ILLINOIS POLLUTION CONTROL BOARD

September 24,

1981

IN THE MATTER OF:

)

R76—21

AMENDMENTS TO CHAPTER

3:

)

WATER POLLUTION

(EFFLUENT STANDARDS)

PROPOSED

OPINION

OF THE BOARD

(by J.D.

Dumelle):

The Illinois Institute for Environmental Quality

now

reorganized

as the Illinois Institute of 1~atura1.Resources

(INR)

filed the original proposal

in this r~iatteron Uovertht~r

23,

1976.

The proposal was a result of

a review of

the

Board’~

effluent standards by the Illinois Effluent Standards Advisory

Group

(TESAG),

which had been formed in October,

1975 at

the

request of the director of

the INR.

The charge to IESAG by INR was

to review the technical basis

upon which Illinois effluent standards have been based and such

additional information as appropriate to adequately define

the

limits and economics of state—of—the—art industrial pollution

abatement technology;

to determine what concentrations of

effluent pollutants can be technologically achieved and at

what costs;

and to assess the applicability of mass discharge

standards as an alternative to, or

in concert with,

the present

Illinois policy of concentration—based standards.

During the

course of its studies,

TESAG restricted its considerations t~

parameters of Rules

406 and 408 of Part IV of Chapter 3

of

th~

Board Rules, and such other parameters that might be regulat ~

under Rule 408.

The findings of IESAG took the form of two reports~

Evaluation of Effluent Regulations of the State of Illinois,

II~QDocument 76/21

(Exhibit 1) and Technology and Economics oL~

Industrial Pollutant Abatement,

IIEQ Document 76/22

(Ex.

5).

Many

of the IESAG recommendations were incorporated into the petition

~r

amendments

to Chapter

3 which

was

presented to the Board by

t:he T~.

The original INR proposal included:

1.

Modification of

the averaging rule

401(c)

to provLd~

for monthly composite samples.

2.

Modification of the effluent standards of Rule

408(a) with respect to the following constituents:

chromium,

copper, cyanide,

iron,

lead, mercury,

pH,

and selenium.

3.

Deletion of Rule 408(b),

the effluent standard for

total dissolved solids

(TDS).

43—367

---

—2—

4.

Modification of the mercury standards of Rule 702(a)

for discharges to sewers and miscellaneous amendments

to the

remainder of Rule 702.

Five merit hearings considering the1proposal were held

between March

9,

1977 and July

12,

1977.

As economic impact

studies considering various aspects

of the proposal were filed,

hearings were set to consider them.

Between April

18, 1~78

and May

8,

1980,

ten economic impact hearings were held.

Since trancripts of these hearings are not numbered sequentially,

citations will

indicate volume and page number

e.g.

(4:590)

indicates p.

590 of

the

transcript of the

fourth day of hearings.

The

record

in this proceeding was generated by over forty

participants.

Motions requesting incorporation of the entire

records and Opinions of three other Board regulatory proceedini.’~

are granted,

and these have been considered.

Eighteen public

comments were filed and considered following first publication

in the

IUinoisR~ister.

AVERAGING RULE

Rule 401(c) presently provides that compliance with the

effluent standards of Part IV is

to be judged on the basis

of

24—hour composite samples, with no grab sample in excess of

five times the standard,

IESAG proposed to replace this with a

rule in which compliance with the standards is judged on the

basis of a monthly average, with no 24—hour composites

in excess

of two times the standard and no grab samples in excess of

five times the standard.

This

is referred

to as the “1,2,5

averaging rule.”

Rule 401(c)

as initially proposed required the effluent

standards to be met

at

all times.

The old

1,5

averaging rule

was adopted after there was overwhelming testimony urging

that averages be allowed

in

order to allow for the nor~ial

fluctuations inherent in any treatment process (R70—8,

3 PCB

405, January

6,

1972).

The concentration

of a given parameter

in an effluent

exhibits variability, which can generally be described by a

normal distribution curve.

According to technical data present~~i,

if a treatment plant exhibits a long term concentration of

~,

the probability is very small

that a daily composite will exceed

2A or that a grab sample will exceed

5A (4:474,

578,

595;

E~cIS

16,

21).

Sources of variability may be inherent in the treatment

process caused by fluctuations of the input.

In an industrial

treatment plant some sources of variable input are controllable

by management, but not all

flows and loads can be equalized

(3:486,

515;

5:752).

Variability may result

from different l~~~is

of operation on different shifts and from changes

in product

43—368

---

—3*

(1:202;

2:341;

3:534;

4:602).

Other sources are less contr3llahle.

In a factory where a large number of small

tanks are flushed at

random intervals,

several could be flushed coincidentally.

Some

waste streams may neutralize each other, while others tend to

add

to each other.

Thus,

a small change in the mixture could result

in extremes in the treatment process

(3:534;

4:692).

Evidence of

numerous sources of variability was presented,

as was considerable

evidence regarding the variability o~specific parameters.

Due to this variability, each treatment plant must he designed

on the basis of its operating ratio for a given parameter.

The

operating ratio is defined as the maximum expected daily

a\Terdge

divided by the long term or thirty day average

(1:173;

3:477,

488,

507; 4:576),

In

a sense the proposed 1,2,5 averaging rule dichat~3

an operating ratio of two.

If a plant were designed to deliv:~r

.~i

long term average of

1,0

rng/l where the standard was 1,0 mg/i,

then

it would have

to have an operating ratio of two or less

in order

to

produce 24—hour composite samples less than two times the

~

standard.

The 1,2,5 averaging rule, however, does not necessarily

require operating ratios of two or less.

If a plant were

expected to have an operating ratio greater than two,

it could

be “over—designed”

to deliver

a

long term average better

than the

standard

in order

to avoid producing 24—hour composites greater

than two times

the standard

(3:535).

While USEPA has observed

operating ratios from below two to

five,

its regulations generally

reflect an operating ratio of two

(4:583 and see CFR Subchapter

‘~fl.

Such a ratio appears generally appropriate

(4:590,

598).

A number of generalizations can be made about the operating

ratio.

If a treatment plant is specifically designed to remove

a given contaminant, the operating ratio will be lower

(3:477,

507; 4:579).

Physical chemical treatment such as

a filter sysbei~

will typically have

a very low operating ratio

(4:582,

599).

At the hearings the Metropolitan Sanitary District of Great.~r

Chicago

(MSD) presented data showing that its municipal treatment

plants exhibit operating ratios for BOD and TSS

in

a range of

between two and three

(3:477).

MSD recommended adoption of an

averaging rule reflecting an operating ratio of three

(3:487).

Caterpillar Tractor Company pointed out that greater

variability,

or a

higher operating ratio,

is

to be expected

with respect to parameters for which treatment

is ineffective

(3:501,

508,

516;

4:570,

610).

As an example, Caterpillar’s

data indicated a higher variability for hexavalent chromium,

for which its treatment is ineffective,

than trivalent chromium

(3:510,

512; 4:603,

615,

619).

This will be discussed further

in the chromium section, below.

One method of dealing v~iithat least some of these difli—

culties would be to modify the Board’s existing scheme of regula-

tion to a method similar to that of USEPA.

The existing Illinois

averaging rule applies

to all dischargers and to all parameters

unless otherwise specifically provided.

This contrasts with

43—369

---

—4—

USEPA’s regulation by industry category, which allows greater

opportunity to make allowance for unusual operating ratios observed

in a given industry.

However,

the technical evidence presently

before the Board is inadequate to adopt separate averaging rules f~r

each parameter

(1:56), and

the

Board declines to do so.

The Board acknowledges that general applicability of the

1,2,5 averaging rule will result in a less than optimal system.

However, the Board also notes that a number of safeguards

exist within the system to minimize these:

1.

Where difficulty

is unique

to a given parameter,

a special averaging rule could be proposed for that parameter;

2.

Where a given facility has difficulties,

a site—

specific regulation or variance could be requested;

3.

The IESAG has reviewed the parameters of Rule 408

in connection with its study on the assumption that the 1,2,5

rule would be adopted.

Where a large operating ratio

is intrin~i~

to the treatment for a given parameter, the recommended effluent

standards for that parameter have been raised

to reflect this

difficulty

(1:193,

203); and

4.

To a certain extent a given industry may be able

to

design and operate to a lower long term average than required

by the standard in order to meet the daily composite standard,

GRAB SAMPLES

Under existing Rule 401(c)

the ratio of allowable grab

samples

to 24—hour composites

is five to one.

Under

the proposed

1,2,5 rule this ratio

is 2.5 to one, with a ratio of grab to

monthly of five to one.

No opposition to the rule on grab

samples was voiced at the hearings.

Data presented by Caterpill~u~

Tractor company tended to support a grab

to monthly ratio of

about five to one (3:504;

4:605,

608;

Exs.

18,

27).

MONTHLY AVERAGE

V~astewatertreatment plants are designed

to meet a long

term or monthly average

(1:197,

203;

4:569,

599; EcIS

19).

If a plant

is designed to meet a certain long term average,

then daily composite averages will exceed that long term aver~ig~:

for reasons beyond the operator’s control

(2:340,

3:477;

4:586; EcIS 16),

Whereas the monthly average is useful

in

plant design,

the operating ratio,

as reflected in the requir~ent

of

a daily composite,

is relevant to plant operation

(4:569,

590).

The long term mean is the best and most data—independent measur~

of process performance

(EcIS

19),

and the monthly average

is

a

good indication of the long term average

(4:576).

43—370

---

—5—

As the Board’s rules are presently written,

the effluent

standards, based on 24—hour composites, do not give design

engineers

a direct indication of the level of performance which

is to be expected

(1:198,

203; 3:535;

4:599).

A design engineer

must

first determine the operating ratio of the plant and

apply this to the Board’s existing standards based on daily

composites to determine

a lower number,

the long term average,

which the plant must meet in order

to avoid violation.

If compliance with the standard

is based on a monthly average,

the Board’s regulations will more directly convey

to the public

the level

of performance which is expected.

Another difficulty with the present 1,5 averaging rule

is that a discharger with a small operating ratio could operate

so that its discharge was constantly just below the maximum

allowable for a 24—hour composite.

In the long run it could

lawfully discharge a much

larger mass of pollutants than a similar

discharger with

a higher operating ratio

(4:599).

The

environmental damage

is closely associated with the total mass o~

a pollutant discharged, and there is no good reason for allowing

a discharger with a tightly controlled system to discharge a

larger mass of pollutants.

By judging compliance on the basis of

the thirty—day average, the distinction

is reduced.

A perceived problem with the change to the 1,2,5 averaging

rule is that alteration of the averaging rule from a 24—hour

composite to a monthly average basis would effect a “doubling”

of the Board’s standards.

This perception is based on the fact

that if a facility

is required to meet a standard of

1. mg/i based

on

a 24-hour composite under the old rule, under

the new rule it

will have to meet

a 24—hour composite of

2 mg/i unless

the present

standard

is changed to reflect the change

in the averaging rule

(1:181,

191,

193,

203).

The IESAG did not agree

that this

is a

“doubling” of

the

standard

(1:186).

For example, consider a discharger who must

meet an effluent standard of 1.0 mg/i.

If it took advantage

of the altered averaging rule and discharged 2.0 mg/i for

fifteen consecutive days, it would be obliged to reduce

the

concentration to zero for the rest of the month in order

to meet

the 1.0 mg/i monthly standard,

assuming flow is constant.

Thus the modification in the averaging rule does not necessarily

authorize any increase in mass discharged over the long run

(1:176;

2:341;

3:529,

535).

The EcIS also indicated that the

modification in the averaging rule would not result

in

a

“doubling”

of the standards in all cases

(13:71).

The exact

effect of the modification of the averaging rule would depend

on the distribution of concentrations shown in the effluents

of given discharger.

A doubling of the standard would be a

worst case extreme.

The IESAG reviewed the effluent parameters on the assumption

that the Board would adopt the 1,2,5 averaging rule.

Had the

advisory group evaluated

the

standards on the basis of

the

1,5

rule,

it would in many cases have recommended

that the

numbers be doubled

(1:181,

189,

191,

193,

199;

2:340).

43—371

---

—6—

The Board finds that the proposed 1,2,5 averaging rule is the

best simple, general averaging rule which could be written

comporting

with

the

technical

evidence.

The

Board will

therefore

adopt

the

1,2,5

averaging

rule.

The

technical

evidence

for

the

parameters

will

be

evaluated on the basis of the modification tn

ECONOMIC IMPACT STUD! ON AVERAGING

As

the

Board

has

previously

noted,

the

averaging

rule

is

not

intended

as

a

modification

of

the

effluent standards.

Rather

it

is

a

rule

of

evidence

which

could

be

characterized

as

procedural

The

issue

of

modification

of the averaging rule centers on whether

the

modification

produces

a

rule

that

is

more

understandable

to

the

affected

public

and

which

more

closely

approximates

the

objective

realities

of

variable

discharges.

Any

relaxation

of

the

standard is incidental to these purposes and should be dealt iith

in connection with the standards.

As such, the rule itself

has

little

or

no

economic

impact.

However,

some

of

the

conclusions

of

the

study

are

worth

noting

and

commenting

upon:

1.

The

study

concluded

that

there

would

be

a

negligible

impact

on

dischargers

who

are

presently

in

violation of the

effluent

standards,

since

these

dischargers would have to

spend money

to

come

into

compliance

whether

the

rules

were

modified or not (12:10,

20,

26; EcIS 16,

31).

A telephone

survey of twenty-five dischargers who had two or

more

samples

exceeding

current

standards

for

one

or

more

of

the

affected

parameters

showed,

that

for

the

most

part

they

had

corrected

the

problems

evident

during

the

study

period,

and

that

they

would

not

alter

their

treatment

process

to

take

advantage

of

any

relaxed

standard (12:10,

25,

28; EcIS 28,

34).

From

a

practical

point

of

view

it

is

likely

that

the

industry

would

continue

to

provide

the

same

degree

of

treatment

since

there

would

be

no

advantage

in

controlling

to

a

lesser

degree

(Ec15

14);

2.

The

economic

impact

study

also

indicated

that

there

~zas

a possibility that a cost of the proposed modified averaging

rule would be an incremental increase in the discharge of con-

taminants to the waters of the State which would result from

the perceived ‘doubling

of the standard (12:9, 48; 13:76;

EcIS 35).

