in terms of EC, and soil salinity is indicated by the

electrical conductivity of the saturation extract (EC,.). See

Table V-6.

Temperature and wind effects are especiall

y

important as

the

y

directl

y

affect evapotranspiration. Periods of high

temperature or other factors such as dry winds. which in-

crease evapotranspiration rates, not onl

y

tend to increase

soil salinit

y

but also create a greater water stress in the plant.

The effect of climate conditions on plant response to

salinity was demonstrated by Magistad and his associates

(l 943).

3

'' Some of these effects can be alleviated b

y

more

frequent irrigation to maintain safer levels of soil salinity.

Plants var

y

in their tolerance to soil salinit

y

, and there

are man

y

ways in which salt tolerance can he appraised.

Ha

y

ward and Bernstein (1958)

32

' point out three: (1).Test

the abilit

y

of a plant to survive on saline soils. Salt tolerance

based primarily on

this criterion of survival has limited ap-

plication in irrigation agriculture but is a method of ap-

praisal that has been used widely by ecologists. (2) Test

the absolute yield of a plant on a saline soil. This criterion

has the greatest agronomic significance. (3) Relate the yield

on saline soil to nonsaline soil. This criterion is useful for

comparing dissimilar crops whose absolute

y

ields cannot be

compared directly.

The U. S. Salinit

y

Laborator

y

Staff (1954)

335

has used the

third criterion in establishing the list of salt tolerance of

various crops shown in Table V-6. These salt tolerance

values are based upon the conductivity of the saturation ex-

tract (EC,.) expressed in mmhos; cm at which a 50 per cent

decrement in yield may he expected when compared to

Crop

Electrical conductivity of saturation

!Hauls (EC,)

at

which yields decrease by about 10 per

ant°

mmh/crn at 25 C

Date palm

I

?manna

Fig

}

4-66

Olive

Grape. ?

4

Muskmelon ?

3.5

Orange, grapefruit, lemon .?

3-2.5

Apple. pear

?

2.5

Plum, pone, peach, apricot. almond

?

2.5

Boysenberry, blackberry, raspberry'

?

2.5-1.5

Avocado ?

2

Strawberry ?

1.5

In Dtisiluous soils. EC, readings

la

given soil silinibn us about 2 mmh/cm higher

then la ocagypsiterons

soils. Date palm would be elected al 10 rnmhicra, grapes ate mmhicen, etc. an

IDIMINOSIS soils.

b

Estimated.

v

Lemon is more sensitive than waste and grapefruit; raspberry more Hun boysenberry and blackberry.

Bernstein 1065b314.

Santos:

?

Yellow sweet clover

?

Meadow Install

?

TABLE V-7—Soil Salinities

in

Root Zone at which Yield

NutUll elkaligra as

?

Perennial ryegrass?

Alsike clover

?

Reductions become Significant

---

6-10

Carina yrandiflora

(Nats1

plum)

Boupinvill a

spectabilis

(Boyainvillu)

Helium *under

(stupider)

Rosrnarinus kekwoodi

(Rmenary)

Dodoon viscose stropur•

puree

Callistemon viminahs

(bottlebrush)

4-6

-Dracaena endiviss

Thujs orierrblis

(arbor vitae)

Junipecus thinensis

(spreading juniper)

Euenymus japonica

trending('

Lantern Camara

Elaesenus pungens

(silverberry)

Xylesma senticosa

Pitt otporum tobira

Pyraesntha Graberi

ligustrum lutidum

(Toss privet)

Bums mictophylka japonica

(Japanese bowed)

2-4

Hibiscus rote•sinensis

ear. Btiliante

Handles domestics

(flambe bamboo)

Tracheteseertnum jas•

roinMdes (tier jasmine)

Viburmsm onus robustum

2

Ilex cornet' Burford

(Burford holly)

Henna cansiienns

(Simian try)

Feijoa seltiro iana

(pineapple pare)

Rosa sp. (ear. Grenoble

rose on Dr. Huey root)

326/Section V—Agri

c

ultural Uses of Water

TABLE V-8—Salt Tolerance of Ornamental Shrubs

(Maximum EC,t's

Waited)

EC, in mmho/cm. at 25 C

0

?2 4?

6?

8?

10 12 14 16 18

2(

Barle•')

Sugarbectsc

Cotton —

Safflower

Ryc

Wheal b

Oats

.i.7.717:711111

Tolerant

?

Moderately tolerant

?

Sensitive

?

Very sensitive

Sorghum

Soybean

Sesbaniab

Rice

d

—

I?

Corn

?

Bernstein 1965b34.

yields of that plant grown on a nonsaline soil under com-

parable growing conditions. Work has been done by many

investigators, based upon both field and greenhouse re-

search, to evaluate salt tolerance of a broad variet y of plants..

In general, where comparable criteria were used to assess

salt tolerance, results obtained were most often in agreement.

Recent work on the salt tolerance of fruit crops is shown in

Table V-7, and for ornamentals in -Table V-8.

