Our team specializes in the evaluation, design and construction of wastewater collection and conveyance systems. We have engineered wastewater collection systems for residential, commercial and industrial developments and larger systems for local governments in North Carolina and Virginia.  For larger systems, we have extensive experience in sewer basin studies and gravity interceptor designs for larger municipalities such as the City of Raleigh, City of Durham, and the Orange Water and Sewer Authority (OWASA). Our pump station and force main design experience includes small submersible pumping
stations, larger submersible duplex and triplex stations, vertical turbine sewage handling stations, and dry-pit/wet-pit submersible stations. Our force main and gravity sewer design experience includes PVC, Ductile Iron, Fiberglass Reinforced Pipe (FRP/GRP), RCP, and HDPE with specific expertise in trenchless design including horizontal directional drilling (HDD), horizontal auger boring (bore and jack) and tunneling (pipe jacking, microtunneling, pipe ramming). Finally, our experience includes gravity sewer and force main rehabilitation evaluations using PACP/MACP/LACP methodolgy and design using a variety of methods including CIPP, slip-lining, centrifugally cast coating systems, and pipe bursting.

Our gravity sewer design experience includes local sewer collection systems for annexations and new development as well as larger diameter gravity sewer systems with pipe sizes up to 72-inch diameter interceptors. We have designed wastewater pump stations ranging in firm capacity from 100 gpm to 9.0 MGD with force main designs ranging in diameter from 4-inch to 36-inch. Our team has studied and designed several low-pressure sewer systems in project areas that could not be served in part or entirely by gravity sewer collection systems. These low-pressure systems have included miles of low-pressure sewer main and grinder simplex and duplex packaged pump stations and STEP systems, as required by the clients.

Wastewater Pump station design

Our Specialties Include:

  • Wastewater collection system evaluations
  • Sewershed and basin studies
  • Gravity sewer design including large diameter interceptors
  • Wastewater conveyance systems - pump stations and force mains
  • Low-Pressure System Designs - Grinder and Septic Tank Effluent Pump (STEP) systems and Pressure Sewer
  • Air Release Valving Distribution and Sizing
  • Water Hammer/Transient Surge Anaysis and Control
  • Hydraulic Modeling
  • Trenchless Crossings for Railroads, Highways and Wetlands/Surface Waters
  • Trenchless rehabiliation including CIPP, Slip-lining, centrifugally cast coatings, and pipe bursting.
  • Fine Screening and Grit Removal

large diameter gravity sewer  experience with trenchless design expertise