However, Rule 402 requires that effluents not cause

violation of the water quality standards contained in Part II

of Chapter 3.

Presumably the general water quality standards

determine maximum levels for the various pollutants which protect

the State’s waters for beneficial uses

(12:60; EcIS

26,

35).

Assuming the water quality standards

are

maintained as required,

there should be no ascertainable danage;

3.

The EcIS noted that standardization with other effluent

regulations

and

USEPA guidelines was an economic benefit of

the averaging rule,

although it could not be quantified

(t:44;

4:568,

651; 12:12,

40, 4~,50; EcIS

28,

34,

37).

43—372

---

—7—

there

should

be

a

small

decrease

in

design

costs

if

compliance

with

the

Board’s

rules

is

primarily

determined

on the basis oE

a

long

term

average

which is more useful to design engineers.

These economic impacts are negligible,

as would he expected

0F

a

rule

which

is

procedural

in

nature;

and

4.

The

study

also

discerned

a secondary cost impact in

sampling

and

analysis costs to the Agency

(EcIS

35).

Should

the Agency go to an

industry

and

monitor

for

thirty

days

the

cost of sampling would be an impact

(12:46,

50; 13:79; EcIS

3,

37).

However,

the Board concludes that this would not increas~~

the cost of enforcement

for two reasons:

first,

a thirty—day

composite may consist of as few as three daily composites;

second,

the averaging rules are alternatives——the Agency can

base an enforcement

actio.n on grab samples or daily composites.

Thus,

the Board finds that there

is little

o.r

no

economic

impact through modification of the averaging rule.

RESPONSE

TO

COMMENTS

ON

AVERAGING

Proof of Violation:

Existing Rule 401(c)

speaks of “com-

pliance” with numerical standards while proposed Rule 401(c)

speaks of “proof of violation.”

The Agency objected

to this

change,

contending that whereas the section is presently wri~t~n

to describe how a discharger demonstrates compliance,

the new

language

is

written

to

state

what

the

Agency

has

to

do

in

or3.er

L;

~,rove

violations

(PC

17).

The

wording

has

been

changed

in

order

to

correctly

expres:~

the

intent

of

Rule

401(c).

“Compliance

with

numerical

stand~-trds”

seems

to

refer

to

Section

39

of

the

Act

which

requires

that

the

purmit

applicant

prove

that

it

will

not

cause

a

violation

of

the

regulations.

This

is

not

the

primary

intent

of

Rule

401(c).

The

averaging

rule

refers

primarily

to

Section

31(c)

which

plnc’~

the

burden

of

showing

a

violation

of

Board

rules

in

an

enforce-

ment

action

on

the

Agency

or

other

complainant,

Accordingly,

Rule

401(c)

has

been

changed

to

read

“Proof

of

violation

of

the

numerical

standards.”

The

averaging

rule

is

intended

primarily

to

protect

the

defendant

in

an

enforcement

action

by

assuring

that

analytical

evidence is statistically significant.

It establishes several

methods of proving violation of the numerical standards.

Rules

~i

permit issuance belong in Part

IX,

not Part IV.

If Rule 401(c) we~~

a rule of permit issuance,

it would apparently require

that the

facility actually be constructed prior to permit issuance and

Lh~i.

it produce grab samples, daily composites and monthly averages ~

than the prescribed limits before a permit could he issued.

This

is

not the proper interpretation or the Board’s intent.

“Determined on the basis of one or

more

of

the followi~

averaqifl~ rules.”

There is indication

that

some

people

interpret

the

present

averaging

rule

as

requiring

both

a

24—hour

cornposit~

43—373

---

—8—

and a grab sample to show a violation,

The language has been

changed to make it clear that the averaging rules are alternativ”5.

Thus,

in an enforcement action a violation may be shown by a grab

sample,

a daily composite or

a monthly average, according to

the respective rules.

Calendar month:

The IESAG proposal provided that the

numerical standards would be judged on the basis of

a thirty—

day running average.

Opposition was expressed to this because

it would require dischargers

to recompute their average daily.

MSD proposed to judge compliance with the standards on the

basis of a calendar month

(1:150; Ex.

7).

IESAG supported

this amendment and no opposition was expressed at the hearings

(1:155;

3:499;

4:612,

637,

639,

654;

5:755,

808;

12: 53;

13: 77;

Ex.

23).

Monthly Average:

Proposed Rule 401(c)(1)

added a requiremt’nt

to

the

IESAG

proposal

that

monthly

averages

be

based

on

at

least

three

daily

composites.

The

language

proposed

by

IESAG

was

subjne~.

to

the

interpretation

that

the

monthly

average

was

determined

only

by

averaging

composite

samples

taken

on

each

day

of

the

month.

There

was

fear

that

this

would

impede

enforcement

and

result

in

imposition

of

this

in

the

monitoring

conditions

of

the

permits.

This

would

be

considerably

more

expensive

than

occasional

24—hour

composite

samples.

On

the

other

hand,

another

interpretation

was

offered

that,

if

only

a

single

grab

or

24—hour

composite

sample

were

taken

in

a

month,

it

would

have

to

meet

the

thirty—day

average

(13:84).

Accordingly,

the

proposal

was

modified

to

require

at

least

threo

24-hour

composite

samples

before

the

monthly

average

applies.

Proposed

Rule

401(c)(1)

provided

that

the

average

of

three

or

more

composite

samples

not

e~cceed the

primary

standard.

Several

commenters

wanted

to

know

which

three

samples

were

to

be

averaged

(PC

1,7,9,10).

Proposed

Rule

401(d)

answered

this

question

by

requiring

that

all

samples

be

included

in

the

average.

Three

commenters

suggested

language

to

the

effect

that

“the

average

of

all

composite

samples

taken

in

a

calendar

month,

when

more

than

two

such

samples

are

taken,

shall

not

exceed

the

prescribed

numerical

standard”

(PC

7,9,10).

The

Board

has

adopted

this

suggested

language

in

substance,

although

the

actual

averaging

rule

has

been

separated

from

the

definition

of monthly average.

~~Com~posites:

In connection with Rule 401(c) (3)

one commenter pointed out that

it is more common

to form daily

composites by combining aliquots than by analyzing individual

grab samples

(PC 9).

As adopted, Rule 401(d)(2) defines

a daily

composite as either the numerical average of all grab samples

or the result of analysis of

a single sample formed by combining

all aliquots taken during a calendar day.

A daily composite

must be based on averaging three or more analyses or a single

analysis of a sample formed by combining three or more aliquot’.

43—374

---

—9—

Flow—weighted Composites:

Proposed Rule 401(c) (2) provided

that no flow—weighted 24—hour composite sample exceed two times

the prescribed numerical standard.

Several commenters perceived

this as a rule on permit issuance which would require monitoring

by flow—weighted composite samples

(PC

6,

11,

15).

This was

not the intent.

Rules on monitoring and permit issuance are

contained in Parts V and IX of Chapter

3.

Rule 401(c)

is

intended to state a rule on what the complainant must show in

an enforcement action (13:80).

The requirement that violation be shown only by a

flow—

weighted composite sample was intended to protect dischargers

from enforcement based on composites which did not accurately

portray the amount discharged in a day because they were

taken during times of abnormal flow.

However, because the

affected public perceives no danger

from this, the Board will

delete the requirement that violation of the daily composite

levels be shown by a flow—weighted composite

(PC

6,

11,

15).

NPDES Limitations:

In proposing Rule 401(c) the Board

had intended that the Agency define composite samples

in an

NPDES permit.

Rule 401(c)(4) provided an averaging rule which

applied only

in the event there was no definition of composite

sample in the NPDES permit.

This required at least three

grab samples to form a composite and nine grab samples to

form a monthly average.

This rule caused considerable confusion

(PC 7).

The Board has adopted the Agency’s comment in substance,

deleted proposed Rule 401(c) (4), and added Rule 401(f), which

provides that proof

of violation of effluent standards contained

in permits be based on the language of the permit.

This is

presently required by Rules 410(a) and 901.

If Rule 401(c) were to include a method of interpretation of

permit conditions there would be a possibility of conflict

if the

permit condition did not truly reflect Rule 401(c).

For the sake

of certainty the Board has added Rule 401(f) requiring the permittee

to follow the permit condition rather than Rule 401(c).

Thus, where

a permit condition is governed by

a Part IV effluent standard,

the

permittee has the right to insist that the permit condition reflect

the averaging rule of Rule 401(c).

However, where the permit does

not follow Rule 401(c)

and the appeal period has lapsed,

the permit—

tee must obey the permit condition.

Grab Samples:

Proposed Rule 401(c)(3) provided that no grab

sample,

whether taken individually or as an aliquot of a composite

sample,

shall exceed five times the prescribed numerical standard.

Commenters perceived this as

a requirement that individual aliquots

of composite samples be analyzed

(PC

1,

7,

9).

This was not the

intent of Rule 401(c)(3)

as

is made clear by proposed Rule 401(e)

which provided that reporting and monitoring requirements are

established by way of permit condition.

To further clarify this

ambiguity Rule 401(d) (3) has been added to the adopted rules

providing that a grab sample

is a sample taken at a single time.

Aliquots of a daily composite are grab samples only

if they are

analyzed separately.

43—375

---

—10—

Reporting and Monitoring Requirements:

During

the

hearings

dischargers construed the proposal to bä

the standards

on thirty—day averages as

a proposal to require monitoring on

the basis of

thirty-day composites.

There was industry opposition

to the proposal on grounds of the cost of thirty—day composites.

The EcIS interpreted

the proposal as not changing the required

sampling frequency (12:44,

50).

The Agency presently has authority

to impose monitoring by daily composites and by composites made of

thirty 24—hour composites,

and does not expect that the proposed

version of Rule 401(c) would result in the increased use of daily

composites or thirty—day composites

(12:15,

42,

50;

13:86; EcIS

4).

The 1,2,5 averaging rule has been construed as requiring

reporting and monitoring on the basis of thirty 24—hour cornposit~’.

samples for the reason that the discharger

“must demonstrate

compliance with the standards”

(13:87).

This interpretation is

wrong for two reasons:

first,

as stated above,

the

averaging

rule

is intended primarily to protect the respondent in an enforcetnent

case, not as a rule on permit issuance;

second,

the averaging r~iI~s

are alternative

so that a single grab sample

less than five times

the numerical standard “demonstrates compliance.”

The rule on

imposition of monitoring and reporting is that the Agency

may

require such monitoring as

is required to accomplish the purposes

of the Act

(Section 39(b).

To avoid unintended interpretations the Board added proposed

Rule 401(e) which stated that reporting and monitoring requirements

are established by way of Rules 501 and 910(f).

Commenters

nevertheless continued to interpret Rule 401 as a rule on reportin’1

and monitoring.

The Board has therefore elaborated on the

function of the rule in 401(e).

Rule 401(c) established a method of interpretation of the

effluent standards of Part IV.

The Agency is to consider it

in deciding whether an applicant has demonstrated that a facility

complies with the effluent standards for purposes of permit

issuance and in writing effluent standards into permits.

In specifying three or more 24—hour samples

to form a

thirty—day composite, the Board does not mean that all NPDES

permits must require at least three 24—hour composites each

month; nor does it mean that the Agency

is limited to no more

than three 24—hour composites per month.

In some circumstances

the daily 24—hour composite may be appropriate,

in other cir-

cumstances

an annual grab sample may be appropriate.

A discharger

is not limited to the number of samples specified

in a permit condition.

He may take as many samples

as he

wants in order

to take advantage of averaging rules.

However,

he must include all samples taken to find the average

(12:56).

UNIFORM STATE-WIDE BASE

LEVEL

EFFLUENT STANDARDS

The effluent standards of Part IV are generally applicable

to municipal and industrial dischargers. IESAG found that

43—376

---

—11—

such uniform state—wide standards have many advantages

(3: 399),

although an exception mechanism was felt to be necessary

(1:56).

Such a mechanism would allow the Board to look at unique aspects

of wastewater or unusual chemical forms that might interfere

with traditional

treatment

process

efficiency

(3:399),

thus

introducing

some

flexibility

into

an otherwise

rigid

system.

Given

that there is insufficient evidence in the record to adopt

specific

standards

for

different

industrial

categories,

there

is little alternative to continuance of the present uniform

standards

method

which was originally adopted by the Board

on January 6,

1972

(R70—8,

3

PCB

401,

421).

Furthermore,

it

is possible

to

obtain

variance

or

site—specific

regulation,

the Board finds such uniform standards to be reasonable.

Section 13(a) of

the

Act specifically authorizes the Board

to adopt

both

water quality standards

and

effluent standards.

This is the practice followed by USEPA, and it should be

beyond

question at this stage of development of pollution

levi.

However, in connection with copper

and

chromuim,

some

common ten

appear

to

have

attacked

the

dual

standard

approach

by

contendi~

that

the

Board

cannot

make

an

effluent

standard

more

stringent

except to protect water quality.

The

water

quality

standards

were

set

on

the

basis

of

protention

of

stream

uses

while

the

effluent

standards

were

set

at

a

level

of

treatability

(R70—S,

3

PCB

401).

On

the

basis

of

treatabitity

considerations IESAG

proposed

relaxation or elimination of

effluent standards for lead, mercury, selenium and TOS,

and

proposed

to

tighten

the

standards

for

hexavalent

chromium,

copper

and

pH.

Citizens

For

a

Better

Environment

(CBE)

and

others

objected

to

relaxation of standards without consideration

of

environmental

effects

on

the

merits.

Industry supported

t’te

principle of treatability with respect to relaxation of standttrds4

but demanded consideration of environmental effects when standerIs

aere made more

restrictive.

Industry

argued

that,

in

the

absence

¶aZ

improvement in water quality, the Board would act arbitrarily

t’

require

increased

treatment

for

its

own

sake.

There

are

a

number

of

reasons

why

dual

regulation

is

desirable.

In

the

first

place

it

allows

dischargers

with

ampt’2

dilution

to

treat

to

one

level,

but

requires water qualitj

limited dischargers to

treat

to a tighter level.

This avoids

unnecessary treatment burdens where there is ample dilution, but

does

not

compromise

environmental

quality.

Secondly,

uniform

state—wide effluent standards prevent monopolization of stream

dilution and assimilative capacity by existing dischargers

(RiO—B, 3

PCB

401, 408).

