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Hazardous Waste Site Management: Water Quality Issues (1988)

Chapter: 7. GROUND WATER CONTAMINATION ISSUES IN SANTA CLARA COUNTY, CALIFORNIA: A PERSPECTIVE

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Suggested Citation:"7. GROUND WATER CONTAMINATION ISSUES IN SANTA CLARA COUNTY, CALIFORNIA: A PERSPECTIVE." National Research Council. 1988. Hazardous Waste Site Management: Water Quality Issues. Washington, DC: The National Academies Press. doi: 10.17226/1063.
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Suggested Citation:"7. GROUND WATER CONTAMINATION ISSUES IN SANTA CLARA COUNTY, CALIFORNIA: A PERSPECTIVE." National Research Council. 1988. Hazardous Waste Site Management: Water Quality Issues. Washington, DC: The National Academies Press. doi: 10.17226/1063.
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Page 121
Suggested Citation:"7. GROUND WATER CONTAMINATION ISSUES IN SANTA CLARA COUNTY, CALIFORNIA: A PERSPECTIVE." National Research Council. 1988. Hazardous Waste Site Management: Water Quality Issues. Washington, DC: The National Academies Press. doi: 10.17226/1063.
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Page 122
Suggested Citation:"7. GROUND WATER CONTAMINATION ISSUES IN SANTA CLARA COUNTY, CALIFORNIA: A PERSPECTIVE." National Research Council. 1988. Hazardous Waste Site Management: Water Quality Issues. Washington, DC: The National Academies Press. doi: 10.17226/1063.
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Page 123
Suggested Citation:"7. GROUND WATER CONTAMINATION ISSUES IN SANTA CLARA COUNTY, CALIFORNIA: A PERSPECTIVE." National Research Council. 1988. Hazardous Waste Site Management: Water Quality Issues. Washington, DC: The National Academies Press. doi: 10.17226/1063.
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Page 124
Suggested Citation:"7. GROUND WATER CONTAMINATION ISSUES IN SANTA CLARA COUNTY, CALIFORNIA: A PERSPECTIVE." National Research Council. 1988. Hazardous Waste Site Management: Water Quality Issues. Washington, DC: The National Academies Press. doi: 10.17226/1063.
×
Page 125
Suggested Citation:"7. GROUND WATER CONTAMINATION ISSUES IN SANTA CLARA COUNTY, CALIFORNIA: A PERSPECTIVE." National Research Council. 1988. Hazardous Waste Site Management: Water Quality Issues. Washington, DC: The National Academies Press. doi: 10.17226/1063.
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Page 126
Suggested Citation:"7. GROUND WATER CONTAMINATION ISSUES IN SANTA CLARA COUNTY, CALIFORNIA: A PERSPECTIVE." National Research Council. 1988. Hazardous Waste Site Management: Water Quality Issues. Washington, DC: The National Academies Press. doi: 10.17226/1063.
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Page 127
Suggested Citation:"7. GROUND WATER CONTAMINATION ISSUES IN SANTA CLARA COUNTY, CALIFORNIA: A PERSPECTIVE." National Research Council. 1988. Hazardous Waste Site Management: Water Quality Issues. Washington, DC: The National Academies Press. doi: 10.17226/1063.
×
Page 128
Suggested Citation:"7. GROUND WATER CONTAMINATION ISSUES IN SANTA CLARA COUNTY, CALIFORNIA: A PERSPECTIVE." National Research Council. 1988. Hazardous Waste Site Management: Water Quality Issues. Washington, DC: The National Academies Press. doi: 10.17226/1063.
×
Page 129
Suggested Citation:"7. GROUND WATER CONTAMINATION ISSUES IN SANTA CLARA COUNTY, CALIFORNIA: A PERSPECTIVE." National Research Council. 1988. Hazardous Waste Site Management: Water Quality Issues. Washington, DC: The National Academies Press. doi: 10.17226/1063.
×
Page 130
Suggested Citation:"7. GROUND WATER CONTAMINATION ISSUES IN SANTA CLARA COUNTY, CALIFORNIA: A PERSPECTIVE." National Research Council. 1988. Hazardous Waste Site Management: Water Quality Issues. Washington, DC: The National Academies Press. doi: 10.17226/1063.
×
Page 131
Suggested Citation:"7. GROUND WATER CONTAMINATION ISSUES IN SANTA CLARA COUNTY, CALIFORNIA: A PERSPECTIVE." National Research Council. 1988. Hazardous Waste Site Management: Water Quality Issues. Washington, DC: The National Academies Press. doi: 10.17226/1063.
×
Page 132
Suggested Citation:"7. GROUND WATER CONTAMINATION ISSUES IN SANTA CLARA COUNTY, CALIFORNIA: A PERSPECTIVE." National Research Council. 1988. Hazardous Waste Site Management: Water Quality Issues. Washington, DC: The National Academies Press. doi: 10.17226/1063.
×
Page 133
Suggested Citation:"7. GROUND WATER CONTAMINATION ISSUES IN SANTA CLARA COUNTY, CALIFORNIA: A PERSPECTIVE." National Research Council. 1988. Hazardous Waste Site Management: Water Quality Issues. Washington, DC: The National Academies Press. doi: 10.17226/1063.
×
Page 134
Suggested Citation:"7. GROUND WATER CONTAMINATION ISSUES IN SANTA CLARA COUNTY, CALIFORNIA: A PERSPECTIVE." National Research Council. 1988. Hazardous Waste Site Management: Water Quality Issues. Washington, DC: The National Academies Press. doi: 10.17226/1063.
×
Page 135
Suggested Citation:"7. GROUND WATER CONTAMINATION ISSUES IN SANTA CLARA COUNTY, CALIFORNIA: A PERSPECTIVE." National Research Council. 1988. Hazardous Waste Site Management: Water Quality Issues. Washington, DC: The National Academies Press. doi: 10.17226/1063.
×
Page 136
Suggested Citation:"7. GROUND WATER CONTAMINATION ISSUES IN SANTA CLARA COUNTY, CALIFORNIA: A PERSPECTIVE." National Research Council. 1988. Hazardous Waste Site Management: Water Quality Issues. Washington, DC: The National Academies Press. doi: 10.17226/1063.
×
Page 137
Suggested Citation:"7. GROUND WATER CONTAMINATION ISSUES IN SANTA CLARA COUNTY, CALIFORNIA: A PERSPECTIVE." National Research Council. 1988. Hazardous Waste Site Management: Water Quality Issues. Washington, DC: The National Academies Press. doi: 10.17226/1063.
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Page 138

