C-SAW battles mixing zone pollution

Earth Island News

Campaign to Safeguard America’s Waters

October marked the 30th anniversary of the Clean Water Act. Even with the Great Lakes dying and the Cuyahoga River on fire, it took a Congressional override of a Nixon veto to make the Clean Water Act law in 1972.

Progress has since been made to control “point-source” water pollution in our country. However, significant problems remain - non-point source pollution (urban and agricultural runoff), wetland destruction, and discharge of persistent toxics, to name a few. Unfortunately, progress has slowed dramatically under the Bush administration, and will continue to do so as long as dischargers aren’t required to meet state water quality standards (WQS) at the “end of the pipe.”

Since 1983, federal regulation has authorized states to apply mixing zone dilution factors to wastewater pollution limits, moving the polluter’s point of compliance with human health and aquatic life standards downstream from the point of release. States, tribes, and commonwealths routinely abuse this discretionary authority to circumvent the most basic objectives of the CWA: to prohibit discharge of toxic substances in toxic amounts, ensure that all waters be swimmable and fishable, and ultimately end the discharge of pollutants into national waters.

This year, coinciding with the Act’s 30th anniversary, Campaign to Safeguard America’s Waters (C-SAW) filed a formal petition with EPA to demand action on the mixing zone (dilution-solution) loophole in the Clean Water Act. (See Winter ‘99/2000 EIJ for more on mixing zones.) The petition was signed by 80 state and national organizations. The Administrative Procedures Act provides C-SAW with the power to sue EPA in federal court if they fail to respond to the petition or fail to respond in a meaningful way.

A state-by-state survey of mixing zone use, published by C-SAW in October 2002, clearly demonstrates that the application of mixing zones across the US is out of control:

  • Tens of thousands of discharges that exceed state WQS - totaling billions of gallons of wastes - are diluted into public waterbodies every day.
  • All manner of pollutants are discharged into mixing zones in excess of WQS: metals, hydrocarbons, organochlorines and other bioaccumulative and persistent toxics, fecal coliform bacteria, suspended solids, and materials that deplete aquatic oxygen.
  • Every state allows discharges into mixing zones to exceed chronic aquatic life criteria - limits for pollutants beyond which there will be long-term impacts to aquatic life. At least 45 states allow discharges into mixing zones to exceed acute aquatic life criteria - limits for pollutants beyond which there will be immediate, mortal impacts to aquatic life.
  • Only three states evaluate the risks to people when human health criteria are exceeded in the mixing zone.
  • No state regulations require a reduction or elimination of mixing zone use over time (aside from the eight Great Lakes states required under federal law to eliminate mixing zones for bioaccumulative chemicals by 2010.)
  • Nearly every state permits mixing zones to be authorized within any state water, for all classes of waters, including within waters containing threatened or endangered species.
  • Only eight states undertake a biological examination of the receiving water prior to mixing zone approval. Only two states claim to perform mixing zone cost/benefit analyses.
  • No states post signs or inform residents of pollutants in mixing zones, and only one state says it maintains public records of mixing zone areas.
  • No state records the individual or cumulative volumes or quantities of pollutants discharged into mixing zones, or the miles of streams, rivers, lakes, or coastal waters under their jurisdiction directly or indirectly impacted by mixing zones.

C-SAW has asked EPA to revise the federal mixing zone regulation to require states to set rules that would: prohibit allowing water quality in mixing zones to fall below the CWA “fishable/swimmable” standard in any portion of a waterbody; require public notice of ecological and human health risks prior to mixing zone approval and afterward, including information on individual and cumulative effects of mixing zone authorizations; prohibit mixing zones in impaired waters or waterbodies containing threatened or endangered species; prohibit mixing zones for pollutants that persist or accumulate in the food chain; require monitoring of mixing zone boundaries to ensure the zones perform as predicted, and; institute procedures for reducing the number and size of mixing zones and an ultimate phase-out of mixing zone use.

-Gershon Cohen, PhD is director of the Campaign to Safeguard America’s Waters.

Take Action: C-SAW’s “The Mixing Zone Manual - How to Stop the Dilution Solution,” is downloadable from the C-SAW and Clean Water Network websites. The Manual describes how mixing zones are used to circumvent water quality standards, and provides ideas and recommendations for opposing or limiting their application. http://www.earthisland.org/c-saw

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