If you recall, Dominion Power has been moving forward with a plan to “close in place” 3.7 million cubic yards of coal ash under the recently finalized U.S. EPA Coal Ash regulation. The plan for Possum Point is to consolidate all of the on-site coal ash into one impoundment. There is estimated to be 3.7 million cubic yards of coal ash. Dominion has collected more than 1 million cubic yards of ash from four smaller ponds, put them in a 120-acre pond that already contains 2.6 million cubic yards of coal ash that they have begun to dewater. Ultimately, the pond will be capped with an impermeable membrane to prevent future infiltration of rain.
These coal ash ponds have been open to the elements and taking on water for decades. Trace contaminants and metals in the coal ash may have already leached into the groundwater, Quantico Creek and Potomac. The State Water Control Board and Virginia Department of Environmental Quality (DEQ) are the regulating agencies that oversee the dewatering of the ponds, though the U.S. EPA maintains authority to review applications and permits for "major" discharges, a distinction based on discharge quantity and content. In January 2016 DEQ and the Water Control Board approved the modifications to Dominion’s Virginia Pollutant Discharge Elimination System (VPDES) Permit allowing the treatment and subsequent discharge of the coal ash waters to Quantico Creek, which flows into the Potomac River.
Several groups including the Prince William County Board of Supervisors had raised concerns with the plan and the speed with which they are proceeding without community involvement and input. In addition to the County Board of Supervisors the state of Maryland, the Southern Environmental Law Center and the Potomac Riverkeeper Network have raised issues about the level of treatment of the water being released to dewater the pounds and the Riverkeepers contend that the large pond where they are consolidating all the coal ash is only partially lined.
Now, the Prince William County Board of Supervisors has agreed to withdraw its appeal of the permit, and Dominion has agreed to steps that go beyond the VPDES Permit requirements. This agreement between Dominion Power and the Board of Supervisors focuses on reduced contaminant levels in the discharged water and independent testing of the levels:
Dominion agrees to provide advanced treatment of all water from the coal ash ponds prior to discharge, regardless of whether this treatment level is needed to meet the required VPDES Permit levels.
- Dominion agrees to take additional hourly samples. If any sample exceed triggers for certain elements (arsenic, selenium, lead, copper, antimony, and thallium), Dominion will provide an additional enhanced treatment step.
- Dominion will only use a State accredited third-party independent laboratory for its VPDES Permit-required sampling and testing.
- Dominion will implement Standard Operating Procedures and Quality Assurance/Quality Control protocols.
- Dominion will regularly post on a publicly accessible website all permit-required test results for public review.
- Dominion and the County will work collaboratively to coordinate on solid waste permitting during the next phase of the closure of the coal ash ponds to ensure that the Board’s and Dominion’s commitments to groundwater quality and environmental protection continue to be met.
- Dominion will reimburse the County for its costs of outside technical consultation services.
Possum Point Power Station is located in Dumfries Virginia in the eastern part of Prince William County that borders the Potomac River and the Quantico Creek. Dominion Virginia Power has not burned coal at Possum Point for 13 years and is unlikely to burn coal to generate power in the future. Possum Point is downstream from nearby drinking water supplies and is unlikely to impact local residents beyond what has already taken place over the decades.
Dominion’s closure plan should include additional site investigation to demonstrate to the stakeholders in the community that the liner in coal ash Pond D is sound. In addition it is essential that testing of groundwater, surface water sediments, and the water treated at the outfalls be done for a broader spectrum of contaminants to include hexavalent chromium to better protect the environment and determine the extent of impact if any from the decades storage of the coal ash on site. Though Possum Point is downstream from nearby drinking water supplies and is unlikely to impact local residents beyond what has already taken place over the decades; the current level of impact needs to be investigated and monitored for the 24 nearby private wells.
Closing the coal ash on site when properly done is probably the best solution. A safe closure requires ongoing monitoring and maintenance that is best accomplished at an operating and regulated plant rather than at a remote cap and leave it location. All physical barriers fail over time this is addressed by monitoring and maintaining the systems.