RECEIVED

RECEIVED

August 2005

CLERK’s OFFICE

AUG 042005

Illinois Pollution Control Board:

STATE Op

ILLINOIS

PoIIu~ipqControl

Boaro

I have attached testimony for the August 25 heanng on Illinois i-’oiluuon

Control Board (IPCB) Proposal: R 2004-025; Proposed Amendments to Dissolved

Oxygen Standard

III. Adm. Code 302.206 for general use waters in Illinois. I

would appreciate the opportunity to present a summary of these comments to the

Board at the hearing.

Thomas J. Murphy, Ph. D.

Emeritus Professor of Chemistry

Environmental Science Program

DePaul University

2325 N. Clifton St.

Chicago, IL 60614

tmurphy@depaul.edu

R04-25;

Dissolved Oxygen Standards

Thomas J. Murphy

Introduction

The rational for this proposed amendment to the Illinois water quality (WQ) staudards~isto

update them since there have been changes to the US WQ Standards. The current dissolved oxygen

(DO) regulations have lead to a marked—and in some ways a remarkable, improvement in the water

quality in the rivers of Illinois. This improvement has had great benefits to the citizens of Illinois in

improving the habitat for native aquatic species, in increased fishing and other recreational

opportunities for residents of Illinois and of other states, and in lower treatment costs for users of

Illinois waters.

It is time to continue this trend, to move Illinois streams to the fishable, swimmable goals of

P.L. 92-500, the Water Quality Act of 1972 and its amendments, and to make the waters of Illinois

more attractive to those who live on them, and to those who use them for recreational and

commercial purposes.

It is unfortunate then that the proposal from the Illinois Association of Wastewater Agencies

(IAWA) proposes less stringent regulations, regulations that will lead to increasedpollutionin

Illinois’ rivers and to a degradation oftheir water quality.

In support of the request to allow additional pollution in our rivers, the IAWA submitted an

Assessment Document based heavily on the U. S. EPA’s 1986 National Criteria Document on DO

(Chapman, 1986; NCD).

Comments

The problems with the NCD and the Assessment Document (AD) are several and severe:

1. The NCD and the AD submitted by the IAWA both contain numerous disclaimers that

most

ofthe data are based on laboratory studies that are not directly applicable to the natural

situations. However, both documents then base their conclusions almost exclusively on the

laboratory data.

In numerous places (see notes), the NCD points this out and qualifies their

recommendations that

natural waters are sign j/Icantly more complex, and that standards

based on ambient measurements would be expectedto be more stringent, e.g.,

more DO

needs to be present to prevent harm.

However, the

three field studies

discussed in the NCD, p. 19-20,

all show sign~JIcant

deleterious effects at DO concentrations below 5 mg/L.

The document concludes, “These

three field studies all indicate that

...

sites with dissolved oxygen concentrations

below 5

mg/L

have fish assemblages with increasingly poorer population characteristics as the DO

concentration becomes lower.”

The proposal before the IPCB is to permit a one-day

minimum of 3.5 mg/L DO for eight months of the year!!

Some ofthe additional problems well documented in the NCD with natural waters compared

to lab studies are: 1) abundant food is

not

provided in the wild and the fish expend more

energy foraging there; in passing additional water over their gills to obtain needed oxygen,

fish expend more energy and are exposed to increased amounts of toxins; fish-are

increased risk ofdisease; and when they are forced to move to the surface or otherareasof

higher DO levels they are at increased risk ofpredation. These and perhaps other causes

result in lower growth rates at low DO levels.

The test endpoint in many ofthe studies is the death ofthe organism. There can clearly be

many serious but less obvious deleterious effects in the fish that have not beeniquantiflei±tbat

may/probable occur at DO levels above the lethal limit. For instance, we knowthatinlügher

organisms one ofthe early effects of deprivation ofoxygen is damage to nerve cells, and to

R04-25; Dissolved Oxygen Standards

Thomas J. Murphy

the brain in particular. No studies are quoted where the effect of exposure of fish to repeated

DO levels above the lethal limits on brain and nerve function was determined.

2. The majority ofthe studies discussed in the NCD done on a relatively small number offish

species, the salmonids. In fact the document states, “More importantly,

data on the tolerance

to low DO concentrations are availablefor only afew ofthe non-salmonid fish.”

3. For DO, percent saturation and mg/L can be mathematically related to one another, but they

are

not equivalent measures ofthe availability ofoxygen

to indigenous organisms. While DO

concentrations are often determined (chemical tests) and reported in mg/L, the availability of

oxygen to organisms depends on its activity—its percent saturation or oxygen tension

(electrochemical test). Thus,

3.5

mg/L ofDO corresponds to 43 of saturation at 25°C,but

only 24 of saturation at 0°C.

