- Utility route analysis
- Subsurface exploration
- Hi rail test borings
- Wetland test borings
- Bedrock tunnel assessment
- LiDAR survey
- Q-system
- Rockfall stabilization design
- Slope stability analysis
- Soil stabilization
- Trenching & dewatering engineering recommendations
Bergen County Utilities Authority (BCUA), operating under an Administrative Consent Order (ACO), entered into an agreement with the New Jersey Department of Environmental Protection (NJDEP) to convert the Edgewater Water Pollution Control Facility (WPFC) into a sewage pumping station and construct a sewage conveyance system to treat wastewater at its Little Ferry WPCF. The approximate length of the proposed sewage conveyance is 16,959 lineal feet, and it will consist of two conveyance methods: approximately 12,685 lineal feet of twin 18-inch diameter High Density Polyethylene (HDPE) force main and 4,450 lineal feet of 48-inch diameter gravity main.
Challenge
The BCUA’s proposed alignment traverses a densely populated area along a limited access utility corridor that crosses through the Palisades Sill bedrock and the Meadowlands wetlands. The need to conduct a geologic conditions assessment of an inactive 130+ year old blasted bedrock tunnel and to complete an alternative route geotechnical investigation along an operational Class III railroad and busy roadways added complexity to the project.
Solution
GZA suggested value engineering to incorporate the review and use of historical geotechnical data of projects completed by GZA and others along the proposed utility alignment. This approach allowed GZA to design a phased geotechnical investigation approach focusing on data gaps discovered during the historical review. GZA is designing three trenchless crossings of tidal rivers, trenching dewatering and excavation, and evaluating in-situ soil stabilization slope stability measures.
Benefit
GZA’s value engineering approach and route analysis saved the client upfront costs in the design of the alignment.