Chrononology of Past Evaluations 



A series of changes in collection and analysis procedures for 

 exposure panels have occurred during the history of this program (Table 

 1) . Changes were made to enhance data collection and increase our 

 ability to discern power plant effects from natural variability in 

 community parameters. 



In 1977, Brown and Moore evaluated the exposure panel program at 

 Millstone using 1968-1974 data. An array of statistical methods were 

 applied to the data to determine strengths and weaknesses of the program. 

 They concluded that the major weakness of the data was the lack of 

 replicate sampling and the most meaninful parameter analyzed was the 

 number of species collected per panel. In fact, Brown and Moore concluded 

 that a signficant impact by power plant operation would require an 

 addition or loss of at least three species per site. Therefore, they 

 recommended replicate sampling to account for interpanel variability of 

 species and their abundances, which would provide a more quantified 

 basis for making decisions. In addition, they recommended a reduction 

 in the exposure period from 12 months to 7-9 months. They suggested 

 that the shorter exposure period would reduce the destructive effects of 

 woodborers, which in the past had frequently resulted in the loss of 

 entire panels, and reduce any time lapse in data caused by a storm 

 destroying an entire rack of panels. 



Battelle subsequently conducted a two year pilot study (February 

 1977 - February 1979) to assess interpanel variability in community 

 composition and species abundance (Battelle 1978, 1979a). They concluded 

 that a minimum of six replicate panels at each site was needed to adequately 

 account for natural variability. These results were based on the deployment 



