Water and wastewater
At each stage in the treatment and distribution of water there is an opportunity to reduce, and in some cases reclaim, both water and energy.
The treatment and distribution of drinking water, and wastewater collection and treatment, are core local government services. While the approach to water and wastewater delivery and the associated infrastructure and energy requirements vary between local governments, water and wastewater systems may also require substantial amounts of energy and release associated emissions. Several examples of energy and emissions associated with water and wastewater systems from various local government corporate energy and emissions plans are shown below.
Proportion of total corporate energy use (%)
Proportion of total corporate emissions (%)
City of Surrey
City of Kamloops
City of Chilliwack
City of Richmond
City of Prince George
Efficiency in water treatment and distribution
At each stage in the treatment and distribution of water there is an opportunity to reduce, and in some cases reclaim, both water and energy. Water use and energy are linked in a water-energy nexus. For example, water treatment facilities require energy to operate. The higher the demand for water, the greater the demand for energy. Reducing the amount of energy used for moving and treating water can result in emissions reductions and cost savings. Reducing water demand can also reduce energy consumption, emissions and costs for residents and businesses. This includes emissions and costs due to hot water heating, which is often fueled by a fossil source like natural gas.
There are several steps in the distribution and treatment of water, and each has an associated impact on energy. In the diagram below, each arrow represents the use of energy in a traditional water and wastewater management system.
Local governments may assess each stage in the system to identify opportunities to reduce energy use and emissions, including conservation measures and efficiency actions.
Increasing fixture and appliance water efficiency is a key strategy in which local governments can play a part. In new buildings, fixtures and appliances that consume significantly less water compared to the requirements of the BC water conservation regulation are commercially available and have been installed widely in jurisdictions or buildings where water conservation has been given high priority. Water efficiency can be the goal of retrofits of existing buildings.
Efficiency and conservation measures on the demand side include:
- Public and building industry education campaigns
- Subsidized water conservation kits
- Incentives and rebates
- Incentives that encourage water conservation in designs for new development
- Metering and pricing by usage
- Addressing water system leakage through monitoring, maintenance and asset management
- Landscape design guidelines and efficient irrigation systems
- Watering restrictions
- Working with major industrial users to reduce demand, and facilitating eco-industrial networking
- Utilizing alternative sources such as captured rainwater, or reclamation of treated greywater or wastewater for non-potable uses, are other strategies that can complement the above demand management actions.
The most significant and energy intensive steps are water treatment, pumping energy to distribute water to end users, and treating the resulting wastewater. Conveying wastewater to the treatment plant may also be energy intensive. Possible actions in each area of distribution and treatment (supply-side) include:
- Efficient pumping systems, capturing energy from water moving downhill
- Installing efficient disinfection equipment, taking advantage of bio processes, and making lighting efficiency and HVAC improvements
- Using green stormwater infrastructure, improving energy efficiency of aeration equipment and anaerobic digestion, and implementing cogeneration and other on-site renewable power options such as solar panels or biomass.
- Surrey Corporate Emissions Action Plan (Note: Surrey shares responsibility for water and wastewater systems with the Metro Vancouver Regional District)
- Kamloops Corporate Energy and Emissions Plan
- Chilliwack Corporate Air Quality, Energy and Greenhouse Action Plan
- Richmond Energy Update Report 2014 (Note: Richmond shares responsibility for water and wastewater systems with the Metro Vancouver Regional District)
- Prince George Climate Change Action Plan
- Every Drop Counts (Environmental Commissioner of Ontario, 2017)