In the Water.

Chemicals used above ground can make their way into water supplies. Municipal water systems in Canada are required to test the water regularly for many chemicals. If you have a private water source (well, spring, etc.), you may be unaware of what is in your water. Also, old pipes in your house or in municipal systems can cause lead contamination. 

Some common chemicals found in water include:


historically used in water piping, some older homes and municipal systems still have lead pipes. Lead is also naturally occurring and may be in your private water source. Lead is extremely persistent in the environment and accumulates in the human body. Exposures throughout your lifetime build up and can cause anemia, kidney and brain and central nervous system damage. Lead exposure can cause miscarriage, stillbirths, and infertility (in both men and women). Babies and young children are especially vulnerable to intellectual and behaviour effects of lead exposure. Fetuses in utero are exposed to lead in the mother’s blood, which have accumulated throughout her lifetime. 

Naturally occurring elements:

elements that occur naturally in soil and bedrock can be present in your private water source. Some examples include arsenic, lead, manganese and nitrates, which can cause cancer, neurological effects, intellectual and behavioural effects and reproductive effects. 

Chemical contaminants, pesticides, and oil:

if your water supply is near an area where a chemical, pesticide, or oil spill occurred, you water may be contaminated. 

Blue green algae blooms:

when water bodies are warm, slow moving, and high in nutrients, naturally occurring blue-green algae can multiply rapidly (“bloom”), forming a blueish green film or scum on the surface of the water. Lawn fertilizers, sewage, and agricultural runoff into water bodies often result in blue green algae blooms. Blue green algae can produce toxins that are poisonous to people, pets, and livestock. 


common in well or spring water, bacteria can be cause for concern because some bacteria, like E. coli, can cause significant gastrointestinal illness. Some wells or springs may have occasional bacteria, while others may have a consistent bacteria concern. Water sources near septic fields or areas of animal waste (pets or livestock) are especially vulnerable to E. coli contamination. 

What You Can Do

  • If you use a municipal water source: test your tap water for lead
  • If you use a private water source: 
    Test your water for bacteria and naturally occurring elements. Testing for bacteria should be done every 6 months. Clean (“shock”) your well if bacteria are detected 

    Contact your local Environment Department to inquire if any chemical, pesticide or oil spills have been reported near your well / spring 

  • Maintain a natural shoreline on waterfront property, avoid using lawn fertilizers and ensure your septic system is properly maintained 
  •  If a blue green algae bloom is present, assume toxins are present 
  • Keep people and animals away from water with blue green algae blooms 

We provide science-based information gathered from trustworthy sources. For further reading, you can check out our sources, which include:

  • Centers for Disease Control and Prevention: Childhood Lead Poisoning Prevention, Pregnant Women 

  • Government of Canada: Guidelines for Canadian Drinking Water Quality – Summary Table 

  • Government of Canada: Be Well Aware 

  • Provincial / Territorial governments Contaminated Sites Management programs (title may differ by location) 

  • Government of Canada: Lead Information Package – Some Commonly Asked Questions About Lead and Human Health 

  • HealthLink BC: Cyanobacteria Blooms (Blue-green Algae) 

  • Canadian Water Quality Association: Blue Green Algae 
  • Government of Canada: Pesticides Indicator