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7 Ground Water Contamination Issues in Santa Clara County, California: A Perspective RONALD R. ESAU AND D. J. CHESTERMAN In the last few years, Santa Clara County has been the focus of state and federal attention in the area of hazardous materials regulation. The discovery of major ground water contamination in 1981 set in motion a local regulatory response that has been the pattern for similar action throughout the state of California. Responsible agencies have also forged new ground with regard to remedial actions associated with existing incidents of contam- ination. Millions of dollars have been spent by private industry on cleanup activities while a cooperative relationship has been maintained between industry and government to the extent that expensive and time-consuming litigation has been avoided in al- most all cases. Now that cleanups are in progress at over 125 sites in the county, difficult decisions with regard to the level of cleanup required must be faced. In addition, it is becoming more evident that funding for cleanups will be a major hurdle in the very near future. Efficient mechanisms must be in place to permit a rapid response to high-priority cases of contamination. BAClIGllOUND The Santa Clara Valley Water District is a public agency es- tablished by special act of the California legislature to provide overall flood protection and supply water to Santa Clara County residents. The county comprises 15 cities, the largest being the city of San Jose. The district's flood protection responsibilities include 120

GROUND WATER CONTAMINATION 121 the planning and construction of facilities to prevent floodwater damage to the county's expanding urbanized areas; its water sup- ply functions include the planning, construction, and operation of facilities to provide an adequate supply of water for the growing municipal and industrial demand. The district is also responsi- ble for contracting with appropriate state and federal agencies to import additional water to supplement the available local supply. Funding for flood control is generated from property taxes, benefit assessments, and some federal assistance. Funding sources for water supply responsibilities include revenue from taxes, water sales, and ground water extraction charges. In terms of direct sales the district is essentially a wholesaler, providing treated water to several private and municipal entities distributing within Santa Clara County. Figure 7-1 shows the boundaries of the various water retailers located in the county. The total quantity of water needed to supply the approxi- mately 1.4 million county residents is currently 400,000 acre-feet per year. This requirement is satisfied by a combination of treated surface water and ground water, with ground water accounting for about 60 percent of the total consumption countywide. The ground water basin underlying the county is relied on heavily, not only for its natural yield but also to treat, store, and distribute a major portion of the imported water the county uses, along with water conserved in local reservoirs. It was recently recognized that authorities were literally over- looking a serious threat to the water quality of that basin arising from activities associated with a major industry in a part of the county popularly referred to as Silicon Valley." In 1981 a large electronics firm reported to the San Francisco Bay Regional Water Quality Control Board (Bay Regional Board) the loss of about 60,000 gallons of waste solvents and water from an underground storage tank farm. A week later, on December 7, 1981, a nearby well of a water utility company was shut down after detecting contamination with trichIoroethane (TCA) at a concentration of 5,800 ppb. During the next year, the Bay Regional Board conducted extensive surveys of all industry that might have underground sol- vent storage tanks on their property. Fuel products were omitted from the initial survey. Solvents were considered a higher priority because of their extreme toxicity, their higher solubility in wa- ter, their specific gravity, and their persistence, or resistance to

