Scientist Spots Strange Substance in Storm Drain Stream to Otonabee River

Nina Munteanu examines small runoff stream to Otonabee River, ON (photo by Matthew P. Barker, Peterborough Examiner)

I was recently featured in the Peterborough Examiner when I reported a strange white milky substance suspended in a small runoff creek leading to the Otonabee River, the town’s drinking water source.

I had my camera on me (I usually carry it on my daily walks through the small cedar forest by the river) and snapped a few shots then sent them along with a description to the nearby school (likely the source of a spill via a storm drain leading to the runoff stream), the city’s environmental department and the local paper. Impressively, all responded to me the same day and all followed up.

Mysterious milky substance suspended in the runoff stream to the Otonabee River, ON (photo by Nina Munteanu)

The school’s principal assured me that they had done a brief survey of their school grounds and parking lot and had seen nothing suspicious. Barry Campbell, a city environmental officer, emailed me to say: “We were able to identify a probable source for the milky discharge from the storm drain. Currently, we are attempting to contact the facility.” He added, “Our approach will be to educate them on how storm sewer systems work and the potential impacts to the environment. Hopefully, by providing information to the facility it will deter future discharges of this nature.” The local paper responded with a request for an interview and a site visit. In his story in the Peterborough Examiner entitled  “What was that stuff in Peterborough’s water?” reporter Matthew P. Barker wrote:

Munteanu said her concern is for the river itself because an imbalance of chemicals could impact not only the river, but the drinking water coming from it.

“In some cases, they serve as nutrients, such as phosphorus or nitrogen, as well as carbon,” she said. “They conspire together with increased light and temperature, which is what we are seeing now, and they can cause algal blooms.”

She said when algae blooms in the river in abundance the water starts to get a musty, earthy smell. “We need to be protecting (the water) and whoever was the proponent of the spill, whether a mistake or not intentional needs to be educated,” she said. “The community needs to be educated a little more about stewarding the riverside too, particularly if you live close by and if you are using what is called the riparian zone.”

Riparian zones are typically a buffering of 10 to 20 metres between the land and the shoreline for animals and vegetation which consists of rich moist soils where divers plant communities can grow.

“It (the river) really should be protected, it should be natural and of course it isn’t,” she said. “The river is actually an unprotected water source.” The Otonabee flows right through the city. “It is a recreational place and yet it is a drinking water source; those two are traditionally not compatible,” she said. “Some places have a dedicated reservoir for drinking water, and no one is allowed in there, it is fenced off, or underground or somehow protected from people using it, but the Otonabee is not.”

Munteanu wonders whether people forget that their tap water is coming from the river. “It is out there, which in some ways is wonderful, but I wonder if people take their drinking water for granted,” she said.

–Excerpt from Matthew P. Barker story in The Peterborough Examiner

Examples of Non-Point Sources of Water Pollution

Urban Rivers: Non-Point Pollution Sources & Urban Runoff

Most city dwellers don’t think much about our water beyond the convenient use of our house taps and showers and knowing (taking for granted) that we have safe clean drinking water to drink, cook with, shower in and even use to flush our toilets and water our lawns. But where does that clean water come from and how does it stay clean? What are the pollution risks to our waterways—not just our drinking water sources (which may—as in Peterborough—be the very river running through the city)—but all the surface and ground water in the watershed we live in.

Most of us might envision the obvious point source polluter: a single source, usually by an industry discharging effluent via a dedicated outfall into a natural water system. 

But we don’t think of the non-point source polluters. Examples include excess fertilizers, herbicides and insecticides from agricultural lands and urban runoff from residential and commercial areas. Urban runoff flushes oil, grease and toxic chemicals (such as PCBs, PAHs, heavy metals and other hormone disruptors and carcinogens) from vehicular traffic and construction into our waterways. Sources of sediment include improperly managed construction sites, sloppy agricultural practices, and ignoring necessary riparian buffers by building too close to a water system. Bank erosion is one of the main consequences with devastating impacts to a stream’s benthic macrofauna and fish. 


