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Water Safety

NCHD tests public and private drinking water for bacterial contamination*. It is recommended that private wells be tested annually for bacteria or more often if there are known problems with well water in your area, especially if you have experienced problems near your well such as flooding or land disturbances, and if you replace or repair any part of your well system. 

Samples must be collected in sterile bottles, which NCHD will provide, and must be tested the same day they are collected.

In addition to bacteria testing, NCHD will also collect water samples for a variety of other tests, including nitrates. We collect the water samples in our Sterling office every Tuesday. Samples must be collected on the same day.
* Per the Manual for the Certification of Laboratories Analyzing Drinking Water, Fifth Edition, EPA815-R-05-004, physical copies of bacteriological sample results are required to be kept on file for 5 years. After the required 5 years has elapsed, the physical copies shall be disposed of.

When Should I Have my Well Tested?

Check your well every spring to make sure there are no mechanical problems; test it once each year for bacteria and once every two to three years for harmful chemicals, such as nitrates. You should also have your well tested if:
  • There are known problems with well water in your area.
  • You have experienced problems near your well (i.e. flooding, land disturbances, and nearby waste disposal sites)
  • You replace or repair any part of your well system

How do I find out if my well is contaminated?

The only way to find out if your well water is contaminated is to test it.

Where do I go to have my well water tested?

The Northeast Colorado Health Department can conduct a bacteria test in its own laboratory, or send the water samples to another lab to test for a variety of other harmful chemicals.

What are the bacteria or harmful chemicals I should test for in my well?

Total Coliform: Coliform bacteria are microbes found in the digestive systems of warm-blooded animals, in soil, on plants, and in surface water. These microbes typically do not make you sick; however, because microbes that do cause disease are hard to test for in the water, “total coliforms” are tested instead. If the total coliform count is high, then it is possible that harmful germs like viruses, bacteria, and parasites might also be found in the water.
Fecal Coliform/E. coli: Fecal coliform bacteria are a kind of total coliform. The feces (or stool) and digestive systems of humans and warm-blooded animals contain millions of fecal coliforms. Fecal coliforms and E. coli are usually harmless. However, a positive test may mean that feces and harmful germs have found their way into your water system. These harmful germs can cause diarrhea, dysentery, and hepatitis. It is important not to confuse the test for the common and usually harmless E. coli with a test for the more dangerous E. coli O157:H7.
Nitrate: Nitrate is naturally found in many types of food. However, high levels of nitrate in drinking water can make people sick. Nitrate in your well water can come from animal waste, private septic systems, wastewater, flooded sewers, polluted storm water runoff, fertilizers, agricultural runoff and decaying plants. A nitrate test is recommended for all wells. If the nitrate level in your water is higher than the EPA standards, you should look for other sources of water or ways to treat your water

How can I protect my private water supply?

Protect your water supply by carefully managing activities near the water source.
  • 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
  • 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 or 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 harsh chemicals, solvents, petroleum products or pesticides in a septic system or dry well

How do I chlorinate my well?

  1. Mix one gallon of household chlorine bleach (Purex or Clorox, do not use artificially scented or unscented bleach) with water in a five-gallon bucket. Pour the mixture down the well casing.
  2. Circulate the water in the well by running a hose from the nearest cold-water tap back into the well until a chlorine odor is detected. After detecting a strong chlorine odor rinse the inside of the casing and the well cap thoroughly before resealing the well.
  3. Run each cold-water tap, both inside and outside the house, including your washing machine, until a chlorine odor is detected. Do not run hot water taps.
  4. Allow the chlorine solution to remain in the system for at least eight hours.
  5. Hook a hose to an outside hydrant and flush the chlorinated water on a bare or weeded area until the strong chlorine smell is gone. Do not flush into septic system or on vegetation.

If you'd like more information, please contact our Environmental Health Manager:

Melvin Bustos
(970) 867-4918 x2262 

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