Bernstein (1965a

313

) gave EC, values causing 10, 25, and

50 per cent

yield decrements for a variety of field and forage

crops from late seeding stage to maturity, assuming that

sodium or chloride toxicity was not a growth deterrent.

These values are shown in Figures V-I. V-2, and V-3. The

data suggested that the effects of EC,. values producing 10

to 50 per cent decrements (within a range of EC,. values of

8 to 10 mmhicm for many crops) may be considered ap-

proximately linear, but for nearly all crops the rate of change

A

y

EC,

ECe

decrements

, either steepens or flattens slightly as the yield

decrements increase from less than 25 to more than 25 per

cent. Bernstein (1965a)

313

also pointed out that most fruit

crops were more sensitive to salinity than were field,

forage, or vegetable crops. The data also illustrated the

highly variable effect of EC, values upon different crops

and the nonlinear response of some crops to increasing con-

centrations of salt.

In considering salt tolerances of crops, EC, values were

used. These values were correlated with Yields at field

moisture content. If soils were allowed to dry out excessively

between irrigations, yield reductions were much greater,

since the total soil water stress is a function of both matric

suction and solute suction and increases exponentially on

.

•

?

500

.

Yield Reduction

250

100

I?I?

I?

I?

I?

1?

1?

1

'The indicated salt tolerances appl

y

to the period of rapid plant

g

rowth and maturation. from the late seeding stage upward. Crops in

each category are ranked in order of decreasing salt tolerance. Width of

the bar next to each cro

p

indicates the effect of Increasing salinit

y

on

y

ield. Crosalines are placed at 10. 25. and 50 per cent y

i

eld reductions.

Approximate rank in order of decreasing salt tolerance is indicated for

additional crops

for

most of which complete data are lacking. (Bower

personal communication

1972)238

b

less

tolerant during seettling stage. Salinit

y

at this stage should not

exceed 4 or 5 mmho/cm. ECe.

'Sensitive during germination. Salinit

y

should not exceed 3

mmho/cm during germination.

d

Less tolerant during flowering and seed-set as well as during the

seedling stage. Salinity at sensit

i

ve stages should not exceed 4

mmho/cm. ECe of soil water.

FIGURE V-I—Salt Tolerance of Field

Crops.

drying (Bernstein 1965a).

313

Good irrigation managern,

can minimize this hazard.

Nutritional Effects

Plants require a blanced nutrient content in the

solution to maintain optimum growth. Use of saline wa

for irrigation may or ma

y

not significantly upset this nut

tional balance depending upon the composition, concenti

tion, and volume of irrigation water applied.

Broadbean ?

Flax

Sunflower

Castor bean

Beans

?

---

Water for Irrigation1327

ECe in mmhojcm at 25 C

0?2 4

?

6?

8 10 12 14 16

Beetsb

?

I

?[II

?

I?

I?11

Asparagus

?

Kale

Spinach

Tomato

Broccoli

Cabbage

Cauliflower

Some of the possible nutritional effects were summarized

by Bernstein (1965a)

a

" as follows:

High concentrations of calcium ions in the solution

ma

y

prevent the piant from absorbing enough pons-

high conconzrazi3ns of

lulls may affxt

the uptake of sufficient calcium.

Different crops var

y

widely in their requirements for

given nutrients and in their ability to absorb them.

Nutritional effects of salinity, therefore, appear only

in certain crops and only when a particular type of

saline condition exists.

Some varieties of a particular crop may be immune

to nutritional disturbances, while other varieties are

severely affected. High levels of soluble sulfate cause

internal browning (a calcium deficiency symptom) in

some lettuce varieties, but not in others. Similarly,

Potato

Corn ?

Sweet potato

Lettuce

?

Bermuda grass

Alkali sacaton. Saltgrass

Nuttallalkali grass

Tall wheatgrass

Crested wheatgrass

Rhodes grass. Rescue grass

Canada wild rye

Western whcatgrass

Tall fescue

Barley hayb

Sweet clovers

Perennial rye

Mounta

i n bromc

Hardinggrass

?

Birdsfoot trefoil

ECe in mmho/cm at 25 C

Bell pepper

0 2?

4 6?

8 10 12 14 16 18 20 22

1?

II?it

?

I

?

I

?

I

?

I

?

I?

I

Onion ?

Carrot

Cucumber,

Squash, Radish

Peas

?

rr*Ima

Celery

Beans ?

50% Yield Reduction

25%

10%

a

See

Figure V-1. (Bower

personal communication

19721338

b

Sensitive during germination. Salinity

should not exceed 3

mmho/cm ECe during germination.

FIGURE V-3—Salt Tolerance of Vegetable Crops•

Beardless wildrve

?

.

?

.

?

.

.

•

Dallis grass. Sudan grass

Strawberry clover

Hubam clover

1111111111MooN

?

ak:a

50% Yield Reduction

25%

I?

I?

t?I?

I?

1

?

1?

I?

