DENVER—As vacuum trucks continue to suck up tainted groundwater from the site of a hydrocarbon leak near a stream in western Colorado, those in charge are beginning to think about the next step: what to do with all that dirty water.
About 180,000 gallons of contaminated water have been pumped out of the ground since the subterranean hydrocarbon seep was discovered near the Williams gas company’s Parachute processing plant, which sits close to Parachute Creek.
One of the main contaminants in the groundwater is benzene, according to Mark Salley, a spokesman for the Colorado Department of Public Health and Environment, which is currently overseeing the remediation efforts. Benzene, a known carcinogen, was also found earlier this month in Parachute Creek in concentrations above the state’s health standard, but levels have since dropped and officials insist there is no threat.
To remove the benzene from the creek, Williams injected air into the surface water to strip the hydrocarbons, a process known as air-sparging. The same technique is to remove surface hydrocarbons that are floating on top of the groundwater.
How to handle all the benzene-infected groundwater is the next question. The recovered water is currently being stored in tanks, and Williams said Friday it is planning to install a water treatment system that can separate the benzene from the water.
“They’re working on the plans right now for a water treatment system,” said Tom Droege, a Williams spokesman. “It’s not in place yet, but once it’s up and running, then they’ll begin to treat the groundwater on a regular basis.”
The system will remove the benzene and any other hydrocarbons from the water through a multistep process. Contaminated water will first go through an oil and water separator. Then, it will move through an air stripper, which works like air-sparging. Finally, the water will be moved through activated carbon polishing tanks.
The treated water will then return to a holding tank, where it will be tested to ensure it meets state health department and U.S. Environmental Protection Agency standards. Once officials have confirmed the water is safe, it will be returned to the aquifer.
Any air emissions from the treatment system will be captured and treated according to the procedures approved by the Air Pollution Control Division of the state’s health department, Salley said.
The system is expected to be functional by the end of May.
