Nature-Based Wastewater Treatment Solutions
Engineered Wetlands: A Historic Perspective
Nature-based wastewater treatment solutions are growing in demand to bridge the gap between traditional lagoon and mechanical treatment facilities. It’s important to know, however, that engineered wetlands are a well-established technology that have been used to treat municipal wastewater worldwide since the 1920’s. Popular in Germany and France, there have also been installations in North America including wetlands in Stephenville, Newfoundland; Oak Hammock, Manitoba; and Bridger Bowl; Montana.
Subsurface Wetland Systems: Understanding the Mechanism
Subsurface wetland systems (also known as subsurface flow wetlands) do not resemble natural wetlands because they have no standing water. They contain a bed of media (such as crushed rock, small stones, gravel, sand, or soil) and vegetation planted on the surface. When properly designed and operated, wastewater stays below the surface of the media, flows in contact with the biofilm that grows on the media and plant roots, and becomes subject to biophysiochemical treatment processes as the result.
Unique Potential of MBWS in Cold Weather Climates
The MAGNA Biofilter Wetland System (MBWS) is an innovative system and in the early stages of adoption. It was developed in response to the needs of small communities within Canada. The unique potential for the MBWS is its ability to meet strict regulatory standards for wastewater treatment in cold weather climates.
MBWS Operational Overview
The MBWS is a naturalized wastewater treatment facility that provides small to medium sized communities with affordable treatment of municipal wastewater, generating water for reuse or environmental discharge. The system combines fine screening, engineered wetlands, and amended media technologies to provide municipalities with a modular wastewater treatment solution that does not increase the operations and maintenance costs or operator requirements for wastewater treatment facility upgrades. It treats wastewater in three stages.:
The first stage is the separation of liquids and solids through fine screening.
The second stage is the conversion of liquid waste to treated effluent through engineered wetlands, which is a technique not often used in Canada, despite historic applications in in other regions.
The last stage, which is optional depending on target phosphorus results, is an additional treatment cell with amended media to capture and bind phosphorus within the wastewater.
MBWS Pond Schematic
MBWS in Action
MAGNA Engineering Services Inc. (MAGNA) and Clearwater County in Alberta, Canada secured approval for an engineered wetland treatment system to upgrade their existing lagoon in cold weather operations.
The system utilizes vertical and horizontal flow wetlands, a recirculation pump, mulch cover, conservative sizing, and a lagoon for storage.
These features provide treatment redundancy so that regulatory discharge permits are approved for year-round operation. The system is currently being monitored to analyze the system’s performance.
The beakers on the right show water samples collected at different stages of the process.
Meeting the Growing Demand
MAGNA is invested in the success of every MBWS installation, and we take pride in delivering a custom solution aligned to the values of the Nation. Nature based treatment solutions are growing in demand to bridge the gap between traditional lagoon and mechanical treatment facilities.