Re: Proposed amendments to dissolved oxygen standard (R04-25)

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OFFlCE

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Dorothy Gunn, Clerk

Illinois Pollution Control Board

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James R. Thompson Center

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100W Randolph St

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Suite 11-500

ollunon Control Eoarcj

Chicago, IL 60601

Dear Ms. Gunn,

In April 2004, the Illinois Association of Wastewater Agencies (IAWA) submitted a proposal to the

Illinois Pollution Control Board proposing to lower the dissolved oxygen criteria from

5.0

mg/I to

3.5

mg/I

during the months of July through February. 1 am writing you to ask that you reject LA WA’s request. The

proposed reduction in dissolved oxygen criteria will not improve the condition of Illinois streams such as

the Fox River, rather it will have the opposite effect by further degrading water quality and harming

aquatic life. The current Illinois standard for dissolved oxygen follows U.S. Environmental Protection

Agency guidelines and past scientific studies do not support a lower standard. Therefore, the Illinois

Pollution Control Board should reject the proposal to lower dissolved oxygen standards.

In 2002, the Fox River was categorized as impaired by the Illinois Environmental Protection Agency. One

of the reasons for the river’s impairment is low dissolved oxygen. The effects of low dissolved oxygen in

rivers such as Fox are well documented. At extremely low oxygen levels, fish kills result. Low dissolved

oxygen levels in the Fox River will also negatively impact fish species that spawn in late summer, and

sportfish such as smalimouth bass are sensitive to low dissolved oxygen levels. Freshwater mussels and

other aquatic macroinvertebrates are also negatively affected by low dissolved oxygen. The aquatic fauna

in the Fox River is already threatened by deteriorating water quality with several species becoming

extirpated from the watershed in recent decades. Lower dissolved oxygen will only exacerbate the

problems the Fox River faces.

Robert Schanzel made the following comments on behalfof the Illinois Chapter of the American Fisheries

Society regarding the proposal: “The Illinois Chapter of the American Fisheries Society does not support

relaxing Illinois’ existing dissolved oxygen standards because insufficient evidence is available that such

action will not have serious and irrevocable consequences for the state’s aquatic biota

that is, the science

does not support the proposed changes.” Schanzel also states “To lower quality standards now, would not

serve the best interests either of Illinois’ citizens or its aquatic resources.”

The condition of the Fox River is impacted by multiple stressors. As these stressors become intensified the

ecosystem deteriorates. The degradation of the Fox River has and will continue to affect the well being of

its residents. In February 2004, over 150,000 residents in Aurora were recommended to boil their water.

A report prepared by Weston Solutions indicated that the majority of the blame for the boil order could be

placed on the deterioration of water quality in the Fox River. The proposed rule change by IAWA will not

improve the condition of the Fox River, but it has the potential to accelerate its declining condition. Thus,

it should be rejected by the Illinois Pollution Control Board.

Thank you very much for your time and consideration.

Sincerely

IO&’~3Ofl~j

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