Background fluorescence, tide, salinity, temperature, and 

 current speed and direction data were also collected prior to 

 and during the dye concentration survey to support the 

 development of the delta-T isotherm data. These data are 

 presented in graphic form in Figures 4 through 8 and in 

 tabular form in Appendix II. 



A small circulation study employing free-drifting drogues at 

 multiple depths was also conducted and the results are being 

 held for later processing. 



2.0 PR OCEDURES AND EQUIPMENT 



2 . 1 Horizontal Control 



Horizontal control points easily discernible on 1:24,000 

 (1 " = 2,000") scale USGS Quadrangle maps were used as control 

 stations for navigation equipment during the survey. The 

 estimated accuracy of determining horizontal control point 

 coordinates in this manner is j^5 ft in vessel locations 

 relative to the Connecticut state grid system. 



2. 2 Vertical Control 



OSI established a temporary tidal benchmark (TbM) at NUEL's 

 dock facilities by correlating recorded tide levels with 

 predicted tide elevations for Millstone Point (NOAA Tide 

 Tables). The elevation of OSI's TBM is 5.2 ft Mean Low Water 

 (MLW) . 



A Stevens Type F recording tide gauge was installed at the 

 NUEL dock facilities and referenced to OSI's TBM. Tidal 

 elevation data was continuously recorded during all survey 

 operations. A specification for the Stevens Type F recording 

 tide gauge is included in Appendix I. 



