fill. Although water quality standards are being exceed d in the immediate vicinity of the waste mass, it is believed that once t e site is isolated to stop the periodic leachate releases and upgradient cpean waters are routed around the landfill that the water quality will again be within standards. I Groundwater (GW) quality was evaluated through two rounds taken from +.\a 22 individual wells installed during this RI. compounds-L, concern are inorganice, many of standards. The contaminant concentrations in groundwater when the existing data base and the two rounds of current are reviewed. The most frequent inorganics iron, manganese, sodium, chlorides, and magnesium. detected at low levels, however no site pattern was the most volatile8 with adjacent wells consistent detections of pesticides or PCBs were A total of 36 surface water (SW) and associated sediment (SQ) samples were analyzed during the RI. The results of the presence of numerous compounds at levels expected of The Phase I1 Program was designed to establish a final site's impact on the surrounding areas and did show Phase I data. The surface water samples exhibited a concentrati outside of the disposal area that indicates migration of cont not taken place to a large extent. The primary compounds det relevant standards were inorganic compounds. No detectable c of pesticides or PCBs were found and only a single validated the presence of any volatile organics (tetrachloroethene at 2 Copper exceeded the aquatic protection standard of 2.9 ppb at with a range of 6.7 to 171 ppb. The surface water program ale sampling of background water quality at Iona Island, located 15 miles upriver from CPSL. The samples from this area also aquatic protection standards for several inorganic compounds copper. The sediment results were compared to NYSDEC guidance docudnts relative to the protection of aquatic environments and have been normalized backgound station at Iona samples, inorganics were the primary compounds of concern, exceedences of the Limit Of Tolerance (LOT) at stai3 & 7), exceedences of the LOT at sta# 4, 7, 12.3 & 15), arsenic (1 If be detrimental to the majority of species, potentially eliminatin these values were exceeded in sisnificant Dortions of the ecosvstkOi:tis highly likely that biota would b; impaired: Sediment criteria-habe been exceeded for one or more metals in 54 out of 60 sediment analyses in the eaetern drainage channel of the Croton Marsh. Sediment criteria ave been predicted based on "no-effect" and "lowest-effect" levels from em irical evidence from both lab and field studies without an attempt to no alize for any toxicity controlling factors in the sediment. Site-specific ests were conducted to determine any impacts from these exceedances as desckibed below. I 3 Overall the sediment samples showed that the area wh'ch exhibited the most occurencee of exceedences of the derived LOT values as the eastern drainage channel of the Croton Marsh. Based on the effec ed sample locations approximately 4 believes the major impact of the site is, however, the waste mass itself and receives periodic leachate releases with drainage channel of the Croton Marsh. 1 A major component of the current work was an intensiv ecological study of the Croton Marsh. Four distinct sampling efforts were u dertaken: macrobenthos sampling, fish survey with tissue analysis, w tlands vegatative surveys, and wildlife habitat assessments. The macrobentho work revealed that the eastern channel of the marsh has lower diversity, evenness, and abundance levels than the other areas surveyed. The fish urvey work revealed that previously identified instances of lordosis nd scoliosis in mummichugs was no longer evident and a large number of fie specie8 exist in the vicinity of the landfill, including short-nosed sturge n. Whole body tissue analysis has shown that fish taken from the area of the Croton Point Landfill contain polychlorinated biphenyls (PCBs) as do fi h from throughout the Lower Hudson River. The contribution of the Croton Po nt Landfill to this contamination is undetermined. Regardless of the sou ce of the contamination, the contamination does present health risks for people consuming these fish. The m S D O H has issued an advisory 0 of fish caught and Blue Claw Crabs from the Lower Hudson R includes the Croton Point area. I i t The wetlands vegetative work was designed to duplicat previous transects established by Buckley, et al. in the early 1970 s. Aerial infraThe results red spectrometry was used as an additional assessment tool showed that although the marsh has transitioned from catta 1 dominated to phragmites dominated, that the biomass has recovered from revious recorded lows and that this increased biomass is contrary to predic ed declines by 1989 (Buckley, 1982). The habitat assessment work reveale that the Croton Marsh is habitat for a wide variety of wildlife including wo species of special concern (sedge wrens and least bitterns). A total