J

a

See Figure V-I. (Bower

personal communscation

1972)338

b

Less tolerant during seedling stage. Salinity at this state should

not exceed 4 or S mmhoicm,

ECe.

FIGURE V-2—Salt Tolerance of Forage

Crops.

high levels of calcium cause greater nutritional dis-

turbances in some carrot varieties than in others.

Chemical analysis of the plant is useful in diagnosing

these effects.

At a given level of salinity, growth and yield are

depressed more when nutrition is disturbed than when

nutrition is normal. Nutritional effects, fortunately,

are not important in most crops under saline con-

ditions; when they do occur, the use of better adapted

varieties may be advisable.

Alfalfa

Rye hav,

Oat haV

Wheat hay b

Orchardgrass

Blue grama

Meadow fortail

Rccd canar y . Big trefoil

Smooth brome, Milkvetch

Tall meadow

oatgrass,

Burnet

Recommendation

Crops vary considerably in their tolerance to soil

salinity in the root zone, and the factors affecting

Clovers, alsikc

?

red

---

328/Section V—Agricultural

Uses

of Water

the soil solution and crop tolerance are varied and

complex. Therefore, no recommendation can be

given for these. For specific crops, however, it is

recommended that the salt tolerance values (ECe)

for a saturation extract established by the U.S.

Salinity Laboratory Staff be used as a guide for

production.

Temperature

The temperature of irrigation water has a direct and

indirect effect on plant growth. Each occurs when plant

ph

y

siological functions are impaired b

y

excessively high or

excessively low temperatures. The exact water temperatures

at which growth is severel

y

restricted depends on method of

water application, atmospheric conditions at the time of

application, frequency of application. and plant species.

All plant species have a tempeature range in which they

develop best. These temperature limits vary with plant

species..

Direct effect on plant growth from extreme temperature

of the irrigation water occurs when the water is first applied.

Plant damage results only from direct contact. Normally,

few problems arise when excessively warm water is applied

by sprinkler irrigation. The effect of the temperature of the

water on the temperature of the soil is negligible. It has

been demonstrated that warm water applied through a

sprinkler system has attained ambient temperatures at the

time it teaches the soil surface (Cline et al. 1969).

3

'

8

Water

as warm as 130 F can be safel

y

used in this manner. Cold

water is harmful to plant growth when applied through a

sprinkler system. It does not change in temperature nearly

so much as the warm water. However, its effect is rarely

lethal.

Surface applied water that is either very cold or very

warm poses greater problems. Excessive warm water can-

not be used for surface irrigation and cold water affects

plant growth. The adverse effects of cold water on the

growth of rice were suddenl

y

brought to the attention of

rice growers when cold water was first released from the

Shasta Reservoir in California (Raney 1963).

332

Summer

water temperatures were suddenl

y

dropped from about

61 F to 45 F. Research is still proceeding, and some of the

available information was recently reviewed by Raney and

Mihara (1967).

334

Dams such as the Oroville Dam are now

being planned so that water can be withdrawn from any

reservoir depth to avoid the cold-water problem. Warming

basins have been used (Rane

y

1959).

333

There are oppor-

tunities in planning to separate waters—the warm waters for

recreation and agriculture, the cold waters for cold-water

fish, salmon spawning, and other uses. The exact nature of

the mechanisms by which damage occurs is not completely

understood.

Indirect effect of the temperature of irrigation water on

plant growth occurs as a result of its influence on the tem-

perature of the soil. The latter affects the rate of water

uptake. nutrient uptake, translocation of metabolites

indirectly, such factors as stomatal opening and plant

stress. All these phenomena are well documented. The

of the temperature of the applied irrigation water

temperature of the soil is not well described. This et

probably quite small.

Conclusion

Present literature does not provide adequate

to establish specific temperature recommenda

for irrigation waters. Therefore, no specific rec

mendations can be made at this time.

Chlorides

Chlorides in irrigation waters arc not generall

y

tw

crops. Certain fruit crops are, however, sensitive to chic)!

Bernstein (1967)

3

" indicated that maximum permi.

chloride concentrations in the soil ran

g

e from 10 I

milliequivalents (meq)

for certain sensitive fruit

(Table V-9). In terms of permissible chloride conce

dons in irrigation water, values up to 20 meq il can be 1

depending upon environmental conditions, crops, and ir

tion management practices.

Foliar absorption of chlorides can be of important

sprinkler irrigation (Eaton and Harding 1959,

3

'

9

Ehlig

Bernstein 1959

3.

'

0

). The adverse effects vary between ev.

TABLE V-9—Salt Tolerance of Fruit

Crop

Varieties

Rootstocks and Tolerable Chloride Levels

in

the Saturat

Extracts

Crop?

Rootstock or variety

Tolerable ler

chloride in salt

extract

Rootstocks

mend

Rangpur lime. Cleopatra mandarin

25

Citrus ?

?

Rough lemon, tangelo, sour orange

15

Sweet orange, citrange

10

Marianna

25

Stone fruit ?

?

