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Options for Enhancing New Jersey's Approach to Regulating Contaminants in Drinking Water
5. Installation of water treatment (e.g., granular activated carbon)
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This proposed approach would be to install water treatment on drinking water supplies vulnerable to contamination by unregulated synthetic organic chemicals. In effect, this option calls for the development of a "treatment technique" drinking water standard in lieu of a chemical-specific maximum contaminant level. The approach would result in a proposal to amend the New Jersey Safe Drinking Water Act regulations to include a treatment technique (e.g., granular activated carbon) as a primary drinking water regulation to reduce levels of currently unregulated synthetic organic compounds. A primary drinking water regulation specifies either a maximum contaminant level for each contaminant of concern or allows the Department's Commissioner to specify a treatment technique in instances where determining the level of the contaminant is not economically or technologically feasible. This strategy represents a proactive approach to protecting
public health in the absence of little or no definitive scientific information on the contaminants being detected. This option asserts that given the uncertainty in the health information available for these contaminants, the current methods of addressing unregulated compounds cannot be applied. In order to develop a maximum contaminant level, a ground water quality standard or an interim ground water quality standard, some minimum amount of toxicity information is necessary. For many contaminants detected in the NJDEP-EOHSI and USGS- NJDEP -CDC studies, even basic toxicity information is lacking. Rather than wait for studies to be completed, this option proposes installation of treatment as a protective measure.
Further, this approach represents the likely action that would be taken if the other options are followed to their logical end-points. That is, the best available technology for removing many synthetic organic contaminants from drinking water is granular activated carbon. Most of the contaminants detected in the afore-mentioned government-funded studies were synthetic organic compounds. If the Department pursued the other options, the likely end result would be to install carbon treatment on numerous public water systems throughout the state.
Granular activated carbon (GAC) or a combination of air stripping (AS) with GAC would be the most likely acceptable treatment technology, although other technologies capable of treating organic contaminants would be considered as well. Carbon filters are very effective at reducing levels of some types of organic chemicals in drinking water, and will reduce levels of those contaminants of concern that are detected by current analytical methods used for compliance purposes. But carbon filters do have limitations and do not reduce levels of all contaminants from drinking water (e.g., lead, arsenic and mercury).
This approach would target drinking water systems that use ground water as source water. The intent is to eventually address all drinking water systems in the state, but it is recognized that this option would be done in a step-wise fashion. There are several ways of determining the "trigger" for action under this approach. One is to install water treatment on drinking water supplies already affected by organic chemical contamination. Water systems that currently have air-stripping due to a maximum contaminant level violation of a regulated organic contaminant would be targeted for water treatment using this approach. Preliminary assessments of Bureau of Safe Drinking Water data show that there are approximately 93 facilities serving 52 public community water supplies with air-stripping treatment technology. These are systems whose ground water has contained a level of a regulated volatile organic contaminant above the maximum contaminant level.
Air-stripping reduces the levels to below the maximum contaminant level but may not be effective at reducing levels of semi-volatile and non-volatile organic contaminants. Granular activated carbon or a combination of air- stripping with granular activated carbon would be the likely acceptable treatment technologies under this approach. It would essentially eliminate the air-stripping-alone treatment technology as an acceptable option for removing organic contamination. Essentially, the presence of an elevated level of a regulated organic chemical would be used as the trigger for action. Studies have demonstrated that semi-volatile contaminants do not often occur in the absence of volatile contaminants as described in Section III.1. of this paper. By using the presence of volatile contamination,
it is likely that most of the systems having semi-volatile contamination will be captured, as semi-volatile contamination in the absence of volatile contamination is rare. Therefore, it may appropriate to use contamination by regulated chemicals as a trigger for water treatment here, unless a better trigger can be established.
Another way to trigger action under this approach is to select systems by their vulnerability to organic chemical contamination. Using the Source Water Assessment Program data, 44% of drinking water wells in the state are considered highly vulnerable to volatile organic chemical contamination. There are no vulnerability assessments for semi-volatile chemicals as a class, however, no wells are considered highly vulnerable to pesticides, which are mostly semi-volatile organic chemicals. It is not known how many water systems these wells represent.
An important consideration in this approach would be the identification of contaminants to measure to determine treatment system efficiency. One possibility would be to use the regulated organic compounds.
Currently the Department regulations require treatment of the source of water if there is a violation of the maximum contaminant levels. However, the Safe Drinking Water Act
does include a provision that allows the Commissioner to require the use of treatment techniques to reduce the level of contaminants which, in his judgement, may have adverse effects on human health, and where it is not economically or technologically feasible to ascertain the level of such contaminant (N.J.S.A. 58: 12A-3). In this approach, it is acknowledged that it is neither economically or technologically feasible to ascertain the level of the unregulated contaminants in the water. As the contaminants may have adverse effects on human health, the Commissioner may require a treatment technique for water systems, as appropriate (i.e., systems that are already contaminated by volatile organic chemicals or that the Source Water Assessment Program designates as vulnerable).
Economic Assessment
Preliminary assessments of Bureau of Safe Drinking Water data show that there are approximately 93 facilities serving 52 public community water supplies with air-stripping treatment technology. These 52 water systems have an estimated total capacity of 136 million gallons per day. Economic information from one water purveyor, United Water -Toms River, indicates that the cost to install one carbon unit at a facility (approximately one million gallons per day capacity) is approximately $1 million. The annual operations and maintenance cost for the unit would be an additional $70,000. Therefore, the installation cost to implement this approach for ground water systems would be approximately $93 million.
Advantages:
Proactive approach to protecting public health.
Addresses ingestion as well as exposures from other potable water uses (i.e., inhalation, dermal absorption from showering, bathing, washing dishes, etc.).
Regulated contaminants, when present, may be used to monitor efficacy of removal technology (i.e., granular activated carbon).
Disadvantages:
Initial cost may be high.
Need to define who/how to pay for the installation of the treatment.
Efficacy of the water treatment will be difficult to monitor in instances where suitable certified analytical techniques are not available.
Does not account for water system vulnerability (as proposed, only systems with contaminant exceedances will install carbon).
The issue of how to relate this approach to surface water systems or to private wells is not fully understood.
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