San Mateo County’s Beach Monitoring Program

Allison Fang beach samplingKeeping You Safe One Week at a Time

San Mateo is lucky to be home to a variety of beautiful beaches and creeks, along both the Bayside and the Pacific Ocean, from the San Pedro Creek watershed emptying to Linda Mar Beach in the north, to Gazos Creek emptying into Gazos Beach in the south. We’re even world-famous with Maverick’s Surf Contest held (mostly) offshore from
Pillar Point Harbor.

While our beaches are a great place to swim, surf or just splash in the foam, they’re also a place where you could become sick through water contact if bacteria, like E. coli, are elevated and exceed State and Federal standards.

You can stay safe and enjoy the beaches, avoiding skin rashes or infections, headache, and flu-like symptoms, by paying attention to warning signs that San Mateo County Environmental Health Services post to alert you to avoid water contact at beaches that have exceeded bacteria standards.

We have your back to keep your health on track, protecting locals and visitors alike. Each week a combination of County staff and dedicated, trained volunteers sample the water at 40 swimming/surfing beaches and creek mouths around the County. Water is analyzed for various bacteria, and if bacteria levels are elevated, signs are posted, and the web page is updated to advise you to avoid any water contact.

20190319 Warning Sign_JennyG

Samples are collected every Monday morning, with results posted on by Wednesday each week. Signs are also posted at access points to monitored beaches and creeks mouths. However, regardless of our postings, you should be cautious by following these general rules:

• Avoid swimming in creek water in general, but especially when the creek is not flowing.
• Avoid ocean or creek water contact during and for three days following a rainfall.
• Don’t swim in ocean water within 100 feet of a creek      mouth entering the ocean.
• Avoid swimming in water that is frothy/foamy, off-colored (brown, reddish or
cloudy), or has an offensive odor.

Stay updated on when it’s safe to swim or surf by signing up for our beach water quality updates at

Interested in helping keep our surfers and swimmers safe?
Join the volunteer beach sampling team by contacting
Water Program Supervisor, Greg Smith at

Leave a Comment

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s