Hazardous Waste Site Management Water Quality Issues (1988) / Chapter Skim
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7. GROUND WATER CONTAMINATION ISSUES IN SANTA CLARA COUNTY, CALIFORNIA: A PERSPECTIVE
7. GROUND WATER CONTAMINATION ISSUES IN SANTA CLARA COUNTY, CALIFORNIA: A PERSPECTIVE
Pages 120-138
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From page 120... ...
BAClIGllOUND The Santa Clara Valley Water District is a public agency established 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.
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From page 121... ...
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 overlooking 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)
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From page 123... ...
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 contamination 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 operations.
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From page 124... ...
The regional boards have responsibility for the oversight of remedial actions, which includes issuing cleanup and abatement orders after the initial 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 coordination 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.
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From page 125... ...
Such recalcitrant parties are usually prodded into action by the threat of EPA's expending funds for remedial actions that it will later recover from the responsible party through litigation. The EPA has had another role in the ground water contam~nation in Santa Clara County through a special study called the Integrated Environmental Management Plan (lEMP)
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From page 126... ...
Discussion In considering these two approaches to ground water contamination, 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 concentrations of contaminants in ground water cannot be reduced to
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From page 127... ...
Therefore, with active cleanup measures, when an acceptable 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 contamination. As discussed earlier, however, this scenario is quite different from the passive approach in the extreme case, in which potentially high levels of contamination would be rn~grating to any nearby drinking water wells.
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From page 128... ...
Whereas the "acceptable" level in the passive case might be the applicable drinking water standard, 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.
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From page 129... ...
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
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From page 130... ...
Problems were encountered, however, when shallow aquifer materials became dewatered because 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.
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From page 131... ...
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.
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From page 132... ...
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~nimum level of effort.
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From page 133... ...
In addition to the relevant technical aspects of a case the public 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 California is very aware of and concerned with water quality issues.
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From page 134... ...
CREAM COSTS TO IS RESPONSIVE? As experience in Santa Clara County has shown, the costs associated with remedial actions to remove ground water contamination can be staggering.
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From page 135... ...
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.
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From page 136... ...
1978. The Story of the Santa Clara Valley Water District, San Jose, Calif.: Santa Clara Valley Water District.
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From page 137... ...
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.
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From page 138... ...
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.
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