Benzene in creek tops drinking water standard
Benzene in Parachute Creek has exceeded the drinking water standard for the first time since the discovery of a Williams natural gas liquids leak near the creek earlier this year.
Colorado Department of Public Health and Environment spokesman Mark Salley said in an email to reporters Thursday that a sample on Wednesday contained a reading of 5.3 parts per billion, which compares to the drinking water standard of 5 ppb.
But he noted that the creek is not considered a drinking water source, although it’s subject to a 5,300-ppb maximum benzene standard to protect aquatic life.
“None of the surface water sampling results demonstrate the water is a risk to public health,” Salley said.
However, the CDPHE on Wednesday notified Williams that its leak constitutes disposal of hazardous waste without a permit. The agency has authority over the cleanup and could pursue fines against Williams.
Wednesday’s benzene reading occurred at the same location where benzene-tainted groundwater is believed to be entering the creek, and where previous readings generally have been in the 3 to 4 ppb range. The contamination is originating from where natural gas liquids leaked from a pipeline leaving Williams’ gas processing plant in the creek valley.
Readings of 1.6 and 1.3 ppb were recorded Wednesday at two testing sites downstream, but no benzene showed up Wednesday at four more-distant sites, including the point where the town of Parachute diverts water for its irrigation system. Benzene dissipates rapidly in creek water and crews also are aerating the creek to speed dissipation.
“Remediation actions continue and will be modified if appropriate to respond to sampling that indicates a significant change in the characterization of the site,” Salley said.