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Water Facts
• What is a Domestic Well?
• Additional Water Wells Affecting Existing Wells
• Testing and protection of private water supplies
Information in this section was found at The Groundwater Foundation, at Colorado Division of Water Resources, in EPA’s "Manual of Individual Water Supply Systems," and the United States Geologic Survey (USGS) > Sustainability of Ground-Water Resources.
Additional information on water well permits can be found at Well Permit Applications.
Basically, a domestic well is a hole drilled into an aquifer. A pipe and a pump are used to pull water out of the ground, and a screen filters out unwanted particles that could clog the pipe. Wells come in different shapes and sizes, depending on the type of material the well is drilled into and how much water is being pumped out.
In Colorado, law requires that every new well in the state, that diverts groundwater, must have a well permit. In order to obtain a permit, a person must file an application for approval of a permit with the state engineer. Over 10,000 applications are submitted for review annually and the staff determines the amount of water available and analyzes the potential for injury to other existing water rights under strict statutory guidelines.
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Pumping ground water from a well always causes (1) a decline in ground-water levels at and near the well, and (2) a diversion to the pumping well of ground water that was moving slowly to its natural, possibly distant, area of discharge. Pumping of a single well typically has a local effect on the ground-water-flow system. Pumping of many wells (sometimes hundreds or thousands of wells) in large areas can have regionally significant effects on ground-water systems.
Over a period of time, wells may fail to produce for any of these main causes:
- Failure of wear of the pump
- Declining water level
- Plugged or corroded screens
- Accumulation of sand or sediments in the well.
- Proper analysis of the cause necessitates measuring the water level before, during and after pumping.
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Information in this section was found at the EPA's Private Wells web page, additional information can be found at the Colorado Department of Public Health and Environment or phone 303-692-3500.
Additional information on water quality can be found at Colorado Water Knowledge
You should test private water supplies annually for nitrate and coliform bacteria to detect contamination problems early. Test them more frequently and for more potential contaminants, such as radon or pesticides, if you suspect a problem.
If you use a private laboratory to conduct the testing, nitrate and bacteria samples will typically cost between $10 and $20 to complete. Testing for other contaminants will be more expensive. For example, testing for pesticides or organic chemicals may cost from several hundred to several thousand dollars.
Many laboratories are available to test water quality. EPA does not test individual homes, and cannot recommend specific labs to test your drinking water, but states certify water-testing labs. You may call your State Certification Officer to get a list of certified water testing labs in your state. Some local health departments also test private water for free. Phone numbers for your local, county, or state health department are available under the "health" or "government" listings in your phone book.
San Juan Basin Health Department has water-testing information. Call (970) 247-5702 for information.
Most laboratories mail back the sample results within days or several weeks. If a contaminant is detected, the results will include the concentration of the contaminant and an indication of whether this concentration exceeds a drinking water quality standard. If a standard is exceeded in your sample, retest the water supply immediately and contact your public health department for assistance. Some problems can be handled quickly. For example, high bacteria concentrations can sometimes be controlled by disinfecting a well. Filters or other on-site treatment processes may also remove some contaminants. Other problems may require a new source of water, or a new, deeper well. If serious problems persist, you may need to rely on bottled water until a new water source can be obtained.
San Juan Basin Health Department has instructions for "Disinfection of Water Supply Well." This information is available at 281 Sawyer Drive, Durango, CO
You can protect your water supply by carefully managing activities near the water source. For households using a domestic well, this includes keeping contaminants away from sinkholes and the well itself. Hazardous chemicals also should be kept out of septic systems.
Periodically inspect exposed parts of the well for problems such as:
- Cracked, corroded, or damaged well casing.
- Broken or missing well cap.
- Settling and cracking of surface seals.
- Slope the area around the well to drain surface runoff away from the well.
- Install a well cap or sanitary seal to prevent unauthorized use of, or entry into, the well.
- Disinfect drinking water wells at least once per year with bleach or hypochlorite granules, according to the manufacturer's directions.
- Have the well tested once a year for coliform bacteria, nitrates, and other constituents of concern.
- Keep accurate records of any well maintenance, such as disinfection or sediment removal that may require the use of chemicals in the well.
- Hire a certified well driller for any new well construction, modification, or abandonment and closure.
- Avoid mixing or using pesticides, fertilizers, herbicides, degreasers, fuels, and other pollutants near the well.
- Do not dispose of wastes in dry wells or in abandoned wells.
- Do not cut off the well casing below the land surface.
- Pump and inspect septic systems as often as recommended by your local health department.
- Never dispose of hazardous materials in a septic system.
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