72 



Portland Disposal Site 



Royal River Project Area 



Depth Difference 



February 1996 Baseline vs. November 1996 UDIVI Survey 



Apparent Accumulation of Pseudo-UDM 



43° 34.000'N 



43° 33.800'M 



43° 33.600'N 



70° 01.800'W 



70°01.600'W 



70°01.400'W 



m 



200 m 



Figure 4-12. Depth difference plot of the November 1996 UDM survey versus the February 

 1996 baseline survey (NAD 27) showing apparent accumulation of pseudo- 

 UDM in close proximity to the PDA buoy, 0.25 m contour interval 



T]ie Portland Disposal Site Capping Demonstration Project, 1995-1997 