If the Board regulated only on the

basis of water quality standards, dischargers would tend to

locate near rivers where ample dilution is available.

They

woate

have to treat only to avoid violation of water quality standard9

and would

tend

to

treat

so

as

to

barely

avoid

doing

so.

New

industry

seeking

to

locate

in

the

same

area

would

then

have

to

treat

to

meet

the

water

quality

standards,

which

would

not

a1~ays

be

technologically

feasible.

Uniform

state—wide

effluent

standdrd3,

on

the

other

hand

impose

a

duty

on

each

discharger

to

treat

tu.

technologically

f6aslble

level,

thereby

preserving

stream

assimt

-

43—377

---

—12—

ative capacity for future dischargers.

This is

a benefictal

use

which should not be abused by allowing existing dischargers

to

impose excessive treatment costs on future dischargers.

GOOD

CONVENTIONAL~

TECHNOLOGY

IESAG evaluated Rule 406 and 408 effluent standards

against the technology and economics of industrial pollution

abatement (1:58).

It identified a level

of technology called

“good conventional treatment” and reviewed the parameters

to

determine what levels could reasonably be achieved by such

treatment.

This is the same standard as was used in settinq

the

existing

standards

and

lies

somewhere

between

BAT

(I3est

Available Control Technology Economically Achievable) and

BPT

(Best Practicable Control Technology Currently Available).

Good conventional treatment refers

to treatment technology~,

Therefore,

IESAG generally did not review industrial processe~3,

but

rather

restricted

itself

to

a

review

of end of pipe treat~n~it

in order to define a uniform minimum discharge which is readily

achieved by

use

of conventional technology, assuming reasonably

careful operation and maintenance

(1:38,

58,

89, 205;

2:373,

393;

Ex.

5).

As

a result, its recommendations are based on

affordability rather than

a balancing of economic against

environmental damage

(1:89;

2:278).

The Board

finds this

approrc~

to be

a reasonable one on which to base effluent limitations.

At the final hearing the Agency was asked to evaluate

whether the technological evidence received at the merit hearings

was still valid in 1980

(15:183).

The Agency responded affir-

matively in a letter

to the Board.

EXCEPTION PROCEDURE

On March 31,

1977 Richard J. T~isselfiled a proposal for

an “exception” procedure.

This would provide a procedure whereby

individual dischargers could obtain permanent,

site—specific

effluent standards from the Agency without

following

the

procedures of Section 27 of

the

Act and Part II of the Procedur~i1

Rules.

This proposal was taken

from the IESAG prooosal to the

INR, but was not included in the INR proposal

to the Board

(1:56,

72,

75,

78,

80;

3:410;

4:641; 5:806),

although IESAG continues to

support it

(3:399).

The Board declines to adopt a procedure which,

in effect,

~auld delegate

to the Agency the power

to grant permanent

variances.

Furthermore, existing procedures for variance’3 and

site—specific regulations should he

adequate

to resolve the

problems which the exception procedure addresses in this case.

While site—specific regulatory procedures are somewhat more

cumbersome than those proposed, the Board notes

that H.B.

1816,

which has recently been passed by the legislature, would

streamline those procedures by eliminating the necessity for

an economic impact study in appropriate cases.

The concept

43—378

---

—13—

of an exception procedure with suitable Board

determined

limitations is, however,

an interesting

approach

to

regulations

which the Board may determine to be acceptable in future

regulatory proceedings.

NEW SOURCE PERFORMANCE STANDARDS

The U.S. Environmental

Protection

Agency

(USEPA)

is

in

the

process of promulgating mass limitation regulations which as a

class are more stringent than those required by Illinois’ eI~fln~it

standards.

In

writing

an

NPDES permit the Agency must incorp~rat:~

the more stringent of the federal

or the state limitations,

~au~:~

Illinois standards give no credit for process changes which result

in

a

low mass discharge,

the Illinois standard could still be vinwe~

as more stringent and be incorporated into the permit instead

of

the new source performance standards.

As an example,

consider the case of

a discharger who e~pen1~

considerable amounts of money building

a

low discharge facility

to conform to new source standards of performance.

His dischar~

will usually contain a much

lower

mass

of contaminants per

unit of production than a comparable existing

facility.

flowe’ier,

if the New Source Performance Standards

(NSPS) do not require end

of pipe treatment,

USEPA

regulations

may

permit the discharge o.

a

low volume,

concentrated

waste

stream,

The

effect of the tilinois

effluent standards would be to require end of pipe treatment;

t~i

addition to the process changes which have been instituted.

Requiring the discharger to comply with both strategies of co,~tr~:

could be very expensive, more expensive than eca~thero~the

T3Oi?d

regulations or USEPA regulations contemplated;

Based on the above considerations the Board has proposed

to adopt new

Rule

412.

This

is intended to provide complete

exemption from

the

effluent standards

for

facilities which are

based on new

source

performance standards.

In situations where

Illinois

regulates a contaminant which

is not regulated under

IJSEPA guidelines applicable

to

the

facility, then the tlttnois

~Fluent

standards will he applicable.

This

excepticn

is

intended

to

apply

only

to

the numerical

standards.

Rule

403

concerning

offensive

discharges

will

cOtit~.:

to be applicable.

Likewise,

Rule 402 will apply.

Illinois

regu-

lations will function where necessary

to protect water quality.

The Agency commented adversely concerning Rule 412

(PC

17),

citing a number of objections:

the

record does

riot support adoptio~

of

Rule

412;

NSPS

always

become

bogged

down

in

litigation

after

promulgation; and,

Rule 910(a)(2) provides a sufficient hasi~for

inclusion

of

federal

new

source

performance

standards

on

a

case

h~’

case

approach.

Rule

412

was

not

proposed

during

the

merit

hearings.

However,

it attempts

to address some of

the

same

problems

the

exception procedure addresses.

The public has made known a

problem

with

the

Board’s

regulations

and

the

Board

has

pro~osed

43—379

---

—14—

a

solution.

The

matter

has

been exposed to

nottce

and

comment

as

required

by

the

Administrative

Procedure

ct

and

none

of

the

affected

public

have

commented.

The

Board

recognizes

that

nothing

in

thi

Illinois

Environnen-

tal

Protection

Act

or

Clean

Water

Adt

(CW&)

requires

adoption

of

Rule

412.

The

Board

also

recognizes

that

some

NSPS

may

be

less

stringent

than

the

Chapter

3

effluent

limitations.

This

is

the

intended

result

of

Rule

412.

Rather

than

deal

with

this

one

industry

at

a

time

by

lengthy

site—specific

regulation,

the

Board

prefers

to

defer

to

USEPA’s

judgment.

The

Board

recognizes

the

potential

difficulty

if

tlSPS

is

tied up in litigation following USEPA promulgation.

However,

Rule 412 is triggered only if and

when

the

new

source

performance

standard

is

incorporated into

the NPDES

permit.

Where

enforce-

ment

of

the

new

source

performance

standard

has

been

stayed

following

litigation,

it

should

not

be

incorporated

into

permits.

Rule

412

will

be

inapplicable

and

the

Agency

will

apply

the

more

stringent

of

the

Part

IV

limitations

or

the

applicable

Best

*vait-

able Technology economically available

(BAT) or best

Practical

Control Technology currently available

(B??) limitation.

The Board also recognizes

that

Rule 910(a)(2)

provides

a

sufficient basis for the inclusion of

new

source

performance

standards on a case by case basis when

the

new

source

performance

standard is more stringent than the Part IV effluent

limitation.

The intent of Rule 412 is to incorporate the MIPS

even where it

is less stringent

than

the effluent limitation of Part IV.

CHANGIS

IN

FORMAT

The

Board

proposes

to

make

a

number

of

changes

in

the

format

of

the

effluent

standards

in

this

rulemaking.

Then

are

in

part

in

anticipation

of

codification

of

Chapter

3

in

compliance

with

regulations

promulgated

by

the

Secretary

of

State

(Ill.

Rev.

Stat.

ch.

127,

Sections

4

and

7;

1

Ill.

*4mm.

Code

Parts

120

and

160).

The

Board

proposes

to

split

Part

IV

into

two

subpartss

subpart A

will

contain effluent standards of general applicabtlitj,

while subpart B will contain site—specfic rules and special

exceptions to

the

effluent standards.

The

Agency

endorsed the format change, but

recommended

that

Rule 411(d) be placed into

subpart

B because it is a genital

exception to the mercury effluent standard.

The

Agenay

has

misunderstood

the

distinction

between

subpart

A and subpart

B.

Subpart B is intended

to contain site—specific rsgulations

and

specific

exceptions.

General

exceptions

belong

in subpart

A.

A

general

exception

to

the

effluent

regulations

is

one

which

is

potentially

applicable

to

any

person

in

the

state.

A special

exception

is applicable to one person or a definitely

ascertainable

number

of

existing

people.

These

could

43—380

---

—15—

site—specific rules,

rules applicable

to named persons, ~r

rules applicable only to existing persons who are described

and who are known by name.

The persons who are the henefthi~art..~s

of

site—specific and special exceptions

of

subpart

B

should

usually be participants

in

future regulatory proceedings t~

adopt rules

in

subpart

B.

They

should

have

individual

notice

that

there

is

a

rule

applicable

to

them.

The word total has been deleted from most of the para.ri~eLsrs

in Rule 408(a).

Rule 408(b) has been added which provides

that unless otherwise indicated concentrations refer

to

the

total amount of the constituent present in all phases whether

solid,

suspended

or

dissolved,

elemental

or

combined,

includin.i

all

oxidation

states.

Where

constituents

ar?

commonly

~nea~3’Lr.~3

as

other

than

total,

such

as

chromium

and

iron,

the

word

“total”

is inserted for clarity.

Rule

408

has

been

added

to

provide

cross—references

t

parameters

regulated

in

Part

IV.

The

Agency

commented

that

the

cross—reference

table

should

be

a

footnote

rather

than

part

o~ L~e

body

of

the

rule,

The

Board

acknowledges

that

this

is

technically

correct.

However,

there are practical difficulties

in placing a

table as a footnote.

The introductory

language,

“the following

table

is provided for cross-referencing purposes,” has been

carefully chosen so as not to be construed

as a rule

lir~i.ting

the scope of Part IV

(PC

17).

The Board has created two new rules,

Rule 411,

Mercury,

and Rule 413,

pH.

pH

has been separated from the body of Rul~’

408 since pH is not subject to the averaging

~

and

h~u3both ~

upper and lower

limit, unlik~3the other paran~ters.

Removal

t)f

pH

makes the rule easier

to state and eliminates a Eootnot~

Much of the discussion

in the record in this proceedinq

centered

on

mercury.

There

were

proposals

and

counterproposal’

all

of which were too complicated

to

clearly

state

as

a

footn~t.~

t:v)

Rule 408.

Accordingly,

mercury has been moved

to Rule 41L

Existing footnote

3 contains a site—specific effluent

st~-indard for

the

Calumet

treatment

plant

oF

Metropolitan

~arut~tt.~

District

of

Greater

Chicago.

This

has

been

moved

and

renumbe::ei

as

Rule

450.

The

special

averaging

rule

for

cyanide

contain~i’~

in existing footnote

3 is

substantially

the

same

as

proposed

~

401(c).

The special

a~zeraging rule

will,

therefore,

be deleted.

MSD

commented

concerning

whether

the

averaging

rule

applie’~

to Rule

450.

The Board has accordingly modified Rule 450

to

reference

the

averaging

rules of

401(c)

(PC

15).

Rule

451

concerning

chioralkali

mercury

discharges

in

St. Clair County

is presently stated as Rule 702(f),

an

exception

to Rule 702.

It is also an exception to old Rule 40R and new

~ule

411.

Although

it

would

he

possible

to

include

Rule

451

43—381

---

—16—

in a section of a subpart B

to

Part

VII,

it

appears

preferable

to lump it into subpart B o~Part IV.

Rule 451

has

also been

modified to include metric equivalents of the mass discharge

limitations

which

are

presently

in

English

units

only.

OIL

(HEXA~1E SOLUBLE

OR

EQUIVALENT)

The

change

in

designation

of

the

parameter

oil

(hexane

~oluhl~~~

or equivalent) and STORET numbers were recommended by the IES~C.

Oil

is presently subject to footnote

2.

The special averaging

rule for oil

is essentially the same as

the

newly adopted ~wer.~ji‘T

rule of 401(c).

Accordingly

the

spectdl

averaging

rule

is

tiel~’I.

CHROM I

TJM

Chromium

is

a

transition

metal

which

has

two

common

o~jdat’wu

states:

trivalent and hexavalent.

Other oxidation state:; a~’~

subject

to atmospheric oxidation or disproportionate to Cr(I’tt)

:~ti

Cr(VI).

Total chromium includes all forms of chromium.

Chromium is usually measured as Cr(VI), while determination

)E

Cr(III)

is indirect.

Cr(VI)

is determined on one half of a

spli.t

sample.

Cr(III)

is oxidized

to Cr(VI)

in the other half.

Cr(TOT)

is determined by measuring Cr(VI)

in the oxidized half.

Cr(ItL~

is

inferred

from

the

difference

between

Cr(TOT)

and

Cr(Vt)

in

th~

original

sample

(Standard

Methods

for

Examination

of

Water

~d

Wastewater,

14th edition,

p.

153).

The Board presently regulates effluents

in terms of Cr(Ilt)

and Cr(VI).

IESAG recommended that

the Board drop the stand~trd~f

1.0 mg/i Cr(III) and adopt a standard of 1.0 mg/l Cr(TOT).

tE~4~G

also recommended

that the Board tighten

its Cr(VI) standard from

the e~cisting0,3 mg/i to 0.1 mg/i.

SOURCCS

OF

CHROMIUM

Chromium

is

rarely

found

Ln

natural

waters.

Nationwide,

the background

is

about

0,00~i7 mg/i

(EcIS

8).

Elevated

chrotiium

levels

are

associated

with

industrial

discharges

(EcIS

8),

~d

i.’~

is

widely

used

in

metal

plating

and coating.

Chromic

acid

i~3use!

to

clean

metal

surfaces

prior

to

plating

and

other

coating

operations.

Hexavalent

chromium

is

commonly

‘found

in

and

used

ir.

the

manufacture

of

inks,

dyes

and

pigments.

