The legacy of sewage sludge disposal in New York bight

摘要: From 1924 until 1987, New York City disposed of sewage sludge by dumping at the 12-mile dumpsite in 20 m water off York-New Jersey coast. Approximately 125 {times} 10{sup 6} m{sup 3} was deposited, peaking early 1980`s. The is head Hudson Shelf Valley, a submerged river channel crossing continental shelf, region sandy sediments that are regularly reworked wave action. introduction chemically and texturally distinct `sludge` sediment provides tracer to study how accumulated anthropogenic deposits dispersed throughout or transferred shelf. This work, begun 1992, focuses on fate material valley, ``downstream`` from dumpsite. Geophysical, chemical, radiological tools were used delineate sedimentary processes, extent contaminant dispersal, longterm dump spoils. Sediment derived has preferentially deposited valley floor relative surrounding resulting unnaturally high accumulation rates upper valley. Dark, sludge-derived being covered cleaner 0 26 km downvalley dumpsite, but ongoing resuspension transport themore » results signal uppermost up 80 Both buried surface ``sludge`` subject biological mixing. patchy occurrence black interbedded sand layers observed suggest occur episodically, probably during major storm events.« less