GROUND WATER CONTAMINATION 123 biochemical degradation, as compared to petroleum products. In the survey, it was found that a significant number of the compa- nies had leaks or spills on their property that warranted further investigation. This discovery concurrently set in motion a response from local regulatory agencies that resulted in the adoption of the nation's first hazardous materials storage ordinance (HMSO), which went on to become the mode! after which the California state regulations were patterned. The HMSO had two primary purposes: (1) to ensure the safe storage and onsite handling of hazardous materials and (2) to protect the quality of the underlying ground water. The ordinance requires soil sampling around all tanks to detect past leaks as well as periodic monitoring to detect future leaks at an early stage before major soil and/or ground water contamination can occur. Through the implementation of the HMSO, a number of new cases of solvent contamination have been discovered, along with numerous instances of petroleum product contamination. Today, the Bay Regional Board ~ overseeing the investigation of over 125 ground water contamination cases. In addition, there are over 350 cases of petroleum product contamination uncovered so far that are receiving essentially no response at all because of a severe lack of staffing. As the remedial actions at the solvent contamination sites proceed the Bay Regional Board is rapidly ap- proaching a most difficult set of decisions that is, to what levels should contamination in the soil and ground water be reduced. These decisions are not only technically complex but are further complicated by economic, political, and value considerations in- troduced by a concerned public rightfully involved in the process. It is the purpose of this paper to consider these issues and how they are currently addressed in the existing regulatory framework. Portions of case studies are provided for examples, as appropriate. REGUI:ATORY AGENCY llOlES An RESPONS~UIT~S Because the roles and responsibilities of regulatory agencies may vary from state to state, a brief outline of the regulatory framework governing remedial actions for ground water contam- ination in Santa Clara County follows. This is by no means an exhaustive review but rather an attempt to describe succinctly those responsibilities that directly relate to the cleanup opera- tions.

124 HAZARDOUS WASTE SITE MANAGEMENT Regional Water Quality Control Board There are nine regional boards In California with surface and ground water quality responsibilities covering the state's various surface drainage basins. Portions of Santa Clara County lie within the jurisdiction of boards in two different regions: the San Fran- cisco Bay Region and the Central Coast Region. The regional boards have responsibility for the oversight of remedial actions, which includes issuing cleanup and abatement orders after the ini- tial definition of the extent of the contamination, as well as issuing permits for the discharge of polluted or contaminated water to streams. The boards derive their authority from the state's 1969 Porter-Cologne Water Quality Control Act, which provides "that the statewide program for water quality can be most effectively administered regionally, within a framework of statewide coordi- nation and policy." The State Water Resources Control Board, under whose policy guidance the regional boards operate, is the mechanism to provide the framework of Statewide coordination and policy. California State Department of Health Services The California State Department of Health Services (DHS) has some responsibilities that overlap those of the regional boards in the area of soil contamination. DHS is primarily concerned with the levels of contamination permissible in case of human contact with the soil. The regional boards' concern, on the other hand, is with the leaching of contaminants from the soil down to ground water. DHS also has oversight responsibilities for the transportation of hazardous materials. Therefore, all removal of soil or other contaminated materials from a site is done under DHS-issued permits. Finally, DHS administers a state Superfund program similar to the federal Superfund. One function of the state Superfund is to provide 10 percent matching funds to federal Superfund sites. In addition, it provides emergency cleanup for surface spills requiring immediate action, as well as funds for relatively small ground water contamination investigations.

GROUND WATER CONTAMINATION 125 Environ~nental Protection Agency EPA adrn~nisters the federal Superfund provided for in the Comprehensive Environmental Response, Compensation, and Li- ability Act (CERCLA). This fund provides for the ranking of sites on the National Priority List. Funds are subsequently encumbered for the cleanup of contamination at sites with no identifiable re- sponsible party (so-called orphan sites) or at sites at which the responsible party fails to cooperate with the regional board in a timely manner. Such recalcitrant parties are usually prodded into action by the threat of EPA's expending funds for remedial ac- tions that it will later recover from the responsible party through litigation. The EPA has had another role in the ground water contam~na- tion in Santa Clara County through a special study called the In- tegrated Environmental Management Plan (lEMP). The purpose of the plan has been to evaluate public health risks from ground water contamination, along with risks from contamination in other media, to compare the relative risks and make recommendations on how best to minimize them in a cost-effective manner through better management practices. In the study, EPA addresses many of the same issues to be discussed in this paper. 1lEMEDL`1 ACTION STRATEGIES The primary goal of any remedial action is to enable the continued safe use of the ground water basin, both as an important source of water as well as an efficient mechanism for treatment, storage, and distribution of local and imported water recharged into the basin. With this in mind, two general approaches toward remedying ground water contamination can be presented: the active versus the passive approach. Active Approach The active approach, as used herein, refers to specific steps taken, first of all, to define the extent of a particular plume of contamination and then to proceed to effectively reduce levels of contamination while maintaining hydraulic control of the plume. Reducing the level of contamination can either be accomplished by some sort of in situ treatment technology or by removing the contaminated soil and/or water for treatment or disposal.

