Comments on DOE Risk Assessment for LEHR Site
Cleanup Action Standards
G. Fred Lee & Associates
VIA e-mail: [email protected]
August 17, 1997
Route 2, Box 2879
Davis, CA 95616
I have completed an initial review of the Revised Draft Final Determination of Risk-Based Action Standards for DOE Areas Volume I and II. This review is attached. I label this initial review since this draft like its predecessor still contains numerous, significant errors in assessing the risk that LEHR site wastes represent to public health and the environment. Further review would likely show additional problems that would need to be corrected. Of continuing particular concern is the inadequate approach toward estimating the vadose zone transport of LEHR site waste to groundwater and the inadequate assessment of the stormwater runoff pathway as a source of constituents of concern for those who use Putah Creek for recreational purposes, especially consume the fish from the creek.
It is highly disconcerting to find that DOE has chosen to ignore DSCSOC comments on basic issues of concern to the public in developing this so-called final draft. If this approach persists then it would be my recommendation that DSCSOC take this matter public and file formal complaints with US EPA and DOE headquarters in Washington, D.C. The public is entitled to a more appropriate assessment of the hazards associated with the LEHR site wastes than DOE has presented so far.
With respect to the stormwater runoff issue even DOE now admits in this draft that it has an inadequate database to assess risk. Over the past two years DSCSOC has repeatedly pointed out the need to develop a credible stormwater runoff monitoring program for the LEHR site. Thus far, neither DOE or UCD has done this. Also they have missed the mandatory July, 1997 deadline established by DSCSOC for the presentation of such program. Both UCD and DOE have been repeatedly told by the RPMs and DSCSOC that this situation can not continue to occur. Both have chosen to give inadequate attention to the situation. Under these conditions DSCSOC is left with no alternative but to file complaints with the regulatory agencies responsible for stormwater management.
DSCSOC has now documented over a two year period repeated continuing significant deficiencies in the LEHR site stormwater runoff water quality monitoring program. There is no question that UCD has been and continues to be in violation of its NPDES stormwater runoff permit through the inadequate monitoring that has been carried out for the LEHR site. There is also no question that since DOE has been responsible for part of this monitoring that it too would be found to be negligent in stormwater runoff monitoring. Possibly both could be reprimand and fined for failing to properly implement a reliable stormwater runoff water quality monitoring program in accordance with current regulatory requirements. It is time to get the regulatory agencies responsible for these issues involved in this matter above the LEHR site RPM staff level.
I will as time permits be preparing a formal complaint that DSCSOC can submit to the regulatory agencies on the woefully inadequate stormwater runoff monitoring programs that DOE and UCD have been conducting for the LEHR site. When completed this complaint will be forwarded to you for filing with the appropriate authorities and the public.
If you have questions or comments on the attached comments, please contact me. I suggest that you forward these to the RPMs and LEHR site Superfund responsible parties (DOE and UCD) indicating that if they feel that my assessment of any aspect of these matters is incorrect they should contact me.
G. Fred Lee, PhD, DEE
Technical Advisor to DSCSOC
DRAFT FINAL DETERMINATION OF RISK-BASED ACTION
STANDARDS FOR DOE AREAS VOLUME I AND II
Dated August 4, 1997
Prepared by Weiss Associates
G. Fred Lee, PhD, DEE
DSCSOC Technical Advisor
August 17, 1997
Overall, DOE's revised draft Risk Based Action Standards contains many of the same deficiencies as commented on in the original draft. There is inadequate assessment of both potential groundwater and surface water impacts due to LEHR site wastes. Significant deficiencies still exist in the stormwater runoff risk assessment which relate to errors made in assessing the significance of chemical constituents as well as pathways involved. The transport of contaminants to groundwater is still based on inappropriate and unreliable vadose zone modeling efforts.
DOE is still persisting with the technically invalid and non-protective approach of only considering a few regulated hazardous chemicals, principally Priority Pollutants as constituents of concern. This approach ignores the large number of potentially hazardous and deleterious unregulated chemicals and the regulated chemicals transformation products that could be hazardous or deleterious to public health, groundwater resources and the environment. This approach also ignores the State of California regulation covering the impact of so-called non-hazardous deleterious chemicals on groundwater resources. DOE, by ignoring the previously made comments on the initial draft in developing this draft, will cause DOE to have to develop yet another draft in which the issues raised in the previous and the current comments are adequately and reliably addressed.
