Drinking Water Resource Library Tag

PFAS In Water Systems: A Canadian Perspective

The Walkerton Clean Water Centre (WCWC) has added a new fact sheet and resources on perfluoroalkyl and polyfluoroalkyl substances (PFAS) in water systems to its Drinking Water Resource Library.

PFAS are a large group of synthetic compounds that are often referred to as “forever chemicals”. They are used in a wide variety of industrial and consumer products, such as adhesives, cleaning products, cosmetics and specialized chemical applications, such as fire-fighting foams. This group of chemicals is resistant to heat, water, oils and grease, making them highly persistent in the environment and able to accumulate in living tissues, taking several years to decades for the body to eliminate. Due to their persistent nature, the chemicals can enter drinking water wells by leaching into groundwater.

The full fact sheet and related resources can be accessed free of charge through the Drinking Water Resource Library, at:

• https://wcwc.ca/wp-content/uploads/2020/12/PFAS-Fact-Sheet-2021-02-23-FINAL-ENG.pdf
• https://wcwc.ca/per-polyfluoroalkyl-substances-pfas-pfoa-pfos/

WCWC creates fact sheets to share information with water professionals. For more information, or to request topics for future fact sheets, please visit  wcwc.ca or contact us at 866-515-0550 or dwrl@wcwc.ca.

Cyanobacteria and Cyanotoxins in Water

Over the past decade, cyanobacteria blooms have emerged as an important issue in the water and wastewater industry. Tory Colling, Scientist, explains what water professionals ought to know about cyanobacteria and cyanotoxins in water:

1. What are cyanotoxins?
Cyanotoxins are produced by some species of cyanobacteria or as commonly known as blue-green algae. These toxins are typically stored inside the cells, but when cyanobacteria cells degrade, the toxins are released.

Cyanobacteria are microscopic bacteria that have some plant-like characteristics. They are commonly called “algae blooms” in the media.

2. Where are they found?
Cyanobacteria naturally occur in freshwater. In fact, they contribute oxygen in our atmosphere. When conditions are favourable, such as warm temperatures and nutrient-rich, shallow and stagnant waters, cyanobacteria can form blooms. Cyanobacteria blooms are made up of densely-populated cells that form discoloured water, which is often described as pea soup or spilt paint with an oily appearance.

Certain cyanobacteria can produce by-products, known as cyanotoxins. When these cyanobacteria cells form a bloom, large amounts of cyanotoxins can be detected.

3. What are the health concerns?
Health concerns can range from liver toxins, neurotoxins, tumor-promoting effects or skin irritation. There are different types of cyanotoxins and each type has different health concerns. The most common cyanotoxin is called microcystin. Microcystin is a liver toxin and can cause tumor-promoting effects.

4. What are some strategies to control cyanotoxins?
Reducing nutrient inputs to source water or effective reservoir/watershed management are long-term strategies to control cyanobacteria and cyanotoxins.

5. How can cyanotoxins be removed from drinking water?
For larger municipal systems, combining effectively operated drinking water treatment processes can provide a multiple barrier to remove intact cells or released cyanotoxins. Some drinking water treatment processes, such as coagulation, flocculation and sedimentation or flotation, are capable of removing intact cyanobacteria cells. While other drinking water treatment processes, such as chlorination or ozonation, are capable of degrading released cyanotoxins, provided there is enough disinfectant concentration and contact time with the disinfectant.

Some very small or private drinking water systems may only rely on point-of-entry (POE) drinking water treatment units. If these private drinking water systems suspect a bloom in the water supply, it is recommended to contact the local health unit and use an alternative water source. Very limited POE treatment units are certified to specifically remove cyanotoxins. However, in 2019, the National Sanitation Foundation (NSF)/American National Standards Institute (ANSI) updated NSF/ANSI Standard 53 to include a protocol to test activated carbons filters to reduce microcystins.

To learn more about cyanobacteria and cyanotoxins, visit WCWC’s Drinking Water Resource Library or contact WCWC’s helpline at helpline@wcwc.ca or 1-855-306-1155.

Managing Legionella Risk In Buildings Through Water Safety Management Planning

The Walkerton Clean Water Centre (WCWC) co-hosted a course, Managing Legionella Risk in Buildings through Water Safety Management Planning. The course was presented by the private sector and federal and provincial partners to provide education on effective water safety management plans to reduce exposure to Legionella.

Course presentations are now available online on the Drinking Water Resource Library (DWRL) and will help building owners, facility managers, drinking water system owners and operators, public health inspectors and healthcare professionals better understand how to write effective water safety management plans based on the ANSI/ASHRAE 188 standard to manage the proliferation of Legionella in buildings.

The Drinking Water Resource Library was developed to provide easy access to trusted resources related to drinking water. The library consists of a catalog of documents and features multiple search functions to ease the research of information. This initiative is part of WCWC’s strategy to enhance the transfer of knowledge to owners, operators and operating authorities of Ontario’s drinking water systems. The DWRL can be accessed from wcwc.ca or at www.drinkingwaterresourcelibrary.ca.