Harmful algal blooms have become increasingly frequent in Lake Erie. In 2011, the lake experienced its worst cyanobacteria bloom in decades, and in 2014, the City of Toledo, Ohio, declared a state of emergency for 500,000 citizens because of the presence of high levels of algal toxins in the city’s drinking water supply. Excess phosphorus is the key culprit.
Given the lake’s importance to the 11 million people who rely on it for drinking water, and the broader economic impacts, governments in Canada and the United States have responded. In June 2015, the governors of Michigan and Ohio and the premier of Ontario signed an agreement to reduce phosphorus inputs to the western waters of Lake Erie by 40 per cent over the next 10 years, with an interim goal of a 20-per-cent reduction by 2020. Federally, both countries have committed to updating their phosphorus load reduction targets for the Erie by February 2016. The results of these efforts will be relevant to decision makers and water managers in other parts of the country, too, as phosphorus management is a key goal in Lake Winnipeg, the Fraser Valley, Lake Simcoe, and other watersheds where water quality is a concern.
Experts acknowledge that to achieve the reductions, more needs to be done to implement best management practices (BMPs) in the agricultural sector, and research continues to determine exactly what practices are most effective. However, contributions from wastewater treatment plants, stormwater, combined sewer overflow discharges, and other point sources are also important contributors. As plans move ahead to meet the targets, decision makers will need to determine where investments are best placed and it is likely the answers will lead to a multi-barrier approach.
The Upper Thames River Conservation Authority (UTRCA) has been working with municipal and agricultural partners to reduce nutrient inputs into the river since the 1970s. Karen Maaskant, a water quality specialist with UTRCA, said the organization has “been making incremental improvements that have looked good, but 40 per cent is a whole new level.” New technologies in these areas may offer some attractive and innovative opportunities for achieving the new targets.
Philip Abrary, president, CEO, and co-founder of Ostara Nutrient Technologies, said that while older phosphorus removal techniques use chemical precipitants, more modern techniques are biological, involving bacteria that feast on phosphorus. Ostara launched in 2005 with a technology developed at the University of British Columbia that removes phosphorus and nitrogen from waste streams by enabling nutrients to crystallize and grow into highly pure fertilizer granules. The granules are then dried and distributed under the brand name Crystal Green, formulated to release nutrients as plants grow. Abrary said phosphorus resources are dwindling globally, so recovery is important.
Kevin Litwiller is the director of business development at Lystek International Inc., an Ontario company that enables plants to convert their waste into a federally registered fertilizer product. Developed in 2000 at the University of Waterloo, the Lystek system uses low-pressure, low-temperature thermal hydrolysis, making it simple to operate. He described the technology as an affordable solution that can be used by small or large municipalities and industries. “Instead of ending up with a Class B biosolid, you have a Class A fertilizer, so it doesn’t have to be over-applied to land to get value out of it,” he said. Their process kills all the pathogens and results in organic material that enriches the soil. A portion of the product can be fed back into anaerobic digesters to make them more efficient, resulting in a lower volume of biosolids and increasing biogas outputs for use as green energy. As well, the final product—liquid fertilizer—is typically injected four or five inches into the soil, greatly reducing nutrient runoff.
Southern Ontario has the largest concentration of vegetable greenhouses in Canada. In its 2014-’15 report, Small Things Matter, the Environmental Commissioner of Ontario noted that 65 per cent of sampled greenhouse operations around Leamington, Ontario, were discharging wastewater with nutrient concentrations higher than provincial water quality objectives. Constructed wetlands are the most commonly used method to treat greenhouse wastewater discharge; however, there is potential for new technologies to play a significant role in addressing greenhouse water pollution.
In 2014, a project was launched by the Ontario Greenhouse Alliance, the University of Waterloo, and Ontario-based companies Soil Research Group (SRG) and AQUA Treatment Technologies to examine this water cycle. As part of the project, SRG looked at several demo sites and technologies in Southern Ontario, evaluating their effectiveness for managing and/or recirculating greenhouse wastewater. In a test site flower-growing operation in Niagara Falls, the technology was proven to remove more than 95 per cent of nitrogen and 60 per cent of phosphorous in addition to removing plant pathogens. If commercialized, the new technology could be a solution for greenhouses that aren’t recycling wastewater but want to treat it. The project was funded under the Canada-Ontario Agreement Respecting the Great Lakes Ecosystem.
Braving the storm
The International Join Commission’s LEEP report notes the significant loading of phosphorus into Lake Erie from urban areas, such as pet waste, lawn fertilizers, and the role stormwater plays in water quality impairments. Imbrium Systems is an Ontario-based stormwater treatment company that has developed a product called the Jellyfish Filter that uses membrane technology to filter out debris, oil, fine particles, and a high percentage of particulate-bound pollutants, including phosphorus in residential, commercial, or industrial settings. The company has also developed a Sorbtive Media product that looks like course sand specifically designed to absorb and retain large amounts of dissolved phosphorus. Applications include green roofs, trench filters, rain gardens, permeable pavements, and proprietary filter systems. The technology allows developers to maximize land use.
“The majority of our work is in urbanized areas, either redevelopment or new construction,” Imbrium director Scott Perry said. “Our technologies can be applied either in combination with detention ponds or wet ponds, for a treatment train approach, or instead of those systems.” Perry said that he believes a regulatory approach to guide stormwater improvements is necessary.
When nutrients have already entered the water body, Ottawa-based WCI Environmental Solutions offers a technology for treating lakes up to several hundred acres in size. Its Enhanced Oxygen System (EOS-2000) is a solar-powered innovation that causes more oxygen to be available to feed the microbes that eat the dead plants and algae, enabling them to continue this process and keep the water clean, instead of letting organic material build up.
Joseph Kennedy, the company’s president, said microbes are nature’s cleaning force. “Healthy aerobic microbial populations are required for healthy soils and water,” he said, adding that maintaining a highly aerobic state locks up the phosphorus present at the bottom of the pond or lake. His company has successfully treated a number of lakes, ponds, and sewage lagoons in Ontario, and has suggested using EOS-2000 to revive dead zones in Lake Erie. He notes that while chemical solutions may offer a quick-fix, they are harmful in the long run. “We need solutions that enhance and support natural processes, so that they’re sustainable,” he said.
Eve Krakow is a freelance writer based in Montreal.