For DOE to release a document that does not address the issue of the hazardous and deleterious chemicals that must be managed in accord with California regulations, after the issue has been repeatedly raised in previous comments on DOE documents, represents a deliberate attempt to avoid facing issues of concern to the public. This approach is counterproductive to achieving the DOE's proposed tight schedule for cleaning up the site. Since ultimately these issues will have to be addressed by DOE, it is far better to address these issues at the initial appropriate time rather than have to, after the fact, address them when DOE, Washington, D.C. or others force DOE, Oakland to address the public's concerns about the inadequate approaches being used by DOE, Oakland in assessing the hazards of the site.
Page 2.1, under 2.2 Objectives, states that "DOE and the regulatory agencies plan to use the results provided herein to choose appropriate standards to guide removal action(s)." In the previous paragraphs mention is made of incremental risk assessments from 10-4 to 10-6 and a non-carcinogen hazard quotient of 1.0. This approach could be inadequate to protect public health and the environment from residual chemicals that could be left at the site based on the estimated hazards. While it is stated that this approach is conservative, i.e. protective, that is only true under certain circumstances. In fact this approach could significantly underestimate the real hazard associated with the site, due to the unregulated chemicals and the transformation products of the regulated chemicals, which are not included in the hazard evaluation.
Page 2-3, first paragraph indicates that the exposure scenario for surface waters is through recreational use. While not mentioned here but included later, bioaccumulation in fish could be one of the most important pathways for transferring LEHR site waste to people. As discussed below the bioaccumulation issues have been improperly analyzed by DOE.
Another significant deficiency with this risk assessment approach is that the exposure scenarios do not include the potential for translocation of hazardous chemicals through plant roots, leaves and flowers from contaminated soils and wastes to the environment. This issue has been repeatedly raised by DSCSOC as an area that must be addressed in LEHR site investigation and remediation. The failure to include this scenario causes this document to be significantly deficient where it should be rejected as an inappropriate development of readily plausible worst case scenario exposures.
Page 2-3, second bulleted item indicates that there is only consideration given to the surface and near surface of the soil as a source of stormwater runoff constituents. Evidently DOE has chosen to ignore the issue raised several times of subsurface constituents being transported to the surface through terrestrial plants.
Figure 2-1, shows Landfill Unit No. 3 in an incorrect position, Landfill No. 3 crosses the UCD stormwater drainage ditch, i.e. the ditch cuts through the top of this landfill. This figure needs to be redrawn, before this report is finalized to show the proper location of the landfill.
Page 3-1, first paragraph, under section 3.1 states with regard to the data sets "...and recorded in the Site database with no substantial errors or omissions." The Site data reports which are presumably the Site database have substantial obvious errors in them that DOE refused to correct. A critical review of these would likely show that there are others errors that are less obvious that are incorporated into this database. The basic problem with the data handling at the LEHR site by DOE is that neither DOE management nor its contractors have had anyone involved in data review who were aware of what is normal data for the parameters measured.
Page 3-1, at the bottom of the page lists the data that was used in this investigation which is restricted to the Limited Field Investigation (LFI) data. It appears that DOE is persisting with what has been found to be an inappropriate approach of conducting a limited field investigation on characterizing the wastes then attempting to use this LFI as a basis for judging the hazard of the site, wastes and contaminated soils. This approach is not valid. DOE was warned when it undertook the LFI that such an approach will not be adequate for characterization of the hazards of the wastes and contaminated soils with respect to evaluating what can be left at the site. A far more comprehensive field investigation is necessary to make such an evaluation than has been done by DOE. This was made clear by Duncan Austin and DSCSOC. The LFI is only useful to identify some of the potentially hazardous situations. It is not adequate to fully identify all of them. This issue will become extremely critical in terms of determining the extent of soil removal that will have to take place around the waste management units.
With respect to not using all of the Dames and Moore data that was collected by DOE because of the limited data base that exists at the site, a review should be conducted of how the Dames and Moore data compares to that of the more recent data.
Page 3-3, fourth paragraph mentions the California Inland Surface Water Criteria. There are no California Inland Surface Water Criteria, these were voided by the courts several years ago. What should be used now is the US EPA's recently released California Toxics Rule Criteria. They are available in an August 5, 1997 Federal Register release as US EPA 40 CFR Part 131 Water Quality Standards; Establishment of Numeric Criteria for Priority toxic Pollutants for the State of California; Proposed Rule.
