SAN FRANCISCO, CA, July 3, 2015 -- According to a new list of impaired waterways in California, more than 40,000 miles of the state's rivers and streams are currently threatened by pollution. Monitoring of rivers, lakes and coastal waters continue to show harmful pollutant levels, based on updates to the list from three of California's nine regional Water Quality Control Boards -- North Coast, Lahontan and Colorado River regions.
Common impairments in California's 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 the state's more than 200,000 river miles, over 40,000 are not meeting at least one water quality goal and still need cleanup 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.
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 the Environmental Protection Agency (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, for example, which borders California and Nevada in the Lahontan region, has a TMDL in place to control stormwater and reduce ongoing impairments from nutrients and fine sediments. The lake's water clarity continues to show signs of improvement from 1997’s minimum of 64 feet to 70 feet 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 to reduce trash, dissolved oxygen, bacteria, and sediment impairments. EPA has also worked to improve water quality in the river through investments in wastewater treatment projects in Mexicali, which have resulted in significant improvements in dissolved oxygen and bacteria impairments.
Work is underway to clean up and restore the approximately 1,000 waterbodies across California previously listed as impaired. The state has developed cleanup plans for over 50,000 river miles and over 160,000 lake acres. Further, it will submit future list updates in 2016 and 2018 for waterbodies 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, the Agency will review and approve a finalized list.
###
