Well Water Testing in Boulder County

Private Wells Should Be Tested Annually

The U.S. Environmental Protection Agency (EPA) recommends testing private wells annually. Without testing, the water quality is unknown, and it could be contaminated with naturally occurring or other contaminants.

Health Impacts of Water Contaminants

A variety of bacteria, parasites, and viruses can potentially cause Well Water Quality problems if humans ingest them. Testing water for each of these would be difficult and expensive. Instead, water testing for total coliform levels serves as an indicator of contamination.

Coliform bacteria can enter well water through various means, including sewage overflows, damaged or malfunctioning sewage systems, polluted stormwater runoff, and agricultural runoff. Private wells may become more vulnerable to such contamination after flooding or fires, particularly if they are shallow, have been dug or bored, or have been submerged by floodwater for long periods of time.

Water Testing Services

• Colorado Department of Public Health and Environment Laboratory provides standard bacteriological, chemical, oil, volatile compounds, and mining waste testing
• Colorado State University Soil and Water Laboratory provides mineral and metals testing. Cost is dependent on testing requested.
• Private Labs
  • Each of the private labs listed below provides bacterial testing. Contact them directly to learn about the testing available, costs, and procedures. Special containers or requirements may be required.

Shock Chlorination

Well water can be contaminated with bacteria from many sources. The most common include repairing the pump or casing without follow-up chlorination, surface water entering the pump or casing, poor construction of the well, or leaks in the well or well casing.

Shock chlorination of a well may eliminate bacterial contamination, but well rehabilitation may be necessary if contamination continues to occur (as in a rusted or leaking casing). If you plan to shock chlorinate your well yourself, follow instructions carefully to ensure bacteria is eliminated.

Learn More

• Testing Your Well
• How to Keep Your Water Well guide for well owners