From the discussion on page 3-3 it appears that DOE has chosen to ignore the unregulated chemicals and the transformation products. This approach is inappropriate and such chemicals must be included in a properly conducted risk assessment through a surrogate compound representing possible worst case scenario situations that could be present from unregulated chemicals.
Page 3-4, under 3.2.2 "Evaluation of Tentatively Identified Compounds"should not be interpreted to mean that DOE has conducted a proper evaluation of unregulated chemicals or regulated chemical transformation products. There can readily be a wide variety of hazardous and deleterious chemicals associated with the LEHR site that have not been detected due to the limited scope of approach that has been used to search for such chemicals.
Page 3-4, section 3.2.3 "Elimination of Background Metals and Radionuclides," more information is needed before we could judge the validity of the approach used to eliminate certain constituents from consideration.
Page 3-4, last paragraph, the division at three-foot depth is not adequate to prevent translocation of hazardous chemicals from below three feet to the surface. At least five-foot depth should be used for that purpose unless UCD and DOE wish to patrol the area in perpetuity to insure that no vegetation with roots that penetrate more than three feet will be allowed to develop at the site.
Page 3-5, last paragraph on "Background Data Sets," it is my understanding that it was recently concluded that there is inadequate data on background concentrations of constituents associated with the LEHR site and that additional data is needed. It is certainly inappropriate to proceed as proposed on page 3-6, first paragraph, last sentence to assume that the RPMs and the public accepts the approach that is used. Both the RPMs and the public have made it clear that there is inadequate background database and that additional data would have to be collected.
Figure 3-1, "Flowchart for Determining the Reasonable Maximum Exposure Concentration in soil," with respect to the first triangle I would want to see how the results of this evaluation would change if the data that has been dropped out because of certain criteria were included in the data set. Would this change the analysis to any significant extent? Some of the reasons for dropping the data are fairly weak, and not necessarily justified. That data may be as valid as the data that is actually used.
Figure 3-2, "Flowchart for Identifying DOE Area-derived COCs in Surface Water," the first triangle should include subsurface soils as well because of the translocation issue. The second left side triangle detected in DOE stormwater from SWL-1 or SWL-2 is not a valid approach. There are other stormwater runoff areas that have not been adequately and reliably sampled. They could show significantly different kinds of data and constituents than have been reported herein. As discussed in previous correspondence on this matter, it is too early to do any risk assessment on stormwater runoff issues since thus far DOE and UCD have still not developed a reliable adequate stormwater runoff monitoring program. At least a year or two of data is needed before a proper risk assessment can be developed for surface water runoff issues associated with the LEHR site. Again, this is an issue that has been discussed in previous correspondence commenting on this and other draft documents developed by DOE. By failing to address this issue, DOE is significantly eroding any confidence that the public and others may have in its ability to properly evaluate the risk associated with the site. This approach, if it persists, will be strongly detrimental to DOE, Oakland since the credibility of the management will be discussed with appropriate regulatory and management authorities for the LEHR site. By failing to address issues it appears that DOE, Oakland wishes to have a confrontation on the credibility of its risk assessment approaches in protecting the public's interest associated with UCD's mismanagement of wastes for which now DOE is responsible.
Page 4-2, fails to mention the HSU-4. As I recall this is the same error that was made in the previous draft of this document. Further, the characterization of the 135-143 feet area does not include the sandy, gravelly lenses which contain water, which have been found by UCD's investigations. The inadequate description of the groundwater hydrology must be corrected before this document is finalized or else the document will be judged inadequate and rejected as an appropriate report on issues.
Page 4-2, fourth paragraph, again ignores HSU-4, this is another inadequate discussion of issues, that causes this final draft to be rejected as a credible document.
Page 4-3, contains another significant deficiency in which DOE is developing documents that do not discuss the current situation. As was pointed out in previous comments on this draft, the flow in Putah Creek has now changed due to a consent decree. DOE should stop releasing documents that are out of date and must start considering the comments that are made by reviewers as part of revising the documents.
Page 4-3, 4.2 "Exposure Scenarios," first bulleted item must be expanded to include exposure to translocated waste items from depths of over three feet below the surface.
Page 4-3, under "Scenario 3," it is not possible to rule out groundwater transport of hazardous chemicals from the LEHR site to the south in HSU-4. Until the flow directions are known for HSU-4 as influenced by ag well pumping it must be assumed that there is a possibility of groundwater transport to the south which could impact water supply wells that exist now or could exist at some time in the future.
With respect to the last paragraph on page 4-3, the PRG values established by US EPA Region IX are not necessarily protective since they ignore some important pathways such as translocation.
