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Mechanical Designer, Yang An, says, “The existing HVAC system for the office area was old and outdated.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.

The post Retrofit of Acton Wastewater Treatment Plant creates sustainable office space that fosters equity, diversity, and inclusion first appeared on Associated Engineering.

Halton Region is a growing municipality in southwestern Ontario, with a population of approximately 600,000. The Region provides high quality drinking water to residents and businesses, and maintains an active program to continuously improve its drinking water system. 

The Region’s Bailie Booster Pumping Station and Reservoir supply water to the Burlington area. As part of its asset management program, the Region retained Associated to upgrade and rehabilitate the pump station and reservoir. The pumping station upgrades include replacing the plumbing, heating, ventilation, and air conditioning systems, booster pumps and piping/valving, chlorine storage and dosing system, motor control centre, standby power and electrical systems, instrumentation and supervisory control and data acquisition system, along with required structural rehabilitation.

The two-celled, underground, concrete reservoir has a storage capacity of 17.5 million litres. The top of the reservoir is grassed, creating a park like setting. Structural rehabilitation of the reservoir involves removing the existing grass surface and waterproofing system and installing a new hot applied rubberized asphalt waterproofing membrane system on the reservoir roof slabs. After membrane replacement, landscaping over the roof is reinstated. The main goal of the waterproofing replacement is to update the reservoir to meet new potable water storage guidelines and minimize the risk of contaminant infiltration. 

The site drainage design and sizing of the reservoir subdrain system considered climate change and anticipated increased frequency of and heavier precipitation events. More extreme seasonal temperatures and increase in relative humidity were considered in the design of the pump station heating, ventilation, and air conditioning system. All process piping will also be insulated to address expected increase in humidity.

Project Manager, Anna Comerton, tells us, “The upgrades to the pumping station must be staged to allow continued operation of the station, as it is an integral part of the Burlington water supply system and cannot be taken out of service for an extended period.” Interruption or reduction of service must be performed during low demand season to accommodate overall distribution system needs. Careful planning and communication with all stakeholders (e.g. Region Operations and contractor) are required, so that individual equipment is replaced and commissioned in a phased manner and minimizes any impact on operations. For example, we replaced one booster pump and associated piping/valving system at a time.

Similarly, replacing the main reservoir fill/draw header has been done in sections so that the period required for station shutdown is minimized (e.g. less than 24 hours) and occurs during low demand season when an alternate station can handle the demand.

Residences surround the project site on three sides in this quiet neighbourhood. Construction was planned to restrict working hours, mitigate noise and dust, identify location of soil stockpiling, provide privacy screening, limit the number and location of construction vehicles, and prohibit idling trucks on residential streets. The Region also has a project ambassador assisting with communicating updates to the community and addressing questions.

Halton Region engaged Associated Engineering in 2018 to complete preliminary and detailed design and tender the rehabilitation works. Construction began in Spring 2021. The upgrades to the pumping station are in progress and are expected to be completed by early 2023. Cell 1 waterproofing was completed in the Fall 2021, and Cell 2 waterproofing is now in progress. Outside works are anticipated to be completed by Fall 2022.

Key personnel involved on this project include Anna Comerton, Joanne Verstegen, Carlos Baez, Roman Gluzman, Roy Gong, Azad Khamforoush, David Holyer, and Behnood Salehi.

The post Rehabilitation of Bailie Booster Pumping Station and Reservoir safeguards reliability of water supply in Halton Region first appeared on Associated Engineering.