Friday August 16, 2024
ESCO Comments from ODEQ with Point Source responses…..
8-30-2024 DEQ follow-up in red below
ESCO Site ECSI 6285
General Comments
1. The Report does not clearly and effectively describe the results of investigations, or the scope of remedial actions completed at the site and, more importantly, describe remaining residual contaminant conditions and the risk they may (or may not) pose to public health and the environment. Data summarization is unwieldy, further making review difficult. Presentation is not helped by including long tables within the text portion of the document and haphazard summarization of important information. Text, figures, and tables may be included as one submittal, with appendices submitted as separate files.
Section 2-Site Background provides (1) Regulatory History in sequential order (Section 2.4) and (2) a list of Applicable Environmental Investigations in sequential order along with a description of each of the ten environmental investigations that Point Source is aware of (Section 2.5).
Section 4-Site Investigation provides a sequential description of post demolition site sampling (Section 4.1).
Section 12-Removal and Remedial Action Report provides a sequential description of remedial actions taken on the site with notations regarding the specific figure that each of these actions is depicted (Section 12.1)
Section 13-Residual Risks provides a description of residual contamination and risk per site area. The areas described are clearly depicted in Figure 7 and have been the same areas consistently used throughout the project by both Bridgewater and Point Source. Each area with residual risk also has a Figure specific to that area.
Any additional detail DEQ can offer on why or which parts of these sections would greatly assist in our effort to make changes to the presentation that clarifies these sections.
There are three exhibits in the body of the report which are placed in order to support a specific discussion. Section 5.2 Nature of Contamination has an exhibit of Contaminants of Interest. Section 7.1 Conceptual Site Model includes a Summary of CSM and Section 9.1 includes an exhibit of Contaminants of Potential Concern. Point Source has included these three exhibits in reports with a discussion of risk- based closure for years without any DEQ Project Managers asking that they be removed so we would appreciate your input as to why they are problematic in this context.
On February 28, 2022, Point Source specifically asked for suggestions regarding report flow and offered some suggestions of our own. We did not receive a response from DEQ. A preferred Table of Contents provided by DEQ would greatly assist our effort.
2. The report is organized in an unusual order. Land and water use determinations, Section 8 should be discussed before developing the Conceptual Site Model (CSM) in Section 7. The title of Section 7, Contaminant Fate and Transport is too limiting if it includes the Location of Facility (LOF) and CSM. Potential
hot spot determinations in Section 7 are made after the risk assessment in Section 9. Much of the residual risk assessment in Section 13 concerns the baseline risk assessment.
We used the report format requested by Fransiska Landes of DEQ in an email dated September 3, 2020. As noted above, perhaps DEQ can provide a table of contents (just section titles) and we will reposition this report in the requested format. I cannot think of any other manner to conclude this topic since we used the report template requested by DEQ. That is correct for the first submittal of the report.
This last submittal was titled an ICP Report although our comments requested to use the VCP process. Attached is a link to our VCP RI/FS guidance, with an outline for a Remedial Investigation report. The last submittal had most of the topics in this outline example.
DETP/24/657 - RI FS ScopeWork Long Form
3. The CSM limits scenarios to those screened in by comparison with Risk-Based Concentrations (RBCs). Instead, the CSM should identify potentially complete risk pathways based on the site's current and reasonably likely future use. RBCs can then be limited to relevant scenarios. For chemicals without DEQ RBCs, DEQ’s recommended approach is to screen using EPA’s regional screening level values.
I am not quite sure as to the meaning of this comment. We presented all potential scenarios in Section
7.4 and provided a clear basis for selection or exclusion. Again, Point Source has approached this aspect of the CSM in this manner for years and has never had a comment regarding the approach from DEQ in the past.
Please address the CSM to identify potentially complete risk pathways based on the current and reasonably likely future use.
Please address the likely future and current RBCs in the CSM. The site is not currently used for occupational uses but may in the future.