126 HAZARDOUS WASTE SITE A~4NAGEM:ENT In situ treatment of soil can mean aeration of contaminated soil by injecting air into the ground to volatilize the contaminants. In situ treatment of ground water refers to the encouragement of biochemical degradation by creating a more favorable environ- ment for the natural degradation processes to occur. Because these treatment technologies are in a more experimental state of development, the method of choice is, almost exclusively, the latter method noted in the previous paragraph: removal and treatment or disposal. Generally, the grossly contaminated soil will be removed and disposed of in a Class ~ landfill. Contaminated ground waters are removed by extraction wells located in the center of the plume. The extracted water is then treated to acceptable levels and discharged to nearby streams. By hydraulically controlling the contam~na- tion, the extraction wells also prevent the plume from spreading further and threatening nearby drinking water wells. Another method of controlling the plume is to introduce a physical barrier at the contamination source usually a bentonite slurry cutoff wall in the ground. This procedure is economically feasible only when extremely- high concentrations are present in a relatively small area. The method wit! almost always be used in combination with extraction wells. Passive Approach The passive approach involves essentially allowing the plume of contamination to spread and dealing with it at the water ex- traction wells that are affected. The water from these wells is then treated to some technically feasible levels that are accept- able to the public, the ultimate consumers. WelIhead treatment includes either air stripping or activated carbon adsorption of contaminants- essentially the same procedure used in the active approach at wells within the plume. Discussion In considering these two approaches to ground water contam- ination, it is important to recognize first that, because of technical considerations, the solution will necessarily be some combination of both alternatives. That is, it is widely accepted that concen- trations of contaminants in ground water cannot be reduced to

GROUND WATER CONTAMINATION 127 zero or to nondetectable levels within any practicable amount of time. This is due to the reasonably well-documented physical processes that govern the movement of contamination in ground water. Therefore, with active cleanup measures, when an accept- able contaminant level is attained and the extraction wells cease pumping, the remaining "plume" can eventually migrate to nearby drinking water wells and result in some measure of low-level con- tamination. As discussed earlier, however, this scenario is quite different from the passive approach in the extreme case, in which poten- tially high levels of contamination would be rn~grating to any nearby drinking water wells. There are many unknowns inherent in this approach that make it very difficult to evaluate, both tech- nically and economically. Technical unknowns include the rate of movement of the plume, the number of wells that might ultimately be affected, and the concentration of contaminant that might be involved. Solute transport models have been used to attempt to predict these unknowns, but they are very often combined with a limited knowledge of important parameters. The resultant predic- tions, therefore, are subject to criticism or very often found to be of little value. Economically, the cost of reducing relatively low levels of con- tamination to "acceptable levels must be evaluated. It is well documented in the literature that techniques for the removal of volatile organic chemicals from water are less effective at lower concentrations. Therefore, the cost-effectiveness of treating much higher quantities of water at low levels of contamination suggests that the passive approach could potentially cost much more over the period of time that surrounding wells require treatment. More research is in progress in this area, specifically through the EPA lEMP study mentioned previously. In addition to the such technical and economic considerations, there are other issues that must be weighed when considering the passive approach. First of all, some mechanism-a local ~Super- fund," if you will-would be necessary to rennburse the drinking water well owner who has been damaged, in a legal sense, by one or more incidents of contamination. Also, in our litigious society, it would seem naive to think that this situation would not provoke a barrage of civil actions, not only from aggrieved well owners but from adjacent property owners as well, citing alleged effects on

