Water Pollution

The ocean provides so much for us – food, medicine and much of the oxygen we breathe. Today, the ocean is facing grave threats from pollutants that enter the ocean and not only harm marine life but also directly impact humans.

Take Action Against Water Pollution

Stewardship of Ocean Life Begins Onshore

You have the power to turn the tide and make everyday changes that will help prevent pollutants and trash from reaching our ocean.

  • Keep trash and chemicals out of storm drains. This includes pet waste. Storm water from storm drains flows into the sea carrying pollutants which can lead to beach closures.
  • Plant a native plant garden. Native plants can help you reduce the use of water and fertilizers.
  • Plant an organic garden. Pesticides from lawns and gardens can wash into the ocean and contribute to water quality issues.
  • Make your own mulch by composting and use organic fertilizer only when needed.
  • Recycle used motor oil. Don’t let motor oil spill on the ground because rain will wash it into the storm-water drains, and from there out to sea, where it can harm or kill marine life. Find an oil-recycling center near you.
  • Dispose of household cleaners properly. Household cleaning products, paint, pesticides, fluorescent light bulbs, and batteries pose a threat to water quality. Find more information about free collection centers.
  • Click here for more ways you can take action against water pollution.

Where Does Pollution Come From?

Point Source Pollution

Pollution can come from point sources, or a single identifiable source, such as factories or wastewater treatment facilities. Factories, including oil refineries, and electronic manufacturers typically release one or more pollutants into water they discharge (called effluents). Some factories discharge their effluents directly into a water body. Others treat it themselves before it is released, and still others send waste to sewage treatment plants for handling. Sewage treatment plants treat human wastes and send the treated effluent to a stream or river and ultimately the ocean.

Visit the U.S. Environmental Protection Agency’s (USEPA) EnviroFacts website to find the facilities near your home. USEPA’s EnviroMapper is an interactive map with the locations of these facilities. In California, the State and Regional Water Resources Control Boards (State Water Boards) regulate the effluents directly into a waterbody (streams, rivers, lakes, reservoirs, and ocean). For more information about water quality monitoring data and assessment information see the State Water Board’s My Water Quality Portal

Non-point Source Pollution

Non-point source pollution (as know as polluted runoff) is the primary source of pollution in California’s ocean. When it rains, when you water your lawn or wash your car, water picks up pollutants and carries them into our storm drains. Unlike the sewer system, most cities do not have treatment plants, or even filters, for this runoff. As a result, the pollutants found on streets, parking lots, buildings, yards and golf courses ultimately enter creeks and rivers, and eventually flow directly into the ocean. The kinds of pollutants found in runoff include motor oil, trash, pet waste, fertilizers, pesticides and dirt. These pollutants harm marine life, endanger human health and lead to costly beach closures.

The four non-point sources of pollution to the coastal ocean: domestic, industrial, agricultural, and marine. Image courtesy of NOAA Ocean Explorer


Oil spills may cause enormous damage to the marine environment and species, human health, coastal tourism, fishing industry, and recreational opportunities. For example, the April 2010 Deepwater Horizon oil spill was the largest accidental marine oil spill, with a release of upwards to 4.9 million barrels. The spill area affected 8,332 species, including more than 1,200 fish, 200 birds, 1,400 mollusks, 1,500 crustaceans, 4 sea turtles and 29 marine mammals. Despite the impacts of oil spill, they are responsible for only approximately 12 percent of the oil entering the ocean each year. According to a study by the U.S. National Research Council, three times this amount (36%) of oil enters the ocean as polluted runoff from our streets and parking lots.

Contaminants of Emerging Concern (CECs)

Contaminants of Emerging Concern (CECs) are a diverse group of chemicals that enter the marine environment through both point and non-point sources. CECs are used industrially, as well as for pesticides, pharmaceuticals, personal care products, and food additives. These contaminants are of emerging concern because they are commonly found in the marine environment and have possible negative environmental and biological implications, yet most have no current regulation for their uses. The State Water Resources Control Board is working with the Southern California Coastal Water Research Project (SCCWRP) to address the issues with CECs through a Science Advisory Panel. See SCCWRP’s CEC Factsheet.

What are the Effects of Water Pollution?

Beach Closures

Have you ever gone to your favorite beach and found that it has been closed due to high bacteria levels? Pathogens (disease-causing viruses and bacteria) originating from human or animal waste can enter the ocean from polluted runoff and accidental releases from sewage treatment facilities, ranches and farms. Runoff from urban areas or discharges from improperly maintained sanitary systems on boats also are sources of harmful viruses and bacteria. Humans aren’t the only ones at risk from bacteria in the ocean. For example, the population of southern sea otters is threatened by a parasitic pathogen, called Toxoplasma gondii, which is hosted by cats and is spread through their feces. Once established, the parasite causes brain damage and often death in marine species.

