IV. Scope of Review and Conclusions

We have reviewed in this proceeding the process and basis for setting contaminant levels, both MCLs and ALs, by DHS. We further have reviewed compliance data reporting on the 25-year period under review in this investigation that was submitted by the respondent regulated water utilities. These data include monitoring and testing data compiled pursuant to MCLs and ALs established by DHS for specific contaminants,⁴ as discussed below. Based on the data presented and the analysis undertaken, we have drawn several conclusions regarding the quality of the water served by the regulated public utilities.

First, as further amplified in this decision, existing MCLs and ALs established by DHS are adequate to protect the public health, and water served by the regulated utilities during those periods for which DHS standards were in place and testing and monitoring data are on the record cannot reasonably be expected to be "harmful or dangerous to health." For noncarcinogenic chemicals, DHS established levels that are expected to pose no health risk. For carcinogenic chemicals, since any exposure is assumed to pose a calculable risk, DHS sets a very conservative level that poses an insignificant cancer risk. The Commission is mindful of the determination made by DHS that a detection of a contaminant above an MCL in itself does not necessarily impact safety. There is a significant margin of safety when MCLs are calculated so that the detections of carcinogenic contaminants above MCLs that were reported in this investigation are unlikely to pose a health risk.

Second, as supported by the utility compliance reports, Staff summary of those reports, and DHS responses, the utilities performed testing and monitoring of each of the substances identified above, in substantial compliance with DHS testing and monitoring requirements during all periods for which monitoring was required. Moreover, some utilities began testing for certain chemicals even prior to the times at which monitoring was required. Pursuant to the testing requirements, the utilities either recorded contaminants as being at or below all applicable MCLs or ALs, or found that contaminant levels exceeded the applicable MCLs or ALs and followed required procedures. We conclude, and the record demonstrates, that once DHS required testing for particular contaminants, the regulated utilities in this investigation were in substantial compliance with the testing obligation.

Third, for all periods during which testing and monitoring data are on the record, all of the utilities were in substantial compliance with existing DHS standards for MCLs and AL's with one exception where litigation with DHS is pending. Detections of contaminants exceeding applicable MCLs or ALs were limited to those summarized in the WD's Reports dated December, 1998, May 17, 1999, and June 4, 1999. None of the detections of contaminants above applicable levels identified in the record of this proceeding warrant further analysis. As a result, we can conclude that for periods during which testing and monitoring data are in the record of this proceeding and during which the utilities substantially complied with DHS MCLs and ALs, the water served by the water utilities was not "harmful or dangerous to health." This conclusion is based upon the test results provided, whether the standard in question was an AL or MCL.

Fourth, some of the data provided requires further clarity. In particular, as we note below, responses to Questions 26 and 27 in the Scoping Memo asked utilities to provide each Commission order to correct or prevent a violation of a water quality requirement and the utility compliance date. We propose to institute a new proceeding that specifically reviews GO 103, which sets quality standards for drinking water supplied by regulated utilities. As a prelude to that formal Commission review, utilities should meet with Staff to ensure the answers to Questions 26 and 27 are precise and complete before resubmitting this information into this new proceeding.