128 HAZARDOUS WASTE SITE MANAGEMENT property values. Lawsuits of this nature could require costly hy- drogeologic investigations to determine liability or relative liability in cases with more than one responsible party involved. Therefore, hidden costs could increase the total cleanup "cost to the nation" significantly. Finally, there are social factors to consider; that is, what is the social value of being able to extract uncontaminated water from a generally pristine ground water basin, as presently exists in Santa Clara County? Will a public with keen awareness of the risks associated with the consumption of these toxic chemicals tolerate a policy allowing the degradation of what is considered to be an important local resource? In contrast, the active approach when strictly applied prevents the migration of contaminants to nearby wells and helps ensure that the "owner" of the plume will continue to assume liability for the cleanup. It also results in a more efficient operation because it treats water with the highest concentrations of contaminants. Critics might argue that this approach results in a significant waste of water. Yet during periods of average to above average rainfall a major ground water basin can perhaps afford to ~waste" the relatively small quantities of water required to effect the hydraulic control of a plume. Responsible parties are currently investigating the feasibility of treating and recharging extracted waters to reduce or eliminate such discharges to local streams and, ultimately, to San Francisco Bay. This discussion has noted only the extremes of each approach and ignored various qualifying hydrogeologic factors. It hap also disregarded the issue of what constitutes, in either case, an ~ac- ceptable" level of contamination. Whereas the "acceptable" level in the passive case might be the applicable drinking water stan- dard, appropriate objectives for ground water cleanup are not as simple to define. Case Studies As mentioned earlier, there are over 125 cases of ground water contamination currently being investigated under Bay Regional Board oversight. Two of the cases that have been subject to inten- sive cleanup efforts are briefly described as examples of the active cleanup technology. A third case one without an identifiable re- sponsible party is discussed as an example of a case in which a

GROUND WATER CONTAMINATION 129 combination passive/active approach is appropriate, at least until the source of contamination can be identified. IBM, San Jose The IBM case, first reported in October 1980, is one of the earliest cases of contamination in Santa Clara County. It is lo- cated near the middle of the county in a part of the basin that is particularly sensitive because of the relatively coarse-grained geologic materials underlying the site. For this reason the gen- eral area Is used extensively for artificial and natural recharge of the ground water basin. The primary contaminants include TCA, trichloroethylene (TCE), and freon 113, all of which have various associated adverse health ejects. IBM responded to the urgency of the situation in an exemplary fashion and to date has expended in the vicinity of $40 million on remedial actions at the site. The boundaries of the contamination plume have been defined to a point about 3 miles downgradient at which concentrations decrease to less than 10 ppb at a narrow geologic constriction. A few wells downgradient of that point have shown trace levels of 2 ppb but are essentially considered beyond the plume area, which measures about 3 miles long and a maximum of 400 feet in width. The cleanup method being used- an active approach is to create a situation of hydraulic ground water control by extracting contaminated water from wells located near the center of the flow- path to create a cone of depression toward which tainted water will flow. The plume is gradually decreasing in size and concentration as contaminated water is extracted. The extracted water is treated either by passing it through activated carbon or by air stripping; it is then discharged to the nearby storm sewer. The Bay Regional Board was at first allowing the discharge of water with a contamination of 100 ppb, but recent evidence that the recharge of that water is causing contamination in a distant well has caused it to revise those requirements. Dis- charged water in areas of potential recharge now must be treated to a concentration of 1 ppb. IBM is currently extracting water at the rate of about 10,000 acre-feet per year-about 7 percent of total ground water extraction countywide. The company has recently submitted, by request, a draft comprehensive plan, which addresses final cleanup objectives

130 HAZARDOUS WASTE SITE MANAGEMENT for the site. Because of concerns regarding the amount of water "wasted" to complete the cleanup, IBM has proposed treating to 1 ppb and delivering the treated water to district-operated recharge facilities. Fairchild Camera ~ Instrument Corporation, San Jose In 1981 Fairchild reported the loss of about 60,000 gallons of TCA and water, which resulted in the shutting down of a nearby water supply well contaminated at a level of 5,000 ppb TCA. The Fairchild site is locater] less than 2 miles southeast of the IBM site in the same sensitive area of the basin. Fairchild has displayed an equivalent level of effort in defining the boundaries of the plume of contamination and proceeding with interim cleanup efforts. The plume extends about 1 mile offsite with high-level contamination remaining in the soil and ground water directly underlying the property. The cleanup approach has been similar to that of the IBM case in that hydraulic control has been maintained by means of strategically located extraction wells. Problems were encountered, however, when shallow aquifer materials became dewatered be- cause of the rate of extraction from deeper aquifers. In order to flush the contaminated shallow aquifer soils, Fairchild reinjected treated water into wells perforated in the shallow zone. This procedure eventually proved to be too time consum- ing, however, and the company subsequently proposed and imple- mented an additional measure to enhance the cleanup operation. A bentonite clay slurry wall has been installed around the perime- ter of the property to encapsulate the onsite heavy contamination down to a natural clay layer at a depth of about 100 feet. Although the construction cost about $4 million, the company decided that the potential benefits justified the cost. The physical barrier al- Tows Fairchild to extract water at a much lower rate within the containment to maintain an inward gradient at the walls of the containment. The offsite operation is also enhanced by ensuring that additional contamination will not migrate from the heavily contaminated area to continue "feedings the plume. Fairchild will soon be submitting a comprehensive plan to propose final cleanup objectives for the site.

