Incorporating Climate Resilience for Municipal Infrastructure into the Updates of Existing Atlantic Canada Water and Wastewater Design Guidelines

In 2019, the Atlantic Canada Water and Wastewater Association (ACWWA) secured support to incorporate climate change adaptation of infrastructure into the updates of the existing guidelines, The Atlantic Canada Guidelines for the Supply, Treatment, Storage, Distribution, and Operation of Drinking Water Supply Systems (2004) and The Atlantic Canada Wastewater Guidelines Manual for the Collection, Treatment, and Disposal (2006). Atlantic Canada is projected to experience an increase in extreme temperature parameters and an increase in the frequency and intensity of precipitation. Critical water and wastewater treatment infrastructure are at risk for flooding, power outages, and other operational climate-related disturbances.

The main objectives of the ACWWA guidelines updates were to:

  • Incorporate climate resilience when investigating, designing, approving, constructing, and operating municipal water and wastewater in Atlantic Canada.
  • Include a new chapter on Climate Resilience into each of the guidelines and update the existing sections to include climate resilience requirements.
  • Build climate adaptation capacity through training workshops, webinars and dissemination of information.

The updated ACWWA guidelines were designed as “living documents” that focus on process. The guidelines also aimed to reference other “active” standards and climate data sources which are regularly updated, nationally recognized, and reliable. Support for this project was provided by Natural Resources Canada’s Building Regional Adaptation Capacity and Expertise (BRACE) program. Funding was also provided by the ACWWA, the Governments of Prince Edward Island, New Brunswick, Nova Scotia, Newfoundland and Labrador, the City of Charlottetown, and Halifax Water.

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Understanding and Assessing Impacts

According to the Climate Atlas of Canada, from 2051-2080 under a high emissions scenario (RCP8.5), Atlantic Canada will experience an increase in extreme temperature parameters and an increase in the frequency and intensity of precipitation, including rain, snowfall, freezing rain, sleet, and hail. As permafrost continues to melt and sea levels rise, there will be more storm surges, wave run-up, coastal flooding, and erosion. Wastewater pumping stations, gravity sewers, wastewater treatment sites, and drinking water sources are examples of infrastructure at risk of spring flooding, power outages, and other operational issues during surge tide and severe rain events in Atlantic Canada. Municipal infrastructure that is not built to withstand these impacts will lead to the disruption of essential services, threaten the health and safety of residents, and accumulate high costs for its replacement. As the region’s water and wastewater industry leader, the ACWWA recognized the susceptibility of Atlantic Canada to the effects of climate change, and saw the need to renew policies and guidelines to promote best practices and maintain a high level of confidence in the integrity of public infrastructure.

For additional climate information, look at the Resources section of this example (below).

Identifying Actions

Two documents are used In the design of water and wastewater infrastructure in Atlantic Canada: The Atlantic Canada Guidelines for the Supply, Treatment, Storage, Distribution, and Operation of Drinking Water Supply Systems (2004) and The Atlantic Canada Wastewater Guidelines Manual for the Collection, Treatment, and Disposal (2006). These documents are used in all four Atlantic provinces and are under the ownership and control of ACWWA who determined updates were required in order to incorporate climate resilience in municipal infrastructure.

The objectives of this project were to update existing sections in the guidelines to include climate resilient requirements, undertake a jurisdictional review for relevant materials, reference up-to-date provincial regulatory requirements, and produce a technical update that reflects advancements in the water and wastewater treatment process and technology. Prior to the start of this project, the CSA S900.1.18 Climate Change Adaptation for Wastewater Treatment Plants was published in 2018 as a standard approach to incorporate climate resiliency into the design process for wastewater infrastructure. Using this standard, ACWWA identified gaps in their existing guidelines. In 2019, ACWWA requested input from stakeholders through the Knowledge Mobilization Plan (KMP) on gaps identified in the guidelines by owners, designers, and suppliers.

Implementation

The Atlantic Canada Guidelines for the Supply, Treatment, Storage, Distribution, and Operation of Drinking Water Supply Systems provides guidance on the development of water supplies. In order to incorporate resiliency, a new chapter on climate mitigation and adaptation was added to the manual, which included a comprehensive review of the strategies available to gather climate change information, assess impacts and risks, and to implement effective adaptation planning. The chapter also references climate change impacts and factors to consider in a climate change context when outlining the steps for planning, designing and operating water and wastewater infrastructure. ACWWA also reviewed existing guidelines in other jurisdictions to ensure the updated guidelines incorporate best practices.

Other additions to the guidelines include:

  • A requirement for an adaptation assessment during preliminary design
  • Identification of the climate adaptation measures
  • Inclusion of climate change projections and impacts to designs
  • Climate change resiliency assessments for projects, PIEVC protocol or equivalent
  • Inclusion of IDF curves and climate change in quantity assessments
  • Inclusion of climate change impacts and resiliency in source water protection plans
  • Energy efficiency discussion for pump selection
  • Edit and update individual treatment processes
  • Improved discussion on flow monitoring within distribution systems

The Atlantic Canada Wastewater Guidelines Manual for the Collection, Treatment, and Disposal provides guidance for the design of infrastructure that collects, treats, and disposes of sanitary sewage. The design documentation requirement of this manual was amended to require the identification of the climate adaptation measures. Some changes to the guidelines include:

  • Modifications of the section on hydraulic gradient to reference an allowance for sea level rise
  • Provision of guidance for post disaster requirements

Awareness training for public works professionals, utility engineers, planners and consulting engineers was carried out in order to understand their capacity to put new guidelines into practice and update the guidelines into their work.

Outcomes and Monitoring Progress

The design guidelines ensure that climate change impacts are a key consideration for the long-term resiliency of water and wastewater projects. The guidelines are not a regulatory document or a form of regulation. Instead, they are intended to compliment regulations by creating engineered systems and documentation that meet industry best practices.

Resources

Link to Full Case Study

Additional Resources:

Additional Climate Information:

Using climate change projections enables better adaptation decisions, as it allows you to better understand how the climate may change. To learn how to choose, access, and understand climate data, visit ClimateData.ca’s Learning Zone.

For more information on variables that may be useful in work related to updating Official Guidelines, visit ClimateData.ca and click “Explore by Variable”. Here you will find pertinent future climate projections related to temperature and precipitation.