Colorado Department of Public Health and Environment approves Suncor dewatering, monitoring, remediation plans with enhancements
The Hazardous Materials and Waste Management Division of the Colorado Department of Public Health and Environment has approved with modifications Suncor Energy (USA) Inc.’s dewatering, monitoring, and remediation plans for the South Secondary Treatment Area on Metro Denver Wastewater’s Reclamation District (Metro) property adjacent to Suncor’s Commerce City refinery. The division’s actions are designed to enhance Suncor’s response to releases of petroleum products from its Commerce City refinery, releases that jeopardize Metro’s infrastructure upgrade that is required to comply with water treatment standards.
The division’s three letters address concerns that dewatering operations that are part of a Denver Metro Wastewater Reclamation District construction project are causing a portion of a contaminated groundwater plume to change direction, spreading hydrocarbons to previously clean areas. A July 9 letter requires weekly sampling for benzene, toluene, ethyl benzene and xylenes (BTEX) in several wells on the Metro property. The division’s July 16 letter requires Suncor to sample three particular locations every other day. If any BTEX chemical is detected above state groundwater standards in the three specific locations, Suncor must immediately manage water extracted from those wells by collecting, treating, disposing and/or discharging it appropriately.
In addition, one letter designates 11 wells currently used for groundwater monitoring as compliance wells. Suncor must take whatever steps necessary to ensure its hydrocarbon plume does not degrade water quality above state groundwater standards at any of these wells, and to prevent the continued expansion of its plume. Failure to do so would violate a Notice of Additional Work the Department issued on May 9, 2012.
In a July 16 letter to Suncor, the Hazardous Materials and Waste Management Division stated: “due to the short amount of time that may be remaining before Suncor must manage produced contaminated groundwater, the division has determined that Suncor shall pursue more than just one preferred option, in parallel if necessary, to ensure that the waste water generated at the South Secondary Treatment Area can be effectively and legally managed.” The division approved Suncor’s dewatering plan, required by the May 9 Notice, with the following modifications:
· Suncor must sample and analyze groundwater for BTEX in three locations every other day and forward the analysis results to the state and Metro Wastewater within two days of sampling.
· If BTEX is detected above state groundwater standards in any of these locations, Suncor must immediately begin treating the water and may not discharge it in Metro’s treatment system unless the utility gives written approval.
· Starting immediately, Suncor must be prepared to truck contaminated water offsite for treatment and disposal, if needed.
· If Suncor cannot immediately treat all contaminated water recovered from Metro dewatering wells and drains, the company must treat it at its existing system on refinery property, truck it to a third-party treatment facility or temporarily store it in tanks on refinery property.
· By July 24, Suncor must submit a new, separate permit application for treating groundwater. The application must assume a worst-case scenario and must request a discharge volume large enough to handle all anticipated dewatering activities in Metro’s South Secondary Treatment Area and other areas – up to 2,000 gallons per minute.
· By August 1, Suncor must install a groundwater treatment system on Suncor’s or Metro’s property (with Metro’s approval) to treat any and all water exceeding state groundwater standards that is extracted as part of Metro’s dewatering activities.
· If future data demonstrates the contaminant plume still is moving toward the dewatering area, Suncor must take aggressive steps to resample wells, install extraction wells to reverse the groundwater flow, and treat all the extracted water or truck it offsite to a third-party treatment facility.
The department’s previous orders for Suncor remain in effect, including water sampling in Sand Creek and the South Platte River. Suncor is responsible for cleaning up the effects of releases from its refinery, regardless of how far downstream they extend.
A related June 25 letter to Suncor from the department’s Air Pollution Control Division and its Water Quality Control Division also requested information from the company specifically related to operation and maintenance of tanks, below ground pipelines and conveyances at the facility.