Lovell, Shalil

10

1

Yunnan

7

Avocado ?

?

1

West Indian

t Mexican

5

Varieties (V) and Rootstocks (R)

Salt Creek,

1613.3

40

Grape

?

Dog Ridge

30

Thompson Seedless, Perlette

V

20

Cardinal, Black Rose

10

Varieties

f Boysenberry

10

Berries

?

?

blackberry

10

Il

Indian Summer raspberry

5

Strawberry

?

?

J

Lassen

t

Shasta

5

Bernstein 1967.12.

---

Water for Irrigation/329

rative conditions of day and night and the amount of

evaporation that can occur between successive wettings

(i.e., time after each pass with a slowly revolving sprinkler).

There is less effect with nightime sprinkling and less effect

with fixed sprinklers (applying water at a rapid rate).

Concentrations as low as 3 mec

j

il of chloride in irrigation

water have been found harmful when used on citrus, stone

fruits, and almonds (Bernstein 1967).312

Conclusion

Permissible chloride concentrations depend upon

type of crop,

environmental conditions and man-

agement practices. A single value cannot be given,

and no limits should be established, because detri-

mental effects from salinity per se ordinarily deter

crop growth first.

Bicarbonates

High bicarbonate water ma

y induce iron chlorisis by

making iron unavailable to plants (Brown and Wadleigh

19551.

717

Problems have been noted with apples and pears

(Pratt 1966)

235

and with • some ornamentals (Lunt et al.

1956))2

' Although concentrations of 10 to 20 meq/1 of

bicarbonate can cause chlorosis in some plants, it is of little

concern in the field where precipitation of calcium carbo-

nate minimizes this hazard.

Conclusion

Specific recommendations for bicarbonates can-

not be given

without consideration

of other soil

and

water constituents.

S odium

_ The presence of relatively high concentration of sodium

in irrigation waters affects irrigated crops in man

y ways.

In addition to its effect on soil structure and permeability,

sodium has been found by Lilleland et al. (1945)

322 and

Ayers et al. (1952)

3

" to be absorbed by plants and cause

leaf burn in almonds, avocados. and in stone fruits grown

in culture solutions. Bernstein (1967) 3

' 2

has indicated that

water having SAR* values of four to eight may injure sodium-

sensitive plants. It is difficult to separate the specific toxic

effects of sodium from the effect of adsorbed sodium on soil

structure. (This factor will be discussed later.)

As has been noted, the complex interactions of the total

and relative concentrations of these common ions upon

various crops preclude their consideration as individual

components for general irri g

ation use, except for sodium

and possibl

y chlorides in areas where fruit would be im-

portant.

Nitrate

The presence of nitrate in natural irrigation waters may

be considered an asset rather than a liabilit

y with respect

• For definition of SAR. Sodium Adsorption Ratio, see p. 330.

to plant growth. Concentrations high enough to adversely

affect plant growth or composition are seldom, if ever,

found. In arid regions, high nitrate water ma

y

result in

nitrate accumulations in the soil in much the same manner

as salt accumulates. the same soil and water managemem

practices that minimize salt accumulation will also minimize

nitrate accumulation. There is some concern over the high

nitrate content of food and feed crops. Man y factors such as

plant species characteristics, climate conditions, and

growth stage are just as significant in determining nitrate

accumulations in plants as the amount present in the soil.

It is unlikel

y

that any nitrate added in natural irrigation

water could be a significant factor.

Problems may arise where waste waters containing rela-

tively large amounts of nitrogenous materials are used for

irrigation. Larger amounts are usually applied than that

actuall

y

required for plant growth. These wastes, however,

usuall y

contain nitrogen in a form that is slowl

y

converted

to nitrate. Nevertheless, it is possible that high nitrate ac-

cumulations in plants ma

y occur althou

g

h little evidence is

available to indicate this.

Conclusion

Since nitrate in natural irrigation waters is

usually an asset for plant growth and there is

little evidence indicating that it will accumulate

to toxic levels in irrigated plants consumed by

animals, there appears to be no

need for

a recom-

mendation.

Effects on Soils

Sodium Hazard

Sodium in irrigation water may be-

come a problem in the soil solution as a component of total

salinity, which can increase the osmotic concentration, and

as a specific source of injury to fruits. The problems of

sodium mainl

y occur in soil structure, infiltration, and per-

meability-rates. Since good drainage is essential for manage-

ment of salinity in irrigation and for reclamation of saline

lands, good soil structure and permeabilit

y

must be main-

tained. A high percentage of exchangeable sodium in a soil

containing swelling-type clays results in a dispersed condi-

tion, which is unfavorable for water movement and plant

growth. Anything that alters the composition of the soil

solution, such as irrigation or fertilization, disturbs the

equilibrium and alters the distribution of adsorbed ions in

the soil. When calcium is the predominant cation adsorbed

on the soil exchange complex, the soil tends to have a

granular structure that is easil y worked and readily perme-

eable. When the amount of adsorbed sodium exceeds 10 to

15 per cent of the total cations on the exchange complex,

the clay becomes dispersed and slowly permeable, unless a

high concentration of total salts causes flocculation. Where

soils have a high exchangeable sodium content and are

flocculated because of the presence of free salts in solution,

subsequent removal of salts b

y

leaching will cause sodium

---

330

/Section 1'—Agricultural Uses of

IVoter

dispersal, unless leaching is accompiished b

y

adding calcium

or calcium-producing amendments.

