Surface water sources, for example, can be contaminated by salts and organic carbon and a number of groundwater sources can be contaminated by nitrates and industrial chemicals.
In turn, water supplies can then be contaminated from these man-made and natural substances, including industrial wastes, pesticides, urban runoff and microscopic organisms [see also How is Drinking Water Treated?].
However, many consider the greatest threat to surface water to be nonpoint sources of pollution, such as runoff from agricultural fields and abandoned mines, and stormwater runoff from city streets and construction sites.
Stormwater is typically not treated before it is discharged, so it can contain a variety of contaminants such as pesticides, nitrates from fertilizers, pathogens from animal waste, and automotive and industrial chemicals. Stormwater is typically discharged to rivers, bays and the ocean.
Water Quality in California
Water quality in California is regulated by several state agencies, including the State Water Resources Control Board (State Water Board) and its nine regional boards – North Coast, San Francisco Bay, Central Coast, Los Angeles, Central Valley, Lahontan, Colorado River Basin, Santa Ana and San Diego – and the Department of Public Health.
The State Water Board enforces clean water laws and administers the Clean Water Grant Program, which funds construction of wastewater treatment facilities. The State Water Board also issues general permits for municipalities and construction sites that try to prevent contaminants from those sources from entering municipal storm sewers.
Water quality concerns are also often involved in disputes over water rights, particularly in situations involving endangered species or habitat.
Microplastics – plastic debris measuring less than 5 millimeters – are an increasing water quality concern. Entering the water as industrial microbeads or as larger plastic litter that degrade into small pellets, microplastics come from a variety of consumer products.
Microbeads are used as exfoliating agents cosmetic washes and large-scale cleaning processes. Microplastics are used pharmaceutically for efficient drug delivery and by textile companies to create artificial fibers. Part of their appeal to hygienic and medical interests is their tendency to absorb surrounding chemicals and later release them. This quality makes microplastics ideal as small commercial sponges, but especially dangerous as water contaminants, potentially carrying harmful chemicals through the food chain as they are ingested.
In 2015, Gov. Jerry Brown signed legislation banning the use of microbeads in personal care products beginning in 2020. A federal ban signed by President Obama in 2015 phases out microbeads from personal care products on July 1, 2017.
Drinking Water Quality
Drinking water standards and regulations are developed by federal and state agencies to protect public health. The federal Safe Drinking Water Act (SDWA) regulates drinking water quality on the national level. Due to the stringent drinking water quality standards in California, the U.S. Environmental Protection Agency allows the state to administer the SDWA.
In California, the Department of Public Health administered the SDWA until July 1, 2014, when the Drinking Water Program and the Environmental Laboratory Accreditation Program responsibilities moved from to the State Water Board.
In California, not all communities have access to safe drinking water. In isolated areas throughout the state, including many communities in the Central Valley, approximately 2 million Californians do not have access to safe drinking water.
With strict and increasing regulations on water quality, high costs of water system maintenance or lack of technical knowledge to apply for grant funding, many regions are at a loss in making substantial water quality and infrastructure improvements.