Heal the Bay, the authors of the Stormwater Report, analyzed data from 12 watershed management groups collected between December 2012 and December 2018.

The non-profit environmental advocacy organization found there are 208 bodies of water in Los Angeles County identified as “impaired” by the California State Water Resources Control Board. This means they contain pollutants such as bacteria, heavy metals, nutrients, pesticides and trash.

The report stated stormwater runoff “poses a serious risk to public and environmental health.” The annual cost of gastrointestinal illnesses caused after people come in contact with polluted ocean waters in the region is between $14 and $35 million.

Heal the Bay said the respective groups tasked with dealing with issues caused by stormwater in the region have made only around 9 percent progress in meeting their goals. That’s despite some having deadlines of 2021, and “nearly 30 years to address stormwater pollution,” the organization said in a statement.

The municipalities’ deadlines range from 2021 to 2037. But if current trends continue, they won’t meet their total collective goal until 2082, Heal the Bay found.

It stated: “Many local cities are drastically behind, resulting in continued poor water quality across our region.”

Stormwater is where precipitation, such as rain or snowmelt, runs over the land. In the natural environment, this is mostly soaked up by soil, runs it other bodies of water, or evaporates. But in an urban setting, like Los Angeles, the water flows off surfaces like roofs and lawns, spreading pollutants into natural bodies of water as it goes.

According to Heal the Bay, stormwater is the greatest source of pollution in the ocean, rivers and lakes of Los Angeles County. The sewage and storm drain systems in the area are separate, meaning while the former is sent to be cleaned before it is released, stormwater runs through streets and storm drains, and out into the water.

The pollutants “pose serious risks to public and environmental health,” Heal the Bay stated. As a result, water quality is “much worse” in the 72 hours after significant rainfall in the region.

Heal the Bay partly pinned the problem on a lack of transparent reporting requirements and processes, meaning the public “who are directly impacted by polluted waters” don’t have access to information on the issue.

Annelisa Moe, water quality scientist at Heal the Bay and lead author of the Stormwater Report said in a statement: “Stormwater has the potential to be a wonderful resource for water supply, recreation, and so much more.

“But right now, it is more of a hazard polluting our waterways. We need to step up cleanup efforts if we are to see water quality improvements in our lifetimes. We should not have to wait 60 years for clean water.”

Moe told The Guardian: “Our beaches are a destination for people from all over the world.

“While we’re allowing contaminated water to flow to these beaches, we’re endangering every person visiting.”

Moe told the outlet: “We need to be very careful about when and where we enter the water.

“We can have a huge storm, and then the next day it can be sunny, 85 F [29 C] and gorgeous. If you don’t wait to swim … you’re at risk.”

The group argued the county’s current permit for regulating stormwater pollution has “failed” to spur improvements to water quality. It is due for renewal in 2020, but Heal the Bay said environmental groups worry it “will be further weakened and compliance deadlines extended.”

But the non-profit found a glimmer of hope in a new funding a program due to be allocated throughout the county next spring. This will boost stormwater funding projects by around $280 million per year, more than doubling the amount spent by municipalities on solving issues.

The County of Los Angeles did not immediately respond to a request for comment from Newsweek.