It

is

also

used

in

leather

tanning

and

in

wood

preservative

treatment

(EcIS

29~

E~.

5,

p.

69).

Another major use

of

hexavalent

chromium

is

to

prevent

cor-

rosion and microbial growth

in cooling systems.

This,

along w.tt~

rinse water

from coating

and

plating

operations,

results

in a

high volume,

low concentration wastestream which presents diffi-

culties in treatment.

Concentrated baths are not generally dts-

43—382

---

—17—

charged and rinses are recycled,

Chromium sources

in platinj

operations are almost exclusively accidental,

including overflows,

leaks, pipe rupture, spills and drippage

(EcIS

53).

Although i~an~’

industries employ chromates

in cooling towers,

few categories

hdve

guidelines for chromium.

Industries which employ Cr(III) directly involve glass,

ceramics, photography, inorganic pigments,

textile dyeing

and animal glue manufacture.

Cr(III)

is being substituted

for Cr(VI)

in plating baths with some success

(Ex.

5,

pp.

93,

107).

Cr(III) may be present in wastewater as

a result of

reduction of Cr(VI)

in

either

a

manufacturing

or treatment

process

(Ex.

5,

p.

107).

CHROMIUM TREATMENT TECHNOLOGY

There are a large

number

of

treatment schemes for chroni.nm,

and many full scale applications achieve Cr(VI) levels of less

than 0.005 mg/i

(Ex,

5,

p.

75,

77).

Where ferrous sulfate

is used as a reducing agent, Cr(VI)

levels

of

0.01. mg/l have

been achieved

(Ex.

5,

p.

79).

Ion exchange applications have

yielded levels as low as 0.025 mg/i

(Ex.

5,

p.

87).

The

most

common treatment for Cr(III)

is alkaline precipitation (2:243;

Ex.

5,

p.

109).

Levels

as

low as 0.02 mg/l have been achieved

(Ex.

5,

p.

114).

USEPA sampled dicharges from severity—three electroplating

operations with chromium reduction facilities.

The average

of thirty—day averages was 0.09 mg/i Cr(VI) and 1.6 mg/i Cr(TOr)

(EcIS

33).

The proposed standard of

1,0 mg/i Cr(TOT)

is somewhat

more stringent than the present standard of

1.0 mg/i Cr(Itt),

since chromium wastestreams usually contain both Cr(III) and

Cr(VI).

Under the proposal

a chromium wastestream may lawfully

contain as much as 0.1 mg/i Cr(VI).

Because Cr(VI)

is included

in Cr(TOT), Cr(III) must be lowered to 0.9 mg/i

to meet the

proposed standard.

No

opposition was expressed at the hearings

either

to going

to Cr(TOT),

or

to the proposed Cr(TOT) stand~r~1.

There

was,

however,

opposition to the tightened Cr(VI) stan~’1~1.

The

recommendation

to

abandon

the

separate

standard

for

Cr(III)

is based on several considerations.

As noted

above,

chromium

is

usually

analyzed as Cr(VI) and Cr(TOT), with Cr(ttt)

inferred from the difference.

This tends to amplify analytical

errors.

Furthermore, the most common treatment

is reduction!

precipitation.

Cr(VI) measures the success of reduction, while

Cr(TOT) measures

the

overall efficiency of chromium removal.

Moreover, USEPA guidelines and published technical literature

are mostly expresses as Cr(Vi) and Cr(TOT)

(2:241).

CHROMIUM

AVERAGING

Under

the proposed averaging rule the monthly standard

for Cr(VI) would be 0.1 mg/i,

the allowable daily average

43—383

---

—18—

would be 0.2 mg/i

and

grab samples would be 0.5 mg/i.

*5

stated

above,

these

limitations are based on an operating

ratio of 2.

However,

Charles N.

Cook of USEPA presented variability

data concerning two dischargers which treated

for

Cr(VI)

(4*570;

Hz. 21).

He

testified

that

ratios

of

2 to

3 were

common

(4*582,

590, 596,

603,

617).

His data indicated an operating ratio

of 2.8 for a weii operated plant treating for Cr(VI)(4:596).

Inspection of USEPA effluent guidelines indicates that

hromium effluent guidelines do not always follow the 2.0

operating ratio which is characteristic of most parameters.

A number of these reflect operating ratios of 2.8 to 3.0

(see 40 CFR, S413.14 and 415.124)(8:868;

9:904).

If operat4tg.4ratios of three are intrinsic to Cr(Vt),

dischargers will have to deliver long term average performance

of less than 0.07mg/i to meet the 0.2 mg/i daily composite

standard.

However, the

record in this rulemaking

doss

not

indicate

that

a monthly average less than 0.1 mg/i can be

consistently achieved with

good

conventional

technoloqy.

The

Board

has

accordingly added footnote

two

to Rule

400(a) providing a special averaging rule for chromium.

Compliance with the primary standard of 0.1 mg/i will be

judged on the basis of a monthly average.

Daily

conpositas

shall not exceed 0.3 mg/i and grab samples shall not exceed

1.0 mg/i Cr(VI).

ENVIRONMENTAL

IMPACT OF CHROMIUM

There is considerable uncertainty concerning the environmenta

effects of

chromium

(EcIS

7,

17,

46).

Acute toxicity to humane

is not

very

great

(9:901),

but Cr(VI) is known to cause lung

cancer and other serious disorders when breathed (EcIS 4).

It is

also known

to irritate mucous linings (EcIS

4,

7).

Cr(III)

toxicity to aquatic life

is not well documented (EdO 4),

althouq!.

it

is

known

to

increase

mucous

secretions

on gills

(EcIS7).

Toxic

effects

have

been noted at as

low

as 3.3 mg/l in soft

water

and

as high as 72 mg/i in hard water (8:870; 9:902,

916; EdO

6).

Actual acute toxicity levels for chromium have not boon set

for aquatic life.

Lethal levels to fish are reported from

17 to 118 mg/i.

Levels as low as 0.032 to 0.05 mg/i, howevec,

have

been

reported

as

lethal

to algae

and

aquatic invertebrates

(8:870;

9:902, 917).

Chromium

also accumulates in sediments.

Worms

and

clams

tend

to have levels the same as

the

sediment.

The Illinois River has chromium in sediments as high as 11

ppm

(17 mg/kg)

(8:866; EdO

7).

One Cr(VI) control strategy involves replacement of chr~nate.&

in cooling systems with other chemicals to control corrosion.

Many of these, such as those which contain phosphonates, also

have adverse environmental effects.

Phosphonates would

provide

43—384

---

—19—

nutrient phosphorus pollution and would necessitate the

use

of

biocides in cooling systems.

To the

extent

the proposal would

encourage

the

use

of

these

alternative

chemicals,

there

is

an

adverse environmental impact offsetting any

benefit

from

decreased

Cr(VI)

discharges

(9:907;

EdO

15).

The

EcI8

concluded

that

the

proposal

would

reduce

chromium

loading of Illinois streams by about 8.7 pounds

per

day

(8:

857;

EdO

13).

This would result in significant improvement of

water

quality

in

several

receiving

streams

(EdO

13,

17).

Several

small

receiving

streams

which

would

receive

dramatic

improvement

are identified

COST/BENEFIT ANALYSIS FOR CHROMIUM

Fifty—four

sources

discharge

some

level

of

chromium

(8:858).

The EdO identified eleven dischargers out of compliance with the

proposed standard for Cr(VI) or Cr(TOT).

This included three

municipalities

and

eight industries (EdO 24).

Because all

three municipalities violated both the existing and proposed

standards,

and

none

have

chronium

removal equipment,

no comptianca

costs were assigned to

them

(8:883; EcIS 29).

If installation

were required,

it

would

cost

essentially

the

same

to

meet

the

existing or proposed standard.

In all three cases the

noncompliance is caused by industrial dischargers.

The munici-

palities would be in compliance if pretreatment were required.

The EdO identified dischargers only by letter.

Of eight

industrial dischargers, five used chromium in metal finishing

and

plating operations

(B,

C,

D, E and J)

(8:857).

Two used

chromium only

for

cooling

water

(A,

I).

One

used chromium

both

for

metal

finishing

and

cooling

water

(K)

(EdO

24,

34).

Therefore,

of

the

eight

potentially

impacted

dischargers,

six

have

chromium

in

process

streams

and

three

have

chromium

in

cooling

water.

The

EdO

evaluated

treatment

costs

differently

for process and cooling water

(EdIS 34).

Of the six process dischargers, one will comply with

the proposed Cr(VI) standard when its treatment facility is fully

operational

(C).

No costs were assigned to this discharger

(EdO

34).

One discharger has equipment for chromium removal,

but will incur additional operating costs

(3).

Some

of these dischargers may not actually be impacted by

the proposal since Rule 402 requires that effluents not causu

violation of water quality standards, and the Rule 203(f)

standard of 0.05 mg/l Cr(VI) in the receiving stream

may

be the

limiting factor.

Three industries discharge to streams having

a 7—day, 10-year low flow of 0

(A, C and 3).

One

discharges

to

a low flow of 1.3 MGD

(D)

(8:881; EdO

14).

The

first three,

and possibly the fourth,

are

probably water quality limited.

Since existing water quality standards appear to impose more

stringent requirements than the proposal (8:868,

874, 881;

9:916,

918), they would apply.

The EcIS did not acknowledge

this and evaluated costs.

43—385

---

—20—

$5800

in increas

annual ;~pensns

(EcIS

39,

40).

The Board

will eliminate

these cosLs

from

the

finai estimates.

The EcIS

rejected as too expensive the

alternative of

separate treatment

for small

Cr(Vl)

sources (8:878; ~ciS 57).

At

0.11

mg/i

discharger

K

is

essentially

in

compliance with

the proposed standard,

Treatment

of

one

or

two of its twenty

small process sources

should

bring

it

under

9.1 mg/i

(8:885,

887;

Ex.

18).

This

would

he

far less expensive

than treatment

of

4 MGD.

Noncompliance

by

discharger

K is largely with the

daily

ma~irnumrather than

the

long

term

average

(8: 887,

890;

~cIS

24).

This is also

the difficulty

cited by Caterpillar

Tractor

Company

(3:510;

Ex.

18),

The Board has addressed this by

providing

for greater

variability

for

chromium

discharges.

This,

coupled

with

greater

control of operations,

spills,

leaks

and main-

tenance, should

allow

Caterpillar

to avoid violation

of

the

daily

maximum without installing

additional

treatment (9:911).

If

the long

term averdqe remains above

the standard, treatment

of

some

process

wastestreams

should

suffice.

The

EcIS

evaluated

the

economic

impact

of

an

alteruatit~

to

the

IESAG

proposal.

This

alternative

provided

a

monthly

standard

of

0.15

mg/i

with

a

daily

value

of

0.3

mg/I.

The

alternative

eliminated

most

of

the

cost of

the proposal,

in—

chiding discharger

K

(EcIS

39).

The

study author

indicated

that the principal

purpose

of

changing the

primary standard to

0.15

mg/i was

to

provide

a

higher

daily maximum

(9:905),

The alternative eliminated all costs

to discharger

K.

Since

the Board

is proposing to adopt a special averaging

rule

for

chromium which allows a daily value of

0.2

mg/i,

the costs

found in this study

are

actually more applicable.

Discharger

D

is

an

electroplater with a monthly average of

0.06 mg/i and a

daily

maximum

of

0,24

mg/I

Cr(VI)

(EcIS

24),

Treatment

costs

are

estimated

at

an investment of

$5000

to

$10,000 and annual

costs

cit

$900

(EcIS

39,

54).

These

costs

will also be

eliminated by the alternative averaging

rule.

Discharger B

is an

cle~tropiatei:

with

monthly

averages

of

about

0.22 mg/i

and daily maximum

of about

1.3 mg/I

Cr(VI)

(i~cIS 24).

Increased treatment costs of

$1300 per year are

estimated.

Discharger

E

is an electropiater which claims to he

in

compliance with

both

the

existing and proposed regulations.

T~gencydata

indicates

it is

not

in

compliance

with

either.

Increased

annual

costs

of

$3200

are

included

for discharger ~

(EcIS

24,

39,

54).

The

remaining

cost

of

the proposal centers

on discharger

I,

who

has

cooling

tower

blowdown

only~

The

study

found

an

investment

of

$1,000,000

and

$160,000

annualized

costs

(EcIS

39,

54).

This

assumes

t:reetmerit

by

ion

exchange.

Discharger

t.

has chromium

levels

of

about

0.2

mg/i

and

apparently

would

not

t43~386

---

—21—

be affected by the relaxed averaging rule

(EcIS

24).

There

is no explanation as to why discharger

I must treat rather than

employ the cheaper substitution of

chromates

in cooling towers.

The

EcIS

relied on the discharger’s

own

estimates (8:876,

886;

9:899).

The impacted population thus consists of dischargers B,

E and I.

The first two discharge process water, the third

cooling water blowdown.

Overall

costs

are

estimated

at

an

investment

of $1,000,000

and

annual operating costs of $164,500

(EcIS

39,

40).

RESPONSE

TO

COMMENTS

ON

CHROMIUM

Two

persons

commented

on

Cr (VI).

Caterpillar

Tractor

Company

states

that

it

has

now

installed

a

state

of

the

art

system

consisting

of

two—stage

pH adjustment, sulfur dioxide

reduction,

precipitation,

coagulation and sedimentation

(PC 10).

tt

states

that

the

proposal

will

not increase the

amount

of

pollutants removed but will result only in a 10

increase in

the frequency of noncompliance.

The Board has modified the

proposal to provide

a looser averaging rule which should bring

Caterpillar’s rate of noncompliance into line.

Allied

Chemical

Company

stated

its

general

opposition

to

tightening

the

Cr(VI)

standard

(PC

3).

Allied appeared at the

merit hearings

and

expressed no opposition to the proposal with

regard

to Cr(VI)

(1:95), but

now

bases its opposition on the

lack of additional environmental benefit.

The EcIS details

environmental

improvements

associated

with

the

proposal

(5: 857),

and

the

Board

has

determined

that

chromium

poses

a

threat

to

the

environment

and

has

resolved

to

deal

with

it

through

both

water

quality

and

effluent

standards

(R79—8,

R71—14,

R71—20,

3 PCB 401,

404,

413).

