DRAFT
LEHR Site Investigation and Remediation Issues of Concern to the Public

Prepared by

G. Fred Lee, Ph.D, D.E.E.
G. Fred Lee & Associates
El Macero, CA 95618

September 1995

Presented below is a discussion of some of the current UCD - DOE LEHR national Superfund site investigation and remediation issues that are of concern to the Davis South Campus Superfund Oversight Committee (DSCSOC) - the public. It is suggested that UCD, DOE and the regulatory agencies that participate as RPM's in the LEHR site investigation and remediation program development and implementation, consider these issues and formulate an approach to address them that can be reviewed by DSCSOC. Adoption of this suggestion will help facilitate the proposed accelerated LEHR site investigation and remediation by addressing key issues that the public finds should be addressed at this time. It is important to emphasize that this discussion of issues is not meant to be all inclusive of issues of concern to the public. Addressing these issues, however, will facilitate LEHR site remediation.

In the discussions presented below, the terms "hazardous" and "deleterious" chemicals are used. "Hazardous" chemicals means those chemicals that are classified as hazardous under US EPA RCRA and DHS Title 22 regulations. "Deleterious" chemicals are all so-called "non-hazardous" chemicals, many of which are, in fact, hazardous and include all chemicals that can impair the use of groundwaters for domestic and other purposes. These include: total dissolved solids; hardness and other constituents that increase corrosion and scale formation within water supply systems and appliances, etc.; taste and odor producing substances; non-conventional pollutants whose characteristics have not been identified and whose hazards - detriments are unknown as well as the conventional pollutants such as hydrogen sulfide, iron, manganese, low dissolved oxygen, etc.

LEHR Site Groundwater Clean-Up Objectives

In order to develop possible approaches for remediation of the LEHR site, it is necessary at this time to define the groundwater clean-up objectives that will be used at the LEHR site. Several of the issues pertinent to this topic that need to be defined are presented below.

Will the LEHR site be remediated in accord with state of California Water Resources Control Board requirements of eliminating all groundwater pollution by hazardous and deleterious chemicals that impair the uses of the groundwaters to the maximum extent technologically and economically feasible?

Will the remediation include removal of all constituents including TDS, potentially hazardous organics that are not now regulated by specific MCL's, taste and odor producing substances, hardness and other substances that impair the use of a water for domestic water supply and/or other purposes that have been derived from past waste disposal practices at the LEHR site?

Are there any constituents in groundwaters that have been derived from the UCD - DOE past and future waste disposal practices at the LEHR site that will not be remediated to the maximum extent technologically and economically feasible as part of developing groundwater remediation programs for the LEHR site?

Scope of LEHR Site Investigation for Remediation of Hazardous - Deleterious Groundwater Pollution Plumes

The UCD - DOE waste disposal practices at the LEHR site coupled with the hydrogeological characteristics of this site have resulted in this site potentially having several large groundwater pollution plumes and a number of smaller, but hazardous - deleterious pollution plumes that represent threats to off-site groundwater quality.

What approach will be used to identify the location of the smaller plumes? What degree of reliability will be achieved in detecting and determining the extent of these smaller plumes?

Since there may be undetected groundwater pollution plumes under adjacent and nearby properties to the LEHR site after the site has been "investigated" that were developed due to LEHR site waste disposal practices, how will the safety and quality of the groundwaters obtained from production wells within the potential sphere of influence of the LEHR site groundwater pollution plumes be assured for as long as the wastes and polluted groundwater are a threat, i.e. forever?

The details of the off-site groundwater monitoring program that UCD and DOE will commit to for as long as the wastes and polluted groundwaters at the site represent a threat should be defined.

UCD and now DOE have been conducting a limited groundwater sampling program of some of the nearby neighbors' wells. This monitoring program has measured only a limited number of parameters of potential concern. The focus of this program has been on determining whether the concentrations of some chemical constituents that potentially could arise from LEHR site past waste disposal practices exceed drinking water MCL's. This monitoring program should be revised so that a more comprehensive off-site groundwater monitoring program is conducted so as to provide for more reliable monitoring for incipient groundwater contamination by LEHR site-derived wastes forever. When will the RPM's develop an off-site groundwater monitoring program that provides a high degree of protection of public health, groundwater resources and the interests of those who utilize groundwaters within the sphere of potential influence of past and, for that matter, future LEHR site waste disposal practices?

