Program Information
Natural Water Recreational Swim Areas (bay, beach, lake, pond)
Alameda County Health, Environmental Health Department (ACEHD) has a collaborative partnership with East Bay Regional Park District to protect public health by monitoring and notifying the public about the water quality conditions at natural water recreational swim areas (lakes, ponds, San Francisco Bay). East Bay Regional Park District has a Water Management program that includes sampling of swim areas on a weekly basis from April to October to evaluate water quality conditions for public safety. Water sample testing is conducted at a state-certified laboratory. The California Department of Public Health sets the health standards for recreational beach water safety.
Alameda County Water Quality Results
Current water quality results at the swim beaches are available here.
In California, water quality agencies use indicator bacteria categories to determine if there is an increased risk to human health. There are four categories of indicator bacteria: the total number of coliform bacteria per water sample, fecal coliform bacteria, Enterococcus, and Escherichia coli. If these indicator bacteria exceed the State standards in a tested water sample, then signage is posted at those locations on the beach to notify the public. The signage uses a simple traffic signal approach which is:
- green = good
- yellow = caution
- red = stop/closed
Green meets State standards, yellow exceeds State standards on one of the indicator bacteria categories, and red indicates closure of the beach due to a water quality emergency. For your safety, please do not enter the water if the beach is closed to swimming.
Water quality conditions in natural recreational areas change constantly. There are a few simple rules to encourage a safe and healthy swimming experience:
- Do not swim in the San Francisco Bay or freshwater lakes for 3 days after a rainstorm due to wind, waves, tidal action, and storm runoff
- Pay attention to lifeguards and water quality signage and information
- After swimming, shower and towel dry as soon as possible
- Keep lake and bay water out of your mouth
- Plan regular restroom visits for children
- Wash hands with soap and warm water after swimming and before eating