Anacostia Riverkeeper Submits Comments to PEPCO Remedial Investigation Report

Monday, April 18, 2016 - 5:29pm

Anacostia Riverkeeper would like to thank the Pepco Benning Road Community Advisory Group (CAG) as well all of the individuals who devoted many long hours to reviewing and assessing the Remedial Investigation Report in order to submit comments and address data gaps.

We have submitted these comments on behalf of the residents of the District of Columbia who are impacted by the issue of legacy pollution emanating from the Pepco Benning Road facility adjacent to the Anacostia River.

Below are comments submitted by Anacostia Riverkeeper including those developed in conjunction with the CAG. 

·       Significant data gaps identified throughout this report should have been identified and addressed sooner given how much time has been taken. DOEE and PEPCO have made many promises to the public of continuous evaluation and oversight, but we have only seen excuses and delays throughout this process, which are reflected by the outcomes of the Draft RI Report. We ask that PEPCO and DOEE be more forthcoming about their expectations for the completion of the RI/FS and that improvements and adjustments be made in order to stand by their commitments to the communities.

·       The additional sampling that will be conducted should not automatically delay work needed for the treatability and feasibility studies. If these activities are carried out in sequence rather than parallel, it will take a lot more time to complete the RI/FS. The table below shows the significance of the delays thus far (delays in red). Whatever work can be done in parallel, should be done in parallel.


Originally Proposed RI/FS Timeline (From Consent Decree and RI/FS Work Plan)

Actual RI/FS Timeline

Approval of RI/FS Work Plan by DDOE

No estimate or deadline provided

December 28, 2012

Obtain Permits (NPS, USACE, DCRA/DDOE)

Within 30 days of RI/FS Work Plan approval

Final permit approved Sept 10, 2013 (Approval took more than 250 days)

Begin RI Field Work

Within 30 days of RI/FS Work Plan approval

January 25, 2013

Complete RI Field Work

Within 120 days of field work start date

December 31, 2014
(field work took over 700 days)

PEPCO's Submission of Draft RI Report

Within 120 days after completion of RI field work

April 30, 2015

PEPCO's Submission of Draft FS Report

Within 180 days after completion of RI filed work or 120 days after approval of treatability study report, if required

Incomplete - Treatability Study (TS) is required and expected to take 6-9 months from approval of a TS work plan and issuance of permits. TS currently on hold, no date identified.

Completion of the RI/FS

Within 18-24 months of consent decree filing

(currently 4+ years and counting)

DDOE Issuance of Record of Decision Regarding Cleanup Actions

Promptly after approval of RI/FS reports

DOEE estimates 2 years after RI/FS completion (from May 2015 status report to the court)

























·    Statements in the report such as the one below (see pages ES-2, 4-30, 4-36, 4-37) are not well understood. These assertions ignore the fact that PEPCO operated a combustion-based power plant for almost 100 years and operates a fleet of vehicles at its Benning Road property. The import or relevance of any asserted differences in the two classifications on PAHs mentioned should be explained and not left open-ended. Since more investigation and forensic analysis is being planned to better define PAH sources, what will be the determining factors to better understand contamination sources?

“This preliminary forensic analysis suggests that PAHs in site soils and stream sediments may be predominantly from combustion related sources (pyrogenic) rather than fuels (petrogenic), although as noted, this conclusion is based on a limited list of PAHs and a limited site-specific background dataset.” (page 4-36)

·       Given the long and relatively complex operational history at the property, has consideration been given to using a Tentatively Identified Compound (TIC) analysis in the follow-up work that has been proposed in the RI, to identify any additional compounds of potential interest? Limiting the number of COPIs too early in the process can result in a sampling and characterization program that is too restrictive (and reduced reporting) that can result in missed potential COCs.

