Installation and monitoring of a constructed wetland at the Amherstview Wastewater Pollution Control Plant

The Corporation of Loyalist Township will pilot the effectiveness of a constructed wetland at the Amherstview Water Pollution Control Plant (AWPCP) to reduce pH levels, and improve overall effluent quality. The objective of this pilot study is to provide a cost-effective method of polishing the effluent of the plant before its eventual discharge into the Bayview Bog, a wetland complex comprised of many different habitats located in Loyalist Township and the City of Kingston. A recent five-year study conducted by Queen's University showed that the pH of the AWPCP's effluent was reduced in the Bayview Bog wetlands, prompting the need to try and mimic these processes within the plant itself. Currently, plant influent is treated through an extended aeration activated sludge process, followed by a two-celled Wastewater Stabilization Pond (WSP) system for passive disinfection. The wetland is designed to handle an average flow of 2,336,000 m3 a year, up to a maximum of 5,840,00m3. For this pilot project, four separate trains will be constructed in the wetland. Queen’s University will research the effectiveness of the optimal planting substrates as defined by the bench-scale testing as well as planting designs to determine the optimal design and substrate for a permanent constructed wetland. Each section will utilize a different substrate (peat, topsoil and sludge) and will be monitored continuously for several years in order to determine which substrate is the most efficient to achieve the treatment objectives listed in Table 1: Anticipated Environmental Benefits. Furthermore, this system may also be valuable in terms of addressing other emerging contaminants, such as pharmaceuticals and other personal care products. Recent studies have shown that an increase in pharmaceuticals in wastewater streams can have deleterious effects on aquatic populations in receiving environments. Constructed wetlands have been shown to be effective at eliminating these contaminants. Employing the use of local vegetation to enhance the landscape of the area and create a natural system that will support local and migratory wildlife, this project is expected to provide a low-cost, natural, zero net-energy polishing step in the wastewater treatment process at the AWPCP. While constructed wetlands have been proven to be effective in warmer climates, little research is available on their performance in colder climates. This pilot is expected to result in guidelines that will allow other Canadian municipalities to design and construct similar systems to address their own specific wastewater treatment needs proving its knowledge value. It is expected that the resulting constructed wetland will act as a demonstration facility. The results from the pilot project will be shared at conferences and symposiums by the Queen's University research team and Loyalist Township staff, and will be made readily available to municipalities. It is anticipated that this pilot-scale project will lead the industry forward in the implementation of constructed wetlands specifically designed to attenuate some of the common water quality issues faced by wastewater treatment facilities throughout Ontario, Canada, and other temperate climates. This project aligns with the Loyalist Township’s Strategic Plan, and the Mission Statement of the Loyalist Township Utilities Department, which is to operate the Township's water and sewage infrastructure in such a way as to protect the health of all users and to minimize the negative impact on the environment by ensuring compliance with applicable laws. (Project description from original funding application)