By Meghan Boian, American Rivers
Commercial sites generate a significant amount of pollution due to their large impervious surfaces such as paved parking lots and rooftops. The most common pollutants that run off from these sites are sediment, nitrogen, phosphorous, zinc, and copper. These can damage the water quality for local rivers and streams.
In September 2015, American Rivers and its partners Natural Resources Defense Council and Los Angeles Waterkeeper filed petitions with the Environmental Protection Agency’s (EPA) Region 9 urging them to use the power granted to them by the Clean Water Act, to protect local waterways from stormwater pollution from commercial, industrial, and institutional (CII) properties. This power is known as residual designation authority (RDA).
RDA can be used by EPA when they determine that a category of stormwater discharge is contributing to water quality violations. Once that determination is made the EPA must require those dischargers to apply for permits to address the polluted runoff coming from their site. The petitions filed were the Los Cerritos Channel watershed in California, and the Dominguez Channel watershed in California. These watersheds are degraded by pollutants coming from stormwater.
How Polluted Runoff is Affecting These Areas
Los Cerritos Channel and the Dominguez California
When it rains in Los Angeles, California, pollution such as zinc, copper, and nitrogen along with other wastes washes off of impervious surfaces and into local waterbodies like the Los Cerritos and Dominguez Channels. This stormwater pollution is one of the major reasons that the State of California and the U.S. Environmental Protection Agency have declared the Los Cerritos Channel and the Dominguez Channel, which run through Los Angeles and empty into the Pacific Ocean, too dirty for recreation, fishing, aquatic life, and wildlife uses.
Commercial, industrial, and institutional sites occupy more than 30% of the land area that drains stormwater into the Los Cerritos Channel and Dominguez Channel watersheds. These sites account for approximately 30% of the zinc loadings, 20% of the copper loadings, and 25% of the nitrogen loadings in the Los Cerritos Channel and 80% of the zinc and copper pollution that reaches the Dominguez Channel. These sites quadruple the pollutant loadings that the Los Cerritos and Dominguez Channels would receive from the entire watershed under natural conditions.
Taxpayers Left Paying the Bill for EPA Inaction
EPA lost an opportunity to require commercial, industrial, and instructional property owners to control stormwater on site with proven, cost-effective green infrastructure practices that will add benefits to the surrounding community. Instead EPA is leaving these municipalities to pay for the clean-up of polluted runoff that is produced on private property.
American Rivers and our partners will keep working towards a solution to reduce polluted stormwater runoff in these watersheds.