Drinking Water (Wells)
In some areas of Jefferson County, a substantial number of residential dwellings receive water from private wells. Although most well water is of good quality there are several contaminants, both naturally occurring and otherwise, which may affect the suitability of the water supply. The department recommends that well water be tested for certain contaminants.
Listed below is information on some of the more common contaminants which may be found in well water.
You're the Inspector
Unlike public water supplies which are continuously monitored, the responsibility for assuring a safe supply of water from private wells rests solely with the homeowner. In Colorado, there are no regulatory standards governing the quality of private water supplies. The maximum contaminant levels (MCLs) mentioned in this brochure relate to regulated public water supplies and are included for informational purposes only. These levels are set by the State and Federal governments and are based upon reasonable health impacts. Individual wells cannot be condemned by any governmental agency due to poor water quality.
Radiation is a natural component of many groundwater supplies in Jefferson County due to the presence of uranium deposits and other minerals. From a health standpoint, uranium and radium-226 are the most important contaminants. Long-term consumption of water containing concentrations of radiation that exceed the safe drinking water standards may result in significant health effects such as cancer and, if uranium is involved, possible kidney damage.
Gross alpha represents overall radioactivity and is used as a screening test for deciding which specific radioactive chemicals to analyze for. The MCL dose for gross alpha is 15 pCi/l (picocuries per liter). A picocurie is a unit of measurement used to determine the amount of radioactive material that is in the water sample. The MCL for radium 226 is 3 pCi/liter. The standard set since 2000 for uranium in drinking water is 30 micrograms/L or 20 pCi/L.
Fluoride is a naturally occurring element which may be present in individual well supplies. In concentrations of approximately 1.0 mg/l (milligrams per liter) fluoride is useful in preventing tooth decay. For this reason it is added to many public supplies. However, if present in levels exceeding 2.0 mg/l, fluoride may cause pitting and mottling (brown staining) of the teeth, especially in young children. It is recommended that after testing you consult with your dentist or pediatrician for recommendations concerning the levels of fluoride in your well water.
Giardia is a significant problem with surface water supplies (creeks, lakes, etc) but it is rarely found in individual wells. Therefore, testing for giardia is seldom recommended for individual water wells. Giardia (brochure)
Nitrate is a chemical that is typically associated with human or animal waste and may result from septic systems, horse enclosures or other such sources. In sufficient quantities, nitrogen-based fertilizer may also impact water quality. Small amounts of nitrates are present in virtually all individual water supplies in Jefferson County. Consumption of water containing high levels of nitrate can interfere with the ability of the blood to carry oxygen and may present a health risk to infants. Levels in excess of 10 mg/l (expressed as Nitrogen) may be significant and should be reported to your doctor or pediatrician for evaluation and recommendations.
Present throughout the soil are naturally occurring bacteria (referred to as coliforms) which may enter the water supply of individual wells. Although coliform bacteria are not pathogenic (disease-causing) themselves, their presence may indicate that other, more difficult to detect bacteria or viruses are also present. The level of coliform bacteria in a sample is reported as "present" or "absent," rather than reporting the number of bacteria.
Testing Your Well Water
Typical well water tests for most areas should include bacteria, nitrate and fluorides. You may consult a private laboratory for testing or you may order bottles from the State Health Department lab by calling 303-692-3074. These bottles and the accompanying forms will be mailed to you. Follow the directions for taking the sample and completing the forms. Then, either take the bottles to the State lab at 8100 Lowry Boulevard, or drop them off at the Jefferson County Department of Health and Environment Golden office at 1801 19th Street for transport to the State lab. The transportation fee is $10.00 (cash or check) and you must have the bottles in our office no later than 8:10AM. Be sure to bring the completed lab forms and a check for the appropriate amount (cash not accepted). Call 303-271-5700 for further information.
Although not directly related to water quality, quantity is an important consideration in judging the suitability of individual wells. The amount of water obtained from a well is related to how much the well produces and how much storage is available. For example, even a low-producing well may prove acceptable if there is sufficient storage of water to meet the peak demand. The actual gallonage requirements are based upon the individual needs of you or your family.
On average, a typical family uses 50 gallons of water per person per day. This figure does not include outside activities such as lawn watering. Many well permits however, do not allow for irrigation, individual permits must be referenced regarding this type of use.
If your water contains contaminants that exceed safe drinking water standards, treatment methods are available for household use. Contact Environmental Health Services at Jefferson County Public Health, 303-271-5700 for further assistance in determining whether treatment is desirable and, if so, what methods are available. Brochures are available dealing specifically with nitrate removal, radiation in well water and giardia.
Last Modified: Oct 15, 2012 02:08 PM