·       The report goes to some lengths to compare PCBs found on the landside with those found in the waterside, including forensic analyses to determine to what extent the landside PCBs likely contributed to the waterside PCBs. This preliminary forensic assessment exhibits some shortcomings that should be addressed in the next phase of work - including: the PCB comparison does not appear to consider the weathering of PCBs and the effect this has on the analysis; the PCB comparison appears to neglect the role of sediments that were removed from overflows/storm drains on PCB transport and contamination; the initial conclusion of the RI that the site is not a substantial contributor appears to contradict previous findings by EPA.

·       Some of the sample results were ascribed to the collection of turbid samples. Further evaluation of these “outlier” results should be provided in the next phase of work since at least some of the COCs (e.g., PCBs) are known to be transported as or facilitated by colloids.

·       We agree with statements in the report indicating that more exposure pathways need to be addressed (pages ES-4 and 7-8). In addition to the current/future construction worker, future industrial worker, and future recreational user scenarios, nearby residents (particularly those who dig on their properties) and in-stream workers (ie Groundwork Anacostia DC employees who regularly work in nearby wetlands and tributaries in the water and sediment) should be evaluated since their properties were likely contaminated when the power plant was in operation. Further, we recommend that anglers are examined according to subsistence fishing practices, not only recreational fishing. If risks to any of these groups will not be evaluated going forward, please explain why not.

·       With regard to the potential exposure scenarios that are listed as being under consideration in the revised BHHRA: these appear to all be relatively short duration exposure scenarios, that would tend to lead to higher cleanup levels than longer-duration exposure scenarios. Given this, detailed attention must be paid to the assumptions that are incorporated into these scenarios.

·       This report continues to state that there have been five historical releases of PCBs on the PEPCO Benning Rd property. For consistency and accuracy this number needs to be changed to “six” throughout the report (RI Report pages 1-3 and 1-6; Appendix Z page 2-1). There were six historical releases of PCBs. EPA has documented six and the July 2012 RI Work Plan was revised to reflect this and other changes and officially re-released in February 2013.

·       Will all contaminants that exceed screening levels and that are determined to be a risk to human and or ecological health on the PEPCO Benning road property be remediated regardless of the source?

·       If contaminants exceeding screening levels are ruled out as having migrated from the PEPCO Benning Rd property (i.e. contaminants are not from PEPCO’s operations); how will the source(s) be further evaluated by DOEE to ensure remediation and how will DOEE and PEPCO work to ensure no further delay in remedial actions on PEPCO property? For instance, if a contaminant deemed to originate off-site is found in the immediate vicinity of a contaminant deemed to originate on-site, how will DOEE and PEPCO ensure that remedial action is taken as soon as possible for the on-site origin contaminant regardless of the off-site origin contaminant found in the same area of the site?

·       We understand that further investigation is warranted on the waterside, but in the meantime will potential remediation options for the landside start to be evaluated much like what has been done to clean up PCB contamination surrounding the cooling tower basins? We suggest this be done as not to delay further.

·       Bird species observations seem incomplete in this report because it missed the migratory species that use the river at other times of the year than November and December (page 3-10.) While winter can be a good time for sighting resident birds, there should have been observations throughout the year, especially given the nearly 2 year duration of field studies.

·       It would have been helpful if the large tables for this report (e.g., Tables 4-1, 4-3, 4-5; Appendix R) were made available in Excel spreadsheets because it was difficult to navigate such large datasets in PDF form.

·       Could the rationale for the screening levels used for this investigation be explained? For example, the use of mean values seems to gloss over potential problems with contamination hotspots (see pages 4-26 and 4-27, giving mean values for PCBs in sediments that are an order of magnitude lower than the peak values in particular samples). If any of the values used here differ from those proposed in the original Remedial Investigation Work Plan (July 2012), please also explain the rationale for changing those values. In addition, if a mean value is to be used, regulatory guidance in many settings proposes the use of an upper confidence limit (UCL) for the mean that accommodates the variability in the sample data and resulting uncertainty in the estimate of the true mean.

