Aecon Construction Group Inc and Kiewit Nuclear Canada Corp. carrying on business under the general partnership firm name Aecon - Environmental Compliance Approval (sewage)

This proposal is for a new Environmental Compliance Approval (ECA) for Aecon Kiewit Nuclear Partners to establish sewage works for the treatment and disposal of construction-related water for the operation of the tunnel boring machine (TBM) used for boring of the condenser cooling water (CCW) tunnels, at a maximum rate of 40 cubic meters per hour for Ontario Power Generation (OPG) Darlington New Nuclear Project (DNNP) in Clarington.

The DNNP will be constructed adjacent to the existing Darlington Nuclear Generating Station, which is approximately 5 kilometres from the nearest town. The tunnelling activities related to this water treatment plant are currently expected to run 24 hours a day, from Monday to Friday, with a potential for extension on Saturdays, for an estimated period of 12 months.

The proposed sewage works include a modular/self-contained water treatment plant (WTP) that discharges after treatment into the existing site stormwater management system, approved under ECA No. 3501-DCKHX5, or is recycled back to the TBM.

The ministry will impose effluent limits and/or monitoring requirements for effluent discharges from the facility.