Also, when will the LEHR site groundwater pollution investigations begin to evaluate the pollution of the second aquifer under the LEHR site? This aquifer is the primary aquifer used by large municipal production wells. A comprehensive groundwater monitoring program of the municipal water supply wells within the potential sphere of influence of the past LEHR site waste disposal practices should be initiated that will detect the presence of LEHR site-derived waste constituents in the groundwaters in the second aquifer before the concentrations of the constituents exceed MCL's for regulated chemicals. Also, what approach will be used to protect the public from harm from the past disposal practices at the LEHR site that have resulted in groundwater pollution by unregulated chemicals, i.e. those for which MCL's have not yet been established?

UCD Campus Waste Disposal Practices at the LEHR Site

The three UCD campus landfills and possibly the UCD sewage treatment plant located at the LEHR site have polluted the groundwaters with a variety of hazardous and deleterious chemicals that are significant threats to groundwater quality, i.e. beneficial uses of these waters. This pollution has been derived in at least part from UCD campus waste disposal practices that were not associated with the UCD LEHR research activities that also polluted the groundwaters at the LEHR site.

Will all groundwater pollution at the LEHR site and off-site be remediated to restore the groundwater quality to the maximum extent technologically and economically feasible? If the pollution of the groundwaters by the UCD campus landfills and the UCD former sewage treatment plant is not included as part of the LEHR national Superfund site investigation and remediation, when will the pollution of the groundwaters from these areas be investigated and remediated in accord with current California Water Resources Control Board regulations governing groundwater pollution by land disposal of wastes (Article 5, Chapter 15)?

Vadose Zone Remediation

How will the contaminants in the vadose zone below former LEHR site waste disposal areas be remediated so that they no longer represent a threat to further groundwater pollution for as long as the waste components in the vadose zone remain a threat?

Remediation Approaches - On-Site Landfills

One of the proposed possible remediation approaches for the LEHR site is the construction of an on-site "RCRA" landfill. This landfill would receive the LEHR site wastes and contaminated soils that currently exist in or near disposal pits, trenches, existing landfills, septic tank and leachfield areas, etc. What will be the possible proposed RCRA landfill design, and how will this landfill be constructed, operated, closed and receive post-closure care (maintenance and monitoring) for as long as the wastes placed in the landfill represent a threat to groundwater quality through contamination of the vadose zone and groundwaters?

How will the eventual failure of the RCRA landfill liners and cover be addressed for as long as the wastes in the landfill are a threat, i.e. forever, in order to prevent future groundwater pollution by LEHR site-derived wastes placed in the proposed RCRA landfill?

How will the high unreliability of the RCRA landfill groundwater monitoring approach in which vertical monitoring wells having a zone of capture of about one foot that are spaced hundreds to a thousand or more feet apart at the point of compliance for groundwater monitoring at the downgradient edge of the landfill be accomplished so that the public can be assured that the inevitable landfill liner leakage will not cause further groundwater pollution at any time in the future from wastes placed in the RCRA landfill?

Will a dedicated trust fund of sufficient magnitude be established by DOE - UCD to ensure that funds will, in fact, be immediately available for as long as the wastes in the landfill will be a threat to address all plausible, worst-case failure contingencies that could occur as a result of on-site RCRA landfill management of LEHR site wastes? If a dedicated trust fund is not established, what assurance does the public have that UCD and DOE will, in fact, make funds available to investigate and remediate the inevitable failure of a RCRA landfill to prevent groundwater pollution by wastes placed in the landfill?

Capping of Existing LEHR Site Waste Management Units and UCD Campus Landfills

One of the proposed possible approaches for remediation of some of the waste management units at the LEHR site is the placement of a "RCRA" or "less expensive than RCRA" cap over the waste management unit. Since RCRA and less expensive than RCRA landfill covers may only restrict, but will not necessarily prevent moisture from entering the landfill and thereby generate leachate that will lead to further groundwater pollution by UCD - DOE LEHR site waste and UCD campus wastes, how will the capping of the former waste disposal areas prevent further pollution of the vadose zone and groundwaters by wastes in the capped waste management unit for as long as these wastes represent a threat to groundwater pollution?