GROUND WATER CONTAMINATION 131 California Water Service Company Well, Los Altos In 1982 it was discovered that a 400-foot-deep standby well owned by California Water Service Company (Cal Water), an area water purveyor, was tainted with carbon tetrachIoride at a con- centration of about 10 ppb. The source of the contamination to date is unknown. After consultation with the responsible regula- tory agencies and public meetings with neighborhood residents, it was determined that the well water should be treated by air stripping at the welihead. By spraying the water into a holding tank, concentrations have been effectively reduced to about 1-2 PP ). A 111~ ~ i~ ^;~at.anrPa-t.h~ 1lnknown contamination ~lUllUU6ll L11= ~__~ ~ source obviously create the need for a passive approach, there remains a concern about finding the source of contamination and defining the plume to protect other wells in the area that are more critical to the water supply. Based on existing and historical land use in the general vicinity, certain landowners are being asked to conduct relatively inexpensive soil gas surveys of their property to identify possible sources of contamination. In addition, DHS will be using the state Superfunds to investigate the area around the subject well by installing monitoring weld to begin defining the extent of the plume. As the investigation proceeds, the approach may be changed to one of active cleanup. CLEANS OBJECTIVES-HOW CIEAN? When considering to what extent concentrations should be reduced in cases of ground water contamination, the regulatory agency has the unenviable task of balancing the cost of remedial actions against the public health risk associated with consumption of tainted drinking water. Even for those chemicals for which drinking water standards or action levels exist, the decision is not an easy one. There are many uncertainties associated with the standards that must be considered when applying drinking water criteria to ground water restoration activities. Current Cleanup Policies As noted previously, there are three agencies-the Regional Water Quality Control Board, DHS, and EPA that have respon- sibility for the oversight of remedial action activities. Although

132 HAZARDOUS WASTE SITE MANAGEMENT each has a different methodology for addressing cleanup objec- tives, there are basically two schools of thought: (1) cleanup to predetermined standards or (2) cleanup to criteria based on an evaluation of site-specific circumstances. The predetermined standards approach simply requires the cleanup to proceed until concentrations in ground water are reduced to applicable drinking water standards or state "action levels." In the case-by-case approach, which has been applied by the Bay Regional Board, cleanup to standards is considered a m~ni- mum level of effort. Beyond that the discharger is asked to prepare a report estimating the cost of three higher levels of effort: cleanup to action levels, cleanup to nondetectable levels, and cleanup to a third level at some intermediate point. The board then considers each case in a public forum to allow comments to be heard from all interested parties. The cost of each cleanup alternative is used as a guideline in deciding on overall cleanup objectives. Other factors, such as the underlying hydrogeology, the areal extent of contamination, and the proximity of drinking water wells, are used to evaluate the risk of contamination spreading to nearby wells or affecting significant portions of the underlying aquifer. Discussion When standards exist for the chemical contaminants in a par- ticular case, the simplest approach, administratively, is to require cleanup to those standards. In sensitive regions of the basin, however, this approach may be inadequate to satisfy not only legislative mandate but also the concerns of the public who are ultimately affected. The Bay Regional Board, in its strategy for establishing cleanup objectives, is attempting to incorporate all relevant infor- mation into its decisionmaking. In the hearing process, the state's nondegradation policy Is used as a starting point for subsequent discussion. That policy requires the maintenance of preexisting water quality unless the board finds that, because of economic and technical considerations, some level of water quality degra- dation is "consistent with maximum benefit to the people of the state" and "will not unreasonably affects beneficial uses. This policy is necessarily quite broad and leaves much interpretation to the board members. There are many important factors for their consideration in reviewing a case.

GROUND WATER CONTAMINATION 133 The location of the contamination is of primary importance. In Santa Clara County, there are widely varying hydrogeologic conditions that affect the way contamination can move once it is released into the ground water basin. The Bay muds, existing along the edge of San Francisco Bay, provide an example of a nearly complete natural containment; contamination at the sur- face would, for all practical purposes, never reach deeper aquifer materials used for water supply. Therefore, in that region of the basin, removing only the heavily contaminated soil may be ac- ceptable. In the forebay zone of the basin, however-the area that recharges the deeper confined aquifers much greater efforts are required. In that area, there are direct hydrogeologic connections between the surface soils and deeper aquifer materials, and the contamination of nearby wells is almost certain unless extensive extraction of contamination is mandated. In addition to the relevant technical aspects of a case the pub- lic hearing process permits input from all concerned parties the retail water agencies, the water district, and, most importantly, the public. The public in Santa Clara County and throughout Cal- ifornia is very aware of and concerned with water quality issues. Statewide public opinion was strongly voiced by the overwhelm- ing passage of a recent ballot proposition imposing, among other things, stringent notification requirements on any designated pub kc official with knowledge of any potentially hazardous discharge to waters of the state. Clearly, the public is demanding account- ability on the part of public officials and therefore should certainly be included in any decisions involving health considerations. Retail water agencies are equally concerned in that local liabil- ity, with respect to serving unsafe water, must be taken seriously. In the wake of a recent multimillion-dolIar lawsuit, at least one local water retailer has refused to pump ground water with any detectable level of organic chemicals. Finally, the district, with management responsibility for the ground water basin, takes a very conservative view on cleanup requirements. One concern is that many of the chemical standards are based on a relatively short time span of data collection and research. As more is learned about the proven or potential effects of these chemicals, a gradual lowering of the standards can be expected. In that case, welihead treatment may be required for what was once considered safe contaminant levels in ground water. Ultimately, the question of equity arises as to whether the resultant