Thus, to permit DO levels less than 25 saturation in the cold

months ofthe year as is proposed, can be expectedto cause harm to fish and other aquatic

organisms.

It could be noted that the oxygen tension at the summit ofMt. Everest

—

commonly referred to as the ‘dead zone’, is only 33 of the oxygen tension at sea level.

4. The DO standard recommended in the NCD is based on a curve fit to the data for about 20

species offish. The curve then gives a best estimate of

the mean LC50 level

for the species

tested. Since

the LC50 level

for

manyfish is above this level, they are clearly NOTprotected

by the proposed lower standard,

and in fact several species studied had

LC50s

above the

NCD recommendations, including channel catfish and large mouth bass. It would be

disasterous to aquatic fauna in Illinois rivers if only those species whose DO requirements

were at orbelow the mean were afforded protection by Ill. WQ regulations.

The data iii Fig 1 of the NCD show that while the young forms of most fish are not adversely

affected by DO levels below 6 mg/L, the young forms of some fish some are, including warm

water fish such as channel catfish, smallmouth bass andperhaps northern pike.

The IAWA Assessment does not claim that 5 mg/L will protect the young forms of all warm

water fish or other aquatic organisms. Rather they make the

totally

unsupported statement

that,

“Warm water species that spawn later during the summer should have adaptationsfor

naturally occurring reductions in DO concentrations expected to occur during warm months.

(Executive Summary)”

Maybe these summer-spawning species evolved when warm waters in Illinois were close to

saturation

(see above) with dissolved oxygen

throughout

the year, when waters were

uncontaminated with anthropogenic, oxygen demanding inputs.

Maybe undocumented, self-

serving statements ofthe IA WA should not serve as the basis for Illinois DO regulations.

6. A major problem with lowering the DO standards is that the proposed concentrations are

much closer to levels that cause damage to indigenous organisms, increasing the risk that a

violation of the standard will cause harm. The usual rule for environmental quality guidelines

is to include a reasonable

safety margin

to prevent damage to the ecosystem from the

unanticipated fluctuations that occur.

7. It could be that the proposed regulations will give sufficient protection to many of the

organisms present in the warm, general use water in Illinois. The problem is whether the

standards will be met—how frequently and to what extent will they be violated. The current

diurnal, daily and weekly variability of the DO concentration needs to be determined before

any change could be supported. How much does it vary and what are the normal and the

R04-25; Dissolved Oxygen Standards

Thomas J. Murphy

highest daily and weekly variation. With no change in the regulations, how often do current

ambient conditions violate the proposed regulations?

8. In addition, the WQ standards are only the first issue. They can and should be written to be

sufficiently protective of whatever species are deemed to require protection. Other important

issues include how the regulations will be implemented, and how they will be enforced. What

additional monitoring will be required and who will pay the costs; what procedures will be in

place to respond to violations (identifying the causes; halting discharges; adding oxygen to

the waters;

etc.);

what will be the procedures for identifying violators, and what will the

penalties for violations of the regulations be. Addressing these questions will be much more

important if the DO limits are lowered as proposed, narrowing the safety factor that should

be part of all regulations.

Conclusions

• There are insufficient data presented in the IAWA Assessment Document to demonstrate that the

proposed weakening of the ambient WQ DO regulations will be protective ofindigenous

organisms. Therefore only a tightening of these standards should be considered to hasten the

recovery of our warm waters to fishable swimmable conditions ASAP. When our warm waters

again maintain sustaining levels ofall native flora and fauna, then perhaps the IPCB can discuss

fine-tuning the DO regulations on those waters.

• WQ criteria need to be based on the oxygen availability—the percent saturation, and the DO

concentrations should

not

be permitted to go below 33 saturation (~5 mg/L at 0°C).

• Before considering changes in the DO regulations, the IPCB needs to determine current DO levels

and their variability in Illinois’ rivers and the DO requirements ofnative aquatic species, and base

proposed changes on those data. What is the need to change the current DO regulations? These

regulations have served Illinois well in improving the.WQ in its rivers, why lower them?

• I do not think that the people of Illinois will support increased pollution of their rivers after so

much time and so many resources have been spent in recent years in improving their quality to

where they now contribute significant recreational and economic benefits to the state. Have we

spent billions of dollars over the past 30 years or so to clean-up ourrivers, to allow the return of

many native species to their former habitat, just to allow more pollutants to be discharged into

them?