SLO County beach is among most bacteria-ridden spots in the US. See the list
San Luis Obispo County is home to one of the most bacteria-ridden beaches in the country, according to the Surfrider Foundation.
The nonprofit environmental organization recently released its 2024 Clean Water Report to “build awareness of issues that affect water quality and your health at the beach.”
The report, published May 20, pinpoints 10 beaches across the United States and Puerto Rico where high bacteria levels consistently exceed state health standards and could put public health at risk.
In 2024, the Surfrider Foundation tested more than 600 sites across the nation, with 80% of samples yielding “at least one high bacteria result that exceeded state health standards,” according to the report.
A total of three California beaches landed on Surfrider’s list of 2024 Beach Bacteria Hot Spots, including sandy spots in San Diego and Pacifica, according to the report.
“The ultimate goal is to use (Surfrider Foundation’s) Blue Water Task Force data to find and fix the sources of pollution and prioritize local efforts to restore clean water locally,” the nonprofit said in the report.
Which SLO County beach has high bacteria levels?
The San Luis Creek mouth in Avila Beach had the ninth-highest levels of bacteria in the United States and Puerto Rico, according to the Surfrider Foundation.
“This is concerning because families often set up their beach blankets at the mouth of this creek to let their children play in its relatively calm, shallow water,” the report said.
It is the third consecutive year the mouth of San Luis Creek has been named a bacteria hotspot by the Surfrider Foundation.
In 2024, 38% of tests at the sampling site came back positive for high bacteria levels, according to the nonprofit.
“That means more than one in every three samples collected fail to meet safe swimming standards at this popular spot for children to play, paddle and splash around in the water,” the Surfrider Foundation said.
The water quality tests revealed that waste from a “warm-blooded animal (or a human)” was in the water. However, the surveys did not differentiate between species.
More testing was being completed to determine the specific sources of pollution in the creek so that the issue can be resolved, the Surfrider Foundation said.
Where are most polluted beaches in US?
According to the Surfrider Foundation, these were the 10 most polluted beaches in the United States and Puerto Rico, based on the percentage of samples that tested high for bacteria in 2024:
- Windmill Beach in Sag Harbor, New York: 43% of water samples
- Ballard Park in Melbourne Florida: 52%
- Park View Kayak Launch in Miami Beach, Florida: 90%
- Playa Crashboat in Aguadilla, Puerto Rico: 23%
- South Sound Thea Foss Floating Dock in Tacoma, Washington: 64%
- Linda Mar Beach in Pacifica: 71%
- San Luis Creek Mouth in Avila Beach: 38%
- Imperial Beach in San Diego: 82%
Kahalu’u in Oahu, Hawaii: 92%
Waikomo Stream at Koloa Landing in Kauai, Hawaii: 90%
How were ocean waters tested for safety?
A total of 60 Blue Water Task Force labs processed 10,120 water samples collected from 604 distinct sampling sites in 2024, the Surfrider Foundation said.
Of those sampling sites, 483 yielded at least one high bacteria result that exceeded state health standards, the foundation said.
“This shows the importance of regular water quality monitoring at the beach to protect public health and safe recreation,” the Surfrider Foundation said.
This story was originally published May 28, 2025 at 10:45 AM.