134 HAZARDOUS WASTE SITE A~4NAGEM:ENT liability and costs are those of the public or of the responsible party. It would seem inequitable to require the public to bear the cost of such treatment when a responsible party was once assuming liability for the contamination. CREAM COSTS TO IS RESPONSIVE? As experience in Santa Clara County has shown, the costs associated with remedial actions to remove ground water contam- ination can be staggering. In general, responsibility for most of the cases of organic solvent contamination in Santa Clara County is being assumed by the company involved in the illegal discharge. The ideal situation is one in which (1) a responsible party can be identified and (2) the identified responsible party has the resolve and financial means to undertake the necessary remedial actions. It has been fortunate that some of the largest incidents in the most sensitive areas of the ground water basin have been caused by large, responsive corporations. In general, they have cooper- ated with the regional board and proceeded with remedial actions in a timely manner. This is not an assured situation, however. In an increasingly competitive business world, there are ob- viously strong economic disincentives for companies that have caused contamination to proceed in a timely manner or even to proceed at all with remedial actions. Furthermore, there are a growing number of cases being discovered in Santa Clara County for which the owner sunply does not have the necessary financial means to remove the contamination. Most of these latter types of cases are small businesses storing motor fuels in underground tanks that have been found to be leaking. Other such contami- nation is caused by small businesses who illegally or negligently handle or dispose of toxic solvents. The threat to the public health from incidents such as these can be as serious as from those caused by larger companies with greater resources. Therefore, because cleanup of these incidents must proceed expeditiously, alternative funding sources must be available. SUMMARY The Santa Clara Valley Water District, as a wholesaler of wa- ter and the management agency of the ground water basin, has a

GROUND WATER CONTAMINATION 135 responsibility to ensure that the basin remains usable as an im- portant element of the water supply in Santa Clara County. As discussed earlier, recent contamination, primarily from leaking un- derground tanks, has threatened that vital resource. In response, regulatory activity in recent years has greatly reduced the possi- bility that future leaks might cause serious problems. The various regulatory agencies involved in cleaning up past contamination have sorted out their respective roles, and an effective working relationship has evolved. Two approaches to remedial action have been discussed: the active versus the passive approach. Although only the extremes of these cases were discussed, various permutations are possible. The consensus of the affected parties the public, the retailers, and this agency-has been that the passive approach is definitely not acceptable. Only when a situation arises in which the source of contamination is unknown has welThead treatment been considered a feasible solution. In their oversight responsibilities the regulatory agencies are faced with difficult decisions with respect to ultimate cleanup objectives. The Bay Regional Board, as a lead agency in cleanup oversight activities, has forged an effective policy for determining cleanup objectives. Its approach considers economic, technical, and public health risk factors in a process aimed at achieving a cost-efl3ective cleanup that is safe and acceptable to the public. Funding for the increasing number of contamination cases being discovered is a growing problem in Santa Clara County. Hundreds of fuel leaks have received little or no oversight due to understaffing in regulatory agencies. As a result, these cases are receiving an unknown level of cleanup effort from facility owners who may or may not have the technical and financial means to address these problems adequately. CONCIUSIONS This paper has attempted to outline the current situation and describe issues that have been faced and continue to be faced in Santa Clara County. Perhaps the primary conclusion reached by responsible agencies in this area is that an informed public input must continue to be an integral part of decisions affecting the public health and environment. Public education and involvement mechanisms must be incorporated into the process not only to

