From The Grand Junction Daily Sentinel (Dennis Webb):
A state official says regulators are seeking to protect Parachute Creek according to drinking water standards even though they technically don’t apply. The comment by David Walker, with the Hazardous Materials and Waste Management Division of the Colorado Department of Public Health and Environment, came after a resident living near the creek downstream of a natural gas liquids leak questioned the standard applying to the creek.
A leak from a pressure gauge on a pipeline leaving Williams’ gas processing plant has resulting in carcinogenic benzene contaminating groundwater and the creek. While some groundwater benzene levels are high, measurements in the creek only once have exceeded the state drinking water standard of 5 parts per billion, reaching 5.3 ppb Wednesday.
While CDPHE regulators have accused Williams of breaking state rules with the groundwater contamination, it technically hasn’t violated any surface water standard because water isn’t pulled directly from the creek for drinking, Walker said. Instead, the state’s Water Quality Control Division’s maximum allowable benzene level in the creek is 5,300 ppb, to protect aquatic life.
Howard Orona has a domestic well about 20 feet from the creek and said it’s probably only 25 feet deep. A citizen representative on the Garfield County Energy Advisory Board, he expressed concern at the board’s meeting Thursday that benzene in surface water could migrate into his shallow well water. “For that creek to be pushing into the groundwater in my case, I would think that would be considered drinking water,” he said.
Walker said that despite the 5,300-ppb standard on the creek, “we are trying to protect to drinking water standards because it’s the correct thing to do.”
Williams tested Orona’s water a few weeks ago and it was benzene-free. On Friday, the company agreed to test it again and continue doing so on a regular basis, something Walker said he would have required had the company not volunteered to do it.
He said he agrees it’s possible for contaminated creek water to reach a nearby domestic well, and testing Orona’s well is the right thing to do. At the same time, he noted that Orona’s well is more than a mile from where benzene is entering the creek, and at least four creek sample points in between aren’t showing any benzene. The contaminated groundwater also is far upstream from his well and shouldn’t reach it underground, Walker said.
The creek also is the source for the town of Parachute’s irrigation supply, but no benzene has been detected at the diversion point.
Benzene in the creek Thursday fell to 4.7 ppb at the area of highest creek contamination.
Williams plans to seek state approval for upgrades to a treatment system to more quickly and thoroughly remove benzene in groundwater before the water enters the creek. CDPHE spokesman Mark Salley warned Friday the change could temporarily boost benzene levels in the creek “as residual groundwater contamination between the treatment systems and the creek is mobilized.” But it’s expected the benzene would continue to dissipate as it moves downstream, as it has been doing, he said in a news release.
From The Grand Junction Daily Sentinel (Dennis Webb):
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.
From The Denver Post:
Benzene levels continue to fluctuate in Parachute Creek near a hydrocarbon spill from a Williams energy gas pipeline.
The state Department of Public Health and Environment reported Friday that a surface water collected from a sampling spot closest to the well on Thursday contained 4.7 parts per billion, down from 5.3 ppb the day before. The federal safety limit for drinking water is 5 ppb.
The limit for benzene in Parachute Creek is 5,300 ppb, set by Colorado’s Water Quality Control Commission at a level deemed protective of aquatic life because the creek isn’t designated as a drinking water supply.
Downstream from the spill, the benzene contamination dissipates quickly. In Thursday sampling, the cancer-causing chemical was not detected 1.5 miles downstream, near the headgates where Parachute diverts water to an irrigation reservoir. The gates have not been open since the spill was publicly revealed on March 16.
Williams is expected to submit plans for improving groundwater treatment near the spill. Trenches to capture contaminated groundwater have been dug and equipment is being used to aerate the creek and soil near the spill to dissipate benzene.
CDPHE spokesman Mark Salley said in a written statement that benzene levels may temporarily increase in the creek after the treatment system upgrades occur “as residual groundwater contamination between the treatment systems and the creek is mobilized.
“But as the data above show, the expectation is that benzene would continue to dissipate as it moves downstream,” he wrote. “Williams will be closely monitoring the situation once the system is turned on, to look for changes that might warrant adjusting its operation, to enhance benzene removal rates and minimize temporary impacts to the creek.”
More Parachute Creek Spill coverage here. More oil and gas coverage here and here.
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