Ocean Standards – CWA §316(b) Regulation

Desalination Facilities And Brine Disposal

State Water Board staff is developing an amendment to the Ocean Plan that would address issues associated with desalinization facilities and the disposal of brine discharges from other sources. Desalination facilities and brine disposal was discussed as Issue No. 4 in the 2011-2013 Triennial Review Workplan. The issue has been identified as very high priority for the State Water Board to address, because several new desalination facilities have been planned along the California coast to augment existing potable water supplies.

During the process of ocean desalination, salt and minerals are removed from salt water to produce fresh water. Other projects, such as brackish groundwater desalination and wastewater treatment/recycling, also generate brine discharges. The salt, minerals, and other compounds are discharged as hyper-saline brine. Brine is denser than the receiving ocean water and, depending on discharge methods, may settle on the ocean bottom. Accumulation of brine on the seafloor may have an adverse effect on marine organisms.

Currently, the Water Boards regulate brine discharges from these types of facilities through the issuance of National Pollutant Discharge Elimination System (NPDES) permits that contain conditions protective of aquatic life. However, the Ocean Plan does not yet have an objective for elevated salinity levels in the ocean, nor does it describe how brine discharges are to be regulated and controlled, leading to permitting uncertainty. The Ocean Plan also does not address possible impacts to marine life from intakes for desalination facilities.

Staff held a public meeting on April 18, 2011 to discuss the planned Ocean Plan amendment and seek input. The amendment is currently envisioned to have the following components: 1) a “narrative” objective for salinity, 2) provisions to minimize impacts to marine life from desalination plant intakes, and 3) implementation provisions. State Water Board staff anticipates that the Ocean Plan amendment will be completed by December 2012.

Studies

As part of the development of the amendment, staff has initiated three studies to gather scientific data and get technical input and scientific recommendations on key issues.

Salinity Toxicity Studies

Researchers at the Marine Pollution Studies Laboratory at Granite Canyon will determine the tolerance of Ocean Plan test species to various concentrations of hyper-saline brine.  All toxicity tests will follow the USEPA methods.  The results of the tests will be used to calculate no observed effect concentrations (NOECs), lowest observed effect concentrations (LOECs), and median lethal or median effects concentrations (LC50 or EC50) for each test protocol and endpoint.  Toxicity tests will also be conducted using a brine effluent sample from a desalination facility.

Expert Panel on Intake Impacts and Mitigation

The State Water Board has contracted with the Moss Landing Marine Laboratory to establish an expert panel to address issues associated with minimizing and mitigating intake impacts from power plants and desalination facilities. The panel members are Dr. Michael Foster, Dr. Greg Cailliet, Dr. Jim Callaway, Dr. Pete Raimondi, and Mr. John Steinbeck.  The panel met on August 8, 2011 and is scheduled to meet again in November 2011.

Expert Panel on Fact and Effects of Brine Discharges

The State Water Board has contracted with the Southern California Coastal Water Research Project (SCCWRP) to establish a panel of experts in the fields of oceanography, plume modeling, ecotoxicology, and marine ecology to answer the following questions related to brine discharge:

  1. What are the potential environmental impacts?
  2. What disposal strategies will minimize impacts from brine discharges?
  3. What models should be applied to predict how brine plumes will behave?
  4. Can cumulative water quality effects associated with multiple brine plumes be evaluated with models?
  5. What are appropriate monitoring strategies for brine discharges?

A meeting was held July 5, 2011 in Sacramento to describe the project and solicit input regarding panel members and issues. A panel of experts has been selected and input from the public has been posted online. The panel will meet several times to develop recommendations for the State Water Board.  A public meeting is being planned for late 2011. The panel will complete a final report in March 2012.

Public Meetings

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