significantly elevated levels of lead in the WLIS-A sediment. 

 The concentrations of mercury were well below the FDA Alert 

 Level . 



In summary, the results of the present survey indicates 

 that the management controls over dredged material disposal at 

 WLIS, initiated by New England Division, Corps of Engineers, have 

 been effective in minimizing the dispersion of dredged material 

 and preventing any significant adverse environmental impacts. 

 Distinct disposal mounds have been formed by disposal operations 

 occurring at taut-moored buoys and appear to be stable with no 

 evidence of erosion or significant transport of material. The 

 "stressed" condition at the disposal site is not attributible to 

 disposal operations but rather to conditions in Western Long 

 Island Sound in general. 



6 . RECOMMENDATIONS 



The DAMOS monitoring protocol for disposal sites in 

 Long Island Sound depends on comparing disposal site conditions 

 with an appropriate reference, i.e., a nearby area of seafloor 

 which is not affected by the disposal events. The WLIS Reference 

 station was clearly more stressed than the survey area. The 

 reason for this may be low bottom water oxygen. However, it is 

 not clear why the Reference station, located only 2 km east of 

 the survey area, should have been more oxygen stressed. Future 

 monitoring should include some near-bottom oxygen monitoring and 

 an additional reference station should be located to document how 

 widespread are the changes measured at the present one. This may 

 not be possible for this area of the Sound because the study done 

 for EPA Region I has shown that low oxygen water exists at depths 

 of 50 feet or more throughout this area in August. While 

 year-to-year variations may be present in bottom water oxygen, 

 extended periods of low oxygen tensions in the range measured can 

 seriously compromise the benthic habitat throughout the whole 

 region. In short, a relatively undisturbed Reference site may 

 not exist in the vicinity of the disposal site. 



7 . REFERENCES 



Benninger, L.K., R.C. Aller, J.K. Cochran and K.K. Turekian. 

 1979. Effects of biological sediment mixing on the 210 Pb 

 chronology and trace metal distribution in a Long Island 

 Sound sediment core. Earth and Planetary Science Letters 

 43:241-259. 



Bokuniewicz, H.J., Gebert, J. A., and R.B. Gordon. 1980. 

 Consolidation of a rapidly emplaced deposit of estuarine 

 sediment. Unpublished report, 42p. 



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