California’s Water Quality 2021 – What’s the Top Water Problems in Major Cities of CA

California hosts over 40 million residents who all require some form of clean drinking water. The number of Californians is expected to rise to near 45 million in another decade.

This presents quite a task, given the state’s notoriety for lengthy periods of drought. Climate experts expect a dip in average annual rainfall, adding the the potential challenges to the future of the California water supply.

Shortage is not the issue at hand, however. The state is quite large and most sources of water travel very far from the main branch, through tributaries, into reservoirs and on to the final municipal water treatment facility.

Along the way, the water often absorbs minerals and chemicals. Areas of agricultural influence are vast and often contribute to chemical water pollution. Californian water is known to contain lots of chlorine and high levels of arsenic in some cases (typically found in private wells).

Common Water Problems by City

California is a large state with municipalities spread quite far apart. This adds variety to the issues each city’s water source deals with. In some areas, there are different problems depending on which part of town you live.


Water Source(s)

Common Problems

Typical Symptoms

Los Angeles

Eastern Sierra Range

San Fernando Basin

Colorado and Feather River Supplies

Hard Water


Itchy Skin

Damage to Clothing

San Diego

Colorado River

Sierra Nevada

Lakes and Surface Water

High Minerality

Hard Water

​Bitter Taste

Appliance Damage

Dry, Brittle Hair

San Jose

Santa Clara Basin

Santa Cruz Mountains Runoff

Chromium 6

Could Be Toxic

San Francisco

Sierra Nevada Runoff

High in Chlorine

High in Iron

Dry Skin

Itchy Clothing

Bitter Taste


Primarily Rivers

Ground Water

​High in Chlorine

High in Ammonia

Weakened Immune System

Rough Clothing

​Damaged Cooling Units

Los Angeles

With so many residents, Los Angeles sources its water from a variety of suppliers. The size of the area dictates a vast network of filtration and distribution sites.

With such a complex treatment program, Los Angeles residents find themselves with water that is often hard. While it sounds like a simple inconvenience, hard water can cause major issues.

It can build up and cause clogs, negatively impact appliances that use the water, and leave clothes washed in the water yellowed and stiff.

San Diego

San Diego also has several water sources including the Colorado River and Sierra Nevada runoff. The water travels through canals and streams to find its way to one of the three treatment facilities the city uses.

The water in San Diego often features a high concentration of various minerals. Even treated water, which is generally safe to use, can have a bitter taste that is impossible to ignore.

San Jose

Notably, tests have shown that the San Jose water supply contains higher than usual counts of Chromium 6. Known as a toxic metal that can cause cancer to those exposed to it, the impacts of drinking water contaminated with the substance is unknown.

San Francisco

The San Francisco water supply comes almost entirely from the Sierra Nevada runoff. This water flows to one of four water treatment facilities owned by the public works department in San Francisco.

Part of the filtration process releases iron and chlorine, which are quickly absorbed by the water. Problems can range from bitter tasting water to impacts on skin like dryness or itchiness.


With so many rivers flowing in and around the city, almost 85% of the water used by its residents is from these rivers. Two big reservoirs hold water before it is transported for treatment at one of the two plants servicing the city.

The relatively pure water is hardened by the presence of the chlorine and ammonia absorbed during filtration. High levels of chlorine can have an effect on the balance of bacteria in your gut, leading to issues with the immune system.