4. DEQ revised vapor intrusion RBCs in June 2023. As part of the revision, DEQ no longer uses the soil to indoor air (RBCsi) scenario for screening, instead relying on soil vapor and groundwater. for screening for vapor intrusion risk. Also, in June 2023, DEQ indicated that we are no longer confident using separate screening levels for urban residential exposure scenarios. As a default, all residential scenarios should be screened using residential RBCs.
As I am sure you are aware the recent DEQ online seminars have addressed this issue and for projects that were already in the review process DEQ indicated that it was not expected that that the new vapor guidance would be expected.
For sites that have not completed a remedial action, the project manager may use updated evaluation using current guidance.
DEQ requests that the updated VI guidance be used in your next RI report submittal.
In your February 15, 2022, comments you requested that we add urban residential even though the site is zoned for industrial use.
Urban residential screening is not needed.
5. The Site is participating in the Voluntary Cleanup Program (VCP), not the ICP. This document is titled an Independent Cleanup Program Final Report. Please correct the title and format of the Report to follow the Voluntary Cleanup Agreement process. When resubmitting the report, consider elements in DEQ’s guidance for a scope of work for Remedial Investigations (RI) and Feasibility Studies (FS).
The site is in the ICP, not the VCP. Point Source and 1535 A1 LLC was informed in writing by DEQ on January 28, 2020, that the site was no longer in the VCP due to “lack of engagement”. Point Source
responded in writing sharing details as to each specific element of DEQ’s prior request we had provided and where that information had not been provided-why not. In any case the site is definitely an ICP site.
The first submittal of the ICP report was at the direction of DEQ in 2020. DEQ commented that the this report should follow the VCP process. The site has a VCP agreement and is not an ICP site.
Specific Comments
Page iii-Executive Summary. Please provide the updated Contaminated Media Management Plan (CMMP) based on this Report.
The CMMP is included as Appendix J of the February 7, 2024, submittal.
Page 1. The bulleted items include a mix of inconsistent descriptions. For example, there is a statement that the ecological risk assessment will be performed, but the human health risk assessment is discussed by reference to RBCs. It would be better to state that screening will be performed using human health and ecological RBCs or that human health and ecological risk assessments will be performed.
Agreed.
Page 10. Other than a suspicion, support for identifying municipal water as the source of chloroform was not provided. Municipal water could have been sampled.
This was a summarization of the Bridgewater findings, not a conclusion of Point Source’s. We do not know where Bridgewater sourced the water to inject in these wells.
Page 11. The statement that all soil sample results for lead were below the leaching to groundwater RBC (30 mg/kg) should be documented.
Agreed.
Page 22. The unlabeled table shows BaP in groundwater, but BaPEq is shown as ND. This should be reconciled because BaPEq concentration should be at least equal to BaP concentration.
This exhibit is clearly labeled as Contaminants of Interest. Correction noted.
Page 27. It is not appropriate to state that an exposure pathway is incomplete if concentrations are below RBCs. Complete pathways should be identified so appropriate RBCs can be used in the screening step. That is a key purpose of the CSM.
We accept that comment. Complete or potentially complete pathways should have been identified in Section6 .
During updates to soil vapor RBCs in June 2023, DEQ stated that soil data will no longer be used to evaluate vapor intrusion. This decision was based on EPA’s experience that soil concentrations do not correlate well with indoor air concentrations.
Discussed in General comments discussion.
DEQ also stated that separate default RBCs for urban residential exposure will no longer be used. The urban residential scenario can still be discussed, but default residential RBCs should be used in the screening
evaluation.
Urban residential screening is no longer requested.
Discussed in General comments discussion.
Page. 29-Section 7. Please address matters outside of the scope of Contaminant Fate and Transport. Low- level contamination in groundwater was attributed to prevalent regional contamination from other cleanup sites without documentation. Similarly, support is needed to document that municipal water is the source of detected chloroform.
Agreed.
Pages 30 and 31-Section 7.4. The CSM should identify potentially complete pathways before screening against RBCs.
Agreed.
Page 34-Section 9.1. Urban residential exposure should be evaluated using residential RBCs. If the RBCs were taken from November 2023, it should be clear that soil vapor intrusion RBCs are no longer being used.
Discussed in General comments discussion.