·       What are the implications of contaminant groups (such as PCBs, PAHs, heavy metals, etc.) found together at sampling locations? For example, what does it tell us about the condition or need for remediation when PCBs and PAHs are found exceeding screening levels at the same location?

·       With regard to the contaminant groups (see above): has or will consideration be given to the role that co-disposal / co-contamination can have on facilitated transport of some contaminants – for example, the transport of PCBs has been documented as facilitated at some sites by co-disposal with solvents.

·       How are potential interactions and cumulative or additive effects going to be handled in the human and ecological risk assessments, given that contaminants overlap at different sample locations and given that many exposure pathways do not expose people or wildlife to just this dose of a single contaminant at a time?

·       The transport and fate of chemicals of concern between media, across the site, and across the study area needs to be further explained. It is not clear that all modes of chemical transport have been identified; implications of extreme weather events and the potential for colloidal transport, for example, need to be better understood and explicated, and health impacts need to be revisited to account for resultant changes in assumptions.

·       What will be done to further evaluate and address any sampling that resulted in false positives or negatives identified in the report? (pages 4-16, 4-17, 4-20)

·       Background sample locations are too close to the contaminant plumes near the PEPCO Benning site. Given that the Anacostia River is a small tidal river subject to dispersal of suspended sediment and its associated toxics upstream and downstream from the source with the tides as well as upstream during storm surge events, and given the length of time during which the PEPCO Benning site contributed contaminants to the river, it is unreasonable to assume this report’s background sites actually exclude contamination from this site. We recommend that the background sites used in the Anacostia River Sediment RI be used for this report as well. Given that DOEE is already using the data from the Potomac sites as background for the Anacostia River, including the stretch covered in this PEPCO specific RI, we see no reason why switching to the Anacostia River Sediment RI background sites should present significant difficulty. (See definition of “background” given on page 4-2)

o   What are the “revised background conditions” for PCBs referenced on page 4-28 that will be assessed in conjunction with the additional field investigation?

·       With regard again to background data: there is a concern that using data from within the Anacostia River which is known to be contaminated to define “site-specific background” conditions is only potentially of use in determining whether the Benning Road facility contributed significantly to an otherwise already impacted waterway. If the intent of the RI/FS process is to lead to actions that help to return the watershed to maximum beneficial uses then this impacted “site-specific background” condition should be supplemented by consideration of an “unimpacted” background condition – which in the case of anthropogenics such as PCBs, would be zero. Otherwise, in the limit, if every source equally contributed to contamination, and the “impacted background” is uniformly equal and elevated throughout the waterway, the inference would be that no-one has rendered an impact “above background” such that nothing need be done: the fact contamination is ubiquitous doesn’t remove the obligation of contributors to minimize long-term impacts.

·       The discussion of the PCB forensic analysis from page 4-37 through 4-47 seems to ignore the possibility that tidal flows could have distributed PCBs from the Benning Road site throughout the tidal portions of the Anacostia River, both upstream and downstream.

·       There has been and continues to be an assumption that contamination has not migrated from the PEPCO Benning Rd property to nearby residential areas. What is it about the fence-line that protects or protected (when the plant was in operation) these communities from contaminants?

o   We strongly recommend that the sampling be expanded to include neighborhoods immediately adjacent to the site since there is reason to expect that smokestack contaminants migrated to these neighborhoods at a minimum. Citing that this is not a requirement of the consent decree is not an acceptable response; PEPCO and DOEE should and have claimed to be committed to the residents of the District and therefore should go above and beyond minimum consent decree requirements if truly committed to community and environmental health.

o   Where contaminants are found near the fence, the extent of the contamination needs to be investigated further and PEPCO needs to continue to follow the contamination regardless of where it is until the full extent of contamination is determined and acceptable levels are detected. For example, screening levels for total PCBs were exceeded at SUS18 (Figure 4-2, Table 4-1) which is near the border of a community area.

o   The direction of the PCE plume (pages 4-50 and 4-51) suggests that migration of contaminants can occur in directions that are not westward as is the assumption for the modeling. This assumption of westward migration of contaminants towards the river may be erroneous based on the PCE contaminants found on the site which is north and west of the historical dry cleaner site (suspected source of pollution) and should be reexamined. This becomes especially important since most of the historically reported PCB spills occurred on the eastern section of the site near Kenilworth Parkside. If migration can occur in directions such as east then you would expect that PCB and other contaminants might be found in Kenilworth Parkside as that is closer to the spill sites than the river.

