, pg. 3 ● The specific purpose for the supplemental sediment sampling should be detailed in Section 1.3.4, Supplemental Sediment Monitoring, in order to guide development of the supplemental sampling and to allow for data gathering to inform a meaningful understanding of the relationship between sediment and fish PCB concentrations at the needed spatial scale.
, pg. 3 ● The spatial extent of locations where high resolution cores provide a datable core chronology is very limited throughout the Xxxxxx River; applying calculated recovery rates from a small amount of relatively rare locations does little to inform the understanding of the recovery of surface sediment PCB concentrations throughout the Xxxxxx estuary. ● Because the high resolution cores can only be collected from continuous deposition, the information from these cores likely will substantially overestimate the rate of deposition and recovery relative to most other locations in the river. ● The high-resolution coring work described in Section 1.3.5, High-Resolution Sediment Coring Program, will wait until the supplemental sediment sampling work "has been received and evaluated." The supplemental sediment sampling will not be done until after the fish, water column, and Be-7 sampling work is done. Given the typical pace of sampling, analysis, data evaluation and reporting by GE on the Xxxxxx River Superfund Site to date, the high-resolution coring work will likely not be done until 2025 or later. The Sampling Plan must specify that the high-resolution sediment sampling work be done this year (2023), as the siting of the high-resolution core locations is not dependent on the results of fish, sediment, or water sampling rather, the siting of high- resolution coring locations is driven primarily by the need to find the limited number of areas in the estuary which are consistently depositional over the period of interest (i.e. since 1992).
, pg. 4 ● Section 1.4, Scope of this Sampling Plan, again highlights the protracted sequencing and schedule for the work. EPA should set the schedule now for when GE is required to provide the submittals, limit the opportunity for additional delays, and specify what, at a minimum, will be required for the work.
, pg. 7 ● It is unlikely that any meaningful understanding of "spatial and temporal conditions for PCBs and additional water quality parameters throughout the Lower River" will be obtained by the specified water sampling, as there are only five sampling locations over the 150 miles of the Xxxxxx estuary. In order to meet the DQO specified here, a much more robust sampling program will be needed to provide the needed spatial resolution. To understand the spatial and temporal conditions in the Lower Xxxxxx surface water, the sampling plan should include (at the start) a sufficient spatial resolution to develop the data needed to allow for development of a sampling plan which will provide the necessary scale. ● Monthly water column sampling will provide limited information on the temporal conditions. Weekly sampling from the primary locations during the spring through fall would provide more useful information on the temporal conditions.
, pg. 7 ● The water sampling to be performed should include sampling outside of the center channel. Each sampling location should include separate samples from east and west of the channel, in the shallower margins of the river, in order to understand the exposure point concentrations in surface water where most of the biological activity occurs in the estuary. It may not be possible to develop any understanding of the relationship between sediment, water, and fish PCB concentrations without sampling outside of the center channel.
, pg. 8 ● Limiting the sampling to a maximum of 12 rounds may result in insufficient information to allow for development of an understanding of the relationship between water, sediment, and fish. EPA should direct GE to collect the data for the foreseeable future until sufficient data are available to meet the DQOs. The plan should also specify the health and safety criteria to be used to allow GE to omit sampling for safety purposes.
, pg. 10 ● Use of a congener-specific method (Method 1668C in the Sampling Plan) is appropriate for this water sampling effort and should be continued. A similar effort should be undertaken in the analytical program for the other important media - sediment and fish - in order to meet the DQO for this proposal, to understand the relationship between fish, water, and sediment PCB concentrations. EPA should also set a specific schedule for submission of the data to EPA and New York State, to avoid delays in data interpretation and conceptual site model development.
