Birchwood Landfill


The liner system includes 2 feet of compacted clay achieving a hydraulic conductivity of 1.0 X 10-6 cm/sec. All of the soil material used for this liner was obtained from the site, but had to be screened to remove rocks. Above the clay liner is a bentonite geocomposite layer with a 60-mil high-density polyethylene sheet membrane. The polyethylene sheet is cushioned by a filter fabric under a 12-inch drainage layer of river rock.

In addition to the lining, CTI provided general civil design services for various support facilities, including roadways, administration building, scale house, maintenance building, personnel building, and wheel wash facility, and leachate collection facilities.

Due to the topography, two sets of 500-gpm pumps are used to lift leachate from collection trenches into a 430,000-gallon storage tank. The storage tank then discharges to a low-pressure pipeline which conveys leachate directly to the Chattanooga Regional Wastewater System.

An integral part of a modern landfill is the gas collection system. At the Birchwood facility, gas is collected and burned in a state-of-the-art flare system.

Further work was later conducted to comply with Tennessee Solid Waste Management regulations related to lining and closing the 50-acre municipal solid waste landfill.


Liner system consisting of:

  • 2 feet of clay
  • Geosynthetic clay liner (GCL)
  • 60-mil HDPE liner
  • Filter fabrics and stone drainage layer
  • Geocomposite drainage layer
  • HDPE leachate collection system with pump station (750 gpm at 160 feet TDH)

Closure system consisting of:

  • Sand gas venting layer
  • Bentonite geosynthetic clay liner (GCL)
  • Geocomposite drainage layer
  • Gas collection system
  • Vegetative clay layer
  • Storm water management system


  • Permitting
  • Planning
  • Surveying
  • Design of liner, closure, leachate collectors with pump station and force main
  • Cost estimating
  • Contract administration
  • Resident project representation
  • CQA services
Project Description

The City of Chattanooga Landfill on Birchwood Pike incorporates multi-layer liners, leachate pumping facilities, a gas collection system, a wheel wash station, and other elements designed to protect the environment in and around the landfill.

Project Details
  • Client: City of Chattanooga, Tenn.