Well Water Study
boy drinking water from a glass

Eastern Boulder County Water Quality Study


Boulder County Public Health has been collaborating with researchers from the AirWaterGas Sustainability Research Network at the University of Colorado to design a study that will provide a robust baseline of groundwater quality in eastern Boulder County. The baseline data will help provide an understanding of current groundwater quality, which will serve as a baseline for comparison if/when oil and gas production in the area changes or increases.

Over the past four years, the researchers have conducted research on the potential impacts to groundwater from oil and gas development in the Denver Julesburg Basin, including:

  • Migratory paths of contaminants
  • Well integrity
  • Mobility and persistence of pollutants in groundwater
  • Methane in groundwater


Currently, knowledge of groundwater quality is limited. The study aims to collect water samples from 400 wells in the Eastern portion of Boulder County until November 2018. This will cover nearly 30% of all domestic water wells in eastern Boulder County.

Sampling Process

The University of Colorado at Boulder researchers, led by Professor Joe Ryan, will coordinate all aspects of the sampling process. The sampling team will:

  1. Schedule a sampling trip to the property that works for the property owner. They will generally need about a 2-4 hour window of time. In most cases, the water sampling will take no more than two hours.
  2. Follow standard operating procedures for sampling private water wells, including taking samples in the pressurized water system as close as possible to the well and before the water enters any treatment system (for example, a water softener). Often, samples will be taken from an outdoor spigot. (Water for outdoor use usually bypasses any treatment systems in the house.) This will include examining plumbing to assure that the house’s treatment systems are bypassed.
    • To ensure the water sampled represents water from the aquifer, and not water that has been sitting in the pipes in the well or cistern, the sampling team will need to allow some amount of water to flow through the system before sampling.
    • Using information about the well from the homeowner or the Colorado Department of Water Resources permits for private wells, the sampling team will calculate a volume of water that should be “purged” before sampling and measure the flow rate of the water pumped from the system to determine a purging time. The team will ask for a location where the pumped water can be discharged.
  3. After purging the well of standing water, the team will collect samples in a set of bottles and flasks to transport to laboratories for analyses.
    • Some of the analyses will be done at the University of Colorado Boulder laboratories and some will be done in commercial laboratories.

Reporting Results

The results of the laboratory analyses will be transferred from the University of Colorado at Boulder researchers to Boulder County Public Health.

  • Each homeowner will be provided with their property’s results, along with a basic guide to interpretation. Any potential water quality issues (for example, exceedances of any drinking water standards) will be noted and Boulder County Public Health staff will be available for consultation.
  • All results will be stored in a baseline groundwater quality database managed by Boulder County Public Health. Results will be available to the public upon request, but will not reveal exact locations or property addresses.


Water samples will be analyzed for:

  • Total dissolved solids
  • Specific conductivity
  • pH
  • Dissolved oxygen
  • Ferrous iron
  • Methane
  • Volatile Organic Compounds (VOCs)

If elevated VOC levels are found, further tests will be conducted. The University of Colorado researchers will share their results with well owners and will report results to Boulder County Public Health in November of 2017 and 2018.

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Water Quality Program

Main: 303-441-1564
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