I used to live in Toronto, not far from the Don River and its magnificent ravine parks. Unfortunately, I couldn’t walk anywhere along the river and not smell its offensive “potty” smells. I quickly realized that throughout my walk there was nothing natural about this river. Much of it was occupied by invasive plants; what was forested was mostly invasive shrubs. There was virtually no wetland; tiny wetland portions that had been placed by the city to “restore” the Don’s riparian area reeked of sewage. 

In a 2009 report, the TRCA wrote:

Flowing through the heart of Toronto, the Don River is one of the Greater Toronto Area’s most degraded rivers. Approximately 80 percent of the watershed is urbanized or in the process of being urbanized. During rainstorms, rain and melt water moves rapidly over paved surfaces, causing rapid fluctuations in stream water levels, erosion of river banks, and stress to aquatic organisms inhabiting the river. In the older urban areas, south of Eglinton, combined sewers that carry storm water and sanitary sewage regularly overflow during heavy rain events, spilling dilute raw sewage directly into watercourses.

The Don River flows over 38 km and its watershed covers about 36,000 hectares, a sizable portion of Greater Toronto. The river suffers from major erosion problems due to unwise urbanization practices. This includes land clearing, removal of natural riparian buffers (including wetlands), building too close to the river, poor management of storm water, and creation of overly large impervious surfaces (e.g. parking lots, houses, roads) exposing the river to flash flooding and destabilizing slopes and riverbanks.

Destabilized bank of Don River

The Don River has been polluted through short-sighted ancient engineering practices that lacked ecological understanding but also through the ignorance and lack of stewardship by the general public. Many slopes have already collapsed. Old landfills in the area, golf courses and manicured lawns are leaching nutrients, organic contaminants and toxic heavy metals into this once magnificent river. Substances include excessive amounts of phosphorus, nitrate, total suspended solids, ammonia, chlorides, and Escherichia coli (that exceed provincial water quality guidelines). Those are just the regular “bad guys”; synthetic organic chemicals from pesticides and pharmaceutical products and an entire host of other Tier II chemicals also find their way into the river via urban runoff and via septic and sewage treatment effluent. Many of these are toxic, persistent, and potentially biomagnifying. They may act as potential hormone disruptors and are potentially carcinogenic to humans. Effects include smothering of bottom-dwelling biota, eutrophication from increased nutrients and reduction in oxygen with consequences to fish and other biota.

“The general public?” you say. How can that be? “How do I pollute the Don River, especially since I don’t live right next to it?” 

Chances are, if you live and work and drive in the Don River’s watershed, you are contributing to its pollution. We can all help reduce impervious surfaces in our properties, neighbourhoods and communities. Reducing these along with more active and responsible stewardship of our neighbourhood watercourses will go a long way to addressing the detrimental effects of urban runoff.

It comes to knowing where the storm drains in your area are located (ALL storm drains lead to a natural creek or river eventually). Here are a few things you can do to protect those natural water courses: 

  • DIVERT your downspouts away from paved areas and install a rain barrel to capture and reuse the rainwater that falls on your roof. This reduces runoff to the storm drains and prevents flooding.
  • STOP using salt, pesticides and fertilizers on your lawns and gardens; these contaminate the water systems and also are toxic to pollinators. Instead, consider moving from a manicured lawn to a more natural green property, friendly to pollinators and less demanding.
  • PLANT trees on your property. Trees help buffer rainfall and sequester carbon.
  • PARTICIPATE in stream cleanups, picking up litter and other unnatural things in the water; adopt a section of a nearby waterway and steward it; start a stewardship group in your community and learn about the ecology of the stream.
  • LEARN more about the watershed you live in. Then act accordingly. 
  • FIND the nearest natural body of water to you and steward it. Then act accordingly.
  • GO for walks in natural parks and relearn things about the natural world. 

Nina Munteanu is a Canadian ecologist / limnologist and novelist. She is co-editor of Europa SF and currently teaches writing courses at George Brown College and the University of Toronto. Visit for the latest on her books. Nina’s bilingual “La natura dell’acqua / The Way of Water” was published by Mincione Edizioni in Rome. Her non-fiction book “Water Is…” by Pixl Press(Vancouver) was selected by Margaret Atwood in the New York Times ‘Year in Reading’ and was chosen as the 2017 Summer Read by Water Canada. Her novel “A Diary in the Age of Water” was released by Inanna Publications (Toronto) in June 2020.

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