Adsorption of sodium from a given irrigation water is a

function of the proportion of sodium to divalent cations

(calcium and magnesium) in that water. To estimate the

degree to which sodium will be adsorbed b

y

a soil from a

given water when brought into equilibrium with it. the

Salinit

y

Laboratory (1954)

3

" proposed the sodium adsorp-

tion ratio (SAR):

Na+

i

Ca++-1-Mg++

"\/

2

As soils tend to dry, the SAR value of the soil solution in-

creases even though the relative concentrations of the ca-

tions remain the same. This is apparent from the SAR

equation, where the denominator is a square-root function.

This is a significant factor in estimating sodium effects on

soils.

The SAR value can be related to the amount of ex-

chang

eable cation content. This latter value is called the

exchangeable sodium percentage (ESP). From empirical

determinations, the U. S. Salinit

y

Laboratory (l954)3J'

obtained an equation for predicting a soil ESP value based

on the SAR value of a water in equilibrium with it. This is

expressed as follows:

[100 a+b(SAR)1

ESP-

fl+a+b(SAR))

The constants "a" (intercept representing experimental er-

ror) and "b" (slope of the regression line) were deter-

mined statistically by various investigators who found "a"

to be in the order of —0.06 to 0.01 and "h" to be within the

range of 0.014 to 0.016. This relationship is shown in the

nomogram (Figure V-4) developed b

y the U. S. Salinity

Laboratory (1954).

3

" For sensitive fruits, the tolerance

limit for SAR of irrigation water is about four. For general

crops, a limit of eight to 18 is generall

y

considered within a

usable range, although this depends to some degree on the

type of clay mineral, electrolyte concentration in the water,

and other variables.

The ESP value that significantly affects soil properties

varies according to the proportion of swelling and non-

swelling cla

y

minerals. An ESP of 10 to 15 per cent is

considered excessive, if a high percentage of swelling clay

minerals such as montmorillonite are present. Fair crop

growth of alfalfa, cotton, and even olives, have been ob-

served in soils of the San Joaquin Valley (California) with

ESP values ranging from 60 to 70 percent (Schoonover

1963).3"

Prediction of the equilibrium ESP from SAR values of ir-

rigation waters is complicated by the fact that the salt con-

tent of irrigation water becomes more concentrated in the

soil solution. According to the U. S. Salinity Laboratory

(1954),

33

' shallow ground waters 10 times as saline as

irrigation waters may be found within depths of 10 feet,

a salt concentration two to three times that of irrigat

water ma

y

be reasonably expected in the first-foot der

Under conditions where precipitation of salts and rain

ma y

be neglected, the salt content of irrigation water

increase to higher concentrations in the soil solution with,

change in relative composition. The SAR increases

proportion to the square root of the concentration; the

fore, the SAR applicable for calculating equilibrium E

in the upper root zone may he assumed to be two to th

times that of the irrigation water.

Recommendation

To reduce the sodium hazard in irrigation wat

for a specific crop, it is recommended that the SA

value be within the tolerance limits determined I

the U.S. Soil

Salinity Laboratory ,Staff.

Biochemical Oxygen Demand (BOD) and

Soil Aeration

The need for adequate oxygen in the soil for optimu

plant growth is well recognized. To meet the oxygen r

quirement of the plant, soil structure (porosity) and se

water contents must be adequate to permit good aeratio:

Conditions that develop immediately following irrigatic

are not clearly understood..

Soil aeration and oxygen availability normally present n

problem on well-structured soils with good quality wate:

Where drainage is poor, oxygen may become limitin!

Utilization of waters having high BOD or Chemical Oxyge

Demand (COD) values could aggravate the condition b

further depletin

g

available oxygen. Aside from detrimentz

effects of oxygen deficienc

y

for plant growth, reduction t

elements such as iron and manganese to the more solubl

divalent forms may create toxic conditions. Other biologics

and chemical equilibria may also be affected.

There is very little information regarding the effect c

using irrigation waters with high BOD values on plan

growth. Between source of contamination and point of it

rigation, considerable reduction in BOD value may result

Sprinkler irrigation may further reduce the BOD value o

water. Infiltration into well-drained soils can also decrease

the BOD value of the water without serious depleting the

oxygen available for plant growth.

Acidity and Alkalinity

The pH of normal irrigation water has little direct sig-

nificance. Since water itself is unbuffered, and the soil is a

buffered system (except for extremely sandy soils low in

organic matter), the pH of the soil will not be significantly

affected by application of irrigation water. There are, how-

ever, some extremes and indirect effects.