Section 9.1.1. This section has a mix of risk assessment results combined with proposed actions. Baseline risks should be presented. Proposed actions can then be presented in another section to show how unacceptable risks will be or were addressed.
Agreed.
Section 10. Cleanup Standards and Hotspots. Acceptable risk levels are standards; RBCs are guidance.
I do not think I understand this comment. We routinely have used RBCs used in this case and have seen others do this as well. We clearly state that we have used the HHRAG (October 2010) as guidance in this section. We routinely have used RBCs used in this case.
Please address this comment.
Page 44-Section 13.0. Residual Risk. This section mainly covers the risk assessment results, which should be covered in the risk assessment section. For sites with proposed caps or other mechanisms that leave contamination, the residual risk assessment can refer to the risk assessment to document the risk if the remedial actions fail or are ineffective.
OK. But I think this comment misses that in addition to Section 13.1 describing the risk, there is a Section
13.2 that discusses Protection of Human Health and the Environment. We will revisit and see how to make this work.
Figures
Figure 1. The location map figure was not provided.
It’s there. Unfortunately got tucked in behind Figure 3 rather than in front of Figure 2. We will fix.
Figure 3. Starting with this figure, the north arrow orientation was switched to the left, not up. In many cases, keeping the same standard orientation may be better to allow for easier comparison of figures.
Where the north arrow is not pointing to the top of the page there is a reason for that depiction. This is a large irregular shaped site and we felt it only made sense to use orientation in the manner that we used it to be able to present data on the figures in a way that was not crowded. We feel this change will result in producing additional figures making the depictions less, not more, helpful. Again, this is a comment we have never had in the past from a DEQ Project Manager. The key is that the north arrow is pointing north.
Figure 20, CSM. Saying “no exposure” is incorrect because exposure can occur below RBCs. The CSM should be used to show relevant screening scenarios, not the screening results.
Agreed.
Fig. 27. TPH. Does “Remedial Action” mean it will occur or has occurred? Please make this clear on the figure.
Figure 27 is labeled “Estimated Residual Contamination”. That refers to the remaining TPH-We believe that is clear.
Tables
Most tables should not include separate RBCs for urban residential exposure. Use residential RBCs.
OK. We were specifically asked to add urban residential in February 2022.
DEQ’s approach uses EPA regional screening level values for chemicals without RBCs.
Agreed.
Average arsenic and lead concentrations should be compared with background means, not upper prediction limits (UPLs).
Agreed.
Table 1. Leaching to groundwater should be screened.
Not quite sure I understand this comment. Even where separation is clearly identified? Separation is a tool that is included in the Stormwater Infiltration study approved by both DEQ and the City. If the determination that leaching to groundwater is an incomplete pathway is accepted then why screen for leaching to groundwater?
Please screen the leaching to GW pathway.
In a January 17, 2024, memorandum (Updated Residential Soil Lead Guidance for CERCLA Sites and RCRA Corrective Action Facilities, EPA Office of Land and Emergency Management), EPA recommends that the regions use a residential soil lead regional screening level of 200 mg/kg, or 100 mg/kg if additional sources
of lead are identified. Use either 100 mg/kg or 200 mg/kg. Regardless, the old residential RBC for 400 mg/kg lead is no longer applicable. For this report, it is acceptable to state both screening values and discuss the uncertainty. There is uncertainty in an occupational scenario RBC because EPA did not recommend a new value. This uncertainty can be acknowledged, noting that when DEQ develops a new worker RBC for lead, it will be below 800 mg/kg.
Agreed.
Table 2. Groundwater is screened using tap water RBCs, although this was not identified as a complete pathway.
Agreed.
The January 2018 data for arsenic should be color-coded to reflect the exceedances of RBCs.
Agreed.
DEQ’s approach uses EPA regional screening level values for chemicals without RBCs, including molybdenum, zinc, and uranium.
Agreed.
Table 3A. For chemicals without RBCs, EPA RSLs should be used. The source of zinc RBCs is unclear.
Agreed.
Please provide a schedule for the submittal of the VCP RI report.
Jim Orr