Re: Searchmont Ski Resort –…

Re: Searchmont Ski Resort – Proposed Wastewater Treatment Plant (WWTP) – Submission to the Environmental Registry of Ontario

To the Ministry of the Environment, Conservation and Parks,

I am submitting this comment in response to the proposed wastewater treatment plant (WWTP) for the Searchmont Ski Resort. These concerns are based on a summary of findings from an independent wastewater treatment expert who reviewed the design brief.

Concerns About Design Flows, OBC Values, and Flow Monitoring

The proposed design flows in Table 3 of the Kresin Design Brief reference the Ontario Building Code (OBC) as the basis for flow generation rates. While the OBC values used for the restaurant and conference room components appear accurate, it is not clear where the value of 225 L/bed for the hotel component was derived. This is not an OBC value. Under the OBC, the applicable design flows are:

500 L/person for a resort hotel 250 L/room for a regular hotel/motel

The design brief does not explain why a non‑OBC value (225 L/bed) was selected, nor does it justify why a lower value is appropriate for this facility. This is a significant concern because OBC values represent peak or maximum day flows, not average day flows. Since the proposed design does not include any up‑front flow equalization, the accuracy of both the average and peak design flows becomes critical to ensuring the plant can reliably handle real‑world peak conditions.

If the development is phased, detailed flow monitoring will be essential to verify actual average and peak flows. This is normally a standard ECA condition requiring the owner to track and report daily flow values. However, the design brief does not specify how daily flows will be measured.

The Napier‑Reid package appears to include a flow meter as part of the tertiary treatment equipment, but this meter is located after the treatment process. A post‑treatment flow meter does not represent the true influent entering the plant from the resort and therefore cannot be used to verify whether influent assumptions were correct or whether peak flows are being exceeded.

To ensure accurate flow tracking, the proponent should install a flow meter on the raw/influent sewage pumping station, where all wastewater first enters the system. If such a meter is already included in the lift station package, it is not clearly shown in the available drawings, and it would not typically be included unless explicitly specified.

Given the sensitivity of the receiving watercourse and the importance of accurate design flows, I request that MECP require the proponent to:

Justify the use of 225 L/bed and explain why OBC‑specified values were not used. Demonstrate that the design flows adequately capture peak conditions, especially in the absence of equalization. Include influent flow monitoring at the raw sewage pumping station to ensure accurate tracking of actual flows entering the plant.

These steps are necessary to ensure the design is protective, robust, and based on defensible flow assumptions.