Installing phosphorous-filtering technology at the farm level

15-08-2018 | |
Installation of a surface water filtration box system in Chatham-Kent
Installation of a surface water filtration box system in Chatham-Kent

Phosphorous loss happens, even if farmers are doing all they can to prevent it. It’s a reality contributing to algae-related water quality issues in Lake Erie – the warmest and shallowest of the Great Lakes in Canada – and one the Canadian government is hoping to solve by investing in on-farm phosphorous-filtration technology.

CAN$ 600,000 has been invested by federal government’s Great Lakes Protection Initiative project to develop and test technologies that remove phosphorous from water flowing through field drainage systems. This farm-focused project is being run by a collaborative community organisation – called the Thames River Phosphorous Reduction Collaborative – in Southwestern Ontario.

Installation of a surface water filtration box system in Chatham-Kent

Installation of a surface water filtration box system in Chatham-Kent

The end goal, say spokespeople, is to develop a “menu” of low-tech solutions that can be customised to fit the different types and growing conditions of farms in the region.

Phosphorous loss a reality despite BMP use

The project’s initial steps involve testing phosphorous filtration technologies on a variety of different farms throughout the Lake Erie basin. These systems, generally, take the form of holding tanks with various filtration materials to bind passing phosphorous (wood chips, steel slag, etc).

Before that, however, just how much phosphorous is being lost still needs to be determined.

Charlie Lalonde, project coordinator for the Collaborative, says phosphorous loss can be a reality on any farm regardless of production practices. Currently, the Ontario average for phosphorous loss on cropland is about half a pound (approximately 220 grams) per acre.

“There’s many factors [..] Cover crops help, using the 4-R’s helps, but there’s still loss. Even if everything is being done there’s potential for loss,” says Lalonde. “The ability to implement systems to intercept phosphorous on farms represents the last barrier in drainage systems.”

Data to inform potential policy

At a recent field demonstration of the first filter system installed as part of the initiative, Louis Roesch – a participating grain and livestock farmer from the region – says his top priority is understanding how much phosphorous he is actually losing, and when he is losing it. “A bad regulation can close a business. We need to have the data first […] then we have something to follow,” he says.

Randy Hope, mayor of Chatham-Kent (one of the Ontario regions central in the initiative) and the project’s co-chair, also reiterated during the event that data generated from the phosphorus filtration system on Roesch’s and other farms will provide context for how Ontario farmers are actually doing when it comes to reducing nutrient runoff.

This, he says, will provide policy-makers with greater context when it comes to imposing – potential – regulations, while helping the agriculture community as a whole understand and alter current best management practices. Hope also says a major end goal is to export what they learn so farmers in other areas. This includes American farmers.

“It’s not saying this one is going to be used in another [production] system. We’re inviting innovation. The important part is it’s flexible.,” he says.

Technology to reflect farm diversity

Lalonde says a handful of different filtration technologies will be tested at different sites. Similarly, the characteristics of each farm test site will differ in soil type, whether it’s part of a livestock or crop operation, topography, and other characteristics. Together, this will help determine how different technologies work in a diverse array of agricultural systems.

Farmer participation in the project is voluntary, and Lalonde says the project is being run through the local agricultural federations. He and his colleagues hope to have a handful of sites operational by October, giving them the ability to start measuring how much phosphorous is being lost between late fall and early spring – the most acute period for phosphorous loss. Measurements will commence over the following three to four years.

Regardless, Lalonde, Hope and Roesch all expressed the need for phosphorous filtration – and possibly reclamation – systems to be as affordable as they are customisable.

Filtration system on Roesch farm

The system is comprised of 2 holding tanks to manage overflow during heavy precipitation events. Phosphorous levels in the water are measured before and after entering the filter. Measurements taken before illustrate how well the farm holds phosphorous, while measurements afterwards calculate the system’s reduction effectiveness. The current cost estimate for this filter system, which handles a 25-acre field, is $ 10,000. However, those demonstrating the system said they anticipate being able to reduce that cost as they learn more about each system.

Matt Mcintosh Correspondent North America