The Board concludes that regulation of Cr(VI) and Cr(TOT)

is preferable to regulation on the basis of Cr(VI)

and

Cr(tIt).

Good conventional treatment is capable of achieving effluent

levels of less

than

0.1 mg/l Cr(VI) and 1.0 mg/l Cr(TOT) on

a monthly basis, and adoption of a modified averaging rule for

Cr(VI) will prevent spurious out—of—compliance reports by

dischargers in compliance with the monthly average

but

in

violation of daily limits.

This will lessen compliance costs

without

significantly

increasing

chromium

COPPER

Copper

exists in

two

common

oxidation states:

Cu(I)

and

Cu(II).

Cu(II)

is stable, while Cu(I) is subject to

atmospheric oxidation

and

tends to disproportionate to Cu

and

Cu(It), but is sufficiently stable to be found in wastewater

(EcIS

5, 17; Ex.

5,

0. 138).

Both Cu(I) and Cu(It) readily

form complexes with a wide variety of ligands.

These can

inter-

fere

in

treatment.

Total

copper

includes all forms of copper.

43—387

---

—22—

IESAG recommended that

the

Board make

its

copper eff1uent~

4

standard more stringent,

from 1.0 to

0.5 mg/i

(1:117,

2:246).

SOURCES

01?

COPPER

Illinois

streams

show

average

levels

of copper far in

excess

of

the

general

use

water

quality

standard

of

0.02

rnq/i

(EcIS

9).

All

river

basins

show

averages

less

than

0.1

mg/I

with

the

following

exceptions:

Mississippi—South Central Basin,

0.177

mg/i;

and

the

Upper

Ohio

Subbasin,

0.143

mg/i.

The

former

is

the

East

St.

Louis

Area which

is

heavily industrial,

with

at

least two major copper dischargers:

Olin

(East Alton) and

the Village of Sauget.

The Upper Ohio

is mostly the Saline

River basin which

is

heavily impacted by coal mining.

Copper

is introduced into the atmosphere from combustion

of fossil fuels containing copper

(EelS

7).

Copper

in rainwater

is estimated

to average 0.031 mg/i,

in excess of the general

use water quality

standard.

Acid rain

may

leach additional

copper from soils and rock.

Atmospheric copper

loading of

Illinois streams and other non—point sources are

thought

to

result in a background of about 0,0086 mg/i

(EcIS

11).

Copper

is widely used

in industry.

Most of

the

sources

for which there are effluent guidelines are industries

irivolv•~d

i~ithe production of copper,

copper compounds or copper pl~ite!

Products.

Copper plumbing

is widely used in industry and

r~sidencesand contributes

a significant amount of copper

to

wastewater,

especially where it carries soft water

(EcIS

6).

Ciling

tower blowdown and boiler cleaning wastewater may

contain copper.

Copper or copper compounds are

used

as cataly~t:

ii

textiles,

tanning, photographic process,

engraving,

inks,

dies, pigments and WoOd preservatives

(ErIE

6;

Ex.

5,

p.

127).

COPPER TREATMENT TECHNOLOGY

The most common treatment for copper

is precipitation of

the

hydroxide

or

oxide

(Ex,

5,

p.

132).

This

is

usually

accom-

plished

by

addition

of

calcium

hydroxide

to

an

acidic

wastestre~wi.

Optimal

pH

is

between

pH 9.0 and

10.3,

where

copper

has

a

solubility

of

about

0.01

mg/i.

In

the

absence

of

comple~ing

agents

precipitation

is

able

to

achieve

final

effluent

levels

viell under 0.5 mg/i

(Ex.

5,

0.

133,

151;

1:17;

2:245;

4:623,

632).

Copper precipitation

is

sensitive

to

pH.

Where

alkaline

wastestreams are treated without pH regulation, pH fluctuationn

may

be

the

cause

of

episodic

high

effluent

copper

levels

(E~.

~

p.

151).

Keystone Industries appeared at the merit

hearings

and

objected

to

both

the

copper

and

pH

proposals.

As

noted,

effic~ent

copper removal requires precipitation at pH

9

to pH 10.3.

tf

the

alkaline

pH

standard

is

tightened

from

pU

10

to

pU

9,

43—388

---

—23—

reacidification prior to discharge will almost always be

necessary.

A number of comments centering on this difficulty

have been received

(PC

2,

PC

3,

PC

8,

PC

9,

PC

10).

The Board

will discuss this problem in connection with the pH proposal

(Rule 413).

In the presence of chelating agents, precipitation yields

final effluent levels of three to four mg/i copper

(4:623).

Such agents are commonly contained in fluxes used for copper

or brass soldering

(4:623) and plating baths

(Ex.

5,

p.

127).

Segregation of wastestreams containing these agents or chelated

copper

is usually the best practice.

These smaller volumes

of compiexed waste can then be given special treatment, which

may be far more cost—effective.

Starch xanthate and sodium borohydrate treatment may be

effective against chelated copper.

These had not been employed

on a full scale in 1977

(4:623).

The Board has since

been

advised that starch xanthate has been employed for wastestreams

of up to 0.2 MGD achieving effluent levels as low as 0.05

mg/i copper

tOlin

(East Alton) v.

IEPA,

PCB

80—170, December 18,

1980, May

1,

19811.

Other treatment processes for copper include evaporative

recovery,

ion exchange, electrolytic recovery, cementation and

reverse osmosis.

Evaporative recovery has been practiced

for over twenty years for copper recovery

(Ex.

5,

p.

143).

Ion exchange is useful, especially with dilute copper, and

is effective against ammonia complexes.

Final effluent

levels as low as 0.03 mg/i have been reported

(Ex.

5,

p.

144).

Ion exchange is rather expensive, but can produce a concentrated

copper output which may be valuable for copper recovery.

Other

processes are also available.

USEPA concentration—based effluent limitations range from

0.15 to 0.25 mg/i

for direct dischargers

for base and precious

metals,

ferroalloy ores and secondary copper recovery categories.

These are considerably more stringent than proposed here.

Any industries subject to these guidelines will have

NPDES

permit conditions based on federal regulations.

Dr. Patterson of IESAG computed concentration based

equivalents of process weight standards using flow figures

for industry categories

(Ex.

28,

p. A—2).

Conversion indicates

that electroplaters are required by USEPA to meet thirty—day

average copper levels of 0.5 mg/i based on

BPT

(Ex.

28,

p.

A—27).

IESAG concluded that a thirty—day average copper standard

of 0.5 mg/i was justified on the basis of reported performance

data.

This level can be achieved without significant incremental

increase in treatment cost associated

with

the present standard

of

1.0 mg/i, based on a twenty—four hour composite.

43—389

---

—24—

ENVIRONMENTAL IMPACT OF COPPER

As noted above, the general use water quality and water supply

standards of 0.02 mg/i are violated throughout the state.

Lowering the copper effluent standard from 1.0 to

0.5 mg/i

could lower the incidence of violation of the water quality

standard and would benefit water users.

Copper has been shown to be toxic to fish at levels of less

than 0.04 mg/i.

It is especially toxic

to young fish.

However,

most fish studies have been done on species not common in

Illinois waters

(EcIS

25).

Estimates of safe levels to Illinois

fish are around 0.011 to 0.018 mg/i for soft water and 0.015

to 0.033 mg/i for hard water

(EcIS

26).

Background copper levels

in excess of these estimates are common throughout Illinois

(EcIS

10,

39).

Although mature game fish can survive levels of copper

in excess of the noted levels, their reproduction is inhibited

at low levels.

Copper also limits organisms beneath game fish

in the food chain.

Toxicity to fresh water invertebrates has

been reported at levels of 0.015 to 0.028 mg/i copper at

hardness levels of 35 to 55 mg/i calcium carbonate

(EcIS

24).

Plankton have shown toxic effects at around 0.04 mg/i copper and

hardness of 100 to 119 mg/i

(EcIS

25).

These hardness levels are

encountered in Illinois, although they are somewhat below average

(EcIS

39).

Even

if the only purpose of the water quality standards

were protection of fish,

it is impossible to maintain the desirable

species in an environment missing the bottom of the food chain.

The EcIS reviewed twenty point source dischargers with one

or more copper analysis

in excess of 0.5 mg/i during 1975

or 1976

(EcIS

32).

For several sources there was inadequate

data to attempt to evaluate any effect of copper downstream

(EcIS

31).

For others there was a diverse aquatic community.

This was attributed to adequate dilution of the wastestream

(EcIS

33).

A third class discharged into receiving streams

without adequate dilution.

There was noticeable degradation

of aquatic life.

However,

there were many factors to which

the stream condition could be attributed, and it is doubtful

that merely reducing the copper levels would result in significant

improvement

(EcIS

33,

47).

COST/BENEFIT ANALYSIS FOR COPPER

The EcIS was not able to quantify any costs or benefits

associated with the proposal

(EcIS

54).

Because copper levels

in Illinois waterways are near or above the water quality

standard and at levels which have been shown to be toxic to

aquatic life,

any reduction in copper

loading should have a

beneficial effect.

The Board, however,

is not able to estimate

the dollar value of this.

Of the twenty dischargers with at least one copper sample

in

excess of

0.5 mg/i during 1975 or 1976

(EcIS

32,

49),

seven of these

43—390

---

—25—

discharge into a sewer system, and in some cases the sewage treatment

plant discharge

is also identified as a potential violation.

Pre-

treatment by the industry would likely solve the municipal problem.

The following

is a summary of the potentially impacted population:

Plating Companies

9

Metal Product Manufacture

5

Municipal Wastewater Treatment Plants

3

Steel Production

2

Printing

1

The Board finds that the impacted population would not be

this large.

Of the listed dischargers, two inject copper wastes

into wells

(EcIS

31) and would be unaffected by this rule change.

Sixteen are presently out of compliance and costs are likely to

be similar for upgrading to meet the present or the proposed rule.

Furthermore, the EcIS ignored the effect of the proposed averaging

rule

in determining the impacted population

(12:98; EcIS 48).

Thus,

some may be able to meet the proposed standard without

making any changes

in treatment.

Some of the dischargers are

to small receiving streams such that water quality standards

may be limiting rather than effluent standards

(see EcIS

34

and Rules 203(f) and 402).

Others may be subject to more

stringent federal standards.

The proposal probably impacts only direct industrial

discharges

to streams with adequate dilution to avoid violations

of the water quality standard.

These are American Nickloid Company

and the Village of Sauget.

There may be additional impacted

dischargers, but they cannot be determined from the record.

Many of the named copper dischargers have participated in this

rulemaking, were sent direct notice of hearings, yet none attended

the EcIS hearings (14:90;

15:153).

Although the EcIS may have

deficiencies, the affected public did not avail itself of

opportunities for challenging

it.

It should be noted that

Keystone Consolidated Industries Inc.

of Peoria was the only

opponent of the proposal at the merit hearings

(4:623).

It

was not identified in the EcIS,

did not attend the EcIS hearings

and has not commented,

although it has received notice.

The Board agrees with the EcIS that the proposal may impose

additional treatment costs on some dischargers in the state.

The Board has not been able to determine with certainty who

will be affected or what their costs will be.

The Board

finds,

however, that the proposal has benefits in the form of improved

water quality,

and that it may have uncertain costs

in the form of

additional treatment.

RESPONSE TO COMMENTS

Central Illinois Public Service Company

(CIPS) is faced with

the construction of new treatment facilities

(PC 13).

Its objection

is based on perceived difficulties in meeting the proposed

standard through precipitation and sedimentation.

It will

obviously have to destroy the chelate for this to be successful

43—391

---

—26—

at meeting either the 0.5 or 1.0 mg/i standard.

Since CIPS

must construct and maintain the same unit processes to meet

either the 0.5 or 1.0 mg/i standard, the cost to treat will be

essentially unchanged.

The regulation should, therefore, have

no impact in excess of the existing standard on new sources or

old sources without treatment which must treat a wastestream in

excess of the old standard.

COPPER SUMMARY

In reviewing the EcIS the Board has considered the en-

vironmental benefits of the proposal.

However, protection

of beneficial uses is not the basis of effluent standards.

The Board has concluded that copper is a contaminant which

poses a menace and that it should receive the best degree of

treatment consistent with technical feasibility and sound

engineering judgment (Rules 203,

401, and 402;

3

PCB

401).

While this may not produce dramatic environmental benefits,

it should aid in reducing the number of water quality violations.

The Board finds that good conventional treatment is suffi-

cient to meet the proposed standard of 0.5 mg/i copper.

In

view of the existence of copper in Illinois waterways in excess

of the water quality standards and at levels near toxic to aquatic

life, any increase in treatment costs is offset by improvements

in water quality.

The Board proposed to adopt the 0.5 mg/i

standard.

DISSOLVED IRON

Dissolved iron may be present in the ferrous

(Fe(II)

or ferric state

Fe(II)

is rapidly oxidized to Fe(III) by

atmospheric o~genunder ordinary wastewater conditions.

Fe(III)

as Fe

is soluble under strongly acidic or basic

conditions.

However, at neutral pH it forms ferric hydroxide

and oxide which are quite insoluble.

Because of this, Fe(III)

is frequently used in water and wastewater treatment to aid in

precipitation of suspended materials

(Ex.

5,

p,

217).

The Board presently has standards for both Fe(DISS) and

Fe(TOT).

IESAG recommended that the Board delete the Fe~DISS)

and regulate only on the basis of Fe(TOT)

(1:18;

2:249).

Iron is the only parameter regulated on a dissolved basis,

other than TDS, and according to testimony received, no other

state or USEPA regulates Fe(DISS)

(2:249).

This, however,

is

no longer true of USEPA.

Treatment for iron is by neutralization, atmospheric oxidation

and precipitation.

This

is capable of meeting the standards

for Fe(DISS) and Fe(TOT)

(Ex.

5,

p.

233).

The Fe(DISS) standard

was adopted with little opposition largely because industry

has no difficulty meeting it (EcIS

7).

43—392

---

—27—

Fe(II)

is similar to cupric copper.

Its toxicity to

aquatic life is similar

(EcIS

17,

19).

However,

it seems unlikely

that much could live under anaerobic conditions necessary to

maintain a significant concentration of Fe(II) without violating

the Fe(TOT) standard.