·       Conclusions from the PEPCO Benning RI risk assessments seem to be inconsistent with what has been concluded for the Phase 1 Anacostia River Sediment RI risk assessments. These need to be addressed:

o   Baseline Ecological Risk Assessment - PEPCO found “little to no potential for ecological risks to the wildlife community from ingestion of prey items containing PCBs” (PEPCO Benning RI at 6-3), but the Anacostia River Sediment RI found possible PCB risks to green heron and kingfishers in Reach 456 (which includes the PEPCO Benning study area) when NOAEL TRVs were used (Anacostia River RI at 139 and Table 10.14).

o   Human Health Risk Assessment - PEPCO concluded that fish consumption presents a risk only for non-cancer effects (PEPCO Benning RI at 6-2), but the Anacostia River Sediment RI found total PCBs were a contaminant of concern for both fish ingestion cancer risks and fish ingestion non-cancer hazards for all reaches of the river (Anacostia River RI at 149).

·       It is unacceptable that little effort has been made to post signs near the PEPCO Benning property warning people not to fish or consume fish caught in the area. We strongly urge DOEE to ensure that sufficient signage is posted up and down the entire river, especially locations frequented by people.

·       The report states that “To some extent, the existing operational and institutional controls that are in place at the Site provide effective exposure prevention measures, and direct contact exposure pathways may be currently incomplete or insignificant.”  While this might be to some extent true for the time-being, incidental land-use controls for operational or occupied facilities do not constitute legally-binding institutional controls or covenants that are protective of human health and the environment. We are pleased therefore to see that the revised BHHRA will reflect some more realistic potential exposure scenarios.

·       The general tone of this RI report seems much more like an opinion piece than a scientific report. PEPCO seems more interested in placing the responsibility on other potential sources rather than uncovering the facts and presenting date in an unbiased manner. For instance, PCE should not be described as a dry-cleaning agent unless it is also described as a solvent potentially used on-site. Either no assumptions should be encouraged, or all the potential scenarios should be explicated together.

·       There is a substantial amount of work that PEPCO and DOEE are going to be engaged in to better understand contaminants found in order to finalize the Remedial Investigation report. We recommend that an additional comment period for RI Work Plan Addendum #3 or at the very least the report on findings following this additional work (second/revised draft RI report) be offered to the public. We realize that this may add more time to the schedule, but with so much new work and information to come it is important to give the public time to review and comment.

·       The report states that “…this CSM will be updated in a separate stand-alone CSM Technical Memorandum.”  The public should have the opportunity to review and comment on this separate CSM Tech Memo. We note that this newly-proposed document was not previously listed as being provided to the public for review and comment: will it be made available for such a review, and if not, please explain the rational since the CSM is a critical component of the RI/FS process.

·       We recommend that PEPCO reassess the way it presents figures and tables for public consideration in this report. At the very least, references to them should be hyperlinked so members of the community accessing the report electronically can have the referenced information immediately to hand. Requiring members of the community to flip between appendices and the main report as they review it in their leisure time puts an extra burden on them as they voluntarily educate themselves about the potential threats to their health and that of their community. PEPCO and DOEE, in their commitment to the community, should do everything in their power to make this report as accessible as possible to those residents who take it upon themselves to read and understand it. The best option would be to include pertinent figures in-line with the pertinent discussions. Many figures in the report combine contaminant name, level, and location in maps that cover much of the most relevant information from the tables. Where a table is still needed, a trimmed version in-line would greatly aid the accessibility of the document.