The statement on page 4-4, section 4.3, "Exposure Pathway Analysis," second paragraph, "Specifically, only a small portion of OU1 and some portions of OU2 surface soil comprise the source term for storm water runoff from the site." This is inaccurate. Again DOE has chosen to ignore the comments that were previously provided on the stormwater runoff system from the LEHR site that must be considered in properly developing a risk assessment. As far as I can know, there is no evidence that runoff from OU1 and OU4 could not enter the LF-1 stormwater runoff site. Further, it is possible that because of the drainage ditch that occurs to the middle of the site which transports stormwater to UCD's drainage ditch near Landfill No. 3, it is possible that DOE areas are contributing stormwater runoff constituents through the top of Landfill No. 3. Further, LEHR site wastes are deposited in Landfill No. 3. Thus far this issue has not been adequately addressed by UCD or DOE.
The issue of flow regimes as part of surface water runoff needs to be examined further before any conclusions on pathways can be reliably developed.
Page 4-6, section 18.104.22.168 "Surface Water Pathways - The Storm Water Runoff Model." The basic modeling approach used in which an attempt is made to calculate the dilution of LEHR site soil derived constituents ignores the fact that many of the constituents of concern tend to bioaccumulate from deposited sediments. For example, mercury bioaccumulates from mercury in sediments through methylation to fish tissue. From the information provided it appears that DOE has ignored this dominant pathway in its stormwater runoff modeling efforts. Without this pathway, the approach used by DOE is technically invalid.
Page 4-7, section 22.214.171.124 "Ground Water Pathway - Vadose Zone and Ground Water Fate and Transport Models," continues to use the vadose zone model that has been found to be unreliable for predicting contaminate transport. Detailed comments were presented on why the modeling effort that was presented by the DOE contractor was not valid, these have not been addressed. Therefore, at this time, this modeling effort is a waste of public funds, since it does not properly reflect how contaminants are transported in the vadose zone.
Also under section 126.96.36.199 "Ground Water Pathway - Vadose Zone and Ground Water Fate and Transport Models," under the second bulleted item it states: "The result of this modeling calculation was that the offsite ground water concentration is estimated to be 0.19 times the onsite concentration in ground water." What attempt has been made to verify this? There is data, does this match? Further, consideration needs to be given as to where onsite does this 0.19 apply?
Page 4-8, section 188.8.131.52, "Biological Media Models," suffers from the same kinds of problems as discussed for Stormwater modeling. The basic assumptions in this modeling effort are not valid for some important transport mechanisms that lead to hazardous conditions offsite.
Page 4-9, paragraph 184.108.40.206, "Surface Water Pathways," in the first paragraph states, "Secondly, ground water is known to flow to the northeast, away from Putah Creek." That statement appears to be true for HSU-2. However, the direction of groundwater flow for HSU-4 is unknown at this time. It is disconcerting that DOE would turn out a report of this type in which these issues have been discussed in detail at RPM meetings, yet are ignored in DOE draft reports prepared months after the RPM meetings where the issues were discussed. This type of approach is strongly contrary to achieving the DOE accelerated time table. This draft will have to be redone to correct for the errors that have occurred throughout it. Most of these could have been corrected and addressed at the time that this draft was prepared, if it had been developed properly.
Page 4-10, 220.127.116.11 "Ground Water Pathways," second paragraph, again a 1/5 ratio is used between onsite and offsite groundwater concentrations. This should be verified through existing data.
Page 4-13, Figure 4-1 "Exposure Pathways Analysis, Scenario #1: Onsite Researcher," assumes that a worker (students) do not ingest aquatic food from Putah Creek. That is an inappropriate assumption. Certainly, this could occur and should be included as a pathway.
Figure 4-3 assumes that HSU-4 does not cross Putah Creek. That assumption is not valid at this time.
Figure 4-3 does not include a pathway for translocation through plants to the surface. This pathway must be included. The dermal exposure should assume in Figure 4-1, 4-2 and 4-3, that the workers come in contact with translocated hazardous chemicals which accumulate within a particular area of the site. The issue is not one of the workers contacting soils at a given soil concentration, but an area that has accumulated hazardous chemicals.
Much of the discussion in Section 5 is technically weak because DOE failed to consider the issues previously raised, about the inappropriate or inadequate pathways and the assumptions used, as part of properly preparing this and other sections.