Water having pH values below 4.8 applied to acid soils

over a period of time ma

y

possibly render soluble iron,

Expressed as mell

---

Water for Irrigation/331

A

?

B

Salinity Laboratory 1954 335

FIGURE V-4—Nomogram for Determining the SAR Value of Irrigation Water and for Estimating the

Corresponding

ESP

Value of a Soil That is at Equilibrium with the Water

---

332/Section V—Agricultural Uses

of

Water

aluminum. or manganese in concentrations large enough to

be toxic to plant growth. Similarly, additions of saline

waters to acid soils could result in a decrease in soil pH and

an increase in the solubility of aluminum and manganese.

In some areas where acid mine drainage contaminates water

sources, p H values as low as 1.8 have been reported. Waters

having unusually low pH values such as this would be

strongl

y

suspect of containing toxic quantities of certain

heavy metals or other elements.

Waters having pH values in excess of 8.3 are highly

alkaline and may contain high concentrations of sodium.

carbonates. and bicarbonates. These constituents affect soils

and plant growth directly or indirectly, (see "Effects on

Plant Growth" above).

Recommendation

Because most of the effects of acidity and alka-

linity in irrigation waters on soils and plant growth

are indirect, no specific pH values can be recom-

mended. However, water with pH values in the

range of 4.5 to 9.0 should be usable provided that

care is taken to detect the development of harmful

indirect effects.

Suspended Solids

Deposition of colloidal particles on the soil surface can

produce crusts that inhibit water infiltration and seedling

emergence. This same deposition and crusting can reduce

soil aeration and impede plant development. High col-

loidal content in water used for sprinkler irrigation could

result in deposition of films on leaf surfaces that could re-

duce photosy

nthetic activit y and thereby deter growth.

Where sprinkler irrigation is used for leafy vegetable crops

such as lettuce, sediment ma y accumulate on the growing

plant affecting the marketability of these products.

In surface irrigation, suspended solids can interfere with

the flow of water in conveyance systems and structures.

Deposition of sediment not onl

y reduces the capacity of

these s

y

stems to carry and distribute water but can also

decrease reservoir storage capacity. For sprinkler irrigation,

suspended mineral solids may cause undue wear on irriga-

tion pumps and sprinkler nozzles (as well as plugging up the

latter), thereby reducing irrigation efficiency.

Soils are specificall

y

affected b

y deposition of these sus-

pended solids, especially when they consist primarily of

clays or colloidal material. These cause crust formations

that reduce seedling emergence. In addition, these crusts

reduce infiltration and hinder the leaching of saline soils.

The scouring action of sediment in streams has also been

found to affect soils adversel

y

by

contributing to the dissolu-

tion and increase of salts in some areas (Pillsbur

y

and Blaney

1966).

33

' Conversely, sediment high in silt ma y

improve the

texture, consistency, and water-holding capacit

y

of a sandy

soil.

Effect on Animals or Humans

The effects of irrigation water quality on soils and pi,

has been discussed. However, since the quality of irriga

water is variable and originates from different sources, tl

ma

y

be natural or added substances in the water which I

a hazard to animals or humans consuming irrigated cr

These substances may be accumulated in certain cerc

pasture plants, or fruit and vegetable crops without

apparent injury. Of concern, however, is that the cone

tration of these substances may be toxic or harmful

humans or animals consuming the plants. Many substat

in irrigation waters such as inorganic salts and miner

pesticides, human and animal patho

gens have recommen

tions to protect the desired resource. For radionuclides

such recommendation exists.

Radionuclides

There are no generally accepted standards for contro

radioactive contamination in irri

gation water. For n

radionuclides, the use of federal Drinking Water Standat

should be reasonable for irrigation water.

The limiting factor for radioactive contamination in

rigation is its transfer to foods and eventual intake

humans. Such a level of contamination would be read

long before any damage to plants themselves could be

served. Plants can absorb radionuclides from irrigat

water in two ways: direct contamination of foliage throe

sprinkler irrigation, and indirectly through soil contamit

tion. The latter presents many complex problems sit

eventual concentration in the soil will depend on the r

of water application, the rate of radioactive decay, a

other losses of the radionuclide from the soil. Some stud: •

relating to these factors have been reported (Menzel et

1963. 3 ' 6

Moorbv and Squire 1963,"

s Perrin 1963.'

29 Men

1965,

32

' Milbourn and Ta

y

lor 1965'17).

It is estimated that concentrations of strontium-90 a

radium-226 in fresh produce would approximate those

the irrigation water for the crop if there was negligible

take of these radionuclides from the soil. With flood or ft

row irrigation only, one or more decades of continuous

rigation with contaminated water would be required befc

the concentrations of strontium-90 or radium-226 in t

produce equalled those in the water (Menzel

personal co

munication

1972).3"

Recommendation

In view of the lack of experimental evidence cot

cerning the long-term accumulation and avai

ability of strontium-90 and radium-226 in irrigate

soils and to provide an adequate margin of safet:

it is recommended that Federal Drinking Wat(

Standards be used for irrigation water.

