48 



levels (which are species specific), these heavy metals act as enzyme inhibitors in organisms 

 (Kennish 1992). NLON-REF was analyzed for Cd and Zn by the NED laboratory in 1986 

 and 1987 (Table 4-1). The values for Cd in 1986 and 1987 were below detection limit 

 and/or less than 3 ppm. Average Cd values for the reference areas in 1991 were equal to or 

 below 0.12 ppm (Table 3-2). Average values for Zn were fairly similar for 1986 and 1991 

 at NLON-REF (Tables 3-2 and 4-1). 



Data collected as part of NOAA's National Status and Trends (NS&T) Program were 

 compared to the NLON data to provide a frame of reference for the NLON reference area 

 data (Table 4-2). The NS&T Program has collected and analyzed coastal and estuarine 

 sediment data from 300 sites since 1984. Two sites in Long Island Sound that were sampled 

 over a period from 1984 to 1987 were compared to the NLON reference area data (NOAA 

 1991). 



The two NOAA NS&T stations most representative of the NLON reference areas are 

 Station LICR located outside the mouth of the Connecticut River (41° 15.833' N and 

 72°20.500' W) and Station ELI in Eastern Long Island Sound (41° 14.000' N and 

 72°15.000' W). Station ELI has been characterized as a sand bottom with >80% of the 

 particles collected > 63 «m (4 phi) in diameter. The data set generated for Station ELI 

 consists of non-normalized values only, due to the lack of fine-grained sediments. Station 

 LICR is described as a bottom made up of 50% fine-grained sediment (<63 um or 4 phi) 

 and 50% sand (>63 «mor4 phi). Two data sets exist for Station LICR: normalized values 

 for the fine-grained sediment and non-normalized values for the sand component. 



In comparison to the normalized and non-normalized data generated at NOAA stations 

 ELI and LICR, the values for NLON reference stations WREF, NLON-REF, and NE REF 

 are equal to or below the NS&T values for Cd and Zn (Table 4-2). There is only a slight 

 elevation in Pb concentrations at WREF when compared to the sandy sediment at ELI. 

 Reference stations NLON-REF and NE REF both have Pb concentrations equal to or below 

 the non- normalized values at ELI. All reference station heavy metal concentrations are well 

 below the normalized values for the fine-grained sediment at LICR. 



PAHs are organic trace contaminants in estuarine and marine environments and 

 consist of carbon and hydrogen arranged in the form of two or more fused benzene rings in 

 linear, angular, or cluster arrangements. They include a wide range of chemicals and enter 

 aquatic environments through industrial and municipal wastewater effluents, oil spills, 

 combustion of fossil fuels, commercial and recreational boating activities, riverborne influx, 

 nonpoint source runoff of materials from terrestrial habitats, and in situ diagenesis of organic 

 matter in sediments. Petroleum spillage and atmospheric deposition are regarded as the 

 major sources of PAHs in the aquatic environment (Kennish 1992). 



Monitoring Cruise at the New London Disposal Site, June 1991 



