The New COA

Draft Agreement

Draft Annexes

• Areas of Concern
• Harmful Pollutants
• Lakewide Management
• Monitoring and Information

Something Old, Something New

CANADA-ONTARIO AGREEMENT RESPECTING
THE GREAT LAKES BASIN ECOSYSTEM

Beach closure

Each day, the urban landscape creeps a little farther across the Great Lakes Basin. The farmlands and woodlots of southern Ontario are being transformed into houses and roads, golf courses and suburban malls. As the population grows the effluents from sewage treatment plants, as well as polluted urban runoff and untreated municipal stormwater have emerged as prime contributors to local water quality problems throughout the basin.

Urban runoff, flowing like a sheet of water off rooftops and over pavement, washes heavy metals, road salt, animal feces, and oil and grease directly into nearby waterways. Stormwater, laden with silt and sediment, muddies streams, suffocates aquatic life and buries fish spawning grounds. And combined sewer overflows (cso), swollen with rainwater, flush untreated sewage into local rivers, streams and lakes. Within 24 hours, the warning signs go up and the beaches are closed, again.

The governments of Canada and Ontario and municipal authorities, working under the auspices of the Canada-Ontario Agreement Respecting the Great Lakes Basin Ecosystem (coa), have been developing and evaluating new stormwater control technologies and sewage treatment techniques to resolve these water quality problems. Under the new COA, Canada and Ontario will continue to build on this work, implementing efficient and cost effective projects to reduce the environmental damage of a rapidly expanding urban population.

To reduce the impacts of urbanization on the natural environment a variety of projects have been developed under the Municipal Wastewater Program. Technologies for sewage treatment, CSOs and stormwater management have been developed and demonstrated. The focus is on sharing the information and experience gained from projects, as well as investigating innovative approaches for reducing cost and managing municipal wastewater.

Municipal Wastewater Program partners include, the Ontario Ministry of the Environment (moe) and Environment Canada’s Wastewater Technology Institute and the National Water Research Centre as well as conservation authorities, Remedial Action Plan (rap) committees and municipalities. The coordinating force behind the program is the Government of Canada’s Great Lakes Sustainability Fund.

If the environmental benefits are not sufficient motivation, facility optimization can also save a cash-strapped municipality a substantial amount of money.

Getting started on stormwater

Sewers in many older municipalities pull double duty. They often carry both sewage and stormwater through a single or combined pipe to the local sewage treatment plant. When a big storm hits, the huge volume of combined sewage, rainwater and all the contaminants carried along in the flow can overwhelm the plant with the result that wastewater may be dumped untreated into the closest lake or river.

“Treating stormwater and runoff is a relatively new concern,” says Sandra Kok, Senior Project Engineer with the Government of Canada’s Great Lakes Sustainability Fund. Historically, communities worried more about erosion and flood control. “Only in the last 15 years or so have we started taking a serious look at the environmental effects of stormwater,” she says.

The art of stormwater management is evolving rapidly. The Great Lakes Sustainability Fund (glsf) and the Ontario Ministry of the Environment (moe) have been helping municipalities assess and test a variety of new techniques for diverting and treating urban runoff and stormwater:

• Various storage systems that hold back stormwater, for hours or days, until the local sewage treatment plant (STP) can handle the extra flow;
• Perforated piping, infiltration trenches and soakaway pits that use the natural attenuation properties of the underlying soil and bypasses the STP altogether;
• Ponds and artificial wetlands that hold runoff until the contaminated sediments settle out and the clear water can be released to local watercourses;
• Cost-effective technologies for better handling of the outflow of CSOs, including chemical treatment and real-time controls, that can on the cost of storage tanks.

In the past, engineers concentrated on how best to handle the huge quantities of stormwater. “Now we are working to improve the design of stormwater ponds and other systems in order to improve the quality of the water discharged,” says Tony Ho, a Municipal Water Specialist with the Ontario Ministry of Environment. “We are looking at wetlands to cut nutrients, and filters to remove grease and sediment, and ultra-violet disinfection to reduce pathogens.”

Homeowners are also being encouraged to do their bit by disconnecting downspouts from the sewer system and diverting precipitation into rain barrels and onto gardens and lawns. In Niagara Falls, a joint GLSF-MOE project achieved a voluntary disconnect success rate of 90 percent among the 4,300 homes inspected. “Downspout disconnects won’t solve the whole stormwater problem on their own,” says Kok, “but they certainly help, especially on a local basis.”

Tackling the stormwater problem requires an array of approaches. For example, no single road drainage system is suitable for all situations. Certainly the conventional curbs and gutters do not reduce stormwater volumes or remove pollutants. In 1997, the Toronto and Region Conservation Authority (trca) and its partners re-evaluated roadside ditches and other related stormwater management practices. “Sometimes you have to go back to your roots,” explains Kok. Grassed swales and roadside ditches hold back runoff and even filter out some of the solids.

The selection of the appropriate option for controlling stormwater depends on many factors including soil type, slope, land use patterns, the depth of the water table, and the distance to water bodies. Contractors for TRCA have developed a electronic spreadsheet which takes into account the full set of selection criteria and determines the bestroad drainage alternative according to the characteristics of the site.

Before you considering expansion or buildingnew facilities, municipal authorities try to optimize the treatment system that is already in place. “We want operators totake a fresh look at the way they run their plants,” says Kok. They can often get a plant operating “at a much higher efficiency than the original design specifications,” she says.

STP experts will “troubleshoot those plants that aren’t meeting the province’s effluent quality limits, looking for design deficiencies, process bottlenecks and operator problems,” says Ho. There are often opportunities for improving flow distribution or modifying chemical dosages or fine-tuning sludge recirculation rates in order to increase efficiency.

If the environmental benefits are not sufficient motivation, facility optimization can also save a cash-strapped municipality a substantial amount of money. Instead of opting for the conventional and more expensive technical fix, installing anew filter for instance, finely tuned STPs are treating higher volumes and generating cleaner effluents for a fraction of the cost. “Its taken ten years, but these optimization techniques are now becoming standard operating procedure,” says Kok.

The STP Optimization Program, funded by the governments of Canada and Ontario, and the participating municipalities, has been applied to some 25 Ontario facilities, saving municipalities in Collingwood, Severn Sound, the Bay of Quinte, Detroit Rive and Hamilton Harbour a total of $66 million to date.

A review conducted for the Village of Coldwater helped itachieve its phosphorus removal target while deferring a $500,000 expansion of its STP, all for a $33,000 investment in staff training and equipment upgrades. And in Burlington, operational changes and minor system modifications reduced phosphorus and nitrogen discharges. This saved the Region of Halton $20-million as extra treatment capacity wasfound as a result of the optimization.

The program helps STPs that need to expand capacity inorder to accommodate local growth, or meet tougher effluent limits because of the condition of the receiving water. “We help them optimize operations,” says Ho, “and change their system to handle higher flows or operate more efficiently without resorting to major construction.” A municipality must field test its revamped STP, and MOE has developed a protocol that supports the use andapproval of innovative STP design and operating systems.

To learn more about COA and the RAPs, contact:
	Environment Canada www.on.ec.gc.ca (416) 739-4809	Ontario Ministry of the Environment www.ene.gov.on.ca (416) 325-4000 or 1-800-565-4923

Top of Page
Français | Contact Us | Help | Search | Canada Site
What's New | Topics | Publications | Weather | Home | About Us