NYC-WTC_000231621

NYC 9/11 Public Portal Document

concentrations in air at Ground Zero. Total and fecal coliforms and heterotrophic plate count were included in the sampling regime to address NYSDOH concerns regarding pathogens in WTC basement and PATH tunnel water.

The discharge at Exchange Place was discontinued around noon on November 2 (previous report of October 31 was incorrect), and PATH tunnel/basement effluent is currently pumped out from the PATH terminal area of the WTC in Manhattan and routed to the Newtown Creek POTW.

Preliminary Results Summary:

General Characteristics: Sample was a light amber color and had a "sewage-like" odor.

VOCs: Eight VOCs were detected in the sample. Chlorodifluoromethane (Freon 22) was detected at a concentration of 1600 ug/L. An analytical standard for this compound was not included in analysis of the samples collected on 10/03/01 or 10/10/01. Notwithstanding, it would have been identified as a "tentatively identified compound" (TIC) if it had been present at significant concentrations in those samples, and it was not. Freon 22 has ben detected in air samples at the site, as well as in basement water samples collected by PANYNJ and others. Methyl-tertiary butyl ether (MTBE) was detected at 110 ug/L, which is slightly higher than the concentration detected in the 10/10/01 sample. Concentrations of the other six detected VOCs were consistent with those detected in the 10/03/01 and 10/10/01 samples.

Volatile Organic Compounds Detected in Exchange Place PATH Tunnel Effluent Date 10/03/01 10/10/01 10/26/01 Compound Result (ug/L) Result (ug/L) Result (ug/L) Chloromethane 10 QE ND ND Acetone 80 QE 90 QR 99 Methylene Chloride 12 17 16 2-Butanone 21 QE 21 22 Toluene 13 18 21 2-Hexanone 10 ND NDQE m/p Xylenes ND 10 12 Methyl Tert-Butyl Ether 68 65 110 Dichlorodifluoromethane ND* ND* 45 QS Chlorodifluoromethane ND* ND* 1600

QE - Accuracy check sample below lower acceptance limit QS- Spike recoveries above upper acceptance limit * Analytical standard not run, hut not detected as a TIC in these samples

Microbiology: Total and fecal coliforms were both detected at 3000 MPN/100 ml. This is an order of magnitude or more less than the level (10* - 10®/100 ml) in "typical" untreated domestic wastewater (Metcalf and Eddy, 1991). The heterotrophic plate count (HPC) result was to numerous to count (TNTC/1 ml).

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NYC-WTC_000231622