The white sandy shallows in a secluded bay of Langford Lake might look inviting, but paddlers beware, a surprise lurks beneath.
“Until you step in it and your foot comes out with white muck all over it,” says Clayton Leachman, one of a handful of residents leading the charge to raise awareness of the lake's plight.
The “white muck” at the bottom of the lake is a collection of pale yellow sediment, described as a potential by-product of rock and mineral stripping in an upland area under development, which has been flowing into the lake since late 2023.
Entering the lake via a stream, fed by a upstream culvert at the end of Wenger Terrace, next to Highway 1, the sediment creates a brown-beige foam, which last year Leachman described as a “toxic bubble bath.”
Downstream, the sediment looks more like a fine sand, which as well as leaving an unwelcome residue on unsuspecting paddlers, also impacts the health of the lake’s ecosystem.
A City of Langford funded environmental investigation has found that in areas where the sediment is accumulating, conditions are “not currently suitable for supporting a diversity of aquatic invertebrate life.”
Results from two sampling locations where sediment deposition is most apparent, were found to have the least number of invertebrates when compared to other sampling sites.
Aquatic invertebrates are “key indicators of water quality” due to their sensitivity to pollution and habitat changes, explains Corvidae Environmental Consulting in its December 2024 report.
“Their presence, abundance and variety can reflect the health of aquatic habitats and the impacts of contamination,” they say.
The smaller number of bottom-dwelling invertebrates in these areas could be attributed to the anaerobic decomposition of plant life, explains the report, which also notes the sediment has created a layer covering aquatic vegetation, "completely obscuring” the lake bottom.
“Anaerobic environments, where oxygen levels are extremely low or absent, are challenging for most benthic invertebrates,” says the report.
The ‘benthic invertebrate investigation’ is the second report carried out by Corvidae on behalf of the city.
While heavy metals were found in the water at the Wenger Terrace culvert, a June 2024 water quality report said the lake posed no threat to human health or aquatic life, and advised removal of the accumulated sediment was not needed.
The most recent investigation recommends ongoing testing and monitoring of the situation; a “wait and see” attitude that has baffled Leachman and other concerned residents.
"Why should I have to go to City Hall kicking and screaming over an environmental issue that should have been resolved on the first day," said Leachman.
Brian Belcher, a professor at Royal Roads University and former aquatic researcher, whose home overlooks the lake, says he too is frustrated and disappointed by the lack of action taken by the city to stop the flow of sediment at its source.
And now Langford is also questioning the recommendations made by the the environmental consultants.
“The initial findings and recommendations from the original biologist were not satisfactory to the city,” said a Langford spokesperson in an email statement. It notes they have engaged "multiple qualified environmental professionals" to investigate the source of the sediment and explore remediation options.
After reaching out to the province for a second opinion, the city says it has been recommended they engage the service of a geochemist, which they are “actively working on.”
“This ongoing investigation is a priority of the city with the goal being an action plan for source control and remediation,” the spokesperson said.
But time is of the essence, says Belcher.
Since samples were taken in August last year for the ‘benthic invertebrate investigation’, Belcher estimates the amount of sediment on the lake’s bottom has “at least tripled,” which he attributes to the rainy season.
The wet fall/winter weather has caused a surge in the volume of water flow, resulting in the increased accumulation of sediment, he says.
“It's certainly changed the ecology because the diving ducks aren't coming … they used to congregate in this area and feed, now they don't go there at all, there’s no point, there’s nothing there for them,” he said.
While the deposits are greatest near the outflow into the lake, Belcher fears finer particles are being transported much further into the lake.
“The basin is being smothered with this sediment, it’s not stopping,” he said.
The only solution he says is to identify the source of the sediment and stop the flow into the underground water system. "I would expect the area to be repopulated quickly after it is remediated."