Page 5-3, third paragraph, the statement is made "ATSDR (1996) concluded that, with the exception of lead and mercury in fish, chemical and radionuclide contaminant levels in Putah Creek surface water, sediments and fish do not pose a significant human health risk." As discussed in materials DSCSOC provided to DOE and the RPMs, ATSDR's assessment is based on a flawed analysis of the data since the US EPA lab doing the work did not use sufficiently sensitive analytical procedures for a number of key parameters to measure the parameters at the potentially significant levels. Further, ATSDR did not incorporate US EPA Region IX critical concentrations in fish tissue in assessing hazards. Dr. W. Taylor has acknowledged that Dr. Lee's comments on the deficiencies in the ATSDR US EPA study are appropriate and that a new study is needed to address these deficiencies, as well as to confirm the initial results.
The statement in the Page 5-3, third paragraph, last sentence, "Therefore, it is relevant to examine here whether the DOE Areas at the Site could be contributing significantly to the lead and mercury concentrations observed by ATSDR in fish." This statement is inappropriate. There are a variety of other constituents of concern at the LEHR site that could be contributed in the stormwater runoff to Putah Creek that must be considered.
Page 5-3, last paragraph shows that DOE does not understand the elements of how the lead water quality criteria were developed. First, there is no lead criteria in the State of California. Second, the criterion values were not based on consideration of bioaccumulation. The analysis presented in this paragraph is fundamentally flawed and technically invalid.
The statement is made on Page 5-3, last paragraph, "Mercury has not been detected in storm water runoff samples from the DOE Areas, at a detection limit an order of magnitude less than the EPA NAWQC." A check for a definition of what NAWQC is, shows that it is not found in the list of acronyms on page A-1. This is more of the inadequate presentation and proofreading of materials that has prevailed through DOE reports for the LEHR site investigation. A check of the 1996 data report, released in June 18, 1997, shows that there is no data for mercury analysis in stormwater runoff.
I do not remember that the RPMs were even notified that DOE has stopped measuring mercury in stormwater runoff. It has been previously found that DOE without approval of the RPMs arbitrarily stopped measuring a number of parameters, such as ammonia which were showing that UCD's waste water treatment plant was violating its NPDES permit. It appears now that mercury was also deleted from the parameters measured, without appropriate review. Certainly if this had been properly reviewed, the DSCSOC would never have agreed to such an approach and would have filed a protest with the regulatory agencies, DOE headquarters and US EPA Washington, D.C. on this issue, based on the importance of mercury as a potential LEHR site bioaccumulation issue. DOE should be immediately ordered to reinstate the monitoring of all of the parameters that it arbitrarily dropped without permission of the RPMs and DSCSOC. This is yet another reason why the stormwater runoff monitoring program conducted by DOE and UCD has been a non-credible program and continues to be one that lacks credibility with respect to protecting public health from LEHR site waste derived constituents.
Further, while I have not yet conducted a detailed review of the 1996 LEHR site data report, a cursory review associated with attempting to examine the recent mercury stormwater runoff data shows that it too was inadequately prepared and proof read as previous DOE LEHR site data reports. The reports present inaccurate, unreliable information on issues of concern to the public, such as water quality standards and in the reporting of units for chemical constituents. A more comprehensive review would likely show the same kinds of problems in this data report as were reported by DSCSOC in the 1994 and 1995 data reports. DOE has still not corrected these errors with the result that the data reports must be considered non-credible presentations of data.
The statement on page 5-4, first paragraph "...do not result in any significant contribution of mercury to the creek above that which might be expected in naturally occurring background soil." is not based on an adequate database to make such a statement.
Examination of Volume II, Page A-10a "Identification of Contaminants of Concern in Surface Water," page A-25 shows that mercury is listed here as a US EPA Water Quality Criterion of 0.0021 mg/L. Those responsible within DOE for developing this table and this value have made a significant error. The US EPA Goldbook criterion for mercury is 0.012 mg/L not 0.0021 mg/L as stated in this table. Further, the detection limit for the LEHR site stormwater runoff of 0.2 mg/L is several orders of magnitude greater than the US EPA water quality criterion which is based on bioaccumulation of mercury in fish tissue, i.e. the primary reason for concern about mercury. The analysis that has been done by DOE on mercury is fundamentally flawed and must be redone by someone who understands the elements of water quality criteria and standards, as well as the elements of water analysis.
