Is It Safe For Your Septic System?

Wastewater enters a septic tank, where particles settle into sludge and oils float as scum. Anaerobic microbes decompose organic waste. Clarified liquid is routed to a drain field, where perforated pipes disperse it across gravel and soil. Pollutants are removed using soil filters, and aerobic microorganisms complete the treatment. Cleaned water progressively seeps into groundwater and neighbouring lakes and streams.

Sodium Lauryl Ether Sulfate (SLES) is an anionic surfactant that keeps fats and organic materials mixed in water rather than separating. This allows more organic matter and nutrients to leave the tank and negatively affect the environment.

Quaternary Ammonium Compounds (QACs) are disinfectants that damage bacterial cell membranes, leading to cell death. They kill the beneficial microbes needed for waste breakdown, reducing septic system treatment efficacy.

Antimicrobials such as disinfectants and antibiotics cause pressure on bacteria within a septic tank to develop genes that make them antimicrobial resistant. This causes the spread of antimicrobial-resistant bacteria, which cause infections that are extremely difficult to cure (Ghanadi et al., 2026).

Altering the pH of a septic tank can cause changes in how effective the bacteria are and how soluble the products put in the septic tank are (Zhou et al., 2019). There is a small pH window where the septic system functions optimally. Cleaning products with a strong pH, such as bleach, can severely impact the effectiveness of the septic tank.

• Avoid household products containing Sodium Lauryl Ether Sulfate, Alkyl Benzene Sulfonic Acid, and quaternary ammonium compounds (e.g., Polyquaternium-37).
• Use septic-safe, biodegradable products and dispose of oil, grease, and petroleum-based products in the garbage rather than down the drains.
• Support environmentally responsible, septic-safe products to extend septic system lifespan and improve its efficiency.

• Frank Fugli — Ulinks Coordinator
• Rob Davis — EcoEthic Advisor
• Dana Alqasasie — University of Guelph
• Jax O'Donovan — University of Guelph
• Nabeeha Fahad — University of Guelph
• Sarah Alsultan — University of Guelph