Petawawa WPCP Net Zero Project (Biosolids and Energy Generation Feasibility Study)

The Town of Petawawa will investigate the technical and financial feasibility of transforming their Water Pollution Control Plant into a Net Zero Resource Recovery Facility. The Town will assess the potential retrofit and upgrade to the plant’s existing anaerobic digestion system targeting an increase in organic loading capacity and biogas output, quality, and storage to offset electrical/heating loads and potentially export energy to the grid. Enhancing the biogas to produce renewable natural gas has the potential to reduce the facility’s GHG emissions by 1,038 tonnes annually through displacement of commercial natural gas. Increased organic loading capabilities coupled with optimal conditioning of current municipal sludge will allow the Town to take in more organics leading to waste diversion and associated GHG reductions. The Town will conduct a region-wide survey to determine additional feedstock opportunities including source separated organic (residential and commercial) as well as liquid sludge from neighbouring wastewater treatment plants. Based on the findings, various design scenarios will be developed to determine the optimal solution to maximize energy generation. The scenarios will be analyzed financially based on payback period and internal rate of return. The implementation of energy efficient measures including the replacement of blowers is expected to reduce the facility’s current annual consumption of 1,098,900 kWh by 20-30%. This study is supported by the Town’s Corporate Energy Management Plan (2014) and Official Plan’s objectives of reducing energy consumption, GHG emissions, and diverting waste. Economically it will support the Town by reducing operating costs and potentially providing revenue from selling excess biogas and fertilizer (bio-cakes) from remaining bio-solids. The Ontario Clean Water Agency (OCWA) is the Town’s Operating Authority for water and wastewater treatment facilities and will act as a consultant on this study. If implemented, OCWA will be monitoring and reporting on the entire process of the proposed project, from business case stage to operations, in order to be transparent with the project’s successes and to determine and identify alternative approaches that may improve the project for future applications. The proposed study will help to identify and provide cost-benefit analyses for technical solutions that are not yet widespread and could be replicated in existing wastewater treatment plants across Canada. (Project description from original funding application)