New York Water Science Center
Problem - In August 2000, eleven sites were sampled from 9 streams within the Croton watershed for pharmaceuticals and other organic compounds associated with wastewater as part of a national study of these compounds in streams receiving wastewater discharges. Results from the national study indicated that streams in the Croton Reservoir downstream of sewage treatment plants had concentrations of target compounds. Detected compounds included pharmaceuticals, detergent degradates, insecticides, caffeine, and other organic compounds (Kolpin and others, 2002). The results indicate that these compounds are commonly present in streams below wastewater treatment plants (WWTPs). Many of these compounds have not been studied until recently, but their occurrence in wastewaters is receiving widespread attention, particularly from the USEPA, and some agencies have begun monitoring for these compounds.
Objectives - Since 2003, a study to assess the occurrence and concentrations of organic wastewater compounds in the New York City watersheds has been conducted through two efforts: (1) sampling keypoint intakes of the New York City reservoir system, and (2) sampling sewage effluent at select WWTPs and the receiving streams above and below the plant's outfalls. The samples collected from the keypoint sites would allow for an assessment of these wastewater compounds in the New York City water supply, and the samples collected from the sewage effluent sites would allow for the assessment of WWTPs as well as the effect of WWTPs on the receiving stream water quality. As New York State continues to invest in WWTP upgrades, these data will provide invaluable information about the effects of those upgrades on the removal and transport of trace organic compounds. In the last several years, the analyte list has expanded to include several pharmaceuticals as well as hormones. Recent results indicate that such factors as wastewater plant technology and the presence of pharmaceutical formulation facilities have a large affect on downstream water quality for these organic wastewater compounds. Further research will focus on long term trends and the effect of advanced treatment on these compounds.