NCDH should continue pesticide monitoring of Nassau County's ground water to provide an advanced warning system in the event contamination of the source water occurs. In 2002, NCDH proposed the additional sampling of 50 public supply and golf course irrigation wells in order to build upon the results of the Pesticide Monitoring Program during prior years (1998-2001). See Appendix F for a listing of proposed public supply well sampling starting in July 2002.
In addition to sampling "high risk" wells, a goal of the NCDH Pesticide Monitoring Program should be to collect and analyze comprehensive pesticide samples from each of the 400 public supply wells in Nassau County.
The UOC (Unspecified Organic Contaminant) MCL of 50 ug/L must be utilized for many of the chemicals analyzed in this Monitoring Program. Although this current MCL is considered to be protective of public health, it is non-specific and individual MCLs for each of the pesticides (and metabolites) analyzed in this Program should be established by the New York State Department of Health or the USEPA.
The detection of perchlorate in 9 of the 60 (15%) public supply wells sampled in Nassau County is a concern. As a direct result of these detections and recent detections from the EPA's UCMR (Unregulated Contaminant Monitoring Rule) source sampling, NCDH had recommended to participating water systems that their UCMR sampling for perchlorate be completed in 2002. The NCDH now requires that all Nassau County public water systems perform annual monitoring for perchlorate at each of their public supply wells.
The results of previous public supply well sampling conducted by NCDH in 1998 and 1999 are briefly summarized in Appendix G.
Appendix H provides a detailed summary of the analysis results of each Nassau County public supply well and golf course irrigation well sampled during 2001.