Urban Water Indicators: Municipal Water Use and Wastewater Treatment
Why is urban water use an issue?
Canadians are among the highest water users in the world. Though Canada is perceived as a country with abundant water resources, about 60% of this water supply flows north and is not readily available or easily accessed where it is needed most—in a narrow 300-kilometre band along Canada’s southern border, home to over 84% of the population. Eleven percent of all surface water and groundwater withdrawn in Canada is used for municipal purposes.
Current water use patterns in some Canadian towns and cities are problematic for both environmental and economic reasons:
- Water shortages: About 26% of municipalities with water systems reported water shortages in the 1994–1999 period. Reasons included seasonal shortages due to drought, infrastructure problems‚ and increased consumption.
- Effects on the natural capability of rivers and lakes to deal with pollutants: Water drawdown, especially in drought-prone areas, decreases water levels and stream flows‚, which affects ecosystem functions as well as impacts on aquatic and terrestrial habitats.
- Drawdown of groundwater: In 1999, about 2.8 million Canadians served by municipal water systems—including municipalities in Prince Edward Island, southern Ontario, the southern Prairies, and the interior of British Columbia—were dependent on municipal groundwater systems. These municipalities experience more frequent water shortages than those relying on surface water.
- Strain on water and wastewater infrastructure and services: Current water use patterns result in higher energy and economic costs associated with supplying and treating drinking water and treating wastewater, as well as the need for increased volume capacity.
- Wastewater dilution: When water use increases, wastewater can become more diluted; wastewater treatment processes are then less efficient at removing wastes.
- Aging water and wastewater infrastructure: Deteriorating infrastructure results in higher losses of water through system leaks, sometimes comprising as much as 30% of municipal water use. Many communities require significant infrastructure upgrades.
What is being done to reduce water use?
Numerous water-saving devices are available for use in homes and businesses. For a low-flow showerhead, the flow rate can be half that of a conventional showerhead. A low-flow toilet can use as little as one-third of the water of a conventional toilet.
Household outdoor water use can be reduced, for example, with more water-efficient landscaping (xeriscaping), lawn watering devices, rainwater collection (rain barrels, cisterns), and efficient car washing practices.
Greywater reuse technology (to reuse water from washing for toilet flushing and outdoor uses) has been pilot tested but is not in widespread use in Canada. Currently, there are substantial regulatory barriers to its implementation, such as existing plumbing codes. Other promising new technologies for some municipalities include alternatives to conventional wastewater treatment systems, such as off-grid sanitary sewage systems (e.g., waterless composting toilets).
Educational and regulatory measures
Jurisdictions are providing educational materials to the public through a variety of means. Internet sites such as the “Water Efficiency Experiences Database,” developed by Environment Canada and the Canadian Water and Wastewater Association, encourage the sharing of knowledge on water use and water efficiency initiatives among municipalities.
The National Action Plan to Encourage Municipal Water Use Efficiency of the Canadian Council of Ministers of the Environment has resulted in the implementation of new government programs and policies that contribute to water efficiency. For example, Ontario and British Columbia have introduced plumbing codes that promote water efficiency.
Measures such as municipal source control programs minimize the entry of pollutants such as metals into sewer systems, thus reducing treatment costs and improving municipal wastewater effluent quality.
Federal and provincial/territorial jurisdictions are exploring strategies to ensure consistent and improved management of municipal wastewater in Canada. In addition, the best practices guide for green technologies of the Federation of Canadian Municipalities promotes the development of sustainable green municipal infrastructure.
In February 2000, the federal government announced the six-year, $2.6-billion Infrastructure Canada Program. This money, along with matching funds from municipal and provincial/territorial governments, will total over $6-billion in investments.
The primary focus of this program is green municipal infrastructure projects, such as projects to improve municipal water and wastewater infrastructure.
Green municipal funds include a $100-million Green Municipal Investment Fund, a permanent revolving fund offering financing in the form of loans and loan guarantees to support project implementation, and a five-year, $25-million Green Municipal Enabling Fund, a fund providing cost-shared grants for feasibility studies. Both funds are administered by the Federation of Canadian Municipalities and focus on innovative environmental solutions that include the promotion of energy reduction and water conservation in Canadian municipalities.
Metering and full-cost, volume-based, user-pay systems provide incentives for households and businesses to conserve water. An increasing number of municipalities are applying sewer surcharges to residential water bills and exploring options for financial incentives, such as low-interest loans, tax credits, and rebates for installing water-efficient devices. Using water more efficiently will conserve water, lower water costs, and extend the life of existing municipal infrastructure.