Picture below: Sackville Landfill, Courtesy of HRM Sackville Landfill Leachate Treatment Facility report, page 1, May 2000
The old Sackville Landfill, on Highway 101, first opened in 1975 and was shut down in December of 1996 due to the environmental damage it was causing. Despite many modifications to the landfill to contain environmentally hazardous materials, the containment was insufficient and leachate leaked into the nearby Sackville River, polluting the water.
Leachate is the liquid created when water seeps through the waste in a landfill, collecting metals, nutrients, bacteria, fungi, and various gases depending on the types of waste found in the landfill. Leachate damage can be prevented with proper lining and/or draining systems set up below the landfill.
A new section of the landfill (Phase B) had been constructed with liners and a leachate collection system. This collection system directed the leachate to a leachate treatment facility onsite (constructed in 1986), leading to a large reduction in the concentration of the leachate. The treated leachate, after leaving the treatment train (involving pre-treatment, anaerobic digestion, and aerated lagoons, amongst other treatment methods), flows into a modified wetland adjacent to the Sackville River. This treatment process has been functioning since constructed, and has been treating leachate at the landfill up to present day since it closed in 1996.
In 2007, Highland Energy began drilling into the old landfill site to collect the pent-up methane gas buried beneath the surface. This gas is being converted into enough electricity to power 2,000 local homes. Highland Energy guarantees there is enough methane gas in the landfill to keep the electricity program running for 15 years, but they speculate it may even be enough for 20 to 25 years.
See below for the response from HRM regarding some questions posted to SRA about the planned transfer of composting leachate to the Highway 101 Landfill Leachate Treatment Plant.