1 1 



"Reinarks#« 



15ie tabttLated water-level elevations are based mostly on measurements made 

 near the aid of May 194S» The more recently coiqpleted i»b11s in Stif folk Cotmty 

 were measiired in Jtine 1944« At the end of that month the water table mer moat 

 of Long Island, as shoim in other representative shalloir wells, was generally 

 at about the same level as it was at the end of May 194S# 



Water levels in supply wells of the New lork Water Service Corporation in 

 Flatbushj BrooldyB, were taken from testimony of Thomas H^ Wiggin, CoiasuLting 

 Engineer, given at a hearing before the Water Power and Control Commission^ In 

 some cases these are static levels of wells in service # 



111 elevations "given in the tatle refer to mean sea levels The elevations of 

 measuring points on the well casings have been determined by differential level- 

 ing done by the Geological Su3?vey» The general order of significance of the 

 water-table elevations is indicated on the map, most of the elevations being 

 given to the nearest tenth of a f oot« Water levels determined at another time 

 than at the end of May 1943 are given to the nearest foot only# 



Where the density of wells is adequate the contours are dratm as fuH lines* 

 Where information is lacking or "vtiere there is some uncertainty as to its inters 

 pretation, the contours are drawn as broken lines* No attempt has been made to 

 draw in the contours below the 60-foot contour in northern Nassau County because 

 many of the wells in that area undoubtedly reach only to perched water tables • 

 That iB true, for example, of wells N 1171 and N 1172 # 



Thexo is a large area in northwestern Suffolk County in which there are few 

 shallow observation wells. The provisional dashed contours there should be re- 

 garded oixLy as suggestive of the general shape of the main water table in that 

 area# Farther to the east, between Lake Ronkonkoma and Carman^ s River, the 

 coverage is better, particularly along two recently completed profiles 