Precipitated Fe(III)

can be toxic by

coating the bottom of waterways and clogging gills

(EcIS

17)

High levels of dissolved,

unchelated Fe(III) are usually encount-

ered only

in very acidic waters where acidity is probably the

limiting factor rather than iron.

The EcIS was unable to identify any costs or benefits

associated with the proposed deletion of the Fe(DISS) standard.

Few permits in fact contain the standard or require monitoring

of Fe(DISS) apart from Fe(TOT)

(EcIS 9).

Based on this, the

Board will delete from Rule 408(a) the standard for dissolved

iron.

LEAD

Lead is a familiar base metal which exhibits many oxidation

states,

the most common of which are Pb(II) and Pb(IV).

T3oth

form stable, soluble complexes and chelates which can result in

difficulties in treatment by precipitation.

Pb(IV) also

forms a number of organic lead compounds.

Total

lead includes

all forms of

lead.

IESAG has proposed that the ~oard relax

its effluent lead standard from 0.1 to 0.2 mg/i.

SOURCES

OF LEAD

Illinois waterways exhibit background levels of lead

of 0.041 mg/l, ranging from 0.003 through 0.086 mg/i.

Elevated

levels in the Ohio and Big Muddy River Basins are associated

with increased lead solubility in waters made more acid by

coal mine drainage

(EcIS

27), while elevated levels in the

Chicago area and northern Illinois are believed associated

with fallout from use of tetraethyllead in automobile gasoline

(EcIS

10,

30).

Lead is widely used in industry for such things as automobile

batteries, fuel additives,

solder,

ammunition and explosives

(Ex.

5,

p.

265).

It is plated onto bolts and bearings as

a protective coating and used in chlorine manufacture.

LEAD TREATMENT PROCESSES

Precipitation followed by

filtration is capable of meeting

the 0.1 mg/i lead standard.

However, clarification by sedi-

mentation is capable of achieving only 0.2 mg/i lead (1:18;

EcIS

5; Ex.

5,

p.

270).

Because of the expense involved in

filtration,

IESAG recommended increasing the lead effluent

standard to this 0.2 mg/i level.

43—393

---

—28—

ENVIRONMENTAL IMPACT OF LEAD

Lead

is toxic to plants and animals and has no known

beneficial nutritional effects.

It accumulates

in animal

tissues and sediments,

and is subject to biomagnification.

There is evidence of chronic lead poisoning

in a significant

fraction of the human population

(EcIS 7).

Toxicity of lead to aquatic life depends on water hardness.

USEPA aquatic life criteria for hardness

levels encountered

in Illinois (14:142,

144; EcIS

50) establish maximum acceptable

lead concentrations ranging from 0.04 mg/i at a hardness of

28 mg/i to 5.8 mg/i at a hardness of

780 mg/i.

24—hour average

acceptable

lead concentrations vary from 0.005 to 0.8 mg/i

over the same hardness range.

The EcIS found that if either

the proposed or existing effluent standard were enforced,

there would be no violations of the aquatic life criteria for

lead in streams receiving lead discharges

(EcIS

50).

COST/BENEFIT ANALYSIS FOR LEAD

Relaxation of the lead standard to 0.2 mg/i could increase

the concentration of

lead in the receiving waterways with

a detrimental effect on water users.

The EcIS examined the

effect on human health, aquatic

life,

industrial water use,

wildlife, shellfish,

recreation and other beneficial uses of

water

(EcIS

50), but was unable to quantify any detrimental

effect,

in part because point sources account for only a small

percentage of the lead load on Illinois waterways

(EcIS

3).

The EcIS estimated cost savings associated with relaxation

of the effluent standard.

Since many affected industries meet

neither the existing nor the relaxed standard, the cost savings

are associated with construction needed to bring effluent levels

to 0.2 rather than 0.1 mg/l.

This savings

is usually the cost of

filtration

less the cost of sedimentation, which is largely

a function of flow (EcIS

59).

Minimum values are based on the

assumption that dischargers having

a single violation can meet

the standard without treatment.

Cost Savings

Minimum

Maximum

Construction

$7,435,000

$16,725,000

Annualized Construction

934,000

2,101,000

Annual Operation and Maintenance

171,000

682,000

Total Annual

$1,105,000

$2,783,000

The EcIS also estimated costs for the thirty—five municipal

plants reporting lead in excess of 0.1 mg/i.

The maximum

estimates are based on treatment by all thirty—five, while

minima assume that only the thirteen with multiple samples

in excess of 0.1 mg/i require treatment

(EcIS

64).

The following

43—394

---

—29—

is a summary of municipal cost savings from relaxation of the

lead effluent standard (ExIS

62,

72):

Cost Savings

Minimum

Maximum

Construction

$13,340,000

$29,985,000

Annualized Construction

1,259,000

2,831,000

Annual Operation and Maintenance

482,000

722,000

Total Annual

$

1,741,000

$

3,553,000

The study notes that municipal plants may need advanced

secondary treatment to comply with federal and state regulations

concerning BOD and TSS.

It is likely that this would result in

compliance with the lead standard (EcIS

64).

Federal grant money

may be available for this upgrading.

Whether it is or not,

the full cost of upgrading is not attributable to the need

to meet the lead standard.

Further, it is extremely unlikely

that a single violation is indicative of the need for treatment.

It is more likely to be a bad analysis or an episode such as

a

spill.

Thus, the minimum savings

is probably a better estimate

than the maximum, and the actual costs would be even less if

some multiple violations represent bad housekeeping.

The Board has received no public comment concerning modifi-

cation of the lead standard, but industry has expressed general

support.

At the merit hearings CBE opposed relaxation of the

lead effluent standards on the grounds of adverse environmental

impact (2:254),

and objected to the argument that the merit

hearings should center on treatment technology, with consideration

of environmental impact reserved to the hearings on the EcIS.

However,

the Agency provided water quality data

(Exs.

29,

31,

36)

at the merit hearings.

CBE did not appear at the EcIS hearings and

has not commented.

The Board

finds that good conventional technology is able to

meet

a standard of only 0.2 mg/l lead and that requiring filtra-

tion prior to discharge would impose an excessive burden on

dischargers.

Considering the limited adverse environmental con-

sequences,

the Board has proposed to relax the effluent standard

for lead from 0.1 to 0.2 mg/i.

SELENIUM

Selenium is similar to sulfur, with which it is often

found associated

in nature.

Example compounds are selenious

acid,

selenic acid, hydrogen selenide and selenium dioxide.

In wastewater seienium tends to occur as elemental selenium,

selenite or selenate.

Selenite is oxydized by atmopheric oxygen

under normal stream conditions, although this can take some time

(2:315; EcIS

9).

IESAG recommended that the Board delete the selenium

effluent standard.

Selenium would be regulated through USEPA

43—395

---

—30—

effluent guidelines and through application o~the Illinois

water quality standards pursuant to Rule 402.

SOURCES OF SELENIUM IN WATER

Selenium is widely distributed in soils and rock at levels

of about one part per million

(ppm).

This probably results in

background selenium levels below 0.01 mg/i

(EcIS

9,

18,

20).

Selenium is present in petroleum and coal at levels of up to

several ppm,

and there is evidence of selenium fallout resulting

from combustion of coal and oil

(EcIS

11,

24).

There are detectable

levels of

selenium in waters in southern Illinois which may result

from strip mining of coal

(EcIS

11,

21), but waters in northwestern

Illinois, where lead and zinc sulfide are mined,

have no detectable

selenium

(EcIS

23,

37).

Major sources of effluent selenium are the mining and

refining of copper and zinc from sulfide ores and the refining

of petroleum,

especially where associated with elemental

sulfur recovery (2:309).

Seven petroleum refineries with de-

tectable selenium effluents were identified

(EelS

35).

The

worst, Marathon Oil Company in Robinson,

is associated with

detectable levels of selenium in Sugar Creek

(EcIS

16,

35,

58,

64).

The selenium discharges, which are believed to come from

the crude oil which is processed, are less than the effluent

standard.

Industrial use of selenium is rapidly expanding.

It is used

in many electronic devices and to form the light sensitive

surface in electrostatic photocopying machines (EcIS

29).

It is

also used in pharmaceuticals,

as an additive to animal

feed,

and in glass manufacture, pigments and some alloys

(EcIS

29).

SELENIUM TREATMENT TECHNOLOGY

Precipitation or coagulation treatment technologies

cannot meet the present 1.0 mg/i standard with any assurance

(Ex.

5,

p.

525).

Efficient removal can be achieved with a strong

acid—weak base ion exchange system, but this is non—selective

and entails simultaneous removal of other ions, rapidly increasing

the cost of treatment for dilute selenium wastestreams

(Ex.

5,

p.

530).

IESAG concluded that there are major uncertainties

associated with defining reliable treatment technology or

economics for selenium control

(1:20; 2:310,

314).

IESAG

therefore recommended deletion of the selenium effluent standard

from Rule 408(b).

SELENIUM ENVIRONMENTAL IMPACT

Selenium is a toxic material which may also be an essential

nutrient at low levels.

Chronic and acute livestock poisoning

occurs from drinking seieniferous water or eating selenium

accumulation plants.

Selenium poisoning, known as “alkali

43—396

---

—31—

disease” and “blind staggers,’ is common in western states

(EcIS 49).

Toxic effects to humans and animals have been reported

at levels as low as 0.05 mg/i in water

(EcIS

520).

Because it

is usually found as an anion,

it

is less likely to associate with

sediments

(2:315),

and it is not known to accumulate in them.

SELENIUM COST/BENEFIT ANALYSIS

The EelS was unable to identify any costs or benefits of

deletion of selenium effluent standard

(EcIS

71).

There are

no recorded instances of violation of the standard (EelS

62),

There are no dischargers considering installation of treatment

equipment.

Although elimination of the standard could raise

the selenium loadings of

Illinois waterways,

the EelS was unable

to quantify any damage

(EelS

71).

The EelS assumed deletion of the selenium effluent standard

would lead to reduced selenium monitoring

(EelS

73),

hut this

is not necessarily true.

Monitoring is not governed by Rule

408, but rather is covered by permit condition

Rules

501

and 910(a)).

In deleting the selenium standard the Board

does not intend to alter the law on reporting and monitoring

of selenium.

This may be required where necessary to accomplish

the purposes of the Act

Section

39(b).

Because of lack of proved control technology and the

ambiguous evidence of environmental damage

in Illinois, the

Board will delete the selenium effluent standard from Rule

408(a).

Selenium will be controlled through NPDES permit

conditions pursuant to effluent guidelines, Rule 910(a)(6)

and the water quality standards of Part II.

TOTAL DISSOLVED SOLIDS

Total dissolved solids

(TDS)

is the filterable portion of

the total residue on evaporation.

ROE

(total)

is a measure of

the nonvolatile material

in a liquid sample.

TDS typically

contains the following ions:

sodium, potassium, magnesium,

calcium, chloride and sulfate.

Most of the other common ions

will precipitate as insoluble salts under usual conditions at

the concentrations necessary for them to form a significant

fraction of the TDS load.

Existing Rule 408(b) provides that no effluent shall exceed

3500 mg/i TDS and that no person shall add to background levels

more than 750 mg/i TDS.

There is an exemption for direct dis—

chargers to the Mississippi River

(R75—6,

25 PCB

77, March

3,

1977;

25 PCB 163, March 17,

1977;

26 PCB 105, June 28,

1977;

Ex.

40;

5:777).

IESAG has proposed that the Board ~eiete

the TDS effluent standard altogether

(1:20; 4:640).

43—397

---

—32—

SOURCES OF TDS

There are both point and non—point sources of TDS.

Northeast

Illinois has high background levels due to soluble materials

leaching from the soil.

Abandoned strip mines,

largely in

southern Illinois also produce high background levels.

Other

diffuse sources include road deicing, irrigation return flows,

and urban stormwater runoff.

An important source of concentrated TDS

is from ion exchange

or water softening backwash (2:228; Ex.

8),

Zeolite water softening

is used by 150 municipalities,

87 of which discharge backwash

directly to waters of the state

(Ex.

8;

2:228; EelS 24).

Power

plants,

industrial process and even pollution control equipment

sometimes produce high TDS streams

(4:460; 4:481;

5:738;

and

see Borden v.

IEPA,

PCB 78—269,

34 PCB

71, June 22, 1979).

USEPA concluded that there was no demonstrated control

technology for TDS

(4:658), and it does not regulate effluent

TDS

(2:319).

There are also no BAT or BPT standards for TDS

(2:326).

Illinois

is the only state which has

a TDS effluent

standard (2:319;

4:659,

711; and Ex.

28, Directory of Federal

and State Water Pollution Standards,

IIEQ Doc. No.

77/06,

March 1977).

TDS TREATMENT TECHNOLOGY

Availability of treatment technology depends upon whether

the TDS

is precipitable

(Ex.

5,

p.

554).

Metals which are

associated with hardness may be precipitated, yielding a reduction

in TDS.

Hardness

is commonly removed through lime softening,

in water treatment plants (4:664).

Although this technology

is

within reach,

it is doubtful whether sufficient benefit would

result in many cases to justify the cost of removal of hardness

from wastewater.

Technology for removal of non—precipitatabie TDS from waste—

water is essentially that applied for desalinization of seawater

to provide fresh water supplies or demineralization of industrial

water supplies

(2:319).

The major process include reverse osmosis,

eiectrodialysis, distillation and ion exchange

(2:231; Ex.

5,

p.

554).

These are very expensive and consume large amounts

of energy.

In addition to deionized water they characteristically

produce a waste stream of concentrated brine

(2:320,

326).

If this

is discharged, the net result will be at best the same as

discharging the original wastestream,

The other alternatives,

landfilling and deep well injection, also pose serious

environmental problems

(2:325;

4:666,

669).

ENVIRONMENTAL IMPACT OF TDS

The study estimated that enforcement of the present TDS

effluent standard would reduce TDS concentrations an average

of 0.6 mg/i throughout the state

(EelS

45).

The mean TDS level

43—398

---

—33—

is 303 mg/i, which is well under the 1000 mg/i water quality

standard of Rule 203(f).

Potential impacts of TDS include impacts

on residential and industrial water supplies, fishing, irrigated

crops and livestock

(EelS

41).

