The City of Alexandria in partnership with Virginia Department of Environmental Quality has implemented a program to prevent, mitigate, and remediate (if needed) contaminated lands within the city. The City adopted an Administrative Procedures for the Development of Contaminated Land, which identified certain types of remediation for a variety of contaminants. Since that time, the City has incorporated language into the City’s Zoning Ordinance that requires contaminated sites to be remediated as part of the development process. The Zoning Ordinance requires contaminated sites to be identified as part of the preliminary site plan submittal, while the final site plan must include plans indicating how the site will be remediated. In an effort to insure these sites are identified, the City maintains a contaminated land site map, which includes information on old landfills, underground storage tanks, and some former industrial sites.
Voluntary Remediation Program
VDEQ has a Voluntary Remediation Program (VRP) that allows for owners of contaminated sites that are not regulated under any of the programs or predates any regulations, to remediate those sites. The VRP consists of a program consisting of six key elements including: 1) a determination of eligibility; 2) submittal of registration fee; 3) report submittals including a site characterization, documentation of public notice, remedial action work plan and demonstration of completion report; 4) establishment of remediation goals based on current and/or future land use; 5) public participation to provide a forum for affected residents; and 6) a Certification of Satisfactory Completion documenting that the cleanup standards have been achieved.
Several sites in the City have entered into this program some are complete others are on going.
Oronoco Outfall – Alexandria Town Gas Site
City Council allocated funding on September 27, 2012 to move forward with the groundwater remediation phase of the project. Site work is anticipated to begin before the end of the year. Visit the Oronoco Remediation Project for periodic progress updates.
In May 2000, the City entered Virginia's Voluntary Remediation Program (VRP) to remediate and clean up the Oronoco Outfall–Alexandria Town Gas Site located at the eastern end of Oronoco Street.
- Since 1975, oily wastes have been intermittently discharging into the Potomac River along Alexandria's waterfront at Founder's Park at the Oronoco Outfall Site. The source of the contamination and waste is a former manufactured gas plant (MGP) facility located two blocks from the waterfront at the corner Lee and Oronoco Streets. The plant was owned and operated by the City during 79 years of its 95-year existence, which spanned from 1851 to 1946.
- Over the last 25 years, the City has taken numerous measures to prevent further discharges of plant-related wastes into the river. However, the extent and complexity of the problem has made the development of an effective and lasting solution a difficult challenge.
- In the late 1970’s the site was redeveloped into a commercial office townhouse complex.
- In 1999, the City received letters from USEPA and the US Coast Guard notifying the City that it must immediately address the issue of ongoing releases into the Potomac River. The City applies and is accepted into the VRP in May 2000.
Interim Corrective Actions to Date
- Installation and operation of the floating oil containment boom with additional oil absorbent booms installed and replaced periodically on the interior to collect contaminants.
- The City has installed and is currently operating a free product removal system that includes recovery wells installed in the source area. The removal of free product from the subsurface will make future remedial efforts more efficient.
- The City successfully completed the relining of the Oronoco Street storm sewer in 2006. The relining has reduced the amount of oily substances infiltrating into the pipe and subsequently reduced the amount of impacted material being discharged to the Potomac River.
The City’s environmental consultant, Marshall Miller and Associates, completed a biotreatability bench scale study for the Oronoco Outfall in 2008. The study was conducted to determine the mixture of air and nutrients needed to effectively reduce subsurface contamination levels along the storm sewer outfall. The study proved successful in that levels of contamination were shown to be significantly reduced via biodegradation after treatment. Subsequently in 2009, Marshall Miller completed a biosparging pilot study to determine how field conditions would affect treatability. This study again proved successful in significantly reducing contamination levels present adjacent to the outfall.
The results of the above studies have resulted in a design for an in-situ groundwater treatment system utilizing biosparging as the primary remedial technique. The design minimizes required infrastructure as compared to traditional pump and treat systems and is capable of preventing contaminates from migrating towards the Potomac River in varying tide and weather conditions. The construction plans were successfully put out to bid in June of 2012. City Council allocated funding for the project on September 27, 2012. The project is expected to break ground before the end of the calendar year and construction is expected to last four to five months.
The construction of the in-situ groundwater treatment system will complete phase one of a two phase approach to remediate the Oronoco Outfall. Once the groundwater treatment system has proven effective in eliminating contaminates from reaching the river, the impacted river sediment around the outfall will be removed via dredging as part of phase two. Phase two is scheduled to be completed within eighteen months of phase one completion.
The City continues to operate its interim measures including the floating oil containment boom and the free product recovery system. Free product recovery is expected to continue indefinitely. Please contact Daniel Imig at 703-746-4070 with any questions regarding the proposed remediation systems or the on-going maintenance activities.
Underground Storage Tank Program
The Underground Storage Tank Program regulates most large underground storage tanks in Virginia and the City. Gas stations are the most common source of these tanks in the City. This program requires that the tanks be maintained so they do not leak and if it has been confirmed that tanks have resulted in a release to the environment, VDEQ requires the site to be remediated. There are cases in the City where tanks have leaked and the VDEQ has required remediation.
The City also has an Environmental Offenses Ordinance prohibiting illegal dumping or discharges to the sewer systems, streams, or on the ground etc. To assist in administering and enforcing this ordinance and to better investigate these type of releases, the City created an Environmental Industrial Unit, which meets monthly with representatives from the Police, Fire, T&ES, Code Enforcement and Recreation, Parks and Cultural Activities.