Eight of the 66 public supply wells tested (12%) exhibited pesticide detections in 2001 and 6 different pesticides were detected in Nassau County public supply wells. TCPA (tetrachloroterephthalic acid), a dacthal metabolite, was the most frequently detected pesticide compound in Nassau County public supply wells, being detected in six of the 66 (9%) public supply wells tested in Nassau County. The detections ranged from 7 ug/L to 17 ug/L. The Maximum Contaminant Level (MCL) for this compound is the generic Unspecified Organic Contaminant (UOC) standard of 50 ug/L.
The 5 other pesticides that were detected in Nassau County public supply wells were: Atrazine, Dibromochloropropane (DBCP), Desethylatrazine, Ethylene dibromide (EDB) and Prometon. Table 1 lists the public supply well, water system and level detected for each detected pesticide in Nassau County.
Table 1 - Summary of Pesticides Detected in |
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| PESTICIDE | WELLS(S) DETECTED |
LOCATION | LEVEL (ug/L) |
MCL (UG/L) |
| Atrazine | N-3704 | WestHempstead W.D. | 0.19 | 3.0 |
| Desethyhtrazine | N-9211 | City of Glen Cove | 0.05 | 50.0 |
| DBCP (Dibromachbropropane) |
N-9211 | City of Glen Cove | 0,11 | 0.12 |
| EDB (Ethylenedibromide) |
N-8010 | Roslyn Water District | 0.07* | 0.05 |
| Prometon | N-4077 | W.A. of Western Nassau | 0.12 | 50.0 |
| TCPA | N-10612 N-9211 N-37 N-12639 N-3704 N-10401 |
Garden City Park W.D. City of Glen Cove Sands Point Village Sands Point Village West Hempstead W.D. West Hempstead W.D. |
7 17 7 10 6 7 |
50.0 |
| * Exceeds MCL of 0.05 ug/L established for this compound | ||||
Only one of the pesticides detected, Ethylene dibromide (EDB), exceeded the Maximum Contaminant Level (MCL) established for the compound. EDB was detected at a level of 0.07 ug/L in Roslyn Water District's Well # 8 (N-8010), exceeding the 0.05 ug/L MCL established for this compound. This well has a history of EDB detections from water system and NCDH routine monitoring and, since 1998, utilizes granular activated carbon (GAC) filtration.
