An oxygen generator, or oxygenator, is in place next to Elk Lake in a purpose-built enclosure at the end of Hamsterly Road to help tackle frequent blue-green algae blooms and increase water clarity in Elk and Beaver lakes.
The oxygenator, connected to a pipe system, pumps oxygen to the lower layer of Elk Lake, which is up to 19 metres deep.
The system tackles nutrients that have accumulated in the lake bottom over the years. When water oxygen levels become low, the nutrient-rich sediment gets drawn back into the water column, a major contributor to algae blooms.
The oxygen keeps the overabundance of phosphorous in the sediment from rising to the surface, said Stephen May, the CRD’s senior manager of facilities and engineering services. May said controlling where phosphorous goes is a key to preventing algae growth.
May said the system can reach the lake’s deepest point. “If it was shallower, it would use a different technology,” he said. “In particular, if a lake is smaller and has different use characteristics, you can use a fountain system like you see in Langford Lake.”
The system has gone through on-site testing and is due to be fully operational within a few weeks, May said. Expertise and equipment were provided by Texas-based Gantzer Water, LLC.
Colin Plant, chair of the Capital Regional District board and a Saanich councillor, said he expects to see an improvement in water quality in the lakes within a year. “And hopefully [we will] not see a blue-green algae bloom in Elk Lake ever again.”
Ingesting water that contains blue-green algae can cause lethal liver damage in dogs, and lead to headaches and abdominal pain in humans.
Both the CRD and the province have put $750,000 into the project, said Plant, noting the equipment is part of a long-term project to improve water quality at Elk and Beaver lakes.
The CRD also has a watershed-management plan to help prevent fertilizers from area fields and road runoff flowing into the lakes, which has led to algae blooms, low oxygen levels and reduced water quality.
Plant said the oxygenator technology is in high demand and has been used widely in the United States.
He said that Saanich South MLA Lana Popham “really went to bat for us” to help secure the provincial funding.
Elk/Beaver Lake Regional Park is the most popular park in the CRD and has both recreational and economic impact, Plant said.
“We wanted to be good stewards of the lake and wanted to do whatever we could to return the quality of the water.”
Fishing and rowing groups have been very interested in the project, he said.
Plant said if the project works well it could be considered at other sites in the region. He said the ideal would be to not need an oxygenator and deal with water quality by restricting what goes into a body of water.
“But for situations like Elk Lake where there already is a significant nutrient buildup at the bottom of the lake, this is a way to address it.”
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