Selenium Map ImageNew federal reports  document that selenium pollution is getting worse and existing water-quality standards for selenium will not protect fish and wildlife.  These scientific findings contradict assurances by the U.S. Bureau of Reclamation, irrigators, and regulators that the selenium problems of the Western San Joaquin Valley and the Bay-Delta are being addressed.

“Even though the poisoned ponds of Kesterson were buried in the 1980’s, selenium continues to pollute the waters and wildlife refuges of the San Joaquin Valley and the Delta,” said Carolee Krieger, Executive Director and President of the California Water Impact Network.

U.S. EPA,  on September 1, 2011, announced that they will propose new site-specific water-quality criteria for selenium that will protect fish and wildlife in the San Francisco Bay and Delta.  The new criteria will be based on results of scientific studies by the U.S. Geological Survey.  C-WIN’s analysis of the reports shows that the science provides the basis for a change in the water-quality standard for selenium from 5 ppb to 1.5 ppb or less.  This change is needed to protect economic resources of the Delta Estuary and Bay including salmon, steelhead, sturgeon and diving birds.

“These scientific documents raise questions about the wisdom of letting the Grassland Drainers continue to use the San Joaquin River as a de-facto drain and whether the existing Central Valley water quality selenium standard of 2 ppb for wildlife refuges is adequate,”stated  Tom Stokely, a water policy analyst with C-WIN.

Mean Daily SeleniumSince 2002, under the Clean Water Act, Section 303, and the Endangered Species Act, the United States Environmental Protection Agency (EPA) has been required to adopt acute and chronic aquatic life criteria for Selenium taking into account the bioaccumulation of this contaminant as it magnifies throughout the food chain often causing reproductive failure, teratogenic effects and death. The terms and conditions also included reevaluating and revising selenium criteria for the protection of semi-aquatic wildlife.  The just released peer reviewed United States Geological Survey (USGS) study, also part of the terms and conditions, models the fate and transport of selenium in the San Francisco Bay-Delta Estuary and as agreed, the report will serve as the basis for revised water quality criteria for the protection of wildlife species.

Existing Selenium Table

*** The graph prepared by CSPA & CWIN (below left) is directly based on the results from the U.S. Geological Survey (USGS) study. The USGS study evaluated a series of selenium exposure scenarios using a set of specific guidelines and modeling choices from the range of temporal hydrodynamic conditions, geographic locations, food webs, and allowable dissolved, particulate, and prey Se concentrations (which we have referred to as “safe levels”). According to the USGS, “The specificity of these scenarios demonstrates that enough is known about the biotransfer of Se and the interconnectedness of habitats and species to set a range of limits

and establish an understanding of the conditions, biological responses, and ecological risks critical to management of the Bay-Delta”.

The following scenarios were evaluated by USGS for a range of hydrologic conditions and residence times  (See Tables 17, 18 and 19 in the USGS report):

  • Predicted allowed dissolved Se concentrations for Bay-Delta transects at different effect guidelines and associated levels of protection (USFWS, 2009b) for a suspended particulate material > C. amurensis > sturgeon food web.
  • Predicted allowed dissolved Se concentrations for Bay-Delta transects at different effect guidelines and associated levels of protection (USFWS, 2009b) for a suspended particulate material>C. amurensis>clam-eating bird species food web.
  • Predicted allowed dissolved Se concentrations for landward transects at different effect guidelines and associated levels of protection (USFWS, 2009b) for a suspended particulate material > aquatic insect > juvenile salmon food web.

The CSPA-CWIN summary graphic of this data shows the results for critical Bay-Delta species, aggregated across all combinations of target tissues (eg. Whole body, eggs, or diets) that have known levels of concerns, as summarized by the U.S. Fish and Wildlife Service.  Results are also combined across all hydrologic conditions for each species.

The ranges of “allowable” or safe levels of dissolved selenium clearly show that, although EPA will need to specify exact safety levels, flow conditions, and species, new standards for the Bay-Delta will need to be substantially less than 0.5 parts per billion dissolved selenium to be protective.


Deformed Duck by HT Harvey and Assoc imageC-WIN and a coalition of 13 other environmental, fishery and tribal interests recently sent a letter to Interior Secretary Sally Jewell, Rod McInnis, Southwest Regional Director for the National Marine Fisheries Service and Jared Huffman, Region 9 Administrator for the US Environmental Protection Agency.  The letter is a followup to an unanswered letter on the same subject to the Bureau of Reclamation dated April 22, 2013.

The letter expresses concerns with reduced monitoring for selenium discharged into the San Joaquin River from the Grasslands Bypass Project.  The reduced monitoring will hide the ongoing pollution from the project, which has received a 25-year waiver of meeting selenium standards in the San Joaquin River and Mud Slough North.  Bird deformities have occurred in the project area such as the black-necked stilt embryo found (above) in the reuse area. (Photo: HT Harvey & Assoc.)

The coalition also expressed concerns with non-compliance with Endangered Species Act conditions of approval.

After 25 years of exempting the drainers from safe selenium standards, now the drainers are proposing to drastically reduce the monitoring for this pollution and have failed to comply with the U.S. Fish and Wildlife Service’s Biological Opinion.

Hiding the pollution does not halt its deadly progress in accumulating in the food chain.  The Delta Estuary, a nursery of slow moving water , creates and environment where the dangers of this pollution will magnify.

The promised mirage of treatment and trucking off this hazardous waste to some landfill so it does not deform migratory birds and waterfowl, remains an illusion.


  1. Coalition Protest Letter: Closure of Grassland Bypass Project (GBP) Data Collection and Review Team (DCRT) Meetings to Selected Members of the Public (pdf)
  2. Opposition To Grassland Bypass Monitoring Reductions (pdf)
  3. Comments on Draft EA/FONSI (DEA) for the San Luis Drainage Feature Reevaluation Demonstration Treatment Facility at Panoche Drainage District’s San Joaquin River Improvement Project (SJRIP) FONSI – 10 – 030 (pdf)