The 1000 mg/i TDS water quality

standard should protect the state’s waters at a level where

there will

be no measurable damage for most of these from

increased TDS loadings

(4:674).

TDS and associated hardness cause considerable damage to

residential and industrial water supplies from corrosion,

scale

and increased soap use.

The annual TDS damage from treated surface

waters in Illinois is estimated to be about $85,100,000

(1978

dollars)

(EelS

40).

Deregulation is estimated to increase this

total by approximately $231,000.

BENEFITS OF TDS DEREGULATION

Dischargers who are presently in violation of the TDS

effluent standard stand to gain from repeal of Rule 408(b).

The EelS identified eighty-seven municipalities which discharged

zeolite water softening backwash directly to waters of the State

(EelS

27).

Fourteen power plants discharge either water softening

backwash or ash pond overflow.

The EelS did not estimate

savings to them

(EelS

26).

Nineteen other miscellaneous dischargers

could incur savings in treatment costs.

The following

is a

summary of the reduction in treatment costs resulting from

deletion of Rule 408(b)

assuming that brine would be landfilled

(EelS

33):

Capital

Annual Cost

Water treatment plants

$

870,000

$7,690,000

Miscellaneous

6,600,000

540,000

Total

$

7,470,000

$8,230,000

PROPOSED ACTION

The Board has proposed to delete Rule 408(b), since there

is no available technology for reduction of TDS in wastewater,

and the environment is adequately protected by the effluent

standards of Rule 203(f).

The Board has proposed to add Rule 976, TDS Reporting and

Monitoring.

Since this rule is primarily aimed at direct, or

NPDES,

dischargers,

it would be more appropriate in Subpart A

of Part IX of Chapter

3.

Accordingly

it will be renumbered

as Rule 918 in the Final Rules.

Section 39(b) of the Act authorizes the Agency to impose

such NPDES permit conditions as may be required to accomplish

the purposes of the Act.

The TDS reporting and monitoring

rule requires TDS reporting and monitoring unless the Agency

finds it not required.

43—399

---

—34—

Effluent TDS monitoring provides a check on possible

violation of the TDS water quality standard.

It provides

a check on monitored as well as unmonitored parameters because

unexplained fluctuations in TDS levels could indicate errors

in analysis or changes in an unmonitored parameter,

pH is the negative logarithm of the hydrogen,

or hydronium,

ion activity in an aqueous system.

Acidity and alkalinity are

closely related terms which are not to be confused with pH.

Acid-

ity is the amount of strong base which must be added

to a solution

to bring it to a neutral

pH.

Alkalinity is the amount of acid

which must be added.

In an unbuffered system,

such as a strong

acid or base in deionized water, pH

is easily related to acidity

or alkalinity.

In a buffered system acid or base may be added

with smaller changes in pH.

IESAG recommended that the Board tighten its effluent range

from pH

5 to pH

10 to pH

6 to pH 9.

Because pH is measured in

different units than the other parameters of Rule 408 and is not

subject to the averaging rule, the Bo~rdhas proposed to adopt

Rule 413 and delete pH from Rule 408.

SOURCES OF ACIDIC OR ALKALINE WATER

pH of natural waters in Illinois shows a south to north

trend of increasing pH.

Background levels of pH 8.4 to pH 9.0

are common in northeastern Illinois.

This

is attributed to

high mineral content in soils.

Background pH in southern

Illinois tends to be more acidic.

Coal mines, both active and

abandoned, produce acid drainage which adds to the naturally

acid waters in southern Illinois (EelS

18).

Coal mines are

not subject to Chapter

3 effluent standards and are already

subject to a pH range of 6.0 to 9.0

Rule

606 of Chapter 4;

40 CFR S434.32(a)).

Point sources of wastewater more

acidic

than

pH 6 are mostly

associated with failures of existing treatment equipment

(EelS

12).

Point sources with alkaline discharges greater than pH 9.0,

however, represent identifiable long term problems.

The most

important alkaline source is caused by algae blooms in treatment

lagoons

(8:831).

Some dischargers have water supplies

in excess

of pH 9.

There are industrial dischargers who violate the

proposed standard because of industrial or wastewater treatment

processes, including addition of alkali to precipitate heavy

metals

(EelS

12,

34).

Most industrial categories have USEPA

effluent limitations

for pH and these are almost always in

the range of 6.0 to 9.0.

43—400

---

—35—

TREATMENT FOR pH

Treatment for pH is simple and inexpensive.

Chemicals are

among the cheapest available,

and equipment is inexpensive even

if fully automated.

Treatment consists of addition of an acid or

base to a wastestream,

Sulfuric and hydrochloric acids are most

common,

although by—product carbon dioxide is sometimes used.

Sodium hydroxide solution is the most common base, even though it

is more expensive than alternatives which include sodium carbonate,

lime and dolomite

(Ex.

5,

p.

468; ECIS

39).

ENVIRONMENTAL IMPACT

OF pH EXTREMES

The EelS evaluated water use impacts caused by changes in pH.

Aesthetics, domestic water use, navigation and power generation

were thought to be not impacted.

Agriculture, commercial

fishing,

human health, industrial and municipal water supply and water

contact and non—contact recreation were impacted

(EelS

22), but

the water quality standard of Rule 203(b) was found adequate to

protect these uses

(EelS

23).

Fish exposed to pH levels below 6.0 show signs of chronic

stress,

although it is difficult to isolate low pH from the condi-

tions that usually accompany it,

such as changes in free carbon

dioxide and increased solubility of metals

(EelS

28).

Alkaline pH increases the concentration of free ammonia in

water,

making it more toxic than the ammonium ion which is pre-

valent under acidic conditions.

This toxicity is increased even

more at high temperatures.

However,

simple dilution with water

of neutral pH produces a large reduction

in free ammonia levels

(8:827).

COST/BENEFIT ANALYSIS FOR pH

The EelS identified benefits of a tightened pH range,

but

they were described as negligible.

To determine the costs of

such tightening,

the EelS reviewed Agency pH monitoring data of

three hundred and thirty-one dischargers who had at least one

violation of the proposed standard.

Two hundred and forty-four

had more than 10

of their pH monitoring data outside the pro-

posed range of pH

6 to

9.

The EelS took this rate as indicative

of actual noncompliance;

it assumed a lower rate could be

corrected without cost (EelS

34;

8:834).

The largest group of non-complying dischargers operated

lagoons as part of their wastewater treatment process.

This group

included 164 of the 244 affected dischargers.

There were 125

municipal,

36 commercial and private lagoons and

3 manufacturing

facilities which operated lagoons and which did not conform to

the proposed limit

(EelS

35).

These dischargers violate the pH

9.0 maximum because of algae blooms in the lagoon during summer

months, which is thought

to be related to consumption of carbonate

and

bicarbonate

by

the

algae

(8:831).

The EelS estimated that

43—401

---

—36—

t1~atmentwould involve an investment of $3,104,000 to $4,910,000

and

an annual operating cost of $302,300 to $463,900

(EelS

44).

This was the largest cost of the original R76—21 pH proposal.

Early

in the hearings the Agency noted this difficulty and

proposed an

amendment providing an exception to the pH limit if

the excursion were “attributable entirely to natural causes.”

The Board incorporated this as proposed Rule 413(d) which

is

intended to cover the algae bloom situation

(Exs.

4,

9;

1:31,

36;

3:348).

The costs noted above are thereby avoided (EcIS

43).

Of the 244 affected dischargers,

the noncompliance with the

proposed standard by 80 was attributed to causes other than algae

blooms.

This group consisted of

25 commercial and private

dischargers,

44 manufacturing facilities,

4 municipalities and 7

utilities.

Investigation revealed that in 55 cases the pH problem

was either nonexistent or had already been corrected without

installation of control equipment

(EcIS

35).

The EcIS also included a category of

6 manufacturing

facilities with background pH above 9.0

in raw water

(EelS

35).

The

study found capital expenses of $160,000 to $170,000 and

annual operating expenses of

$43,700 to $45,000 for this group

(EcIS

45).

The natural causes exception of proposed Rule 413(d)

is not

intended to cover this situation.

However, existing Rule 401(b)

provides an exception for contaminants caused entirely by back-

ground levels.

The study assumed this was inapplicable.

The

Board regards the background exception as applicable where high

pH surface water is passed through a process with additions of

only

traces

of

alkali.

However,

it

is

doubtful

whether

this

would

apply

to

well

water

discharged

to

the

surface

because

the

well

water

content

is

riot

“background~ with

respect

to

the

surface

water

content.

The EelS computed compliance costs for five dischargers

with insufficient treatment and for

five

with

frequent

failures

of existing equipment.

These included 2 commercial and private

dischargers,

6 manufacturing facilities,

I municipality and 1

utility

(EelS

35,

36,

44),

The municipal violation was caused

by

insufficient

treatment

in

the

public

water

supply

system

(EelS

36).

Capital

costs

were

estimated

at

$210,000

to

$510,000

with annual expenses of $207,000 to

$246?,400.

The overall cost estimates eliminate costs to dischargers

out of compliance because of algae blooms and costs for treatment

systems already installed.

The costs are estimated for sixteen

dischargers with insufficient treatment, with frequent treatment

system failures and with high pH water sources.

The EelS estimated

capital outlays of $370,000 to $680,000 with annual expenses of

$250,700 to $291,400

(8:838).

43—402

---

—37—

RESPONSE TO COMMENTS

Five comments concerned proposed Rule 413(c),

the averaging

rule for pH

(PC

3,

PC

7,

PC

9,

PC

10,

PC

14).

The existing Rule

408(a) range of pH

5 to 10 is not subject to averaging.

At the

merit hearings Allied Chemical and Caterpillar Tractor suggested

that some sort of

averaging

rule

should

be

adopted

with

the

tightened range

(1:95;

3:523; 4:694).

In the proposed Order

the

Board put out for comment Rule 413(c),

an averaging rule based

on 99

compliance with the tightened ranges, as suggested by

Caterpillar (3:524).

Effluents which are monitored so as to provide a permanent,

continuous

pH

record may be outside the listed range

for a total

of not more than fifteen minutes in any day provided the excursion

is accidental and less than one pH unit above or

below

the

listed

range.

This rule is similar, though not identical to,

a recently

proposed USEPA rule which would be applicable to Agency—issued

NPDES permits where

it is more stringent than the state rule

(40

CFR

§401.17;

45

FR

81,

182, Dec.

9,

1980).

Two

commenters suggested that the Board withhold action on

the pH averaging rule until

final

action

by

USEPA

(PC

7

and

PC 9).

Others suggested that the Board adopt averaging rules more like

those proposed by USEPA or requested more complex rules than either

proposed Rule 413(c) or §401.17

(PC

3,

PC

10,

PC

14).

The Board

declines

to follow either suggestion.

This rulemaking

is nearly

five years old and should not be further delayed.

The proposed

pH

averaging rule is supported on the existing record.

If

it

appears that a more complex rule is needed or if it appears

desirable

to adopt USEPA’s final

rule,

affected persons may

propose modification of Rule 413 in

a new rulemaking.

Four commenters complained

of the difficulty of meeting the

tightened pH range

while improving copper treatment efficiency to

meet the proposed copper standard

(

PC

2,

7,

8,

10).

Typically,

to remove copper a base is added to cause precipitation.

Optimum

removal

is at a pH of

9 to

10

(Ex

5,

p.

151).

The

Village

of

Sauget STP maintains pH 8.7, while Olin Corporation

(East Alton)

operates at pH 9 to pH

10

(PC

7 and PC

8).

Precipitation

results

in a sludge and a clarified wastewater

stream which has a pH approximately equal to the pH to which the

wastewater was adjusted

to cause precipitation.

If this were in

excess of the

limitation on maximum pH

it would have to be

reacidified prior to discharge.

Although the cost would he small

compared to other treatment, reaciclification entails addition of

a unit operation.

Malfunction could

result

in violation of the

minimum pH standard, with greater potential

for environmental

harm (4:625).

Only copper dischargers have complained about the pH

9 limita-

tion.

The Board notes,

however,

that treatment for the following

parameters frequently involves elevated

pH:

barium, cadmium,

~omi,

27~P2~4~~

and zinc

(Ex.

5,

pp.

27,

48,

43—403

---

—38—

Accordingly

the

Board

has

proposed

to

add

Rule

413(d)

(2),

an exception providing that the pH 9 maximum limitation may be

exceeded if the elevated pH level:

is caused by the addition of alkali

in the waste—

water treatment process to cause precipitation of barium,

cadmium,

chromium,

copper,

lead, manganese,

zinc or other

similar contaminants,

in which case the upper limit shall

be pH

10 and subsection

(c) shall not apply

to the upper

limit.

The exception only applies where alkali

is added as part of

the treatment process.

If a listed contaminant is treated by some

other method, the exception does not apply:

i.e. the mere presence

of a listed contaminant does not excuse compliance with the pH

standard.

The rule lists the Rule 408(a) contaminants commonly

treated by elevating pH.

If other similar contaminants are

treated by addition of alkali to cause precipitation, the

exception will also apply, whether they are regulated by Rule

408 or not.

One commenter requested modification

of the “natural causes”

exception to cover “causes beyond the control of the discharger,

specifically including, but without thereby limiting the generality

of the foregoing, process upsets, equipment failure, strikes of

operating personnel and Acts of God”

(PC

8).

As noted above, the

“natural causes” exception was intended to cover only algae blooms

in treatment lagoons.

The Board declines to extend the exception.

The Board further notes that Rule 413 would be applicable under

the listed circumstances, although prompt notification of the

Agency and reasonable corrective measures would be considered in

mitigation of any penalty under Section 33(c)

of the Act.

Because the “natural causes” exception

is

apparently being

misunderstood, the Board will modify

it

in the proposed rules,

second notice Order.

Rule 413(d) (1) will provide that the pH

9

maximum may be exceeded

if the elevated pH level

is caused entirely

by algae in treatment lagoons.

Natural causes seems to infer such

things as high background pH and Acts of God, and does not really

describe algae blooms

very

well.

Although the algae are natural

enough, the lagoon is an artificial

impoundment receiving partial-

ly treated sewage.

The combination of

circumstances

leading

to

the

violation is very unnatural.

The term “excursion” has also been deleted from Rule 413(d).

This is usually used to indicate a short-term violation.

There

is evidence that the algae-related pH violations show a diurnal

cycle with daytime excursions and failing pH at night

(8:832).

