Treatment variability for wetland wastewater treatment design in cold climates

The purpose of this article is to highlight the growing need for small-scale, passive, natural systems that can serve our needs in water pollution control both in small communities and larger urban developments. Engineered wetlands represent one potential wastewater management option that exhibits promise in satisfying community requirements for contaminant and pathogen removal. However, the Canadian climate presents special challenges for constructed wetland treatment systems whose functional reliability is not nearly as well developed as currently available, more conventional, but less sustainable treatment options. The goal of this article is to present some of the key issues that require more fundamental understanding if engineered wetlands are to become a predictable, mainstream approach for decentralized wastewater treatment. Two critical factors limiting the advancement of treatment wetland technologies are a standardized approach to elucidate extant process mechanisms and a basis with which to make more meaningful comparisons within and between systems that naturally evolve and mature with time.