Tuolumne County Profile - Community Indicators Project
Tuolumne County Profile Executive Summary Tuolumne County Profile Introduction Health and Safety Education and the Arts Natural Resources and Recreation Economy and Infrastructure Acknowledgements Conclusion
Natural Resources and Recreation - Tuolumne County Profile
Natural Resources and Recreation

Water Quality

Why is this important?

High quality drinking water is essential to human health. Contaminated water can cause disease, birth defects, infant mortality, and increased cancer rates. Our drinking water originates from rivers, lakes, streams, reservoirs, springs, and groundwater wells, with most of the surface water transported through man-made earthen ditches.

What is the measure?

Drinking water quality is measured by levels of biological and chemical contaminates as reported per the two major water districts.

Maximum Contamination Levels (MCL), or drinking water standards, are limits of chemical contaminates allowed in drinking water. More stringent than MCL’s, Action Levels (AL) are levels at which water managers must cut off any source of water leading to drinking water use until remedial steps have been taken.

Bacteria and other biological contaminates are used as indicators for waterborne illnesses. These include viruses, bacteria, and protozoa that may come from sewage treatment plants, septic systems, agricultural livestock operations, and wildlife.

How are we doing?

Based on the current water quality standards and using the two largest water suppliers’ tests, our drinking water is essentially pollutant free.

The 2003 water quality reports for the Tuolumne Utilities District (TUD) show that TUD met standards for all but two of the 18 tested contaminates. TUD did not meet the standards for iron & manganese. Groveland Communities Services District (GCSD) met all standards in 2003.

Tuolumne County - Central Sierra Mountains