Revitalizing an Historic Downtown

In the past decade, the City of Dover experienced considerable population and prosperity growth. However, City planners believed there was yet another opportunity for further improving life in the City and the local economy: redevelopment of the historical Dover waterfront along the Cocheco River to add more recreational access and business activity, as well as opening another transportation corridor. The major limitation to these plans was a three‑mile section of the Cocheco River itself, from Dover to its confluence with the Piscataqua River. In order for many commercial water craft, tourists, and possibly commuters, to reach Dover safely by river from downtown Portsmouth, the river channel needed to be deepened to remove sediment that collected in the river since its last dredging in 1906.

Opening the path
With the help of New Hampshire's federal Senators, the U.S. Army Corps of Engineers (the Corps) was assigned to design and implement the Cocheco River dredging project. However, as a federal agency, the Corps held that it was not required to obtain State and local approvals for its operations. This responsibility fell to the City, which decided to bring in GeoInsight because of its innovative approach. GeoInsight used data generated by the Corps to reduce the time and expense required to meet the substantial regulatory information requirements. In a series of direct meetings and negotiations with State and federal regulatory authorities, GeoInsight helped the City to secure acceptance of the project within the highest levels of the New Hampshire Department of Environmental Services (NHDES), which dramatically accelerated the project schedule.

Salvaging safely
Impacts in the riverbed sediment left by riverside manufacturers decades ago meant that the Corps could not dump dredged material at sea, as it normally would, and it elected instead to build an upland disposal cell to receive and dewater the dredged spoil. When competing priorities prevented the the Corps from completing the cell on the City's preferred schedule, the City again turned to GeoInsight, who completed design, contract bidding, and construction oversight of the five-acre, lined spoil dewatering and disposal cell in a five‑month period to get the project back on track. The design incorporated a number of strategically important features including serving as a de facto cap over an old, unregulated solid waste and ash landfill, dewatering of spoil and treatment of the effluent at the City wastewater treatment plant, and supporting construction of a recreational area over the final cap.

When metals in the cell effluent posed a treatment issue, GeoInsight developed an innovative and practical modular treatment process that included treatment residuals into the cell to reduce metals in the dewatering effluent at the source. To reduce costs, GeoInsight trained City Public Works staff to run the treatment system on its own.

Digging up the funds
In addition to completing the groundwork with regulators to push the project forward and engineering a novel solution in a complex physical and regulatory setting, GeoInsight assisted the City in finding ways to help pay for the project. The design and operation of the cell was carefully tailored and documented to meet the Corps's requirements and ensure that it would fully reimburse the City for costs associated with Corps's use of the cell. GeoInsight also assisted the City in obtaining NHDES approvals to sell excess space in the cell to other government entities and municipalities for disposal of impacted sediment from other dredge projects, as well as debris from a portion of the projected waterfront redevelopment area. The success of the regulatory and funding processes for the project allowed completion of the river channel restoration on a schedule coordinated with the City's waterfront redevelopment plan.

Moving mountains
"GeoInsight really made this project happen. Without their permitting, technical, and economic problem-solving abilities on our team, we could have been spinning on this initiative for years. The road to this project's completion is now in sight, and that's good for everyone involved."

-- Dean Peschel, Environmental Programs Manager, Dover, NH