State Groundwater Program Falls Short On Monitoring, Pollution Prevention

posted in: May 1996 | 0

The state Department of Health has the legal responsibility to ensure that the water residents of the state drink is pure and healthy. To this end, it establishes maximum contaminant levels (most of which match federal MCLs) and monitors test results of wells used as drinking-water sources in all systems, public or private, that serve more than 25 people.

The Department of Health also has responsibility to protect groundwater sources from contamination. Its principal means of doing this has been to develop regulations on new cesspools and injection wells, so that potential contamination sources are not located near operating wells. In addition, when spills or leaks of potential pollutants occur, it has authority to require the responsible parties to clean up the affected area.

How effective are these programs?

Monitoring

Testing of wells provides an indication of the extent and degree of contamination of groundwater sources. As such, it is vitally important to know not only what is in the water that comes out of the home tap, but also what might be found in areas of the underground aquifers far removed from drinking water sources. Hawai`i’s geology makes it easy for contaminants to travel throughout a given aquifer. If an agricultural chemical (such as EDB) is found to contaminate wells in the upper reaches of an aquifer, it is, according to scientists, only a matter of time before that contamination reaches wells downslope.

But the Department of Health requires testing only of wells that contribute to drinking-water sources. If contamination exceeding the maximum allowable levels occurs in four consecutive quarterly samples from a drinking-water well, usually that well is pulled out of operation, the testing protocol is dropped, and the well is (literally) erased from the Department of Health’s maps of contaminated well sites.

As a result, the Department of Health has no clear idea of the movement of contaminant plumes or trends in contamination levels of wells pulled from service. This is freely acknowledged by the Department of Health. It has acknowledged that, “The present groundwater monitoring system in Hawai`i is not designed to determine cause and effect relationships between pollution sources and groundwater quality. Central to this problem is the fact that wells used for supply purposes, or wells that have good chemical quality monitoring information, are generally not located in the vicinity of pollutant sources. … [S]upply wells are generally located inland away from areas where salt water intrusion and other sources of contamination may be a problem. Since these supply wells provide only regional background information, the actual degree of contamination resulting from pollutant sources can rarely be determined.”

Blind Tests

The Department of Health has also come under frequent attack (usually from William Dougherty, one of the state’s few water quality watchdogs) for the insensitivity of the tests it uses to detect the presence of contaminants.

The recent disclosure of the presence of dieldrin and chlordane in O`ahu wells provides an excellent example of Dougherty’s point. Back in 1986, the U.S. Geological Survey had confirmed the presence of dieldrin in wells in Kalihi (9 parts per trillion) and Moanalua (8 ppt), using a test able to detect contamination in the part-per-trillion range. Dieldrin again showed up in tests run three years later and appeared on the groundwater contamination maps published by the Department of Health in 1990.

When the wells were retested two years later, using a method able to detect dieldrin only at a concentration of 100 or more parts per trillion, the results were negative. As Dougherty says, the less sensitive test results did not mean that Dieldrin was not present; rather, the testing method was simply unable to see it. The water-contamination maps that the DOH published for 1991 disclosed no contamination of any type at the Kalihi and Moanalua sites.

Under Department of Health rules mandated by the Environmental Protection Agency under the Safe Drinking Water Act, testing for dieldrin and other unregulated pesticides must be performed every five years. Last year, the Board of Water Supply contracted for such testing to be done by a California laboratory.

Results of those tests were disclosed in late March. Chlordane and dieldrin were found in the Jonathan Springs well in Kalihi, while dieldrin was found in wells at `Aiea, `Aina Koa, Halawa, Ka`amilo, Kaimuki, and Kalihi. Concentrations of dieldrin ranged from 60 parts per trillion (at Jonathan Springs) to 10 ppt (at Halawa). Although there is no maximum contaminant level in Hawai`i or at the federal level for Dieldrin, California has established a limit of 50 parts per trillion. Acting on that basis, the Board of Water Supply closed the Jonathan Springs well.

For Dougherty, it was a bitter vindication. When he had raised a ruckus in 1992 about the erasure of Dieldrin contamination in Kalihi and Moanalua from DOH maps, he was dismissed by Department of Health officials, who claimed that their more recent tests had not “confirmed” the presence of Dieldrin in the wells. Dougherty told Environment Hawai`i that it was not vindication he sought, but simple honesty — and safe water.

In 1993, the Department of Health stopped printing the groundwater contamination maps altogether — an action taken, officials say, to save money. In March, a staffer at the DOH Safe Drinking Water Branch said that updated maps were being prepared and should be available later this year. In the meantime, the Department of Health prints out computer lists of contaminated wells, based on quarterly test results going back five years. (However, the quarterly tests are not conducted on wells where no trace of contamination appears four quarters in a row; such wells are tested far less frequently.) The lists do not indicate the level of sensitivity used in the tests or whether the water was tested before or after treatment (in the case of Central O`ahu wells).

Protection?

The state’s groundwater protection strategy is primarily a list of goals. When the Natural Resources Defense Council prepared a report on Hawai`i groundwater in 1993, it stated, “Perhaps one of our greatest criticisms of the current [DOH] Protection Strategy is that, although it discusses the need to adopt actual protective measures, it fails to provide any process for assessing what measures are needed or to conduct the administrative tasks necessary for their adoption.”

One of the elements in the state’s groundwater protection strategy is an “anti-degradation policy.” As the NRDC points out, on its face, this suggests that the state simply will not tolerate actions that will degrade water resources. However, the NRDC adds, “in the DOH Protection Strategy, the phrase takes on a slightly different meaning. Under the DOH policy, degradation of water quality is not to be allowed for those water resources with existing or future beneficial uses, with highest priority being given to protection of the beneficial use of drinking water. Implicit in this approach is the decision not to attempt to protect those groundwater resources that are not currently being used beneficially or currently projected for future beneficial use.”

This approach has led to what the DOH calls a “differential management strategy,” where, as the NRDC notes, the state affords different levels of protection “for different aquifers or water sources, depending on their importance for beneficial uses (primarily drinking water) and on their vulnerability to contamination. It is essentially a triage management system…”

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For Further Reading

L. Stephen Lau, Organic Chemical Contamination of O`ahu Groundwater, Water Resources Research Center Technical
Report No. 181 (University of Hawai`i at Manoa), July 1987. Lau summarizes the results of a series of studies undertaken by the University of Hawai`i in response to widespread concern in the early 1980s about growing chemical contamination in the central O`ahu plain.

Laura King and Clyde Murley, authors; Will Freeman, principal researcher, “Groundwater in Hawai`i” (Natural
Resources Defense Council), 1993.

Volume 6, Number 11 May 1996

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