The Clean Water Act’s antidegradation policy is found in section 303(d) (and further detailed in federal regulations) and its goals are to 1) ensure that no activity will lower water quality to support existing uses, and 2) to maintain and protect higher quality waters.  Antidgradation is the third key component of water quality standards (WQS), which encompass: 

1. Designated uses – states set one or more designated uses for each waterbody (e.g. drinking, recreation, aquatic life) and these uses must be protected.
2. Water quality criteria – are numeric and narrative criteria considered necessary to protect each designated use (e.g. 5 mg/l dissolved oxygen).
3. Antidegradation policy – is a process used by states to protect existing uses and protect high quality waters.

How It Works

States must adopt an antidegradation policy and methods for implementation that adhere to the following tiered framework:

• Tier 1 – protect existing uses – permit no activity that would eliminate, interfere with or lower water quality necessary to support existing uses.

• Tier 2 – maintain high quality waters – avoid or minimize any lowering of the water quality of waters that exceed standards.  In order to allow additional pollution loading, it must be shown that the increase is necessary, there are no reasonable alternatives to increasing the pollution, and the activity generating the pollution provides important economic or social development to the community (ie jobs, sanitary services, etc.).

• Tier 3 – protect outstanding waters – strict protection, no degradation allowed.

Antidegradation review is triggered by major programs and permits including wastewater discharge permits from industries and municipalities.

Although Iowa has an antidegradation policy on the books, parts of it are missing (no Tier 3) and other parts are inconsistent with the federal requirements and the policy is not properly implemented. The Iowa and Cedar Rivers are designated as warm water significant resource, contact recreation, and in the urban areas (Iowa City and Cedar Rapids) the rivers are also designated for drinking water. Most of the river receives Tier 1 review, with some very limited portions receiving Tier 2 review for a “high quality resource.”

The problems with Iowa’s antidegradation policy are:

Tier 1 Review is inconsistent with federal law and not being implemented – Iowa rules extend Tier 1 protections to all waters of the state, but the rules do not have a proper implementation procedure to assure protection of existing uses.  In general Iowa DNR asserts that existing uses do not need to be protected if the use is not designated.  We have numerous examples of wastewater permits issued without disinfection that discharge to waters where primary contact recreation (swimming, kayaking, childrens play) is occurring as an existing use, but where that use is not currently designated.  DNR’s position is they determine permit limits based on criteria for designated uses, not existing uses.  That policy is inconsistent with the federal Clean Water Act.  DNR also states that as long as current water quality standards are being met, existing uses are protected without consideration of evidence to the contrary.  An example of this is the recent proposed permit for Cedar Rapids, where proposed increased permit limits for ammonia, Carbonaceous Biochemical Oxygen Demand, and Total Suspended Solids could adversely affect existing aquatic life uses. Specifically, the increases of these pollutants could contribute to the impairment of aquatic life uses in the Cedar River 2.5  miles downstream of Cedar Rapids were mussel populations at the Palisades Kepler State Park are declining.  An adequate Tier 1 review would disallow these increased limits as they do not protect and maintain existing uses (i.e. mussels are dieing).

Tier 2 review is limited and inconsistent with federal law – Iowa limits Tier 2 review to those waters where water quality “significantly exceeds” levels necessary to protect existing uses, whereas under federal law, waters must only “exceed” these levels. Thus Iowa provides only very limited Tier 2 protection to less than 3 % of Iowa’s 71,665 miles of rivers and streams that are designated either High Quality or High Quality Resource.  Most waters with water quality that exceeds minimum standards are denied this more stringent review of new or increasing pollution sources. EPA has noted this problem as early as 1997 and has repeatedly told Iowa DNR that limiting Tier 2 protections to this small subset of Iowa waters is not consistent with the Clean Water Act.  Even for the 3% of waters that do get Tier 2 protections under current rules, Iowa DNR does not have adequate implementation procedures to assure that increases are necessary for important economic or social development.  An example is the recent proposed permit limits for the City of Quasqueton where DNR drafted a permit that would have allowed increases in ammonia discharged to the Wapsipinican River, a High Quality Resource Water.  After objections from the environmental community, and discussions with the City of Quasqueton, it was determined that the increases in permit limits were not necessary and the City was happy to have their permit renewed with the existing limits.  If a proper Tier 2 review had been done prior to the drafting of the permit, the increases in permit limits would never have been proposed.  

Tier 3 - Iowa DNR has no rules or implementation procedures for Tier 3 antidegradation protection and has no Tier 3 waters designated. Rules and implementation procedures to nominate some of the best waters in Iowa for this protection need to be added.