Dominion Crystal City

Dominion Crystal City Transformer Spill

Substation Location

Substation Location


DEQ created this webpage to provide access to technical reports and correspondence for the petroleum release at the Dominion Power Transformer Substation in Crystal City, Arlington County, Virginia.  DEQ staff will typically post reports or correspondence on this webpage within 30 days of receipt, after staff have reviewed the information and confirmed that it is complete.


Links to Documents

Technical reports from the responsible person and DEQ correspondence can be found by clicking Links to Documents

Case History

On January 24, 2016, Dominion Power notified DEQ of a release of approximately 13,500 gallons of mineral oil from a transformer at the Crystal City substation.  An electrical failure in the transformer caused pressure to build up inside the equipment, resulting in a structural failure.  Emergency response actions performed by Dominion included the recovery of free phase mineral oil from gravel fill around the transformer and from several cable vaults in and around the substation.  Mineral oil was also recovered from a storm water manhole on Fern Street immediately outside the substation. 

DEQ, Arlington County and USEPA checked downstream locations in the storm sewer system.  At that time, there were no indications of mineral oil beyond the immediate area of the facility. However, on February 3rd, DEQ received reports of oil sheen on the Potomac River as far downstream as the Woodrow Wilson Bridge.  The source of the sheen was ultimately tracked to Gravelly Point and the Roaches Run Waterfowl Sanctuary.  On February 4th, the United States Coast Guard (USCG) federalized the incident and established a Unified Command structure that included the DEQ, the District of Columbia’s Department of Energy & Environment (DOEE), the Environmental Protection Agency (EPA), and other affected parties.    USCG deployed booms at Gravelly Point to contain the release.  Tri-State Bird Rescue in cooperation with the National Park Service and US Fish and Wildlife Service responded to reports of impacted wildlife.  They recovered several Canada Geese mortalities and captured a number of oil-impacted Canada Geese for rehabilitation.  Many of these were later released back into the environment.

USCG obtained samples of the sheen from Roaches Run and samples of the mineral oil from the transformer spill.  After reviewing analytical comparisons between these samples, on February 12th, Dominion agreed to assume responsibility for the sheen on Roaches Run.

On February 19th, USCG formally announced that the Unified Command was standing down from the Emergency Response phase and transitioning the site to the Remediation phase.  This consensus decision was based on the absence of any new sheen, no additional wildlife mortalities, and the identification of the oil source as the failed transformer.  From this point forward, the Virginia DEQ would take the lead on remediation efforts.  The USCG and DOEE remain available for support as requested.

Study Area

Study Area

Current Status

The Emergency Response Initial Abatement and Site Characterization Phases of corrective action have been completed.  Dominion submitted their Site Characterization Report (SCR) to DEQ on August 31, 2016.  The SCR documented the following tasks:

  • Borscope (video) inspection of the nearby storm sewers. The inspection did not reveal any mineral oil in the sewers.
  • A Dye-trace test.  A non-toxic dye was placed in vaults and storm sewer manholes in and around the substation.  Sampling packs were placed at various locations in the storm sewer system.  There was a possible observation of dye at the storm sewer outlet into Roaches Run; however, results from the sampling packs did not indicate the presence of dye from the test.
  • Geophysical survey of the area surrounding the substation.  This was accomplished primarily to locate utilities and select locations for the soil and groundwater investigation.
  • Installation of four groundwater monitoring wells.  Mineral oil was not detected in either soil or groundwater samples.

In addition, Dominion has continued weekly observation of the storm water inlet in front of the substation and at Roaches Run and Gravelly Point.  There has been no visual observation of oil at any of these locations.   Based on the absence of any visual observation of oil at these locations, DEQ agreed to allow Dominion to remove the containment booms on July 19, 2016.

DEQ responded to the SCR in a letter dated October 7, 2016.  We noted that conditions at the site during the dye test were not the same as when the spill occurred.  The heavy snow, that occurred in January caused storm sewer flows and groundwater table elevations to be significantly different than they were during the recent testing.  In addition, the storm sewer and vault configurations are different following the cleanup and substation upgrades.  Therefore, the dye test results may not provide a complete assessment of the path that the mineral oil took to reach Roaches Run.  Consequently, DEQ has requested that Dominion continue with Post-Site Characterization Monitoring.  Specifically, we requested that they:

Continue with weekly observations of the vaults, manholes and storm sewer outlets at Roaches Run;
Submit a plan to DEQ for deployment of booms and pads in the event that product is observed at Roaches Run;
Re-sample the groundwater monitoring wells in October 2016 and January 2017; and

Report the sampling results in Post-Site Characterization Monitoring Reports.

Dominion submitted the monitoring reports on November 15, 2016, and March 6, 2017.  Free product was not observed in any monitoring well.  Petroleum constituents were not detected in groundwater samples.   Trace levels of Total Petroleum Hydrocarbons (TPH)-Diesel Range Organics and TPH-Oil Range Organics were detected in some samples.  These detections are considered background levels not attributable to the mineral oil spill.  TPH levels were consistent throughout the monitoring period.

Dominion submitted weekly observation reports to DEQ by e-mail through March 12, 2017.  Based on the absence of any visible sheen or product at the inspection locations, DEQ informed Dominion that the weekly inspections could be discontinued. 

Based on the lack of observed impact to surface water since the end of February 2016 and the favorable results of the groundwater monitoring, DEQ decided to close the Pollution Complaint file.  DEQ staff prepared a closure memo and a closure letter was sent to Dominion on April 6, 2017.

Post-closure tasks will include proper abandonment of the groundwater monitoring wells and removal of any remaining booms.

For further information, please e-mail the DEQ Case Manager, Joe Glassman at or write to: Virginia Department of Environmental Quality, Northern Regional Office, 13901 Crown Court, Woodbridge, VA 22193.   Please include the Pollution Complaint number, PC 2016-3142, in all correspondence.


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Virginia Department of
Environmental Quality
P.O. Box 1105
Richmond, VA 23218
(804) 698-4000

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