Lily BarkauGroundwater Section Manager Cheyenne(307)777-7072
Tyler HarrisUIC Program Project Manager, Cheyenne(307)777-5501
Steven LooseGPC ProgramUIC Program Project Manager, Lander(307)335-6942
Laurel MorrowUIC Program Project Manager, Cheyenne(307)777-7608
Cherrie NelsonPavillion InvestigationGPC Program 
Project Manager, Cheyenne
John PassehlUIC Program , Federal Facilities Project Manager, Cheyenne(307)777-5623
Troy SandersUIC Program Program Manager, Cheyenne(307)777-6081
Justin ScottUIC Program Project Manager, Cheyenne(307)777-7511
Taylor SpiegelbergUIC Program Project Manager, Lander(307)335-6752
Nicole TwingKnow Your Well , Gillette-Madison Wellfield Project
GPC Program and Federal Facilities Program Manager, Cheyenne
Kira WeberCAFOsProduced Water PermittingGPC Program 
Project Manager, Cheyenne
Common Contaminants

Well owners should be aware of the potential contaminants that could impact their drinking water. Groundwater can be contaminated by natural processes, land uses, waste disposal practices, and spills or leaks. A contaminated water supply is unsafe to use without treatment even though you may have used the same water for years without getting sick.

The following people are especially susceptible to illness caused by contaminents in water:

  • Infants
  • Young children
  • Pregnant women
  • Elderly
  • People with compromised immune systems

The contaminants listed below are the most common contaminants in Wyoming.  Any of them could cause long or short-term health problems.

For additional information, or constituents not listed above, the EPA Drinking Water Treatability Database has information on treatment options for numerous additional chemicals. 

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Find a Laboratory

The laboratory you choose should provide specific sampling instructions and clean bottles to collect the water sample. Carefully follow instructions for taking samples. Sampling is the most important part of testing. A carelessly collected sample can give you inaccurate results. Check with individual laboratories to get prices. Ask how soon you should expect results and about the information that will be provided with the test results. A good lab should help you interpret the results and make sense of the scientific data.

This information is provided to assist homeowners in finding an analytical laboratory for water analysis, inclusion on this list does not indicate WDEQ endorsement of the lab or the services provided.

Wyoming Department of Agriculture Analytical Lab
1174 Snowy Range Road
Laramie, WY 82070
Ph: (307) 742-2984

Pace Analytical – Montana Laboratory
150 North 9th St
Billings, MT 59101
Ph: (406) 254-7226

Energy Labs 
1120 South 27th St        2393 Salt Creek Hwy        400 West Boxelder Rd
Billings, MT 59101         Casper, WY 82601             Gillette, WY 82714
Ph: (800) 735-4489        Ph: (888) 235-0515            Ph: (866) 686-7175

Wyoming Analytical Laboratories, Inc.
1660 Harrison St             625 Center St
Laramie, WY 82070        Rock Springs, WY 82901
Ph: (307) 742-7995         Ph: (307) 362-3176

Intermountain Laboratory
1633 Terra Ave                 1701 Phillips Circle         541 Garden Dr., Unit O
Sheridan, WY 82801        Gillette, WY 82718          Windsor, CO 80550
Ph: (307) 672-8945           Ph: (307) 682-8945         Ph: (970) 460-0055

Town of Pinedale Microbiology Laboratory
55 Pinedale South Road
PO Box 709
Pinedale, WY 82941
Ph: (307) 367-2348

Protect Your Well

Know exactly where your well is located on your property, and keep well construction and maintenance records.  Remember to disinfect any equipment that will be used inside your well prior to use.

Keep potential contamination sources , such as fuel and chemical storage, septic tanks, or livestock away from your well.  To better understand how a contaminant source can impact your well water, review our Groundwater Contamination fact sheet

Know exactly where your septic system is located on your property, maintain it regularly, and keep maintenance records.

A big part of protecting your well from contamination is keeping surface water, which often carries contaminants, from entering your well.

  • To keep water from ponding around your well, make sure the soil slopes away from the well.
  • If you hear water freefalling into the well, find out where the water is entering your well.

Maintain the integrity of your water well. 

  • Check visible casing, sanitary seal and well cap for damage regularly.  Repair or replace missing or cracked components with commercially manufactured parts immediately. 
  • All vents should be covered with a fine mesh screen to prevent animals and debris from getting into the vent.

Properly plug and seal any unused or abandoned wells.

If you do need to drill a new well, be sure to review the DEQ fact sheet on locating new wells before you begin.

