Infrastructure Design & Engineering

Type

policy

Designing for Low Carbon Infrastructure

Equipment for the Naramata Treatment plant was purchased according to full life cycle cost assessment including power consumption. The model of UV reactor chosen was the most power efficient. Planned pipe twinning will supplies treated lake water to residents and untreated upland creek water for agricultural properties / RDOS.

Ensuring that infrastructure systems evolve toward low carbon, more sustainable solutions requires implementation of efficient, innovative technology and best practices, as well as an evolving engineering and design process.

The Regional District of Okanagan-Similkameen (RDOS) retrofitted the community of Naramata’s water treatment and distribution system with a heat exchanger that uses the ambient temperature of the treated water to heat and cool the building, substantially reducing energy consumption.

Water distribution will make maximal use of gravity feeding, avoiding unnecessary pumping. RDOS will eventually completely de-couple the municipal and irrigation water supplies, decreasing the volume of water that needs to be treated, further reducing energy consumption and operations costs.

Community Examples

Regional District of Okanagan-Similameen: Naramata’s Energy Efficient Water Treatment

Engineering and Design Processes

Low carbon design can start with green infrastructure policy.

As government policy, regulatory requirements and technology evolve, engineering and design processes will need to adapt in order to achieve local government objectives.

Design processes that are responsive to sustainability and emissions objectives include:

• Integrated design processes, that include inter-departmental teams;
• Life cycle costing;
• Integrated Resource Recovery (IRR) approaches that focus on revenue opportunities associated with energy or materials flows;
• Sensible use of existing empirical design standards, and ensuring these are as up to date as possible; creating designs that respond to the unique context; and
• Frameworks and considerations for balancing tradeoffs and decision making – such as a triple-bottom line evaluation.

Technology and Best Practices

Energy use and emissions intensities of equipment and systems may be improved through measures such as:

• Efficient, innovative technology (e.g. energy-efficient pumps, distribution and collection systems, and wastewater treatment systems)
• Utilization of renewable energy sources to heat, cool or power systems and spaces, ideally within the site (e.g. ground source heat pumps or solar hot water panels)
• Energy recovery or production within systems – for example:
  – Heat recovery from wastewater using heat pumps, providing heat to the treatment facility or processes, or to external buildings.
  – Heat production and/or power produced from biogas digestion of wastewater biosolids;
• Siting strategically locate potential energy sources (e.g. wastewater treatment plants) near facilities that can take advantage of the resource (e.g. new compact developments);
• Composting and other climate-friendly systems for managing wastewater biosolids and organic waste;
• Combining degradable organic waste with biosolids in biogas digestion systems, and co-locating wastewater and organics recycling facilities; and
• Incorporation of reduced carbon materials (e.g. fly ash concrete) in construction.

Other Issues to Consider

Centralized vs. decentralized systems: Centralized systems (e.g.wastewater treatment systems) are often more cost-effective due to economy of scale. However, consideration should be given to how these advantages measure up against piping wastewater over a longer distance, and the ability to recover and utilize resources (e.g. treated water reuse and heat recovery for heating adjacent buildings).

Some projects may elect to manage wastewater by storing it in holding tanks and having those tanks pumped regularly – however, consideration should be given to how this method could result in additional emissions due to transporting the wastewater.