What is Backflow and Why Does It Matter?

Backflow occurs when water flows in the reverse direction, potentially carrying contaminants from private plumbing systems into the public water supply. This can happen due to:

  • Back-siphonage: Caused by pressure drops in the main water supply (e.g., during water main breaks).
  • Backpressure: When a customer’s water pressure exceeds the supply pressure.

Both scenarios pose risks of cross-contamination, introducing harmful bacteria, chemicals, or medical substances into the potable water system.

How Does a Backflow Preventor Work?

A backflow preventor is a mechanical device installed in the plumbing system that stops contaminated water from reversing into the public water main. During pressure changes—whether from a main break or overpressurization—this device blocks contaminants from moving upstream.

Why Introduce a Backflow Prevention Program?

  1. Protecting Public Health: Backflow preventors are critical in preventing contaminants from entering the water supply. Their use reduces the risk of waterborne illnesses and ensures compliance with public health regulations.
  2. Compliance with Standards:
    • The National Plumbing Code mandates the installation of backflow preventors.
    • The CSA Code B64.10 requires annual inspections of these devices.
    • The Office of Drinking Water obligates water utility operators to safeguard potable water from contamination.

  3. Minimizing Risks and Costs:
    • Contamination events could necessitate costly flushing or replacement of water mains and damage the city’s reputation.
    • Regular inspections are a proactive and cost-effective measure to mitigate these risks.

Benefits of Backflow Prevention

  • Enhanced Public Safety: Protects residents from exposure to harmful contaminants.
  • Regulatory Compliance: Aligns with National Plumbing code requirements.
  • Cost-Effective Risk Management: Prevents expensive remediation efforts following contamination.

Contact a Certified Inspector for an inspection of your system.