Q. How will DDOE provide the 3rd Quarter and final test results?
A. DDOE has received multiple requests for various data elements and data sets regarding the testing that has been done over the past few years. The DDOE Director’s letter to residents dated 3/27/2009 stated that SSP&A will provide Q3 test reports. These reports have been mailed to residents in advance of the final homeowner reports that will interpret cumulative results for the complete study.

 

Q. When will DDOE provide the latest testing results to EPA and ATSDR?
A. The District has submitted the Papadopulos test results to EPA Region III and ASTDR. To-date, DDOE has not received feedback from these agencies.

 

Q. What was the basis for DDOE to propose a remedy selection and what protocols and standards were employed by DDOE?
A. DDOE proposed a remedy selection based on the S.S. Papadopulos test results. The community was provided a comment period prior to final remedy selection. The protocol and standards employed by DDOE regarding the Riggs Park assessment and remediation are set forth in the proposed remedy selection document.

 

Q. Will DDOE test the soils at residents' homes?
A. A resident expressed concerns that children playing in yards, etc., within areas overlying contaminated ground water might be exposed through contaminated soil and requested information on direct soil testing.  Surface soils can be readily contaminated from spills from filling lawn mowers, etc. However, when viewed from the perspective of evaluating soil vapors contaminated from the groundwater plume, testing soil is problematic because it would not exclude this source of contamination. EPA has previously addressed this issue and indicated that testing soil matrix directly is not considered a reliable indicator for evaluating vapor intrusion risk due to factors such as loss of VOCs (volatile organic compounds) during sampling and the difficulty of using partitioning equations to calculate corresponding soil gas concentrations. Soil test data are typically used as a secondary line of evidence in vapor intrusion assessments. Ground-water, soil gas, and sub-slab data are used to estimate indoor air concentrations after application of an attenuation factor. *. [* see ITRC (Interstate Technical & Regulatory Council) 2007, Vapor Intrusion Pathway: A Practical Guideline, VI-1, Washington, DC, Vapor Intrusion Team. <www.itrcweb.org> - DDOE has no immediate plans to test soils at this time.
 
Q. Some monitoring wells in Oglethorpe alley are apparently not functional at this time – will additional wells be installed at that location?
A. As the remediation phase of this project is conducted under EPA’s authority, this question is better addressed to USEPA Region 3, c/o Mr. Andrew Fan. DDOE understands that the existing wells in the alley are sufficient to develop the needed data. Accordingly, EPA has not required Chevron to install additional monitoring or recovery wells at the site, in particular in the Oglethorpe alley.

 

Q. When will the free-product (gasoline) under the District homes be removed?  
A. Present testing has not substantiated that free liquid gasoline product is present under resident’s homes in significant amounts. DDOE plans to assess any correlation between the contaminants found under the homes [beneath the sub-slabs] by the Papadopulos study and the groundwater.

 

Q. How will the contaminated groundwater plume under District homes be specifically addressed?
A. At present, groundwater sampling and remediation is being conducted under the authority of EPA Region III in accordance with the Administrative Order of Consent between Chevron Corporation and USEPA. EPA Region III confirmed that Chevron submitted a work-plan to EPAR3 by 4/20/09 regarding the next phase for the project enhancements including: details on the angle wells, oxygen-curtain, and below ground recirculation vault technology.

 

Q. What will be the time frame for cleaning up the groundwater contaminants?  How many homes will this protect?
A. At this point it is not practicable to assign a specific time-frame at which point the District’s groundwater would be cleaned up. When EPA’s final remedy selection is implemented, construction is complete, and the system fully operational, it will be possible to provide a more accurate time-frame for the groundwater to return to “beneficial use” conditions as required by District regulations. The completed system will address the petroleum plume and will apply to the whole community.

 

Q. What is the significance of the used oil and associated “pits” at the former Chevron facility?
A. The used oil USTs at the facility were excavated under oversight of the MD Department of Environment (MDE), the agency with jurisdiction over the former Chevron gas station. It was determined that the removals did not result in any significant damage to the remediation wells located on the site which are still functioning.  MDE monitored these removals in accordance with MDE’s testing requirements. DDOE requested and received this information from MDE. There was no information regarding so-called “pits” at the site. DDOE is investigating the possibility that these tanks may have contained contaminants other than those normally associated with gasoline products.

 

Q. How will DDOE ensure that adequate monitoring and oversight is provided during field work in the Riggs Park Community?
A. EPA has determined that on-site oversight is unnecessary for the well-gauging and sampling performed by Chevron’s contractor - Gannett-Fleming, Inc. Due to resident concerns DDOE’s Director agreed to provide limited on-site oversight to the degree practicable. Resource limitations required that an audit protocol be adopted by DDOE in lieu of 100% full-time on-site oversight. DDOE plans to continue to provide limited oversight of the Chevron contractor field work.

 

Q. How does this enforcement action comply with current environmental justice policy?
A. DDOE’s Office of Enforcement & Environmental Justice (OE&EJ) rendered opinions respecting the EJ policy applicable to this clean-up in letters to residents dated 9/22/2008 and 10/17/2008. The OE&EJ continues to maintain awareness of the Riggs Park clean-up operations. 

 

Q. DDOE has apparently suspended meetings with the Riggs Park Citizens Advisory Committee (RPCAC) and the community-at-large – why?
A. The RPCAC has not been disbanded. DC Councilmember Bowser’s position was that, from the government’s perspective, meetings could be suspended until such time as DDOE or DOH has new information to distribute. The community-at-large is encouraged to continue to meet as needed to discuss issues. DDOE has determined that the most efficient use of limited staff resources requires that DDOE participate in meetings when there is significant information that it must convey to the community. 

 

Q. Why are residents having difficulties accessing the information in the Administrative Record – both at Lamond-Riggs Library and on the DDOE website?
A. In addition to the Chevron gasoline release administrative record which is in-place at Lamond-Riggs Public Library, DDOE has provided a supplemental Administrative Record which supports DDOE’s proposed remedy selection. In addition to assisting resident access to information as much as possible with respect to the website and the community library reference documents, DDOE will provide a DVD containing the complete Administrative Record to individual residents upon request. DDOE’s Director addressed these issues in a letter to residents dated March 27, 2009.

 

Q. How will new homeowners in the community be informed of the status and impact of the cleanup project?
A. The community’s information needs will continue to be addressed by the responsible government agencies. New owners are encouraged to contact DDOE, DOH, USEPA Region III and the US Agency for Toxic Substances and Disease Registry with their concerns regarding human health and the environment. They should also stay in touch with their Councilmember’s office.