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 "M"
Macdoel
Mad River
Madeline
Madera
Madison
Magalia
Malibu
Mammoth Lakes
Manchester
Manhattan Beach
Manteca
Manton
March Air Reserve Base
Maricopa
Marina
Marina Del Rey
Mariposa
Markleeville
Marshall
Martinez
Marysville
Mather
Maxwell
Maywood
Mc Farland
Mc Kittrick
Mcarthur
Mcclellan
Mccloud
Mckinleyville
Meadow Valley
Meadow Vista
Mecca
Mendocino
Mendota
Menifee
Menlo Park
Mentone
Merced
Meridian
Mi Wuk Village
Middletown
Midpines
Midway City
Milford
Mill Creek
Mill Valley
Millbrae
Millville
Milpitas
Mineral
Mira Loma
Miramonte
Miranda
Mission Hills
Mission Viejo
Modesto
Mojave
Mokelumne Hill
Monrovia
Montague
Montara
Montclair
Monte Rio
Montebello
Monterey
Monterey Park
Montgomery Creek
Montrose
Moorpark
Moraga
Moreno Valley
Morgan Hill
Morongo Valley
Morro Bay
Moss Beach
Moss Landing
Mount Baldy
Mount Hamilton
Mount Hermon
Mount Laguna
Mount Shasta
Mountain Center
Mountain Ranch
Mountain View
Murphys
Murrieta
Myers 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.