, pg. 11 ● It is unlikely that the DQOs for the fish sampling will be met by the specified fish sampling, as there are only five sampling locations over the 150 miles of the Xxxxxx estuary. In order to meet the DQO specified here (including "to collect data across the main ecological segments of the Lower Xxxxxx, spanning the full spatial extent as well as various turbidity and salinity conditions that occur throughout the estuary") a much more robust sampling program will be needed to provide the need spatial resolution to meet the DQOs. ● EPA should direct GE to also gather fish samples, at a minimum, from all of the secondary locations. ● The presence of walleye, a species often targeted and consumed by people, should be determined at each freshwater sampling location, and collected/analyzed to evaluate the exposure point concentrations for Lower Xxxxxx walleye consumers. ● In order to meet these DQOs, the spatial resolution of the fish sampling effort will need to be improved. Use of only five existing sampling locations across the entire estuary will not improve EPA’s understanding of the distribution of PCBs in Lower Xxxxxx fish, the human health and ecological risk at issue, or the relationships between fish, sediment and water.
, pg. 12 ● The analytical program, based primarily on the use of the Aroclor Sum Method, will not allow for the DQOs to be met. In order to understand the relationships between fish, sediment, and water the congener methodology should be used for fish as it is for water. ● Fish PCB data would help evaluate sources of PCBs, but Aroclor data will not provide useful information. Because the primary source of PCBs in the Lower Xxxxxx is from the GE plants, PCBs in the Lower River will be highly weathered. Analyzing only 5% of the samples with method 1668C, spread among species and locations, will provide minimal useful information. Also, total PCB concentrations as reported as Aroclor totals will require adjustment (“homologue equivalents”), which adds considerable uncertainty to the PCB values. The New York State Department of Environmental Conservation (“NYSDEC”) has strongly urged EPA to use congener analysis for all fish tissue in the lower river. ● In oral discussions, EPA has stated the Aroclor–Congener relationship broke down at a total PCB of about 0.15 ppm. Among NYSDEC’s 379 lower Xxxxxx River samples from 2021, 47 (12%) had a total PCB less than or equal to 0.15 ppm, and 115 (30%) had a total PCB less than or equal to 0.25 ppm. Histograms (the first is truncated at 1 ppm and the second shows all samples) show that the lower concentrations are dominated by white perch and striped bass. We can also expect that the added Xxxxxx Xxxxxxxxxx Bridge area samples and more marine species will have lower concentrations. Using Aroclor analysis risks too many samples with inaccurate lower concentrations. ● Using PCB Aroclor analysis in fish rather than PCB congener analysis will substantially limit the information on the spatial distribution of PCBs and the relationships between water, sediment, and biota.
, pg. 14 ● The list of target species should include those species which are often consumed by people. An updated survey of human fish consumers may be needed in order to refine the list of targeted species, while a review of the fish species consumed by piscivorous wildlife may also need to be taken into account in identifying target species. ● Striped bass are listed but collection information (target numbers, timing of sampling) is omitted. Since striped bass show pronounced differences in PCB accumulation between males and females in the spring, with males generally having higher concentrations, targets should include equal numbers of both males and females [Males have higher PCB concentrations than females in the spring by a factor of 2.4-4 at both Albany and Catskill sampling locations]. Also, striped bass in the fall tend to have higher PCBs than in the spring, particularly in females [both males and females have higher PCB concentrations in the fall by a factor of 2+ for males and 3 for females]. If the objective of collecting striped bass is to provide information relevant to human health, samples should be collected in both spring and fall. These considerations should be applied to other adult species (eg. bass). For example, males have higher PCB concentrations by a factor of 2+ for both largemouth and smallmouth bass. ● Pumpkinseed are listed but not specified as “yearling,” to be consistent with the Upper Xxxxxx sampling. ● GE should expand the fish sampling program as suggested by NYSDEC to include blue crabs throughout the species range in the estuary. The plan calls for blue crabs to be collected only at Tappan Zee and the Xxxxxx Xxxxxxxxxx Bridge. Since blue crabs are available further upstream, blue crab samples should be collected at additional upstream locations at least as far as Kingston. It would also be useful to have survey data from the public as to where people are catching blue crabs for consumption.