Harmful Algal Blooms

Phytoplankton are microscopic single-celled organisms that exist at the base of food chain in most freshwater and marine ecosystems. The oxygen for every other breath we take comes from the products of marine phytoplankton photosynthesis!

Phytoplankton – Image courtesy Sally Bensusen, NASA EOS Project Science Office.

When there is an oversupply of nutrients and ideal physical conditions, phytoplankton can form algal blooms. An algal bloom which threatens or damages the environment, human health or surrounding economies is considered a Harmful Algal Bloom, or HAB. Algal blooms can occur naturally or can be triggered by pollution. In California, the HAB groups of greatest concern are Pseudo-nitzschia, Alexandrium, Heterosigma, and Microcystis. Certain species can produces toxins that are harmful to human and marine mammals which include domoic acid, paralytic shellfish poisoning, and cyanotoxins.

The California Department of Public Health coordinates a routine monitoring program along the California coast to sample mussels and other shellfish like clams and scallops for the presence of Paralytic Shellfish Poisoning and domoic acid toxins. Commercial shellfish harvesters are also required to provide weekly shellfish samples to CDPH for Paralytic Shellfish Poisoning toxin assay and domoic acid analysis. If toxin levels are high enough, warnings and quarantines are issued to protect the recreational fishing public and shellfish consumers.

Mercury in Seafood

Ocean pollution can also come from airborne sources. Coal-fired power plants and chlorine factories release mercury into the air, which eventually settles into the ocean. Mercury is a neurotoxin that can cause damage to the brain and nervous system. Mercury enters the systems of marine organisms and bioaccumulates, or increases, as larger fish eat smaller fish contaminated with mercury. Top predators in the ocean, such as swordfish and tuna, often have the highest concentrations of mercury. For this reason, doctors recommend limiting the consumption of some types of fish and shellfish. For more information on which fish and shellfish to avoid, consult the Monterey Bay Aquariums Seafood Guide or the U.S. EPA’s website.

What is the State of California Doing?

Water Quality

Rain Gardens are a form of LID.
Image: Jefferson County Department of Health.

The State Water Resources Control Board (Water Board) is responsible for the protection of the quality of the ocean water for the enjoyment of residents, businesses, and tourists. The State Water Board regulates the discharge of treated water, including the ocean and beaches.

Low Impact Development (LID) is a strategy to use permeable surfaces, such as green roofs and bioswales, to reduce the amount of polluted runoff that enters storm drains. In May 2008, the California Ocean Protection Council (OPC), passed a resolution to support the use of LID strategies.

Clean Beaches

California has some of the most popular beaches in the country and therefore, keeping it’s beaches healthy is a top priority for the State. California beaches are visited by tourists and residents about 150 million times a year to swim, wade, surf, and dive. Beach visitors spend over $14 billion each year in California. Therefore, California has the most extensive and comprehensive monitoring and regulatory program for beaches in the nation.

California has invested $100 million in Clean Beach Initiative grants to fund local projects that reduce bacterial contamination along the coast. The State has also funded research to development more rapid detection methods for knowing when to post beaches, tracking the sources of contamination, and studies to better understand the relationship between bacterial indicators and incidence of disease.

Watch this video to learn more about the Clean Beach Initiative

For a comprehensive analysis of beach water quality in California see Heal the Bay’s Beach Report Card that grades 500 beaches a week based on the previous 30 days of monitoring results. Check back often for the latest grades!

Areas of Special Biological Significance

In an effort to preserve biologically unique and sensitive marine ecosystems for future generations, California has designated thirty-four coastal areas as Areas of Special Biological Significance (ASBS). These ASBS were established in the 1970s, and they cover roughly 500 miles (32 %) of state shorelines (mainland and Channel Islands). The California Ocean Plan requires protection of the species and biological communities from undesirable alteration in natural water quality in an ASBS through the prohibition of waste discharge. An ASBS is part of California’s network of Marine Managed Areas. For more information about Areas of Special Biological Significance, see the State Water Board’s website.

Watch this video for more information about Areas of Special Biological Significance

What is the Federal Government Doing?

The White House’s National Ocean Council is currently finalizing a National Ocean Policy Implementation Plan to “address some of the most pressing challenges facing the ocean, our coasts, and the Great Lakes”. This plan includes several actions to reduce the impacts of point and non-point sources of nutrient pollution, such as reducing rural and urban sources of excessive nutrients, sediments, toxics, and pathogens, minimizing impacts of hypoxia and HABs, and addressing the threats caused by toxic chemicals and land-use practices.

The US Environmental Protection Agency’s Office of Water operates under a number of federal mandates to prevent water pollution and enact measures to improve water quality, including the Clean Water Act, the Marine Protection, Research, and Sanctuaries Act, the Beaches Environmental Assessment and Coastal Health Act, and the Coastal Zone Management Act, among others. Some of the programs developed by the US EPA to satisfy these mandates include Green Infrastructure/Low Impact Development, a pollution discharge permit program, a storm water program and the wastewater management office.

For more information:

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