California Water Quality Directory
Find detailed information about water quality in cities and ZIP codes across California. Discover which contaminants might be present and understand how they compare to EPA and recommended limits.
Cities starting with "D"
Daggett
Daly City
Dana Point
Danville
Darwin
Davenport
Davis
Davis Creek
Death Valley
Deer Park
Del Mar
Del Rey
Delano
Delhi
Denair
Descanso
Desert Center
Desert Hot Springs
Diablo
Diamond Bar
Diamond Springs
Dillon Beach
Dinuba
Discovery Bay
Dixon
Dobbins
Dorris
Dos Palos
Dos Rios
Douglas City
Downey
Downieville
Doyle
Drytown
Duarte
Dublin
Ducor
Dulzura
Duncans Mills
Dunlap
Dunnigan
Dunsmuir
Durham
Dutch Flat
About Water Quality
Water quality is a measure of the suitability of water for a particular use based on selected physical, chemical, and biological characteristics. In California, water quality can vary significantly by location, affected by factors such as:
Understanding Contaminants
Water contaminants include a wide range of substances from natural minerals to industrial chemicals. Some have health implications, while others affect taste, odor, or appearance of water.
EPA Standards
The Environmental Protection Agency (EPA) sets legal limits for contaminants in drinking water. These standards protect public health by limiting the levels of contaminants allowed.
Health Guidelines
Beyond EPA limits, there are often stricter health-based guidelines recommended by scientists and health organizations for optimal water quality.
Common Contaminants
Common water contaminants in California include arsenic, lead, nitrates, bacteria, pesticides, and industrial chemicals that can vary by region.