Industrial
| Project | Cell 6 – 2 Rough Grading and Ground Water Trench Phase II |
| Client | Waste Management (DRPI) |
| Design Professional | Geosyntec |
| Location | New Castle, DE |
| Job Size | 1 – 3 Million |
| Duration | 6 months |
| Date of Completion | February 2013 |
Project Overview
Preparatory grading for future twenty acre landfill cell and installation of large groundwater diversion trench under area of future cell. The new landfill cell was scheduled to be opened in 2013 and this preparatory work had a tight schedule for completion prior to March 2013.
- Landfill subgrade preparation for cell 6-2; including 19 acres of grading to 0.1’ tolerance utilizing GPS earth moving equipment
- 190,000 CY of earthwork (cut/fill, import & removal of unsuitable material)
- Installation of 1200 LF of Groundwater Diversion Trench ( 8’w x 10’h tall stone and non-woven filter fabric around 12” perforated HDPE groundwater diversion pipe) installed from 10’ to 40’ in depth
- Clearing and grubbing of 3 acres
- Installation of erosion and sediment controls for 24 acre site
- Installation and maintenance of temporary pump pits and dewatering throughout project
Key Challenges
WM planned on utilizing only onsite soil material for making structural fills. A large portion of the material planned for use from onsite had moisture content too high to be utilized in the fall and winter months for structural fill. Corrado found and procured acceptable structural fill material locally in short order to finish the project on schedule and within budget. Over 20,000 CY of structural fill was imported with no negative impact to the final completion date.
A large portion of the new landfill cell was to be constructed over an area previously used as a construction debris landfill and concrete plant. Corrado carefully separated the material as it was removed in order to recycle the concrete and minimize the trash that ended up in the operating landfill. Corrado worked with WM to redesign portions of the cell to minimize the quantity of trash to be removed from the area being prepared for subgrade of the new cell to help reduce cost and protect valuable landfill airspace for WM.
The deepest section of the groundwater diversion trench was placed adjacent to public roadway utilized by tractor trailers and public for landfill access. Support of the excavation at the roadway was performed using a soldier pile and lagging system. There was minimal impact to traffic on the public roadway and the excavation withstood the rainfall from Hurricane Sandy with minimal damage.