DEQ recommends sampling your well water annually. Water well owners in areas of potential oil and gas development should test for additional constituents.

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Understanding Your Results

DEQ recommends that you test your drinking water. As a private well owner, you are solely responsible for the quality of your drinking water. It is up to you to decide when and how to test your water.

Once you receive your lab results, the first question people usually ask is whether a detected chemical poses a health threat.  Lab results can be confusing and make it tough to understand if a detection is at a level that should be of a concern, or that could require treatment. Especially when labs may be reporting a concentration in one measurement, such as parts per billion (ppb or ug/L), and the comparison standards are listed in parts per million (ppm or mg/L), or visa-versa. If you are having trouble understanding your lab report contact the analytical lab for assistance. Ask the lab if there are any contaminants that present a health risk.

To determine if water is generally safe to drink, water test results are compared to the US EPA National Primary Drinking Water Regulations table of contaminants and the Secondary Drinking Water Standards.  The EPA Drinking Water website also provides information on potential health effects associated with various drinking water contaminants.  Arsenic and You can help you understand arsenic in drinking water and how to minimize your exposure.  In addition, there is a table below to assist with understanding your lab results.

The Environmental Council of States has created an web application for well owners to get feedback about potential health concerns and water treatment options, Be Well Informed. Wyoming is a partner in the  web application, but please note that not all constituents that Wyoming utilizes as part of domestic classification of groundwaters are included. The Understanding Your Test Results document included on this page can provide information regarding additional constituents. 

It is a good idea to follow-up with a second test before you decide if any water treatment is needed. When considering a water treatment device, make sure its specifications match up to the substances and concentrations you wish to treat. Also, there are performance testing programs for treatment systems, such as the NSF International.

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Every March 13th is “Know Your Well Day”, but any day is a good day to learn moreabout your water well and drinking water supply.

If you live in a rural area, it is likely that your daily water supply comes from a well on your property. More than 75 percent of Wyoming’s population relies on groundwater for part, or all, of their drinking water supply. This water comes from more than 90,000 wells.

Your Well and Water, and Your Responsibility
You are solely responsible for the maintenance of your private water well, and are required to maintain it in such a condition that it does not contribute to contamination of groundwater. The Wyoming State Engineer’s Office regulates permitting and construction requirements for water wells. Properly maintained wells help to protect the groundwater that supplies your well. It’s a good idea to regularly inspect your well, and immediately correct any issues that you see.

Federal, state, and local government agencies provide education and technical assistance to private well owners through programs such as Know Your Well; however, private well owners are ultimately responsible for maintaining their wells and having their water tested. This means that the water quality of private water wells is not checked unless you take action to have your water sampled and tested. Knowing your water quality is the first step in protecting your family. Having your water tested regularly gives you an idea if there are issues with your well that may need to be addressed.

Know your well construction

Do you have a copy of your water well permit?  This record contains important information for your well, including: construction information such as materials used to construct the well, depth of the well, and the interval from which your well may draw water from. A copy of your water well record, if completed and filed, can be found by searching the Wyoming State Engineer’s Office e-Permit database. Note: new users will have to register prior to using the e-Permit database system.  Please contact the Wyoming State Engineer’s Office at 307-777-6150 for all questions regarding well permits and construction records for private water wells.

Get your well tested

Well owners should be aware of their water well quality, and the potential contaminants that could impact their drinking water. Groundwater can be impacted by natural processes, waste disposal practices, land use activities, improperly maintained or constructed wells, as well as spills and leaks. An impacted water source may be unsafe to use without treatment, even if the water has been used for many years without people getting sick. Our Common Contaminants page has detailed information about bacteria, nitrates, and other contaminants in Wyoming groundwater that may affect your health in the long or short-term.

Remember, as a private well owner, you are solely responsible for the quality of your water. DEQ recommends sampling annually for a select list of constituents (bacteria and nitrate) and every 5 years for a comprehensive list of constituents. You should test when there is an unexplained illness in the household, if there are changes to the taste, color or odor of the water, if there are spills of chemicals or fuel near your well, or if your neighbors find contaminants in their well. Water well owners in areas of potential oil and gas development should test for additional constituents. Contact an analytical laboratory to get sample pricing, bottles, and specific sampling instructions.

Contact Information

For more information, please contact our Groundwater Program:

Lily Barkau, Water Quality Groundwater Program Manager

Nicole Twing, Know Your Well Program Manager, Cheyenne