EMC News – The future of the Tay River looks brighter thanks to a three-pronged initiative by the Town of Perth that will lead to significant improvements in water quality over the next decade.
The town’s strategic plan, “Community Plan 2022,” includes specific initiatives over the next 10 years that will help remove contaminants entering the river from Perth’s water treatment plant and sewage lagoon, as well as run-off from storm sewers.
Some of the innovative solutions Perth will use to accomplish these goals should serve as a model for other small communities to follow, said Trish Johnson, senior environmental consultant with the town’s engineering consulting firm, R.V. Anderson Associates. “This integrated concept is really the kind of thing that makes a green community. They’re not only leading by example, they are actually challenging existing practices and creating new best practices.”
Ordered by the provincial Ministry of the Environment to begin treating waste water discharged from its water treatment plant, Perth was faced with the prospect of having to construct a multi-million dollar treatment plant. Instead, the town has chosen what Johnson described as a low cost, low-tech solution to the problem. This summer the town will call for bids to install a geotube to filter the water being discharged from the water treatment plant. The geotube, a textile membrane, will filter solids from the water before it is returned to the river. These solids include alum, a chemical used in the purification of drinking water.
Geotubes are already being used to treat sewage in other communities, including Eganville, but Perth will be the first municipality to use the technology to purify run-off from its water treatment plant, said Johnson.
The environmental consultant credits the town with having the vision to pursue this lower cost option rather than building an expensive treatment plant. With government grants for such projects no longer available, Johnson said, “I’m beginning to see the end of an era of big, shiny plants.”
The geotube solution will also be in place much sooner than the more costly option of building a plant, which would have required a lengthy process of approval. “You are not going to see any solution quicker than what we’re currently looking at for Perth,” said Johnson.
Treating the discharge from Perth’s water treatment plant on-site rather than at the town’s sewage lagoon offers the added benefit of helping to prolong the life of the lagoon. Having to process the water treatment plant run-off at the lagoon would mean tying up capacity equal to the discharge from 80 homes, said Johnson. “What the town is doing now is saving their precious lagoon capacity,” she added.
The capacity of the lagoon, which was built in 1961, has a direct impact on the town’s potential for future population growth. According to a report prepared by R.V. Anderson Associates, the lagoon was designed to serve a population of 8,500 people, but has the capacity to serve a maximum of 12,013. In order to maximize the lagoon’s capacity, the town is implementing initiatives to reduce “inflow and infiltration” of water which doesn’t require treatment into the lagoon from a variety of sources. One source is private sump pumps which are improperly connected to the sanitary sewer system. The town’s flow management program approved in 2011 includes $100,000 to seal manhole covers and $150,000 to repair and seal sewers, each of which is expected to reduce unnecessary flow into the lagoon by 10 per cent.
Other actions identified in the town’s strategic plan include efforts to “support and foster further resident awareness and water in the plan is a pilot project to install a new treatment option intended to help maximize the life of the lagoon. Referred to as a Submerged Activated Growth Reactor (SAGR), this project will see the creation of a channel of rocks or shredded tires in the lagoon. This will create a habitat for micro organisms to help filter them out of the water in the lagoon more quickly.
To assist with this project the town is applying to the Federation of Canadian Municipalities (FCM) Green Fund, which provides 50 per cent funding up to a maximum of $175,000 to test new technology. If the pilot project is successful, said Johnson, the fund also provides 80 per cent grants for full implementation.
The cost of the pilot project is $350,000. The full cost of the SAGR technology at the lagoon will be under $3 million, said Johnson, compared to $5 to $6 million for a new lagoon, or $25 million to construct a sewage treatment plant.
The consultants’ report identifies discharge of storm water from town catch basins as by far the largest source of run-off into the Tay River from the town. Storm water represents a flow of 760,000 kg per year, compared to 36,205 kg per year in residue from the water treatment plant, and 33,376 kg per year from the lagoon.
Although the Ministry of the Environment currently does not regulate the quality of storm water run-off entering rivers, noted the R.V. Anderson report, “storm water represents the largest and most visible impact on the river.” Perth’s Community Plan 2022 includes plans to improve the quality of run-off from catch basins.
Johnson said once all these improvements are in place, “this is going to be a real five-star green community.”