Are We Close to the Finish Line? – Measuring Trash Reductions in Bay Area Stormwater
Numerous urban creeks and shorelines in California are listed on the Clean Water Act’s 303(d) list as impaired by trash. The virtual elimination of trash from municipal stormwater systems entering these receiving waters is currently (or likely will be) mandated by NPDES permit requirements in California. Trash reduction requirements need to be consistent with established TMDLs and the “Trash Policy” currently under development by the State of California. To comply with trash reduction requirements, municipalities in the Los Angeles and San Francisco Bay regions have installed numerous trash “full capture” devices to-date. Others are enhancing institutional controls such as street sweeping and storm drain cleaning. In order to verify that required load reductions are achieved as a result of these actions, municipalities are (or will likely be) required to design and implement trash monitoring and assessment strategies. Routine, practical and reproducible monitoring methods to detect reductions in trash from stormwater, however, have yet to be developed. We will provide an overview of the pilot trash assessment strategies and methodologies currently being implemented by the Santa Clara and San Mateo countywide stormwater programs, and present results and lessons learned to-date. Trash assessment methods that will be presented include on-land visual assessments, quantitative receiving water assessments and “flux” monitoring, and full capture operation and maintenance verification protocols. Trash assessment methodologies currently being tested by the Bay Area Stormwater Management Agencies Association (BASMAA) via a Proposition 84 grant will also be presented.