NYC-WTC_000188137

NYC 9/11 Public Portal Document

The attached computer output documents DEP’s compliance with condition 312d- 1 of the USEPA’s Filtration Avoidance Determ ination (FAD) dated May 1997, requiring weekly sampling of New York City-owned wastewater treatment plants and twice monthly sampling of surface-discharging non-City-owned wastewater treatment plants (WWTPs). The output is divided into two sections. The first section compares the effluent concentrations of State Pollutant Discharge Elimination System (SPDES) permitted parameters with the limits listed on the SPDES permits currently on file with the Division of Drinking Water Quality Control Effluent analyses listed as “SPDES Violations’’ under each plant arise from any single exceedance of SPDES permit limits, and so results that are not actual SPDES violations may be included. In other words, means for biochemical oxygen demand and coliform bacteria concentrations are not calculated. The abbreviations “A.M.” or “G.M.’’ in the “SPDES Limif’ column of the output indicate that the noted parameter limit is based on an arithmetic mean or geometric mean of all available observations collected within the month respectively. “SPDES Violation[s]” listed for parameters whose limits are based on means of several measurements should not be considered actual permit violations. If these abbreviations are absent from the “SPDES Limit” column, the reader may assume that the limit stated on the permit is a single-limit value, and that the violation noted is, strictly speaking, a SPDES permit violation. In accordance with the FAD and the monitoring requirements of the SPDES permits of certain plants, composite samples are taken once annually at those plants. When a composite sample is collected, a separate line under the “Parameter” column notes that the sample was a composite. During the time frame of this report, an annual composite sample was taken at Morningstar Foods. The second section of the report is simply an output of the raw data. Parameters not detected in the effluent are indicated with a minus (-) sign, meaning “less than”, next to the detection limit. For example, -0.10 in the NH3 column means that the total ammonia concentration in the effluent was less than the detection limit of 0.1 mg/L. Errors occurring in the field or in the lab are noted by -110 or -105 respectively. The reader may note that some observations appear to be duplicated. DWQC District Laboratories collect periodic field duplicate samples in accordance with their QAPPs. Therefore these duplicated dates refer to data from two separate samples. This report tabulates data only. Information on suspected treatment problems and/or courses of action in response to poor treatment at Catskill or Delaware District WWTPs are described in Filtration Avoidance Deliverable 312e.

NYC-WTC_000188138