Reducing Water Runoff and Bacteria Levels to Improve South OC Water Quality


In a presentation at the California Stormwater Quality Association (CASQA) quarterly meeting on July 15, 2021, the OC Stormwater Program shared how data from a number of sources is enabling the measurement of dry weather bacteria load reduction as a result of structural and non-structural (source control) strategies in South Orange County (compared to a baseline period of 2003-2007). In most receiving waters, the reduction in bacteria loading is estimated to be >90%. This is great news for south Orange County beaches - just check the 2020-2021 Heal the Bay Beach Report Card for proof.
The real story behind these numbers is how partnerships between the municipalities of south Orange County, water/wastewater agencies, transportation agencies, and watershed/water quality stakeholders, have made this progress possible. For example, water use efficiency strategies promoted by water agencies have contributed to a reduction in dry weather runoff (referred to as “urban drool”) measured at >70% in some areas (compared to the 2003-2007 baseline years). See the following website for more information on these and other efforts to improve water quality in south Orange County: