The California Department of Transportation agreed Wednesday to install pollution controls on all state highways to reduce the flow of toxic storm water into the ocean and streams. The decision came after to decade-long lawsuit between the California Department of Transportation, the Natural Resources Defense Council and Santa Monica BayKeeper.
Caltrans had previously stated the pollution controls were ineffective and costly. Although the final numbers are still being calculated, it is expected to cost approximately $5 billion to install the controls in Los Angeles County alone.
According to the agreement, Caltrans is required to install the storm-water controls in all new highway or freeway projects. For older highways, construction crews will install them during improvement projects that involve more than three acres, such as interchanges or road widenings.
The drainage controls will vary from drain filters and screens to detention basins and sand traps. According to the NRDC, if the filters were installed along an 8.6-mile area on the San Diego Freeway from the Santa Monica Freeway to the L.A. International Airport, 60 tons of pollutants a year could be removed. Storm runoff from California’s roads, cities and industrial sites constitute the state’s top threat to water quality.