Page 5-4, first full paragraph, states "...DOE storm water runoff from Lift Station 1 represents less than 10% of the total lead concentration measured in Putah Creek." This means that lead from the DOE site could be a contributor to excessive lead that ATSDR found in fish tissue. While it is not a dominant source, it could be a contributor to this problem at some times and therefore should be controlled.
Page 5-4, third paragraph is an attempt by DOE to claim that it only contributes about one percent of the lead to Putah Creek. Even one percent could be a significant contributor to the excessive problem under conditions where the concentrations in the fish are just above the critical levels. Many regulatory requirements specifically include a contributor to a problem as being of significance. At this time, the analysis of lead from the LEHR site stormwater runoff is such that it is not possible to rule out lead from the site being a contributor to the problem found by ATSDR.
Page 5-4, the statement in the fourth paragraph, "Therefore, specifically for lead, it is possible and even likely that surface soil in the DOE Areas is not the only source of contaminants in the runoff." That is an obvious statement that does not need verification. It is a contributor to the thus far identified problems and there may be many others, that are yet unidentified because of the inadequate studies that have been conducted by DOE and UCD in the stormwater runoff area.
The statement on page 5-5, third paragraph, "For the other radionuclides, at the time of maximum dose RESTAD vadose zone calculations show no breakthrough to the unsaturated zone, and thus no risk via this pathway." It is not clear what is meant by "no breakthrough to the unsaturated zone," does DOE mean saturated zone? Breakthrough from where to get to the unsaturated zone? The materials of concern are in the unsaturated zone. Further, the vadose zone modeling that has been done is not technically valid and does not properly characterize vadose zone transport.
Page 5-5, third paragraph, again mentions the 1/5 ratio between onsite and offsite groundwater. This needs to be verified before it can be accepted as valid.
Page 5-7, second paragraph states:
"Evaluation of the data shows significant uncertainty in establishing the relationship between storm water and site soil concentration, in large part because the data set for storm water samples is limited (six total samples available) and the sample results for certain radionuclides are often negative (indicating background concentrations of those radionuclides were greater than the measured concentrations in storm water)."
The same kind of problem occurs for other parameters as well. DOE has not conducted an adequate stormwater monitoring program to even fulfill its own superficial modeling approach, much less, a proper evaluation of the impact of stormwater runoff from the LEHR site on the potential risk to public health and the environment.
Tables 5-1 through 5-12 are not based on a proper evaluation of potential risk for a number of parameters in important pathways of concern to the public. DOE needs to reconsider the original set of comments prepared on the initial draft coupled with these comments and start over with respect to this risk based evaluation, especially as it relates to groundwater exposure and surface water exposure.
Section 6 of this draft report suffers from the same problems as Section 5 and other sections. It contains significant errors and inappropriate approaches for estimating risk.
In the references page R-2, the US EPA reference to 1986 should be changed to 1987.
There are significant problems with Volume II - Attachments Table A-11a where concentrations of constituents for minimum detection are listed as zero. That is an inappropriate approach. The actual detection limits used during the tests should have been listed at that point. The handling of data in this set of tables has been improperly done and needs to be redone by someone who understands the topic area. Further, whoever did this work has gotten carried away with significant figures where the average concentrations of some parameters, such as in Table A-14a for iron, where eight significant figures are presented for the average concentrations of iron.
In Volume II - Attachments, page B-5 presents background soil statistics for metals. It has been previously concluded that there is an inadequate data base to develop such a table.
Table C-1 on page C-5 "Volatile Contaminants of Concern in Soil and Their Associated Henry's Law constants and Kd Values," does not mention chloroform. Was no chloroform found in any of the samples in the DOE areas?
As discussed previously, Attachment E has a number of significant errors in the approach used and needs to be redone where more appropriate approaches are used to characterize stormwater runoff risks.
Page E-13, Table E-5 "Possible Site Impact of Non-Radionuclides to Putah Creek Surface Water," is a presentation of the approach of assuming that there is a constant ratio between stormwater runoff concentrations of constituents and the concentrations of the constituents found in soils. That approach is technically invalid. It would take a massive database, many orders of magnitude greater than what exists, to establish such a relationship with any reliability.
A chemical not addressed in this assessment of risk is dioxin. Because of the ubiquitous nature of dioxin and especially because it is associated with many wastes, dioxin should be investigated as a pollutant in the DOE areas. UCD's waste management activities at LEHR could have contributed dioxins at elevated concentrations compared to background, which could now be causing hazards to public health and the environment. DOE should be required to do a comprehensive review of dioxins present at the site to insure that this is not a problem.
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