From the Denver Business Journal (Cathy Proctor):
All but one of the latest tests of Parachute Creek in western Colorado, near where an estimated 241 barrels of natural gas liquids spilled after a valve malfunctioned, detected no carcinogenic benzene, according to an update from the Colorado Department of Public Health and Environment…
Test results from nine out of 10 locations on Parachute Creek failed to detect benzene, a cancer-causing agent, according to the health department’s update, issued Friday.
The one location that tested positive, identified as CS-6, has repeatedly tested positive for relatively low levels of benzene since tests started, according to Walter Avramenko, the public health department’s hazardous waste corrective action unit leader. The health department is overseeing the cleanup of the spill. On July 8, the CS-6 location had 3.9 parts per billion of benzene, up from 2.8 parts per billion detected on July 5 and nearly double the 1.9 parts per billion detected on July 1, according to the department’s update.
“That location has had benzene levels fluctuate up and down, between non-detectable and 5 or 6 parts per billion,” Avramenko said. “In my opinion, it’s not significant to see this kind of change.”[…]
“The cleanup is going very well,” Avramenko said.
From The Denver Post:
Benzene levels at a point in Parachute Creek near the Williams Co. gas plant spill doubled in a week to 3.9 parts per billion Monday, just short of the 5 ppb considered safe for drinking water.
The Colorado Department of Public Health and Environment said new sparging systems at the sample point and upstream are being installed to stop contaminated groundwater from reaching the creek north of Parachute. The new systems will be turned on the week of July 22.
Benzene contamination has not been detected at any other test points, including where the town of Parachute diverts creek water, typically for irrigation, a health department news release said.