When it rains in the Bay Area, stormwater floods into the Bay laden with three main types of pollution: industrial discharges, city runoff, and sewage spills. The water that washes over more than 1,600 industrial sites carries toxic chemicals into storm drains, which discharge into creeks and the Bay. And as rain flows wash over the streets, buildings, and parking lots of the Bay Area’s cities, pollutants flow down storm drains into creeks, rivers, and the Bay. Rain storms also often overwhelm the sewer pipes running under our streets, causing them to overflow and dump untreated wastewater into the Bay.
Stormwater runoff is a mix of anything and everything that builds up in cities and industrial facilities: trash, construction debris, automotive fluids, industrial waste, petroleum residue, coal dust, soot, pesticides, fertilizer—all of which mix together into a toxic brew that runs into the Bay every time it rains, usually with little to no treatment. Making matters worse, these pollution pulses often coincide with sewage spills into the Bay.
Storm water is the largest source of pollution to San Francisco Bay. When it rains, pollution like trash, oil, pesticides, fertilizers, household chemicals, and legacy toxic pollutants are washed into the Bay without being treated or filtered. Paved concrete and asphalt surfaces on roofs, driveways, streets, buildings, and parking lots send rainwater rushing into gutters and storm drains. This storm water – carrying all the pollution it collects along the way – then gets emptied into creeks and sloughs that flow into the Bay, or into the Bay itself.
Each pollutant can have a negative effect on the plants, animals, and people that depend on the Bay. Some examples include:
- Fertilizers contribute to growth of algae, which can be toxic to both humans and animals.
- Pesticides pollute many Bay Area creeks to the point they cannot support healthy fish populations.
- High levels of PCBs and mercury concentrations make many Bay fish unsafe to eat.
- Copper pollution causes salmon to lose their ability to find their spawning streams.
- Nickel is lethal to shorebirds.
- Oil and grease weaken the cardio vascular systems of fish and other animals.
- Bacteria and other pathogens can make waterways unsafe and cause illnesses from recreational activities like boating and swimming.
- Dirt from construction zones and eroded creeks clouds the water, destroying habitat and impeding healthy plant growth.
- Trash such as plastic bags and bottles clogs waterways and can suffocate and disable wildlife.
- Cigarette butts release microplastics laced with toxic chemicals that become lodged in the digestive tracts of seals, birds, and many sea creatures.
What is Baykeeper Doing to Stop Stormwater Pollution?
One of the main ways we’re working to stem the tide of toxic runoff is by investigating industrial facilities that release harmful contaminants like heavy metals, chemicals, and oil. During the rainy season, our field team documents and samples the runoff from industrial facilities suspected of releasing pollution into the Bay or one of its tributaries. When we catch an industrial polluter in the act, we take legal steps to hold them accountable, often resulting in a legally binding agreement to compel the facility to undergo a cleanup (see map, below, of our industrial cleanup cases).
The rest of the pollution that makes its way into the Bay via storm drains is the collective debris of urban life, which includes everything from cigarette butts to lawn fertilizers and motor oil. The responsibility to control this pollution lies with city governments. And in the case of highways, CalTrans should be controlling the pollution. Unfortunately, many Bay Area cities and regulatory agencies have failed spectacularly to prevent polluted runoff from ending up in the Bay. That's why Baykeeper is advocating for stronger regulations to make cities and state agencies tighten controls on trash and other common stormwater runoff pollutants.
We’re also enforcing those stronger regulations. In 2016, we won a $100 million settlement to overhaul San Jose’s stormwater system, historically one of the biggest contributors to trash and bacteria runoff pollution in the Bay. Their improvements include significant investments in green infrastructure, which utilizes natural elements to filter out pollutants from urban runoff, and better maintenance of their storm and sewer pipes to prevent pollution. We’re continuing to work with San Jose to help it serve as a model for other cities in the years to come.