- Water Quality Program
- Swim Beach Water Quality Monitoring Program
- Current Swim Beach Water Quality Conditions
The East Bay Regional Park District's goal is to protect public health by monitoring swim beaches. The District's pool facilities are treated with chlorine to control potentially harmful bacteria that may be present in the water. In natural, un-chlorinated water bodies (Examples: ponds, lakes, and San Francisco Bay), bacteria levels can change over time, so Water Management takes samples on a weekly basis from April to October to evaluate water quality conditions at public swim areas. Using the California Department of Public Health's "Draft Guidance for Salt Water Beaches and Draft Guidance for Fresh Water Beaches, East Bay Parks collaborates with both Contra Costa and Alameda County Departments of Environmental Health to inform the public about current conditions and safe recreation choices. We regularly post up-to-date data and information on water quality at natural swim areas.
Possibly thousands of bacteria are present in un-chlorinated swim water at any time, some more harmful to human health than others. It is not possible to test water samples for all types of harmful bacteria, so health professionals focus on a few "indicator" bacteria that are typically found with harmful bacteria. In California, water quality agencies use four indicator bacteria categories: the total number of coliform bacteria colonies per sample, fecal coliform bacteria, Enterococcus and E. coli. If bacteria levels at swim areas exceed state standards for these bacteria, swimming could pose increased risks to human health.
New signs at swim areas represent current water quality conditions with a traffic signal. A green light means that our indicator bacteria test results are below the maximum levels and meet state standards. A yellow light means that one or more of any of the indicator bacteria at that location is above the daily maximum level and exceeds state standards. A red light means that the beach is closed due to a water quality emergency. For your safety and the safety of others, do not enter the water if the beach is closed.
Swim Beach Data will remain posted at our fresh water lakes along with these new traffic signal signs for your information and convenience.
To have a fun and safe experience swimming in the parks, we encourage you to follow a few simple rules:
- Do not swim in lakes or bay for 3 days after a rainstorm
- Pay attention to the lifeguards and water quality information
- After you leave the water, shower and towel dry as soon as possible
- Keep lake and bay water out of your mouth