NYC-WTC_000175761

NYC 9/11 Public Portal Document

104 East 25th Street 10th FL New York. New York 10010 www.atc- enviro .com J- 212.353.8280 Fax 212.353.8306 ASSOCIATES INC.

October 19, 2001

Mr. Mohamed Hemida NEW YORK CITY BOARD OF EDUCATION Environmental Health & Safety Unit 28-11 Queens Plaza North Long island City, New York 11101

RE: WATER SAMPLE ANALYSIS RESULTS STUYVESANT HIGH SCHOOL 345 CHAMBERS STREET NEW YORK, NEW YORK ATC PROJECT NO. 41617-0546

Dear Mr. Hemida; At the request of the New York City Board of Education (NYCBOE), ATC Associates Inc. (ATC) submitted a water sample that was collected from a sink tap at Stuyvesant High School (the “Site"). ATC was informed that the sample was collected by a teacher from Room 705 at an unspecified tap, was then given to the NYCBOE personnel, and subsequently forwarded to ATC. The sample was reportedly collected on October 11, 2001. ATC submitted the sample to a qualified laboratory for analysis for RCRA 8 heavy metals.

The sample was submitted to New York Environmental & Analytical Laboratories, Inc. for analysis. Laboratory results indicated that Barium was detected at 2.23 milligrams per liter (mg'l) which is above the New York State Department of Health Drinking Water Maximum Contaminant Level (MCL) of 1.0 mg/l for this metal. Two additional heavy metals were detected above their respective MCLs: chromium at 0.11 mg/l (MCL: 0.1 mg/l); and lead at 0.42 mg/l (MCL: 0.015 mg/l).

Further, the method detection limits (MDLs) reported by the laboratory for cadmium and selenium were above the MCLs for each of these metals. This means that, although the laboratory report indicates that these two metals were undetected to a specified lower limit (the MDLs), the MDLs for these two substances were above the MCLs. Therefore, it is possible that both of these metals may be present at concentrations above the MCLs, but not detected by the laboratory. This condition may have been caused in part by the lack of the required preservative (nitric acid) in the sample container. In addition, the sample was observed to be highly turbid. When analysis of a highly turbid water sample is conducted, heavy metals are invariably detected at elevated concentrations due to the composition of the suspended solids, rather than actual heavy metal contamination in drinking water. Therefore. ATC concludes it is unlikely that this result represents actual drinking water quality at the Site.

ATC recommends that additional sampling and laboratory analysis be performed at the undisclosed tap under more controlled conditions. Further, the tap should be flushed to remove any visible solids prior to sampling.

The laboratory data is attached. If you have any questions concerning this report, please feel free to call our office.

Sincerely, ATC ASSOCIATES INC.

Frank Galdun Technical Director R\envirtVrank9Wata\boeVn4A7metal5

CONFIDENTIAL, CITY_21MC100_003432869 SUBJECT TO PROTECTIVE ORDER NO. 2, SEPT. 2008

NYC-WTC_000175761