---

Water

for Irrigation/333

SPECIFIC IRRIGATION WATER CONSIDERATIONS

Irrigation Water Quality for Arid and Semiarid Regions

Climate.

Climatic variability exists in arid and semiarid re-

gions. There can be heavy winter precipitation, generally in-

creasing from south to north and increasing with elevation.

Summer showers are common, increasing north and east

from California. Common throu

g

h the western part of the

country is the inadequacy of precipitation during the grow-

ing season. In most areas of the West, intensive agriculture is

not possible without irrigation. Irrigation must supply at

least one-half of all the soil water required annually for

crops for periods ranging from three to 12 months. •

Annual precipitation varies in the western United States

from practicall

y

zero in the southwestern deserts to more

than 100 inches in the upper western slope of the Pacific

Northwest. The distribution of precipitation throughout the

year also varies, with no rainfall during extended periods in

many locales. Often the rainfall occurs during nongrowing,

seasons.

The amount of precipitation and its distribution is one of

the principal variables in determining the diversion require-

ment or demand for irrigation water.

Land.

Soils in the semiarid and arid regions were developed

under dry climatic conditions with little leaching of weather-

able minerals in the surface horizon. Consequentl

y

, these

soils are better supplied with most nutrient elements. The

pH of these soils varies from being slightly acidic to neutral

or alkaline. The presence of silicate clay minerals of the

montmorillonite and hydrous mica groups in man

y

of these

soils gives them a higher exchange capacity than those of

the southeast, which contain kaolinite minerals of lower ex-

change capacity. However. organic matter and nitrogen

contents of arid soil are usuall

y

lower. Plant deficiencies of

trace elements such as zinc, iron. manganese are more fre-

quently encountered. Because of the less frequent 'passage

of water through arid soils, the

y

are more apt to be saline.

The nature of the surface horizon (plow layer) and the

subsoil is especiall

y

important for irrigation. During soil

formation a profile can develop consisting of various hori-

zons. The horizons consist of geneticall

y

related layers of

soil or soil material parallel to the land surface, and they

differ in their chemical, physical, and biological properties.

The productivity of a soil is lar

g

ely determined b

y

the na-

ture of these horizons. Soils available for irrigation with

restrictive or impervious horizons present management

problems (e.g., drainage, aeration, salt accumulation in

root zone, changes in soil structure) and consequently are

not the best for irrigated agriculture.

Other land and soil factors of importance to irrigation are

topography and slope, which may influence the choice of

irrigation method, and soil characteristics. The latter are

extremely important because they determine the usable

depth of water that can be stored in the root zone of the

crop and the erodability and intake rate of the soil.

Water.

Each river system within the arid and semiarid por-

tion of the United States has quality characteristics peculiar

'to its geologic origin and climatic environment. In consider-

ing water qualit

y

characteristics as related to irrigation, both

historic and current data for the stream and location in

question should be used with care because of the large

seasonal and sporadic variations that occur.

The range of sediment concentrations of a river through-

out the Year is usually much greater than the range of dis-

solved solids concentrations. Maximum sediment concentra-

tions ma

y

range from 10 to more than a thousand times the

minimum concentrations. Usually, the sediment concentra-

tions are higher during high flow than during low flow.

This differs inversely from dissolved-solids concentrations

that are usuall

y

lower during high flows.

Four

g

eneral designations of water have been used

(Rainwater 1962)

35

' based on their chemical composition:

(I) calcium-ma

g

nesium. carbonate-bicarbonate; (2) cal-

cium-ma

g

nesium. sulfate-chloride: (2) sodium-potassium,

carbonate-bicarbonate: and (4) sodium-potassium, stilfate-

chloride. This t

y

pe of classification characterizes the chem-

ical properties of the water and would he indicative of re-

actions that could he expected with soil when used for ir-

rigation. Although a listing of data for each stream and

tributar

y

is beyond the scope of this report, an indication of

ranges in dissolved-solids concentrations, chemical type, and

sediment concentration is given in Table V-10 (Rainwater

1962).35'

Customarily, each irrigation project diverts water at one

point in the river and the return flow comes back into the

mainstream somewhere below the system. This return flow

consists in the main of (I) regulator

y

water, which is the

unused part of the diverted water required so that each

farmer irri

g

ating can have the exact flow he has ordered;

TABLE V-10—Variations

in

Dissolved Solids, Chemical

Type.

and Sediment

in

Rivers

in

Arid and Semiarid United States

Dissolved solids

?

Sediment

Retion

?

concentrations,

?

Prevalent chemical type*

?

concentrations.

mg/1

?

mtllb

From

?

To

?

From

?

To

Columbia River Basin

?

<100?

300 Ca-Mg, C-b ?

<200?

300

Northern Calilorria

?

<100

?

100

Ca-Mg. C-b

?

?

<200?

+500

Southern California.....

?

<100 +2.000

?

