More than 40,000 miles of California’s rivers and streams are currently threatened by pollution, according to a list of impaired waterways submitted by the state to the U.S. Environmental Protection Agency (EPA). Monitoring of rivers, lakes and coastal waters in California continues to show harmful pollutant levels, based on updates to the list from three of the state’s nine regional Water Quality Control Boards—North Coast, Lahontan and Colorado River regions.
Common impairments in lakes are due to mercury and other toxic metals in fish. High temperatures, sediment and toxic metals are found in many rivers and streams. Of California’s more than 200,000 river miles, more than 40,000 are not meeting at least one water quality goal, and still need clean-up plans, known as total maximum daily loads (TMDLs). Of the 1.6 million acres of lakes and reservoirs, over 80,000 acres are not meeting water quality goals, and still need TMDLs.
“Clean water is vital to California's public health, economy, recreation and wildlife - now more than ever during our extreme drought,” said Jared Blumenfeld, EPA’s Regional Administrator for the Pacific Southwest. “EPA is working alongside the state as it continues the critical efforts needed to protect and restore California's damaged waters.”
The federal Clean Water Act requires states to monitor and assess their rivers, lakes and coastal waters and submit a list of impaired waterways in need of cleanup plans to EPA for review. This year, California submitted its 2012 updated polluted waters list based on data collected through 2010 for the North Coast, Lahontan and Colorado River regions.
Lake Tahoe, which borders California and Nevada in the Lahontan region, has a TMDL in place to control storm water and reduce ongoing impairments from nutrients and fine sediments. Lake Tahoe’s water clarity continues to show signs of improvement from 1997’s minimum of 64 ft to 70 ft in 2013.
In the Colorado River region, there are added impairment listings for toxicity, pesticides and other pollutants in the New River, a binational river that originates in Mexicali, Baja California and ends at the Salton Sea in Imperial Valley, California. Several TMDLs are already in place for the New River to reduce trash, dissolved oxygen, bacteria and sediment impairments. EPA has also worked to improve water quality in the New River through investments in wastewater treatment projects in Mexicali, which have resulted in significant improvements in dissolved oxygen and bacteria impairments.
Work is under way to clean up and restore the approximately 1,000 water bodies across California previously listed as impaired. California has developed cleanup plans for more than 50,000 river miles and over 160,000 lake acres. The state will submit future list updates in 2016 and 2018 for water bodies in the other six Regional Water Boards.
EPA is adding Lake Topaz, also bordering California and Nevada, to the state’s 2012 list of impaired waters based on high mercury levels in fish. Following public comment on the listing of Topaz Lake, EPA will review and approve a finalized list.
Source: U.S. EPA