Renfrew Wastewater Treatment Plant

Project Dates: July 2025 to August 2025

Services Provided: Waterproofing membrane installation, expansion joint upgrades, and structural reinstatement

Client

Ontario Clean Water Agency (OCWA)

Consultant

Paterson Group

Project Type

Membrane & Waterproofing, Expansion Joints

GroupCMG was engaged to upgrade the walkway membrane and expansion joints at the Renfrew Wastewater Treatment Plant, operated by OCWA. Work involved removing and reinstating steel guardrails, stairs, and landings, along with modifying nearby electrical utilities to enable construction access. Concrete surfaces were shotblasted for prep, then coated with the Tremco PUMA Extreme Wear System. Pre-compressed foam expansion joints were also installed to support structural movement and waterproofing performance.

Project Challenges

Working within an active wastewater treatment plant required strict safety compliance and daily hazard management due to nearby open pits. Temporary removal of stairs and guardrails had to be carefully phased to maintain access for staff. The fast-cure membrane system demanded precise coordination, skilled installers, and close manufacturer involvement. Unexpected extensive slab cracking also required additional prep work to meet application standards.

Solutions Implemented

Paterson Group was the consultant for the site, which involved key training and safety components in addition to the actual project work.

Safety, Planning & Access

Crew members completed online training and on-site orientations before work commenced, along with daily hazard assessments and safety briefings.
Developed a detailed sequence for removing and reinstalling guardrails, stairs, and landings with minimal impact on operations.
Established temporary safety measures during construction to ensure that site staff had continued access.

Membrane Application & Oversight

Partnered with a specialized waterproofing subcontractor familiar with high-performance membrane systems.
Coordinated frequent check-ins with the membrane manufacturer to ensure full compliance with product specifications and application methods.

Crack Mitigation & Joint Detailing

Conducted a joint site survey with the consultant to identify and document all slab cracking in need of repair.
Cracks were routed, cleaned, and sealed per Tremco’s installation guidelines.
Installed new expansion joints to bridge the slab transitions and maintain long-term flexibility.

Results

The project delivered a restored, durable, and fully waterproofed walkway system designed to meet the high standards of a wastewater treatment facility. The new membrane not only enhances performance and aesthetics but also protects against long-term water infiltration and environmental wear. The addition of new expansion joints will also help the system adapt to seasonal movement and mechanical stresses.

“Firstly, thank you and your team for the open communication, workmanship and adhering to schedule during this critical project. OCWA will highly recommend CMG to other areas should these services be required!”

— Austin Mitchell (Senior Operations Manager, OCWA)