The 30-year-old Sechelt landfill is not contaminating the regional water supply, though the dump is leaching into groundwater, says a report released by the Sunshine Coast Regional District Sept. 2.
SCRD chair Ed Steeves requested the report in response to comments from MLA Harold Long that the Sechelt landfill might be leaching into Chapman Creek. The SCRD board voted to send a copy of the report to Long.
This was the latest shot in an ongoing debate between Long and the SCRD over the future of the Chapman Creek watershed and a proposed gravel mine on private land near the water intake.
"Harold is trying to say we're probably more involved in harming our watershed than this gravel mine could be," said Celia Fisher, director for Elphinstone. "I find that offensive."
The report, prepared by solid waste management coordinator Cathy Kenny, summarizes the past environmental studies and ongoing monitoring of the Sechelt landfill. The dump is located at the top of Dusty Road, northwest of Chapman Creek. At its closest point, the creek is about half a kilometre from the dump.
The dump is not lined, which means leaching into surface or groundwater is possible. In 1996, the regional district hired a consultant to study the groundwater flow under the dump by measuring the electrical conductivity of the ground. That study suggested the groundwater flow was predominately south.
In 1993, 1996 and 1999, the regional district dug wells around the dump to monitor groundwater. The consultant, Piteau Associates, concluded leachate from the dump would migrate vertically through layers of sand and gravel, then hit bedrock and flow south toward Chapman Creek, west toward Trail Bay or possibly to the head of Porpoise Bay.
To check for leaching, twice a year the SCRD tests surface water in Irgens Creek, which flows parallel to Dusty Road from the dump to Porpoise Bay, and in Chapman Creek, both above and below the water intake. There is no sign of leachate impact on either creek, said the report.
The SCRD also monitors groundwater twice a year. The shallow wells show only minimal leachate impact, "likely due to leachate at these locations being highly diluted by natural groundwater," said the report.
The water from three deep wells is contaminated by leachate, most likely from fish waste that was composted at the dump in the mid-1990s, but the leachate amounts are lower at the deeper levels.
"Most of the organic loading is gone from the leachate before it reaches bedrock," said Kenny, due to natural filtration and biological processes.
She said those groundwater leachate levels are declining over the years, presumably as the remaining fish waste decomposes.
