DEQ announces sampling results for Carlile wells


Search for source of water problems continues

By Sarah Pridgeon

The Department of Environmental Quality confirmed this week that testing and laboratory analysis are now complete for the wells near Carlile that suddenly ran dry or acidic in the fall. The DEQ is now working with landowners to explain their individual results and provide advice.

A total of 55 locations were tested, 32 of which were domestic wells from the area 18 miles northeast of Moorcroft, and several constituents were found to exceed the regulations and guidelines followed by the DEQ.

Almost half the locations tested were found to be outside the acceptable range for pH levels, which is set at between 6.5 and 8.5 by the Wyoming Water Quality Rules and Regulations. Of the 25 locations outside that range, 11 were below 6.5 and 14 were greater than 8.5; four wells were identified as having pH below a level of 4.

Of those tested, 44 domestic or domestic/stock wells also exceeded recommended levels of total dissolved solids. The report does note, however, that groundwater samples from a statewide United States Geological Survey study in 1984 suggested that only 30 percent of Crook County wells had concentrations of total dissolved solids below the limit and the current results are within the range of values reported in that study.

Total coliform was found to be present in a total of 13 locations, seven of them domestic wells. These bacteria are naturally present and used as indicators that other, potentially harmful, bacteria may also be present, perhaps due to human or animal waste, insecure wellheads or nonfunctioning or improperly installed equipment.

One well tested during the study exceeded standards for overall radioactivity, while four showed high levels of radiums 226 and 228. All but one domestic or domestic/stock well exceeded suitability standards for sulfate, but all three substances were noted by the DEQ to be naturally occurring and influenced by factors such as geology.

Anomalous instances of ammonia, aluminum, beryllium, boron, iron, manganese and chromium were also found at various wells during the test. All private well owners are now being provided with their individual results and the DEQ has said it will be working with them to address questions and concerns.

The DEQ is also conducting fingerprinting in an effort to type the acid that has been detected in the low pH wells. Meanwhile, an advisory group has been set up to investigate the water quality issues in the study area.

The executive committee overseeing three working groups consists of one representative each from DEQ, Water Development Office, State Engineers Office, Oil and Gas Conservation Commission and the City of Gillette. An independent consultant has also been hired to assist with data review and investigation.