May 17, 2013
Williams Update on Activity Near Its Parachute, Colo., Facility
Company Response Continuing to Show Progress in Protecting Parachute Creek, Recovering Increasing Volumes of Hydrocarbon Fluids
- Benzene levels in Parachute Creek continue to decline with only one sample location currently showing any detectable level of benzene.
- Comprehensive aeration and air sparging program credited in removing trace benzene from defined area of the creek as well as from groundwater
- Recovering increasing volumes of hydrocarbon fluids from recovery wells; Approximately 420 gallons (10 barrels) recovered in the last week; 6,766 gallons (approximately 161 barrels) total
Surface water samples from Parachute Creek indicate that Williams continues to make progress in its remediation efforts to remove benzene from a defined area of Parachute Creek, as well as from groundwater.
Of the 17 total creek testing locations, only one is currently showing a trace level of benzene. This test location, which is about 1,300 feet from the spill site, showed a benzene level of 1.7 parts ug/L on May 16. Benzene level detections at the various test locations along Parachute Creek have steadily declined since May 2. For a look at Parachute Creek test results since May 1 click here.
Williams is using air sparging technology to strip benzene from water. Air sparging involves the injection of air into surface water and/or groundwater. It is a U.S. Environmental Protection Agency-accepted method for effectively reducing concentrations of certain hydrocarbons from water.
Williams is using pumps to pull hydrocarbon fluids from recovery wells. Williams has recovered about 420 gallons (10 barrels) of hydrocarbon fluids from May 10 to May 16. Since the response began on March 8, the company has recovered about 6,766 gallons (approximately 164.1 barrels) of hydrocarbon fluids from the site.
Additional Remediation Plan in the Works
Williams is in the process of installing a water treatment system as part of its long-term remediation plan. The system (which currently has an expected June in-service date) will be constructed to remove ground water from the aquifer using recovery wells and subsequently treat the recovered water to remove hydrocarbons so that the water can be safely returned to the aquifer. Treated water will initially be contained in tanks and tested to confirm it meets Colorado Department of Public Health and Environment and U.S. Environmental Protection Agency requirements prior to discharging the water back to the surface, where it will infiltrate into the aquifer through a groundwater recharge area. After this confirmation, samples will be collected continuously throughout the process to monitor water quality and the performance of the system.
Summary of Williams’ Response since March 8:
- Working cooperatively with Colorado Oil & Gas Conservation Commission, Colorado Department of Public Health & Environment, the U.S. Environmental Protection Agency, other agencies, local government authorities, and neighbors
- Donating pumping equipment to the Town of Parachute to help enhance the town’s irrigation system.
- Visually monitoring Parachute Creek for indications of hydrocarbons every 30 minutes
- Installed numerous sample points and monitoring wells to determine the extent of affected groundwater, including:
- 45 sub-surface probe/electrical conductivity locations
- 76 temporary monitoring points (TMPs) to determine water levels, monitor for hydrocarbons, monitor air-sparge system performance and collect samples for analyses.
- 22 long-term monitoring wells to determine water levels, monitor for hydrocarbons, and collect samples for analyses
- Six hydrocarbon-recovery wells
- Recovering hydrocarbons from wells and monitoring points
- Installed nine absorbency booms in Parachute Creek, which are replaced regularly.
- Installed surface water aerator in Parachute Creek in the midst of previous trace level benzene detection points.
- Installed surface water air sparging devices in Parachute Creek at areas impacted.
- Constructed trench near the point where groundwater enters creek and installed an underground air-sparge system in the trench near the bank of Parachute Creek.
- Upgrade of the air sparge blower to increase aeration of groundwater and Parachute Creek
- Ten vertical sparge wells adjacent to the previously-installed air sparging trench to provide aeration of groundwater
- Performed extensive soil excavation in the area of the leak
- Colorado Water Quality Control Commission says the actual benzene standard on the creek is 5,300 ug/L (micrograms per liter) to protect aquatic life
- Parachute Creek sample just upstream of Colorado River confluence shows no benzene
- No detectable level of benzene shown at the point where the Town of Parachute diverts water for its irrigation well
For more information visit AnswersforParachute.com
Williams Corporate Media Contact: Tom Droege 918-573-4034
Williams Colorado Media Contact: Donna Gray 970-285-5526