CORNFIELD SHOALS 



The Cornfield Shoal s disposal site (Fig. G-l ) is located 6.5 km south 

 southwest of the entrance to the Connecticut River, approximately in the middle 

 of Long Island Sound. This site has been used in recent months for the disposal 

 of spoils from the North Cove project in Old Saybrook, Conn. Sediments in the 

 area are generally clean sands with some gravel present in isolated areas. 



Bathymetry 



Navigation control for operations at the Cornfield Shoals site is provided 

 by trisponder stations installed at the Old Saybrook Lighthouse at the entrance 

 to the Connecticut River and at the Lyme Point Lighthouse farther west. Two 

 surveys have been made at the Cornfield Shoals site; the first on January 30, 

 1978, (Figure G-2(a-k)) and the second on July 30, 1978 (Figure G-3(a-k)). Both 

 of these surveys depict the disposal site as a gentle depression in the center 

 of the site, with a relatively steep slope to a shoal area on the southern 

 margin. 



There is, however, a 1.5 meter discrepancy between these two surveys such 

 that the July survey is more shallow. This is a constant offset in the data, 

 since all contours and profile plots have essentially the same features and the 

 offset is the same for all profiles negating a mistake in the tidal corrections. 

 It appears that a draft correction was probably not applied to the July survey, 

 however, this cannot be confirmed until another survey has been completed. 



In spite of the correction problem the bathymetric data at Cornfield 

 Shoals is incapable of defining the presence of a spoil mound at this site. 

 Although point dumping was used at this site, the spoils have not formed a dis- 

 tinctive topographic feature on the bottom. Furthermore, side scan sonar 

 surveys in this area have failed to detect any change in the bottom indicative 



of spoil material . 



