Park County Water Quality Mapping Project

The CGS conducted a Park County Water Quality Mapping Project for the Coalition for the Upper South Platte (CUSP), with funding and project support from Park County and the Park County Land and Water Trust Fund (LWTF). It is anticipated that this will be updated with additional groundwater sampling data collected in 2016.

Data was compiled (as of the end of 2015) from the following sources:

  • USGS Well sample database (compilation of USGS sample data from multiple sources)
  • USGS Spring sample database
  • Other USGS publications not in master database
  • CUSP 2011, 2012 and 2014 sample events
  • Colorado Department of Parks and Wildlife
  • R. Butler thesis, Colorado School of Mines

Additional water quality data was requested from Park County for approximately 92 public water supply locations identified in the Colorado Department of Public Health and Environment public water supply database, but was not received.

Wells and springs were assigned a hydrogeologic unit. In many cases, location data relative to unit outcrop patterns provided sufficient information in data source documentation to make a clear designation. However, uncertainty in unit designation existed in other cases due to location uncertainty in original source data. Where surficial deposits of alluvium or glacial drift cover bedrock, depth information was used to discriminate between surficial or bedrock. Many of the sample locations in the database do not have depth information, which imposes additional uncertainty. In a few cases, the source data included hydrogeologic unit designations. Due to the various sources of uncertainty, hydrogeologic unit designations were assigned a confidence level value of 1, 2, or 3, with 3 representing the least confidence, based on the factors of uncertainty.

A limited number of sample locations have data from multiple sampling events at the same well or spring. Data analysis for these locations used the maximum value detected, unless it was identified as an anomalous outlier. Where feasible, dissolved water quality data was used preferentially over total data.

The CGS devised a method to assess how well the existing database may represent water quality conditions in each hydrogeologic unit delineated in the recent geology and groundwater resources assessment for Park County (Barkmann et al, 2015). It is emphasized that the existing database spans a time period of several decades and the data do not represent a synoptic view of water quality conditions. There may be both long-term and seasonal variations in water quality conditions within the data that add variability to this assessment.

Pie and Stiff Diagrams (downloads below) were generated from the available water quality data to assess water types by hydrogeologic rock unit. Additionally, water constituents having Colorado/EPA primary and/or secondary maximum contaminant levels (MCLs) were mapped using circles of varying sizes that were blue for concentrations at or below the MCL and red if they exceeded the MCL.

Barkmann, P.E., Sebol, L., Fitzgerald, F.S., and Curtiss, W, 2015. Geology and Groundwater Resources of Park County. Colorado Geological Survey, Colorado School of Mines, Golden, Colorado, Open File Report OF 15-11.

Figures Organized Alphabetically by Rock Units

Water Type – Stiff Diagrams (40×48″)

Antero Stiff Diagram
Belden Stiff Diagram
Benton-Niobrara Stiff Diagram
Dakota Stiff Diagram
Garo Stiff Diagram
Laramie-Fox Hills Stiff Diagram
Maroon Stiff Diagram
Minturn Stiff Diagram
Morrison Stiff Diagram
Pierre Stiff Diagram
Precambrian Stiff Diagram
Quaternary Stiff Diagram
South Park Stiff Diagram
Tallahassee Creek Stiff Diagram
Tertiary Stiff Diagram
Wagontongue Stiff Diagram

Water Type & Quality – Pie Diagrams with Total Dissolved Solids (TDS) (40×48″)


Water Quality – Total Dissolved Solids (TDS) (40×48″)

Antero TDS
Belden TDS
Benton-Niobrara TDS
Dakota TDS
Garo TDS
Laramie-Fox Hills TDS
Maroon TDS
Minturn TDS
Morrison TDS
Pierre TDS
Precambrian TDS
Quaternary TDS
South Park TDS
Tallahassee Creek TDS
Tertiary TDS
Wagontongue-Trump TDS