The low permeability layer of the current RCRA landfill cap cannot be readily inspected to determine when failure of this layer occurs. Several companies have developed leak detectable low permeability layers that can be used in landfill covers that if properly operated and maintained can prevent leachate generation in a RCRA landfill.

Will any RCRA landfill or waste management unit that is proposed to be remediated by capping include the use of a leak detectable cap that will be operated and maintained for as long as the wastes within the landfill or unit represent a threat, i.e. forever? Will a dedicated trust fund of sufficient magnitude to operate and maintain these leak detectable covers be established? If not, how can the public be assured that UCD and DOE will, in fact, make funds available to operate and maintain the covers so that at no time in the future while the wastes are a threat will sufficient moisture enter the landfill or waste management unit to generate leachate that leads to further groundwater pollution?

Since RCRA landfills and RCRA landfill covers do not necessarily provide for true groundwater quality protection from pollution by wastes managed in these types of landfills or capped areas for as long as the wastes in the landfill will be a threat, does UCD - DOE want to leave hazardous - deleterious wastes at the LEHR site that will be a threat to groundwater quality forever and thereby assume the liability for future LEHR site ad infinitum monitoring and maintenance as well as the possible eventual further remediation of the site?

It should be understood that the potentially impacted public will require that UCD and DOE prevent further pollution of the groundwaters associated with LEHR site wastes for as long as these wastes represent a threat. Therefore, it could be appropriate for UCD and DOE to conclude that it may, in the long-term, be more technically valid and cost-effective to remove all hazardous and deleterious wastes and contaminated soils from the LEHR site and manage these at a larger, more suitable site with other wastes.

Reliability of Hydropunch Sampling

The RPM's for the LEHR Superfund site have been using groundwater sampling procedures, such as a hydropunch, that obtain some undefined sample of groundwater at the point of sampling. These sampling procedures, while less expensive, are well-known to not necessarily provide reliable samples of the aquifer system in the region where the samples are collected. In order to use this approach, it is important that the reliability of this and, for that matter, all groundwater sampling procedures that are used be understood and defined. At this time, there are significant deficiencies in the LEHR site groundwater quality data reported to the public due to failure to define what waters are actually being sampled and the reliability of the sampling procedures used to properly characterize the aquifer in the vicinity of the point of sampling.

What water is sampled by the hydropunch sampling of the groundwaters that has been used at the LEHR site? At what specific depth were these samples taken? How well do the samples that were obtained by hydropunch and similar procedures represent the water column at the site where the samples were obtained? Could pollution plumes of LEHR site-derived waste be present below or nearby the sampling point that have not been detected by the sampling approaches used?

These same questions apply to the sampling by the groundwater monitoring wells. Basically, what is the reliability of the various sampling approaches that have been used relative to the potential areas where groundwater pollution plumes could occur associated with past waste disposal practices at the LEHR site? This issue should be evaluated so that the public understands how reliably the LEHR site remedial investigation is being carried out compared to the potential for groundwater pollution to be present at this site.

Upgradient Monitoring Wells

At this time, the LEHR site remedial investigation is relying on one upgradient monitoring well for the upper stratigraphic unit (HSU-1) and the upper aquifer (HSU-2). The composition of the waters obtained from these wells is highly variable. This variability and possible lack of representativeness of the upgradient groundwater makes reliable detection of pollution by LEHR site-derived wastes questionable. The net result is that significant amounts of groundwater pollution could occur at the LEHR site which would not be detected based on statistically significant increases in chemical constituents in the downgradient wells compared to the upgradient wells.

In order to improve the reliability of detection of downgradient pollution by LEHR site-derived wastes, it will be necessary to establish a much more reliable assessment of upgradient background groundwater quality. When will reliable upgradient groundwater quality be established at the LEHR site, and how will the reliability of the upgradient quality measurements be determined?