Three separate tests were made to evaluate the effects of the new 

 inlet on pollution concentrations in the study area. Test results are 

 summarized in Table 3-5. One pollution source was simulated in Raritan 

 Bay (see Fig. 3-64 for location of release point), representing the 

 effluents discharged from the Middlesex County Trunk Sewer Outfall. 

 Pollution concentrations from that source were lower in all three of 

 the major water bodies of the study area with the new inlet installed; 

 this showed that the new inlet would reduce the influx of Raritan Bay 

 wastes to the study area. Table 3-5 presents the results of a similar 

 test series, but simulating the major sewer outfalls in Upper New York 

 Bay (see Fig. 3-64). For this source of pollution, concentrations in all 

 three major water bodies of the study area were increased. Table 3-5 also 

 presents the results of the tPiird pollution test series, for which the 

 local sources of pollution input in the Shrewsbury and Navesink Rivers 

 were simulated (see Fig. 3-64.). For conditions of these local sources, 

 concentrations throughout the study areas were substantially reduced. 



Table 3-5. Effects of plan 3 on average dye concentrations.' 



Test 



Sandy Hook Bay 



Navesink River 



Shrewsbury River 



Raritan Bay ^ 



Base 

 Plan 3 



186 



174 (-6 pet) 



99 



94 (-5 pet) 



102 

 96 (-6 pet) 



Upper New York Bay' | 



Base 

 Plan 3 



1,039 



1,072 (+3 pet) 



649 



862 (+33 pet) 



694 



854 (+23 pet) 



Navesink River' 



Base 

 Plan 3 



55 



45 (-18 pet) 



372 



285 (-24 pet) 



82 



39 (-53 pet) 



Shrewsbury River' 



Base 

 Plan 3 



71 



48 (-33 pet) 



129 



75 (-42 pet) 



634 



356 (-44 pet) 



Dye concentrations in parts per billion; 



Initial concentrations = 100,000 parts per bilUon. 



Pollution source. 



The reduction in pollution concentrations in the study area from the 

 Raritan Bay source is attributed to the fact that tidal flow in and out 

 of the new inlet reduces the present exchange of flow between Lower New 

 York Bay and Sandy Hook Bay; therefore, less of the polluted water of 

 Lower New York Bay is drawn into the study area. The increase in pollu- 

 tion levels in the study area from Upper New York Bay pollution sources 

 is caused by pollutants (from this source) which disperse largely into 

 the ocean; a small percentage of this waste is then transferred from the 

 ocean to the study area by tidal exchange through the new inlet. The 

 peak dye concentration thus arrived in the study area later during the 



62 



