Lagoon Water Quality and Testing
For immediate release: June 30, 2021
Contact: Dante Hall, Acting Director of Public Works, dhall@fostercity.org, 650-286-3214
Heal the Bay released its “Beach Bummers” list Tuesday, June 29, and three of the state’s top ten polluted beaches identified are in Foster City (Erckenbrack Park - No. 2, Gull Park - No. 4, and Marlin Park - No. 8) and part of our City’s enclosed lagoon network. Each year, Heal the Bay distributes an annual water quality report card grading 500 California beaches “A” through “F.” This was similar to the list published by Heal the Bay last year, when some Foster City beaches also made the list.
In February 2021, the City hired Environmental and Public Health Engineering (EOA) to investigate the source of bacteria detected in our Lagoon and confirm sample results collected by the County Department of Environmental Health Services (EHS). As part of the scope of work, EOA will recommend strategies to control elevated levels of Enterococci (or E. coli). E. coli is the sole indicator now used by the State Water Resources Control Board threshold to protect recreational uses from the effects of pathogens in brackish and marine waters.
The contract with EOA calls for 12 samples to be collected every other week from March 2021 through August 2021. This schedule intentionally includes the end of the wet season, the possibility of storm events occurring during or before sampling and extends through much of the summer season. The samples are also being evaluated for DNA source markers to determine whether the source of the bacteria is from a human, dog, goose, or seagull.
Initial monitoring results revealed two of the six samples collected to date had E. coli levels near or above the State's threshold. No human DNA source markers were detected in any of the samples. Based on these results, it is unlikely that human waste from sewer leakage or other sources is present in our lagoon system. In contrast, goose and seagull DNA markers were detected in some of the samples.
“While human waste could contribute enterococci and other FIB to the Lagoon, there are many other sources of FIB, including wildlife and pets. These other sources of fecal material generally pose less of a threat to the health of swimmers compared to human waste,” said Managing Scientist Bonnie de Berry, Certified Professional in Stormwater Quality from Environmental and Public Health Engineering (EOA),
The City will continue to collect samples approximately every other week throughout the summer recreation season and further evaluate the need for future control measures to protect beach water quality.
###