136 HAZARDOUS WASTE SITE MANAGEMENT allow public input on decisions affecting human health but also to enlighten the public with regard to the difficult trade-o~s sur- rounding environmental decisions. This kind of process will enable mutually acceptable solutions to be reached with much greater ease. A final conclusion that becomes more evident as the techni- cal realities of ground water contamination become more widely understood not only by the regulatory community but also by the public at large is that there is necessarily some degree of risk that simply must be accepted. Various preventative programs are now in place to drastically reduce the possibility of future incidents causing serious ground water contamination. Yet exist- ing contamination caused by past handling and storage practices will be present for many years. The reality is that even if suffi- cient funds were available, it would prove technically impossible to remove all of the contaminants from the ground. The obvious result is that some trace level of contamination in the water sum ply in some areas may, unfortunately, be inevitable. Admittedly, the health risk associated with consuming tainted water may be minimal in comparison to other environmental risks with which we live. It continues to be important, however, to strive for ways to reduce those risks as much as is technically and economically feasible. BlBlIOGllAPlIY California Department of Water Resources. 1975. Evaluation of Groundwater Resources: South San Francisco Bay, vol. 3. Sacramento. December. California Regional Water Quality Control Board, San Francisco Bay Region. 1986. South Bay Site Management System Reports. Oakland, Calif. May. Ford, J. 1978. The Story of the Santa Clara Valley Water District, San Jose, Calif.: Santa Clara Valley Water District. Himmon, K., D. Schwartz, and E. Soffer. 1986. Santa Clara Valley In- tegrated Environmental Management Project, Revised State I Report. San Francisco, Calif.: Environmental Protection Agency. May. Suffet, I. H., and M. J. McGuire. 1980. Activated Carbon Adsorption of Organics from the Aqueous Phase, vole. 1 and 2. Ann Arbor, Mich.: Ann Arbor Science Publishers, Inc. TRY Consultants, Inc. 1984. South Bay Groundwater Contamination Task Force, Agency Coordination Project. San Francisco, Calif. December. U.S. EPA. 1984. Groundwater and Drinking Water in Santa Clara Valley: A White Paper. San Francisco, Calif.

GROUND WATER CONTAMINATION 137 PROVOCATEUR'S COMMENTS N orb ert Dee ~ would like to make some general comments about the paper and about other related issues. First, the paper is very good in discussing risk management and the hazardous waste management issues facing a water district. What we have learned over the last 5 years of RCRA and Superfund implementation is that not all ground water is equal. In addition, we have learned that we can make very costly and technical mistakes by going in with a shove! just to do something. In the Superfund discussion earlier, the point was made that not all ground water is equal and that therefore, in making cleanup decisions, consideration must be given to the use, value, and vul- nerability of ground water. This is a differential protection policy, which is not accepted by everyone. At present, EPA has a cIassi- fication system based on differential protection that has been sent out for public review and comment. In the example discussed in the paper, $40 million was spent cleaning up a site. Should we do the same level of cleanup if the site had no effect on a pub kc water supply? The Safe Drinking Water Amendments of 1986 also protect drinking water from contaminants that could affect human health by protecting the weDhead area. This is a form of differential protection. Earlier, some arguments were made against the macro ap- proach of classification and data collection and in favor of a micro approach. My response to that brings to mind an incident from Alice in Wonderland. Alice was walking down a path when she reached a fork. She asked the Cheshire Cat which way she ought to go. The cat responded by asking where she wanted to go, and when Alice said she didn't know the cat said, "Then it doesn't matter which way you go." We need to do better than Alice, and a macro policy can direct us. This, to some degree, has been the problem we have had over the last 5 years. If we focus our atten- tion on priority areas based on classification, then we know which path we are taking and the issue of specific data will be answered by the implementation of the policy.

138 HAZARDOUS WASTE SITE MANAGEMENT ~ would like to make a few more comments on the paper. Be- cause ~ do not know the specifics of the Fairchild or the IBM sites, the question ~ pose may be unanswerable. The question is this: Would or should California have proceeded differently if the areas were not vulnerable, if they did not have an irreplaceable water supply, or if a public water supply had not been threatened? In other words, if the site had been in another location in California, would we have made or should we make the same decision? This is a risk management question. Another point about the cleanup at the Fairchild site also concerns risk management. If the cleanup of the site requires air stripping and we are in a nonattainment area on volatiles, is this good management? In addition, the pump-and-treat method used in these site cleanups did not look at the depletion of the ground water resource by discharging the treated ground water to the San Francisco Bay. Again, are we looking at the full picture, managing our risk properly? This is the same question David Miller asked earlier. What are we trying to do? The last point ~ would like to address is that the approach followed in the paper ~ differential protection and risk manage- ment. Yet the state has a nondegradation policy. How are these two compatible?

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Hazardous Waste Site Management addresses current methods used in the regulatory process with respect to water quality cleanup levels. Information and perspectives on the adequacy of these methods are provided by representatives from water utilities, industry, and environmental groups. Setting environmental standards, establishing and meeting ground-water protection goals, and specific approaches to setting goals are also fully examined.

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