Phosphorus pollution choking the life out of Lake Simcoe

When algae blooms in Ontario's Lake Simcoe, it is so thick that it is visible from the air.

At times, the blue-green scum that muddies the water can even be dangerous to humans and animals. In 2020, the Simcoe Muskoka District Health Unit sounded the alarm about the potential harm of toxins resulting from an algae bloom at Cooks Bay in Innisfil, warning people not to consume water from the lake.

The algae blooms are connected to an invisible threat — phosphorus pollution that is choking out life in the lake.

About 70 kilometres north of Toronto, Lake Simcoe, the largest lake in southern Ontario aside from the Great Lakes, has long been a vital natural resource and an integral part of provincial history.

Environmental advocates assert little has been done to improve phosphorus levels in the lake despite a provincial plan to do so dating back to 2009. In 2009, the province received unanimous all-party support for the Lake Simcoe Protection Plan, a legislative framework aimed at safeguarding the watershed. The cornerstone of the plan was the reduction of phosphorus pollution to 44 tonnes per year, a measure deemed crucial for the protection of cold-water fish and the prevention of excessive weed growth and algae blooms.

However, phosphorus levels in Lake Simcoe are still clocking in at 90 tonnes per year, far higher than the 55 tonnes per year goal set by the plan for 2023.

Jack Gibbons, chair of Lake Simcoe Watch, laments that this essential objective has yet to be achieved. Instead, phosphorus pollution has been on the rise, posing a grave risk to the lake's ecosystem.

“We are going in the wrong direction,” said Gibbons. “Unfortunately, the province has still not developed a plan or a budget to achieve the 44 tonnes per year goal.”

Since 2015, the phosphorus pollution in some years has reached levels of 90 tonnes. The 44 tonnes is the level that is necessary to protect the lake’s cold-water fishery and prevent excess algae blooms and weed growth, Gibbons added.

Gibbons told Canada’s National Observer that homes and businesses can reduce the amount of stormwater and phosphorus pollution that flows into Lake Simcoe by installing rain barrels, cisterns and permeable pavement and by creating rain gardens, soakaway pits, wet ponds and wetlands.

The primary source of phosphorus pollution is fertilizer used on nearby farms that reaches the lake through runoff from fields. Urban stormwater runoff accounts for 25 per cent, according to Lake Simcoe Watch. As stormwater flows over paved urban surfaces, it picks up phosphorus, which eventually finds its way into the lake.

Natural sources contribute 14 per cent of the phosphorus, including wetlands, forests, meadows, streambanks, and groundwater. The rest comes from long-distance atmospheric sources, private septic systems, sewage treatment plants and other contributors such as pits, quarries, construction sites and unpaved roads.

In recent weeks, town councils in both Bradford West Gwillimbury and Georgina unanimously passed resolutions demanding the province take immediate action to address the growing threat to the lake's health.

Jonathan Scott, councillor for Ward 2 in the Town of Bradford West Gwillimbury, highlighted that the Lake Simcoe Protection Plan mandated a 10-year review, originally scheduled for 2018.

"The province has allocated $24 million in funding for the creation of a phosphorus recycling facility, and we have secured $16 million in federal funding for this project, which needs to progress through design, construction and operation," said Scott.

The purpose of the project is to treat the runoff water from the region, removing the phosphorus before it enters the lake, said Scott. The current phosphorus levels are at unacceptable limits, he added.

Scott told Canada’s National Observer that farmers have already made considerable efforts at great personal expense to reduce phosphorus reaching the lake. Measures include systems to collect and cleanse runoff water of phosphorus, and mitigate erosion and nutrient runoff resulting from agricultural activities, he added.

According to the Canadian Light Source (CLS), researchers hailing from the Swedish University of Agricultural Sciences in Uppsala are delving deep into the intricate world of soil sensitivity, investigating the profound impact of phosphorus — both occurring naturally in soil and introduced through manure or fertilizer — on these sensitive soils and the local aquatic ecosystems.

Phosphorus plays a pivotal role as a vital nutrient for crops and is a key component of various fertilizers, including animal manure. While essential for plant growth, an excess of phosphorus can have detrimental effects on water quality near agricultural areas, the researchers found.

“We can help inform farmers on how to cope with problems with sensitive soils and help prevent phosphorus from leaving these soils and entering into waterways,” said Faruk Djodjic, associate professor in the Department of Aquatic Sciences and Assessment at the Swedish university.

According to a report by Lake Simcoe Watch, farmers can play a vital role in preventing phosphorus runoff into the lake, thus preserving water quality and the ecosystem. This is achieved through the implementation of best management practices, which encompass effective strategies such as crop residue management, strip cropping, crop rotation, cover crops, nutrient management, vegetated buffer strips, streambank fencing and streambank stabilization.

These measures effectively reduce erosion and nutrient runoff from agricultural activities. Furthermore, the report recommends the restoration of areas near streams and rivers through the establishment of vegetated buffer strips and streambank improvements, particularly within 30 metres of water bodies, to further mitigate phosphorus pollution. Collectively, these efforts safeguard the health of Lake Simcoe and its surrounding environment, the report added.

Gary Wheeler, spokesperson for the Ontario's environment ministry, told Canada’s National Observer the province is committed to protecting and restoring Lake Simcoe and its watershed.

“Together with watershed partners, we share the responsibility of implementing the phosphorus reduction strategy, which is part of the Lake Simcoe Protection Plan,” said Wheeler. “Last year, the province announced a funding allocation of $24 million to an entity to design, build and operate a phosphorus reduction project in the Lake Simcoe watershed. There is a total of $40 million in provincial and federal government commitments allocated toward the project.”

Wheeler said, currently, the ministry is exploring opportunities to build and operate the project to help reduce the amount of phosphorus entering local waterways. This includes working with local municipalities to complete the project or having the Ontario Clean Water Agency support some or all of the development and operation of the project using the provisions included in the Supporting Growth and Housing in York and Durham Regions Act 2022, Wheeler added.

In its Lake Simcoe phosphorus reduction strategy, the ministry said: “The phosphorus issue is not just about a healthier future for Lake Simcoe’s cold-water fish community. Millions of dollars in tourism business, tens of thousands of jobs, safe, clean drinking water for local communities and the quality of life throughout the region depend on a healthy Lake Simcoe watershed.”

According to the ministry, phosphorus, while essential for all living organisms, can negatively impact water quality when present in excessive amounts. Various sources contribute to the presence of phosphorus in Lake Simcoe.

“Some phosphorus comes from specific point sources, such as a sewage treatment plant or stormwater outfall. Some phosphorus enters the lake through diffuse, or “non-point sources,” as a result of landscape conditions and day-to-day land use practices in urban and rural areas,” the ministry added. While some of this diffuse phosphorus loading is natural, much of it can be better managed by the practices of individuals and businesses throughout the watershed, the ministry said.

According to the Lake Simcoe Region Conservation Authority , individuals can play a role in reducing phosphorus in stormwater runoff by using phosphate-free products, directing excess water to lawns and gardens and practising responsible car washing. Using native plants and phosphate-free fertilizers also help reduce phosphorus inputs.

This story was produced in partnership with Journalists for Human Rights for the Afghan Journalists-in-Residence program funded by the Meta Journalism Project.