December 6,2011

Lesley Flowers

Dear Ms. Flowers:

Thank you for your letter of November 29,2011, expressing your concerns about how the Sudbury & District Health Unit handled the early October blue-green algae bloom in the vermillion River. comments from the public we serve are always

The Health Unit and the Ministry of the Environment (MOE) have, over the past several years, developed a protocol that is to be followed by both agencies. The following explains that protocol.

The Health Unit and the Ministry of the Environment do not proactively check local waterways for the presence of blue-green algae. There are several reasons for this, one of which is the number and size of our waterways. With current levels of
staffing, it would be impossible for either agency to undertake such a process. That is why the investigation of blue-green algae is a complaint-driven process that relies on sightings reported by the public and, in particular, people who own or occupy waterfront properties.

The key issue relates to risk. Blue-green algae are natural phenomena and common in our waterways. However, they are not a potential risk to health until there is a “bloom”, or large numbers of blue-green algae in one area. When the Health Unit receives a report of a suspected blue-green algae bloom, a public health inspector is immediately sent to investigate. Because not all blue-green algae blooms contain toxins, the investigation is done to determine whether or not the bloom contains a species of blue-green algae that can produce toxins. The investigation consists of:

  • a visual check to confirm that the growth in the water does in fact appear to be blue-green algae;
  • taking photographs as evidence in case the bloom dissipates or moves to another location; and
  • taking samples that are sent to the MOE laboratory in Toronto to determine if a toxin-producing species of blue-green algae is present.

Once the lab receives the sample, it usually takes from two to four business days for analysis. The MOE lab, which is the only lab in Ontario certified to do this kind of detailed analysis, sends the results to the local MOE office, which then forwards
them to the Health Unit. Thank you for your comment regarding the time it takes for lab results. we have forwarded your concern to the local MOE office attention Brian McMahon (

When the Health Unit receives positive test results, it immediately starts the notification process. This consists of hand delivering a letter from the Medical Officer of Health, along with a fact sheet from the Ministry of the Environment, to  residents in the immediate area of the bloom. The Health Unit then issues a news release to local media. The resident notification process does not occur when blooms are identified in an area that is accessible by water only, in remote areas, and in areas where blue-green algae have been previously identified.

Blue-green algae are not anchored in one place and are easily moved by wind and water currents. You can see blue-green algae in front of your property in the morning and it can be gone by the afternoon. To thrive, blue-green algae prefer slow-moving or stagnant, shallow water with an abundant supply of nutrients (usually phosphates and nitrates). ln a rapidly flowing or moving body of water, ihe algae are normally dispersed and diluted. Blue-green algae can also raise and lovuer ihemselves in the water to catch the sunshine they need to grow.

ln the case of the blue-green algae sighting on the Vermillion River, the Health Unit followed the protocol described above. As an added precaution, Health Unit staff also inspected the intake area of the Vermillion Water Treatment Plant and determined that a blue-green algae bloom was not present there.

The information that the Health Unit distributes door-to-door advises people who draw their water from the surface body to find an alternative supply of water for consumption-not just while the blue-green algae bloom is present, but on a permanent basis. Once a water body has experienced a blue-green algae bloom, it will most likely experience it again under similar circumstances. As far as swimming, bathing, or laundry are concerned, the information distributed by the Health Unit advises against such activities as long as the bloom is present and close to water intake lines or beach fronts’ Repeated sampling would not reduce the risks from blue-green algae. The blooms are mobile and can be dispersed, but they can also reoccur without warning. Once blue-green algae have been detected in a water body, the water body will always be at risk. That is why we ask residents in the area of a blue-green algae bloom to be on the lookout for it and to report any sightings to the Health Unit’

I hope that this letter has addressed your concerns. lf you would like to discuss the matter further, please call Allan McDougall, Environmental Support Officer at705.522.9200, ext.442.

Penny Sutcliffe, MD, MHSc, FRCPC
Medical Officer of Health/Chief Executive Officer
cc: Marianne Matichuck, Mayor, City of Greater Sudbury
France Gelinas, MPP
Jacques Barbeau, Councillor, Ward 2
Linda Heron, Vermillion River Stewardship

Download letter.