19 



habitat of the upper river zone versus the brackish and saUwater environments of the middle 

 and outer zones (Figure 2-7). 



Also in the summer of 1995, SAIC and NAE selected an 800 m x 800 m area in 

 the southeast comer of PDS as the Royal River Project Area (Figure 2-8). The southeast 

 quadrant of the disposal site was selected due to limited historic disposal activity and 

 availability of basin features that would act as namral containment measures to restrict the 

 lateral spread of the dredged material mound. SAIC completed a baseline bathymetric 

 survey over the 0.64 km- PDS project area in August 1995 for comparison with all fumre 

 project survey results. 



2.2.2 Dredging Operations, Fall-Winter 1995-96 



In late October 1995, the taut- wired disposal buoy "PDA" was deployed at 

 43° 33.790 'N, 70° 01. 514 'W, at the center of a small basin within the Royal River 

 Project Area at PDS (Figure 2-8). Dredging operations in the Royal River were scheduled 

 to commence in mid-November 1995 with a target completion date of late December. 

 Operational difficulties with the contractor's dredging equipment, however, caused 

 significant delay in the initiation of material excavation, as well as slow progress once 

 dredging was initiated (Figure 2-6). By late December 1995, no dredged material had left 

 the Royal River for disposal at PDS. The delays in the Royal River dredging operations 

 began complicating other projects utilizing PDS for disposal. 



In South Freeport, ME, a small improvement dredging project at a local marina in 

 the Harraseeket River was scheduled to provide additional CDM for the completed Royal 

 River pseudo-UDM deposit. If dredging operations in the Royal and Harraseeket Rivers 

 were completed in the correct sequence, the marina project would have produced a total of 

 10,000 m^ of capping material to supplement the volume of available CDM from Royal 

 River. Approximately 2,800 m^ of sediment dredged from the Harraseeket River was 

 deposited to the north and west of the PDA 95 buoy position between December 19, 1995, 

 and January 5, 1996, introducing fresh dredged material into the project area before any 

 material was dredged from the Royal River. When this complication was detected by NAE 

 in early January 1996, the remaining 7200 m^ of material was redirected to the U.S. Coast 

 Guard Class A disposal buoy ("DG"; Figure 2-8). 



By January, the first barge loads of material had left the Royal River for disposal at 

 PDS, but was directed to the DG buoy in an attempt to streamline the dredging and 

 disposal operations before Royal River sediments were deposited within the project area. 

 From January 6 through February 15, a total estimated barge volume of 22,000 m^ of 

 Royal River material was deposited at the DG buoy. After mid-February, however, no 

 further progress was made by the dredging contractor. The Royal River dredging project 



The Portland Disposal Site Capping Demonstration Project, 1995-1997 



