Description
Organization: NAVFAC, Army Corps of Engineers
Team Name: NAVFAC /ACOE Team
Related Acquisition Topic(s): Alpha Contracting, Integrated Product Teams (IPT), Partnering
Description:
The Navy took advantage of many innovative opportunities during performance of the environmental closure of the Allen Harbor Landfill at the former Naval Construction Battalion Center (NCBC) in Davisville, RI. Because the 15 acre landfill that accepted various waste from 1946 through 1972 is immediately adjacent to a recreational boating harbor, consideration beyond textbook ones were factored into the Navy's decision making process. The result was a very successful project resulting in high client satisfaction.
The presumptive remedy for the closure of a hazardous waste landfill is to place a Resource Conservation Recovery Act (RCRA) Type -C landfill cap on it. The key component of a RCRA-Type C landfill cap is the impermeable layer, designed to prevent precipitation from infiltrating the waste and potentially flushing contaminants from the landfill. However, Northdiv's Remedial Project Manger was concerned that extending the impermeable layer into the harbor, as would be necessary at this location to completely cover the waste and debris, could lead to failure from tidal influences. To address this concern, he approached the landfill technical experts in the U.S. Army Corps of Engineers’ (ACOE) Omaha office to assist the Navy in determining potential tidal effects on the impermeable liner. This cooperative effort between the two agencies lead to the technical determination that the impermeable layer should extend no further down the slope to the harbor than elevation 14' MSL. The regulatory community was concerned that ending the liner at that elevation would pose at least two problems. Precipitation would enter the landfill and contaminated groundwater would exit from the landfill through the unlined slope. However, the Navy/ACOE team made the technical arguments that precipitation would run off the slope before it had time to percolate into the waste and, more importantly, no groundwater pathway from the landfill to the harbor existed that was carrying contaminated groundwater.
The next issue involved how to protect the slope to the harbor. The Navy wanted a design solution which minimized or eliminated any need to cut back the existing slope. Past waste disposal practices at the site included placing large debris right up to the water’s edge. In some locations, a fifteen foot high bluff resulted. However, though the slope was as steep as one to one in some locations, it had demonstrated stability by weathering Hurricane Carol in 1954. It was illogical to cut back the slope and destabilize it. The use of a sheetpile wall had previously been discussed but was rejected by the state. The state objected primarily for aesthetic reasons though they did cite technical objections that a sheetpile wall would not meet the state’s requirement for a 3 to 1 slope for closure of a sanitary landfill and that sheetpiling could corrode at the water line. A stone revetment solution was accepted.
A related issue was the need to find a solution which provided cour protection at the toe of the revetment, a lesson learned from the McAllister Point Landfill closure project. At McAllister, the top lift of the toe of revetment rock was placed such that the top of the rock was at the grade of the harbor floor. Yet, after less than one season, unanticipated scour action had exposed the till face of that top lift of rock. The Navy Risk Assessor advocated a new wetland be constructed along the face of the landfill. This wetland would meet a number of project needs. It would dampen the effect of tidal action at the toe of the slope and eliminate the potential for scouring. It would eliminate the need to perform even limited sediment and debris removal at the toe of the slope as this area would be effectively capped by the new wetland. It would be a proactive effort to meet or even eliminate future Natural Resource Damages claims. Finally, and most importantly to the local community, it would provide a beneficial reuse opportunity for the clean dredge spoils to be generated as part of the Town of North Kingstown’s initiative to have the entrance channel to Allen Harbor dredged.
A final initiative employed by the Navy Design Manager was to include representatives from the Remedial Action Contractor’s (RAC) office early in the CLEAN contractor’s design process. RAC engineers and construction managers attended monthly design meetings and participated in design reviews. They developed the construction workplan concurrent with the team’s review of the 30% design package and the final workplan was submitted within days of the 90% design submission. Using this Navy/CLEAN/RAC team approach, we were able to mobilize 8 months after initiating design and only 6 months after signature of the Record of Decision (ROD). Additionally, we had no delays related to the constructability of the finished design as they were all sorted through during the design process. The design phase of the project was awarded to EA Engineering, Science, & Technology under Contract Task Order (CTO) 0067 of contract N62472-92-D-1296(CLEAN Contract) on 27 September 1996 for $1,248,503.00. The construction remedy was awarded to Foster Wheeler Environmental Corporation under CT0 0025 to contract N62472-94-D-0398(RAC Contract) on 24 December 1997 for $9,602,127.00. Foster Wheeler commenced performance in early 98 with remediation completed 30 June 1999. By using fill from previous work and from excavations at the Allen Harbor Landfill, the project is almost $2 million under budget despite a large change for a sizeable quantity of unforeseen PCB contaminated soil. As a result of the cooperation of the design and remediation agents, Navy project managers, EPA and State regulators, and the community this project was a win-win all around. The project allowed faster transfer of property at NCBC Davisville, while saving needed BRAC dollars during remediation, improving the ecology and enhancing the appearance of the site. It should be noted that the project received a Maryland state design award for EA Engineering, Science, & Technology. The design project manager was Christi Davis, the contract specialists were George Shirley (design) and Claude Graff (remediation). The contracting officer was David Rule, the remedial project manager was Phil Otis and the construction NTR’s were Paul Briegel and Christi Davis. The Foster Wheeler site superintendent was Daniel Sullivan.