However, the Board intends the lagoon exception to apply even if

elevated pH persists for days or weeks.

The Agency objected to inclusion of a definition of pH in

Rule

413.

The Board has in the past been criticized for

unexplained abbreviations and finds that it

is preferable to

include the definition.

43—404

---

—39—

The Agency also objected to inclusion of proposed Rule

413(c),

the pH averaging rule.

The Agency was particularly

concerned about the impacts on the aquatic community of small

fluctuations

in stream pH,

even if within the water quality

standards.

The Board declines to delete the pH averaging rule.

The effluent standards are set on the basis of technological

feasibility.

There is ample evidence that it is not feasible to

maintain pH within the 6—9 range 100

of the time.

Furthermore,

most Illinois streams have adequate buffering capacity to damp

out small swings

in effluent pH.

In conclusion,

the Board finds that good conventional

treatment

is capable of meeting the range of pH

6 to

9 when

allowance is made for averaging,

algae blooms and the necessity

of treatment for some parameters

at elevated pH.

The Board

proposes to adopt Rule 413 with the modifications discussed above.

MERCURY

Elemental mercury is a well—known dense, volatile metallic

liquid,

having two other common oxidation states,

mercurous and

mercuric.

Volatile organic alkylmercury

(II) compounds are

formed in natural systems.

Mercury changes oxidation states

readily and moves freely between solid, liquid and gaseous

phases.

This is

an important factor in the extreme environmental

danger associated with mercury (EelS

22,

29,

37).

Total mercury

includes organic, inorganic and metallic forms (2:301).

IESAG originally proposed to relax the effluent standard and

the s~erdischarge standard for mercury from

0. 0005 to 0.003

mg/l.

Four amendments to the proposal were made at the merit

hearings.

The first Agency amendment concerned existing Rule

702(d) which proscribes discharges to the sewer system which cause

violations of water quality standards

(Ex.

4,

9).

The Agency

suggested addition of language making it clear that Rule 702(d)

covered only discharges to sewers and proscribed conduct by a

discharger

to the sewer which caused violation of water quality

standards by the treatment plant.

As stated, Rule 702(d) appears

to cover all discharges and to require application of water

quality standards to the water in the sewer.

The clarifying

language was acceptable to all participants but was inadvertently

omitted from the proposed Order of February

19,

1981.

The Board

will adopt this as Rule 702(d)

(3:361).

The second Agency amendment sought to add to a footnote

Rule 408(a) applicable to the mercury standard

(Ex 11).

This

provided:

**If the Agency determines that levels above 0.0005 mg/i

are the result of additions that cannot be removed from

the wastewater influent or eliminated from the manufactur-

ing process, effluent levels up to 0.003 mg/i will be

allowed.

43—405

---

—40—

An MSD amendment incorporated elements of the first Agency

amendment and proposed some minor editorial changes

in Rule 702

(3:460).

It added to Rule 408(a)

a footnote with the following

language:

**Compliance with the numerical standard by private treat-

ment works that treat only domestic wastes and publicly

owned treatment works shall be determined on the basis

that within any monthly period the daily 24-hour composite

samples shall meet said standard no less than 70

of the

time.

IESAG stated its opposition to the Agency and MSD amendments.

Instead it suggested the following alternative

(4:639;

Ex.

23):

**Mercury is to be eliminated from use or contained at the

source whenever feasible.

If the Agency determines that

total containment or elimination is not feasible, effluent

mercury shall not exceed 0.003 mg/i.

SOURCES OF MERCURY

Because of its unique properties, mercury

is

widely

used

in

electrical equipment and other instruments.

Contact with waste—

water is usually not attendant with use,

However, much of this

mercury probably winds up in wastewater as a result of breakage

or disposal.

Dental work probably introduces some mercury into

wastewater during preparation (2:293; EelS

35; Ex.

5,

p.

313).

Mercury is used in the chlor-alkali industry and in electrodes,

as well

as in pesticides, paints, pharmaceuticals and cosmetics

(EelS

39;

Ex.

5,

p.

312).

It is also released in mining and

smelting operations,

as a catalyst in industrial reactions and

Kjeidahl nitrogen assays

(EelS 35;

Ex.

5,

pp.

312,

314;

PC 4).

Fossil

fuel burning causes some mercury fallout

(EelS

37) and

even laundry products contain some (4:432;

5:800; EelS 38).

Mercury

is naturally widely distributed

in the lithosphere

at a level of about

1 ppm

(EelS

29).

Illinois sediments normally

contain about 0.5 ppm mercury, and Chicago area sediments are 0.2

to 3.5 ppm (4:437).

Mercury does not long remain in solution but

associates with sediments

(2:295; 5:729;

Exs.

29B,

31B,

33,

34,

35,

36B).

Most mercury in streams arises from domestic sources and

various non—point sources

(1:167;

2:304).

MSD found an inverse

correlation between mercury and the level

of industrialization in

areas tributary to its plants.

The lowest levels come from its

most industrial area, around Calurnet, while the highest were from

newly constructed, non—industrial suburbs

(3:430;

Exs.

15,

16).

This is attributed to washing compounds, soiled clothing, food,

water supplies, water softening chemicals,

road deicing chemicals,

atmospheric fallout,

soil and debris in stormwater

(1:159; 3:412,

432; 5:770,

800).

43—406

---

—41—

MERCURY

TREATMENT

TECHNOLOGY

Because of the extreme environmental hazards associated with

mercury,

IESAG

recommended

that

the Board base its mercury effluent

and

sewer

discharge

criteria

on

best

available

technology

rather

than good conventional technology

(1:89;

2:279,

285).

This repre-

sents a unique departure from the Board’s approach to the other

effluent standards.

The most common treatment method for mercury is precipitation

of the sulfide.

This is very efficient in removing mercury, but

it will achieve levels of only around 0.010 mg/i.

Mercuric sulfide

is more soluble at pH levels greater than pH

9.

Excess sulfide can

produce complex ions which interfere with treatment efficiency

(2:

277;

Ex.

5,

p.

317).

Different ion exchange processes are effective against

inorganic and organic mercury.

Inorganic mercury is usually

converted to a mercuric chloride complex prior to treatment with

an anionic exchange resin.

This is the predominant species

present in chlor—alkaii wastestreams.

Cationic exchange resins

are also available.

Methyl mercury acetate has been removed by

ion exchange.

Treatment of inorganic mercury

is effective to

levels of 0.001 to 0.005 mg/i.

Coagulation with aluminum or iron salts or lime is capable

of lowering mercury levels to as low as 0.0005 mg/i

(2:279,

297,

300;

Ex.

5,

p.

322).

Adsorption on activated carbon yields levels

less than 0.00025 mg/i for dilute wastestreams.

Adsorption has

been shown to be effective against organic mercury as well as

inorganic

(2:279;

Ex.

5,

p.

324).

Sulfide precipitation, ion exchange and coagulation have

been employed full scale; other treatment methods considered by

ISEAG have been done only on a pilot scale

(2:277).

IESAG

identified

ion exchange and coagulation as the best available

technology

(2:279;

3:398).

ENVIRONMENTAL IMPACT OF MERCURY

The environmental effects of mercury are well known and

detailed in the study

(EelS

21,

88,

140).

Dischargers conceded

that it was extremely dangerous and no one argued against

employing best available technology at a minimum.

(1:164;

3:S22;

5:770,

800;

PC

12).

Mercury

is

extremely

insoluble

in natural waters.

Elevated

concentrations do not long persist.

The mercury precipitates or

is adsorbed onto suspended matter which settles.

However, the

mercury does not remain in the sediments but is cycled back into

the environment.

This is in part due to conversion of solid,

insoluble forms to organic mercury compounds,

such as dimethyl—

mercury.

Mercury also accumulates in tissues.

Levels tend to

be higher in creatures which are higher on the food chain.

Chronic mercury poisoning can result in man (EelS

23).

43—407

---

—42—

COST/BENEFIT

ANALYSIS

FOR

MERCURY

The proposed relaxation of the mercury effluent standard

could result in a slight increase

in mercury in the environment.

The EelS concluded that this cost would be negligible

(EcIS

131).

On the other hand,

it identified substantial benefits in the form

of reduced treatment costs.

The EelS identified seven industries,

five municipal waste—

water treatment plants,

seven educational

institutions and three

miscellaneous dischargers potentially affected by the mercury

proposal

(EelS

62,

72,

75,

79).

Estimates of cost were about

$166,100,000 to treat to 0.0005 mg/i and $1,830,000 to treat to

0.003 mg/l.

This would have resulted in a net annual savings of

$164,300,000 if the original IESAG proposal had been adopted

(EelS

82).

The proposed Order of February 19,

1981 was not identical

to the proposal and amendments considered by the EelS.

There

is, however, sufficient information in the EelS to estimate the

costs of the Board’s proposal which grants the relaxed effluent

standard only under certain conditions.

To qualify,

a discharger

must eliminate use of mercury

in most cases.

Other conditions

such as mercury ordinances or inspection programs can be met with

minimal expense.

Only the Vandalia Correction Center uses mercury

in

a

manner

which

is

inconsistent with qualification for the

relaxed standard and all others are expected to qualify.

Even

that facility will probably elect to cease its mercury use.

If

not, treatment is expected to cost $294,400 per year

(EelS

80).

This amount will be deducted from the savings.

The savings must also be adjusted to delete all savings

associated with Monsanto Company and the Village of Sauget,

since

they now operate under a site—specific rule and would not be

impacted by the proposed relaxation,

These costs are $18,251,000

and $733,000 per year to treat to 0.0005 and 0.003, respectively

(EelS

80).

Making

these

adjustments,

the

net

savings

from the proposal

should be $146,500,000 per year.

DISCUSSION

AND

RESPONSE TO COMMENTS--MERCURY

IESAG originally proposed a standard of 0.003 mg/i mercury

based

on

best

available technology (EelS

2).

Objections to the

relaxation of the standard were raised at the hearing by CBE,

the Attorney General and the Agency (1:164,

171,

218;

2:283).

Most dischargers in the State are presently in compliance with

the 0.0005 mg/i standard.

Although best available technology is

always able to achieve 0.003 mg/i mercury,

it is often able to

achieve lower levels

(Ex.

5,

p.

319).

The absolute relaxation

in

the

standard

could

offer

an

incentive

to

existing and potential

dischargers to increase levels of mercury to above that which they

could reasonably achieve.

This

is unacceptable

in view of the

extreme hazards of mercury.

43—408

---

—43—

As noted above,

amendments were proposed by the Agency, MSD

and IESAG

(Exs.

2,

4,

9,

11,

12,

23).

These focused on elimination

and containment of mercury

(1:164;

2:279,

286,

305).

The Board

has combined the amendments with other suggestions made

in the

hearing to develop a proposal.

Only a single general objection

was received

(PC

12).

Other comments centered on details of the

proposal.

These will be discussed with the general discussion of

the proposed language.

Simply stated, those who comply with the elimination and

containment provisions will be required to apply best available

technology.

Those who do not,

in particular those who make

unnecessary use of mercury, will be required to treat to

0. 0005

mg/i.

The Board recognizes that this may be very expensive.

However,

the cost is justified in view of the hazard.

Rule 411(a) sets a standard of 0.0005 mg/i

for effluent

discharges of mercury.

This is subject to two exceptions

contained in Rule 411(b) and 411(c).

Each of these essentially

allows discharge levels of 0.003 mg/i if the other stated

conditions are met

Rules

411(b) (2) and 411(c)(3)

(3:356).

The

exception of Rule 411(b)

is applicable to all dischargers while

Rule 411(c)

is an alternative applicable only to publicly owned

or publicly regulated sewage treatment works

Rule

411(c)(1).

Rule 411(b)(1) provides as a condition for the relaxed

effluent standard that “mercury is not used by the discharger,

or

mercury

is used and its use cannot be eliminated”

(1:164;

2:286;

3:353,

355,

448).

The Board intends that persons who make unneces-

sary use of mercury in such a manner that

it

comes into contact

with wastewater should be obliged to devise some means of treating

mercury to 0.0005 mg/i.

The

Board

is

not

aware

of

any

existing

direct industrial dischargers of mercury who would not satisfy

this

condition.

It

is

directed

against

dischargers

who

might

choose to locate

in the State in the future

(3:449).

Rule 411(b) (2) sets as a condition of the relaxed standard

that the effluent mercury concentration is less than 0.003 mg/i.

This is essentially an alternative effluent standard.

A specific

reference has been made

to the averaging rule of Rule 401(c).

The

exception

applies

if the monthly average

is less than 0.003,

daily averages less than 0.006 and grab samples

less than 0.015

mg/i

(2:280.).

Rule 411(b) (3) provides as a condition to the relaxed stand-

ard that the discharger

is

“providing the best degree of treatment

consistent with technological feasibility, economic reasonableness

and sound engineering judgment”

(3:355).

This language is taken

from. Rule 401(a), and is intended to cover a situation where, for

example,

a discharger is capable of achieving 0.001 mg/i either

through treatment or housekeeping practices.

The Board does

riot

intend to allow such a discharger to relax his vigilance and raisu

his monthly average to 0.003 mg/i

(3:448).

Rule 411(b)(3) specifically provides that

a discharger may

meet the condition without treatment for mercury.

In the context

43—409

---

—44—

of a permit application, the Agency may

review

the

discharger’s

operation for whether

it

meets

the

conditions

of Rule 411(b).

The Agency may determine that no treatment would amount to the

best degree of treatment within the meaning

of Rule 411(b)(3).

Proposed Rule 411(b)

(4)

provides

as

a

condition

to

the

relaxed effluent standard that the discharger have an inspection

and maintenance program likely to reduce the level of mercury

discharges.

In connection with the similar proposed Rule 702(b)

(4)

one commenter suggested that language be added to specifically

cover the case where an inspection and maintenance program has

already been successful in reducing the level

of mercury discharges

(PC 4).

Accordingly, the Board will insert language into Rule

411(b) (4)

so that it reads,

“likely to reduce or prevent an increase

in the level of mercury discharges.”

The Agency commented that Rule 411(b) (4) should be deleted

and that it should be required only by way of permit condition

(PC 17).

The intent of Rule 411(b) (4)

is

to firmly establish

the Agency’s authority to require this permit condition.