LOCATION: ASHTABULA, OHIO
DATES: NOVEMBER 2012 – NOVEMBER 2013
CONTRACT VALUE: $3,000,000
ROLE: SUB CONTRACTOR
Approximately 120,000 cy of organic silts impacted with PCB’s, metals, and PAH compounds were mechanically dredged. In addition, White Lake mechanically dredged approximately 11,500 cy of sand/gravel from non-impacted portions of the AOC. Our purpose built fleet of equipment was a perfect fit for the job. Dredging operations included the use of our custom Case CX460 long reach excavator equipped with real-time RTK GPS positioning and custom environmental bucket as well as our flexibly deployed sectional barges.
The project required work in an active harbor lined with small boat docks and moored vessels on both embankments as well as active large commercial docks; close coordination with Vessel Traffic Control was critical.
White Lakes’s in-barge de-watering process and customization of equipment was the key component to the efficiency of this project. A complex dewatering system consisting of geotube and sand/bag filter installed on board the dredge minimized transport of water, maximized efficiency, and sped up offloading and transport portions. Because much of the process was conducted in the barge(s), minimal additional shore space was required. This was critical due to the limited space available and requirements to minimize impact to port operations.
TRANSPORTATION & DISPOSAL
White Lake offloaded and treated all impacted sediments on shore with a calcement stabilization process to pass paint filter test. They were then mechanically offloaded to highway trucks using our Sennebogen 835 RHD material handler for final disposal and beneficial reuse in capping a local existing industrial CAD lagoon.
The project required the use of smaller, maneuverable, limited draft material barges to access restricted areas. There were two heavily trafficked low clearance bridges required to be transited for a majority of the dredging located in the upper portions of the channel. We customized and lowered the profile of our work and tug boats to allow for unimpeded transfer of materials to the offloading pad, going under the two low clearance movable bridges without opening them which greatly reduced disturbance to local traffic and business.