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.Read More
The spread of COVID-19 is an evolving situation that the Walkerton Clean Water Centre (WCWC) is acting upon. WCWC will continue to serve its clients and is making new resources available to the water sector daily through the Drinking Water Resource Library and the Helpline.
WCWC has added a dedicated section to the Drinking Water Resources Library containing links to guidance documents, fact sheets and free webinars related to COVID-19 for water professionals. This online system provides access to a variety of trusted resources and features multiple search functions to assist our clients in their search for information.
As well, WCWC staff will continue to respond to technical calls and provide information related to drinking water treatment processes, equipment, operational requirements and environmental factors through the Helpline. Staff will respond to inquiries during business hours, Monday to Friday, as we always have.
Visit www.wcwc.ca/drinking-water-resource-library/ and scroll down to view the folder of resources on the COVID-19 pandemic and the water sector or contact the Helpline at 1-855-306-1155 or firstname.lastname@example.org.Read More
Do you have questions about drinking water or issues with it? The WCWC helpline has answers. Lindsay Ariss, Technician, answers your questions about the helpline:
- How does the helpline work?
The helpline provides information and educational resources to those who work with drinking water (owners, operators and operating authorities) and the public.
2. What kind of questions can you answer?
Information and resources are provided to address questions or challenges related to drinking water including treatment processes, equipment, distribution, operational and regulatory requirements, training and environmental factors.
3. Who answers my questions?
You will be directed to a staff member who has specific expertise related to your question.
4. What if you don’t have the answers to my questions?
If WCWC staff are not able to answer your questions, you will be referred to the appropriate contact. These include manufacturers, sales representatives, water professional associations, government agencies/departments and other stakeholders.
WCWC staff have years of experience and technical knowledge and strive to provide you with tailored information relating to your query. Access the helpline, Monday to Friday 8:00 a.m. to 4:00 p.m., by calling 1-855-306-1155 or emailing email@example.comRead More