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Delta Mercury Control Program Is Being Considered for Adoption by the Central Valley Regional Water Board April 13, 2010 by Cassie N. Aw-yang cawyang@somachlaw.com |
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On April 22, 2010, the Central Valley Regional Water Quality Control Board (Central Valley Water Board) will consider whether to adopt a proposed program to control methylmercury and inorganic mercury in the Sacramento-San Joaquin Delta Estuary (Delta). The program would involve adoption of a total maximum daily load (TMDL) per federal law for mercury and other amendments to the water quality control plan for the Sacramento and San Joaquin River Basins (Basin Plan). The proposed program addresses beneficial uses of the Delta’s waters, fish tissue objectives and an implementation program to achieve the objectives. The program’s requirements would apply to a wide range of sources, such as municipal and industrial wastewater discharges, urban runoff, irrigated agriculture, and managed wetlands. If adopted, the program would have significant regulatory and economic impacts by requiring source control, monitoring and studies as part of a comprehensive effort to reduce mercury inputs to the Delta. Background In 1990, the Central Valley Water Board found that elevated levels of mercury in Delta fish posed a consumption risk to humans and wildlife. One such type of mercury identified is methylmercury, which is considered to be the most toxic and bioavailable form of mercury. As a result of the finding, the Delta was added to the region’s list of impaired water bodies maintained in accordance with the Clean Water Act. The listing requires the Central Valley Water Board to develop a program to control mercury to eliminate the impairment. This includes development of a TMDL. A TMDL is the total maximum daily load of a pollutant that a water body can assimilate and still attain beneficial uses, such as the protection of humans and wildlife that consume locally caught fish. The Central Valley Water Board determined that the sources of mercury in the Delta are primarily inputs from upstream watersheds and within-Delta sources. These inputs include gold mining activities that began in the 1850’s, wetlands and open water habitats, municipal and industrial wastewater, agricultural drainage, urban runoff, and atmospheric deposition. The Central Valley Water Board also determined that the Cache Creek watershed is the most significant source of inorganic mercury to the Yolo Bypass, where large areas are being converted to wetlands. The Proposed Program and Basin Plan Amendments The Central Valley Water Board’s stated goal of the proposed mercury control program is to reduce the methylmercury in Delta fish to levels safe for human and wildlife consumption. The major elements of the proposed Basin Plan Amendments are: • A new beneficial use designation for the Delta and Yolo Bypass for commercial and/or sport fishing (COMM); • Numeric objectives for methylmercury in fish tissue that are specific to the Delta; • An implementation plan to control methylmercury and total mercury known as the “Delta Mercury Control Program”; and • A surveillance and monitoring program. The Basin Plan does not currently include a beneficial use of commercial and sport fishing (COMM) for the Delta. COMM extends to uses of water for commercial or recreational collection of fish, shellfish or other organisms including, but not limited to, uses involving organisms intended for human consumption or bait purposes. The program would amend the Basin Plan to include the COMM designation applicable to waterways within the legal Delta boundary, including the southern Yolo Bypass and within the Yolo Bypass upstream of the Delta. The proposed program includes numeric objectives for methylmercury in Delta fish tissue referred to as “fish tissue objectives.” Central Valley Water Board staff considered a range of alternatives for the fish tissue objectives. The alternatives varied based on the amount of fish consumed by humans and the position of the fish in the food chain (i.e., trophic level). Trophic level 4 fish are the top predators (e.g., catfish or bass); trophic level 3 fish are mid-food chain fish (e.g., bluegill); and trophic level 2 fish are the first step in the food chain. The alternative being proposed for the program would establish objectives of 0.08 and 0.24 milligram per kilogram (mg/kg) in fish tissue for large trophic levels 3 and 4 fish and 0.03 mg/kg for small trophic levels 2 and 4 fish. These objectives purportedly are protective of threatened and endangered wildlife and would allow humans to consume safely 32 grams per day of Delta fish and a moderate amount of commercial fish. To achieve the fish tissue objectives, the proposed program includes an implementation program or “Delta Mercury Control Program” with actions and time schedules to reduce methylmercury and total mercury sources to the Delta and Yolo Bypass. The implementation program consists of two phases. Phase 1 (from about 2011 to 2020) would require dischargers to develop and evaluate management practices to control methylmercury. Phase 1 includes total mercury mass limits and requires mercury minimization programs for discharges permitted under the National Pollutant Discharge Elimination System of the Clean Water Act (e.g., municipal wastewater discharges). The three largest stormwater agencies (Sacramento, Stockton and Contra Costa County) must implement pollution prevention measures to reduce mercury discharges in urban runoff. Dischargers must conduct methylmercury control studies to develop and evaluate management practices to reduce methylmercury discharges. These studies are required for wastewater treatment plants, large municipalities with urban runoff, irrigated agricultural lands, managed wetlands, and state and federal agencies with water management projects that produce and/or transport mercury. The implementation plan would require discharges to work with community-based organizations to develop and implement an exposure reduction program for people that eat Delta fish. In addition, Phase 1 includes a schedule and milestones for reducing mercury from the Cache Creek Settling Basin and establishes a schedule for development of upstream TMDLs. As proposed, the Central Valley Water Board must review the program at the end of Phase I to consider whether to modify the fish tissue objectives, allocations and/or the final compliance date for the allocations; implement management practices and schedules for methylmercury controls; and adopt a mercury offset program for dischargers who cannot meet their TMDL load and wasteload allocations. The program review will also involve consideration of other potential public and environmental benefits and adverse impacts of attaining the allocations. Phase 2 of the program (from about 2020 to 2030) would require implementation of the methylmercury controls identified by the Phase 1 studies consistent with any revisions to the Basin Plan adopted at the end of Phase 1. Phase 2 would also involve the continued implementation of inorganic mercury control efforts. The proposed Basin Plan amendments include a monitoring program to assess compliance with the fish tissue methylmercury objectives and the methylmercury and total mercury implementation program. The program includes fish tissue and water monitoring. Conclusion and Implications At its April 2010 meeting, the Central Valley Water Board will consider whether to adopt the proposed program to control total mercury and methylmercury in the Delta. If adopted, the program would require compliance with mercury-related water quality objectives by 2030. The program’s elements would have significant regulatory and economic impacts for those deemed responsible for discharges of mercury into the Delta. Failure to implement the program may result in costly enforcement actions. Further, the Central Valley Water Board estimates the costs to implement the methylmercury control studies of Phase 1 to be between $5.5 and $14.7 million. The costs to implement the Delta Mercury Control Program could be between $3.9 and $26.5 million per year, with most of the costs being incurred after 2020 (i.e., during Phase 2). For more information regarding the Delta Mercury TMDL or the TMDL process in general, contact Cassie Aw-yang at cawyang@somachlaw.com. Somach Simmons & Dunn provides the information in its Environmental Law & Policy Alerts and on its website for informational purposes only. This general information is not a substitute for legal advice, and users should consult with legal counsel for specific advice. In addition, using this information or sending electronic mail to Somach Simmons & Dunn or its attorneys does not create an attorney-client relationship with Somach Simmons & Dunn. |
