1-2 



Environmental Impact Statement. Construction permits were granted and 

 in October 1973 an NPDES permit was issued by the Connecticut DEP, 

 authorizing operation of the facility through June 1977 and specifying 

 monitoring and reporting requirements as well as discharge limitations 

 and criteria. The subsequent NPDES permit, effective June 30, 1977, 

 stipulated that UI: 



...submit to the Commissioner a summary report 

 concerning all biological monitoring studies. 

 Such a report shall address the relationship 

 of monitoring data collected after station 

 start-up to baseline data collected prior to 

 station operation. 



It is in response to this requirement that this summary report is 

 presented. 



The format and general approach to the summary report is 

 intended to maximize the utility of the data collected for the United 

 Illuminating-sponsored environmental study programs, both with regard to pro- 

 visions of the permit requirement and to the scientific community. The 

 basic format reflects consideration of The Connecticut River Ecologi- 

 cal Study monograph (Merriman and Thorpe, 1976) which sxommarized nine 

 years of monitoring data and special studies related to the Connecticut 

 Yankee Haddam Neck nuclear plant. The two efforts are similar in appli- 

 cation of multi-year monitoring program data to consider impacts largely 

 related to impingement, entrainment and thermal addition; however, they 

 differ significantly in program structure and content. 



The objectives of the New Haven Harbor Ecological Studies 

 Summary Report are twofold: first, to describe the ecology of New Haven 

 Harbor; and second, to identify and evaluate possible impacts of the 

 generating station on the harbor ecosystem. There has been no previous 

 comprehensive ecological study of New Haven Harbor with which compari- 

 sons can be made. Incorporated into the data base for this report are 

 results of Ul-sponsored programs, including preoperational and opera- 



