Many people know they shouldn’t surf after a significant rain event, but few are aware that severe health risks include flesh-eating bacterial infections.

Surfrider Foundation CEO Chad Nelsen says this is a rare ‘worst case’ scenario, but can occur and so can a whole host of less serious infections and illnesses, which is why the organization is on a mission to address the dangers posed by polluted runoff.

They are tackling the problem on several fronts — by monitoring water quality, spreading awareness of health risks, sharing actions individuals can take to reduce runoff, and advocating for clean water policies at a local, state, and federal level.

“One of the things that is particularly dangerous about surfing or swimming after it rains in Southern California, is it rains pretty infrequently so we get a huge buildup of different toxins and pathogens,” said Nelsen. “Then, when it does rain, that toxic cocktail washes off our streets and yards into the storm drains and out to the ocean.

This run-off carries pesticides, herbicides, heavy metals, plastics, and fecal matter that contain multiple disease causing organisms. These pathogens can cause eye, nose, and throat infections; skin rashes; fevers; upper respiratory illness; gastrointestinal illnesses; and yes, even flesh-eating streptococcus infections.

Up to 1.5 million people get sick annually from swimming in polluted beaches in Los Angeles and Orange Counties alone, with a public health cost of up to $50 million, according to a UCLA and Stanford University study.

“One significant thing unique to surfing after a rain is that surfers are completely immersed in the water so it gets in their eyes, ears, nose and through and also often their sinuses — thus the dreaded post surf nose drip!” said Nelsen.

To minimize risks Nelsen advises all ocean goers follow the “72 hour rule” and wait three days before entering the ocean after significant rainfall. Studies from the Surfrider Foundation have shown that health risks decrease by approximately 50 percent each day following a rainstorm, as the saltwater and sunshine kill bacteria.

Run-off issues are particularly pernicious in LA, both because there is a large pollution producing population and because there are many impermeable surfaces.

“Urbanized Los Angeles is around 90% impervious, so rain never has a chance to absorb or hit anything natural; it travels on man made surfaces from the second it falls out of the sky until it drains into the ocean,” said Nelsen.

Just one inch of rainfall in LA can create up to 8 billion gallons of polluted runoff, according to data from the US Geologic Survey.

Fortunately, there are many solutions that help direct water into the earth instead of the ocean.

Santa Monica is already a leader in this regard, and requires people to design their roofs and gutters to direct water flow into their yard where the ground naturally absorbs it.

This is part of a growing “green infrastructure” trend being implemented across California. Other solutions include vegetative swales in between the sidewalk and street and the use of decomposed gravel in the place of pavement.

There are also many steps individuals can take to mitigate run-off pollution, which can be as simple as remembering to pick up dog poop or as complex as redoing garden landscaping with native plants. Nelsen said people can learn more about these strategies by visiting

The Foundation also encourages people to get involved in its advocacy efforts as it pushes clean water and pollution reduction legislation on a national scale. On Monday Surfrider is hosting a ‘Virtual Ocean Recreation DC Hill Day’, pressuring federal leaders to enact policies to protect our coasts and oceans.

Nelsen said people who are interested in helping out should visit and sign their petition calling on congress to allocate $10 billion annually for 10 years to the EPA’s Clean Water State Revolving Fund. He also encouraged all Angelenos to get involved with the Surfrider LA chapter by visiting