Ca•Mt, C•b; Ca-Mg, S-C

?

<200 +15.000

Colorado River Basin

?

<100 +2.500 Ca-Mt, S•C; Ca-Mg, C-b.. .?

<200 +15.000

Rio Grande Basin

?

<100 +2.000 Ca-Mg, C-11; Ca-Mt, S-C

?

+300 +50,000

Pecos River Basin

?

?

100 +3,000 Ca-Mt, S-C ?

+300 +1,000

Western Gulf of Mesita Basins

?

?

100 +3.000 Ca-Mg, C-0; Ca-Mg, S•C; Na-P, S-C

?

<200 +30,000

Red River Basin...

?

<100 +2,500

Ca-Mt, S•C; Na-P,

S-C ?

+300 +25,000

Arkansas River Basin ?

?

100 +2,000 Ca-Mg, S-C; Ca-Mg, C-b; Na-P, S-C ?

+300 +MOOD

Platte Rivet

?

?

100 +1.500 Ca-Mg,

C-b; Ca-Mg,

S-C ?

+300 +7,000

Upper Missouri Rim Basin

?

?

100 +2.000 Ca-Mg, S-C; tia-P, C-b; Na•P. C-b.. . <200 +15.000

Ca -Mf. C-b= Calcium-matnesium. car b onats-bicarbonate. Ca-Mg.

S

. C.. Ca lcium-matne sium. suliste-chlwid

e.

Na-P, C-b=Sothurn-potassium, carbonate-bicarbonate. Na-P, S-C= Sodium-potassium. sullate-chloride.

Annual Load

b

Sediment concentration= ?

Annual Stramflow

Rainwater 1962351.

---

334/Section •—Agricultural Uses of Water

(2) tail water, which is that portion of the water that runs

off the ends of the .fields; and (3) underground drainage,

required to provide adequate appiication and salt balance

'in all parts of the fields. The initial flush of tail water may

be somewhat more saline than later but rapidly approaches

the same quality as the applied water t Reeve et al. 1955).3"

Drainage and Leaching Requirements.

In all irrigation a

g

ri-

culture some water must pass through the soil to remove

salts brought to the soil in the

w

ater. In semiarid areas. or

in the transition zone between arid and.humid regions, this

drainage water is usually obtained as a result of rainfall

during periods of low evapotranspiration, and no excess

irrigation water is needed to provide the drainage required.

In many

arid regions, the needed leaching must be ob-

tained b

y

adding excess water. In all cases, the required

drainage volume is related to the amount of salt in the ir-

rigation water. That drainage volume is called the leaching

requirement (LR).

It

is possible to predict the approximate salt concentra-

tion that would occur in the soil after a number of irriga-

tions b

y

estimating the proportion of applied water that will

percolate below the root zone. In any stead

y-state leaching

formula, the following assumptions are made:

•

No precipitation of salts occurs in the soil;

•

Ion uptake by plants is negligible;

•

There is uniform distribution of soil moisture through

the profile and uniform concentration of salts in the

soil moisture:

•

Complete and uniform mixing of irrigation water

with soil moisture takes place before an y of the mois-

ture percolates below the root zone and

•

Residual soil moisture is negligible.

A steady state leaching requirement formula has been

developed b

y

the U.S. Salinit y Laborator

y

(1954)"

3 de-

_ signed to estimate that fraction of the irrigation water that

must be leached through the root zone to control soil salin-

ity at any

specified

level. This is given as:

Ddw

?

EC;,,

LR =

—

D

i

,„?

ECaw

where LR is the leaching requirement; Da„., the depth of

draina

ge water; D

1 ,„, the depth of irrigation water;

the salinity of irrigation water; and EC

d „., the salinity of

water percolating past root zone.

Hence, if EC

d

,.., is determined by the salt tolerance of the

crop to be grown, and the salt content of the irrigation

water EC

i

„• is known, the desired LR can be calculated.

This leaching fraction will then be the ratio of depth of

drainage volume to the depth of irrigation water applied.

Because the permissible values for EC d

,• for various yield

decrements for various crops are not known, the EC, for

50 per cent yield reduction has been substituted for ECa••

The actual yield reduction will probably be less than 50

per cent (Bernstein 1966). 3

° This EC. is the assumed aver-

age electrical conductivit y

for the soil water at

saturation

the whole root zone. When it is substituted

for the

E(

the actual EC, encountered in the root zone will be

than this value because, in many near steady state si•

tions, the salinity increases progressively with increase

depth in the profile and is maximum at the bottom of

root zone.

Bernstein (1967)" has developed a leaching frac

formula that takes into consideration factors that con

leaching rates such as infiltration rate, climate (evapotr;

piration), frequency and duration of irrigation, and.

course, the salt tolerance of the crops. He defines

leaching fraction as LF = I — where LF is the lez

ing fraction or proportion of applied water percolal

below the root zone; E, the average rate of evapotransp

tion during the irrigation cycle, T„; and I, the average

filtration rate during the period of infiltration, T