Retrofit of Acton Wastewater Treatment Plant creates sustainable office space that fosters equity, diversity, and inclusion

Halton Region wished to retrofit its decommissioned filter area at the Acton Wastewater Treatment Plant in Halton Hills, ON to create a new, sustainable administrative building designed with equity, diversity, and inclusion in mind. A growing municipality of about 600,000 in southern Ontario, the Region owns and operates seven wastewater treatment plants, as part of its responsibility to provide wastewater management services for the municipality.

Following the construction of a new stand-alone filter building at the Acton Wastewater Treatment Plant, the Region wished to retrofit the decommissioned filter building, repurposing the filter wing and combining it with the office wing to create a new administrative building. This adaptive reuse approach reduces the embodied carbon footprint by minimizing the need for new construction.

The Region engaged Associated Engineering to provide engineering services for the filter building retrofit and various plant upgrades. As the prime consultant, Associated's scope of work includes critical elements such as the demolition of the existing process infrastructure, building mechanical services for the retrofitted space, and structural retrofit and backfilling of the existing filter tank, and repurposing of the space as offices.

In addition to the retrofit and facility upgrade, the Region wanted to implement energy-saving options to reduce the facility's environmental impact. Funding is available for green initiatives to support this goal. Project Manager, Roy Gong, shares, "We proposed and reviewed several options with the Region, and completed a feasibility study to document the viability of potential approaches."

Some of the green initiatives explored to reduce environmental impact included alternative heat sources, such as a hydronic heating system and geothermal heating. The team also investigated the benefits of upgrading the heating, ventilation, and air conditioning (HVAC) system.

Mechanical Designer, Yang An, says, "The existing HVAC system for the office area was old and outdated. We determined the most practical way to serve the retrofitted administrative building is to install roof-top units for conditioning the space. We proposed a new HVAC roof-top unit with better energy-efficiency. Variable air volume boxes are being installed for different rooms to tune the air flow and lower energy consumption when the space is unoccupied."

During preliminary design, the Region requested that we incorporate Equity, Diversity, and Inclusion (EDI) concepts into our design, aligning with their new EDI policy. The EDI design concepts significantly altered the original design, in particular the changing rooms, locker rooms, and showers. Roy tells us, "Working closely with our architectural subconsultant, we developed solutions to minimize the impact on the overall design and re-work efforts. The Region acknowledged the scope of these changes and accommodated the additional work required."

This collaborative approach demonstrated Associated's commitment to delivering a design that meets Halton's evolving needs and creates a more inclusive and equitable workspace

During detailed design, the Region asked our team to explore solar thermal wall installation, a technology used to capture and use solar energy to preheat the ventilation air for buildings. Yang explains, "Also known as a transpired solar collector, a solar thermal wall is a passive solar heating system designed to reduce the energy required for heating, especially in industrial and commercial buildings." Our team's investigations with a local supplier determined the feasibility of this option.

Currently, the team is working towards tender phase. The project team's flexibility and agility in responding to the Region's requested changes, combined with strong communication and a collaborative relationship between the Region, our subconsultants (Brown+Storey Architects and Eramosa Engineering), and our in-house team have created a successful teaming environment and the design of a sustainable workspace that fosters equity, diversity, and inclusion.