How to Stop Biofilm: Safeguarding Your Plumbing and Tanks

Biofilm is a slimy, glue-like layer of bacteria and microorganisms that coats the inner surfaces of pipes and storage tanks. This resilient colony acts as a protective fortress for dangerous pathogens like Legionella and E. coli, shielding them from disinfectants and posing a significant health risk. Preventing its buildup is crucial for maintaining water safety.

Understanding the Enemy
Biofilm thrives in stagnant water, on rough surfaces, and where nutrients and warmth are present. Once established, it is notoriously difficult to eradicate completely. Therefore, a proactive prevention strategy is essential.

Key Prevention Strategies

1. Eliminate Stagnation: Keep water moving. Regularly flush all taps and outlets, especially in low-use areas of a building. For storage tanks, ensure recirculation pumps are functioning to prevent dead zones where water sits.
2. Control Temperature: Keep cold water below 20°C (68°F) and hot water above 55°C (140°F) at all points. Biofilm grows rapidly in tepid water. Use thermostatic mixing valves at the point of use for safety, not by lowering the tank temperature.
3. Maintain Disinfectant Levels: In systems where potable water is treated, ensure a consistent residual disinfectant (like chlorine) is present throughout the network. This residual helps inhibit microbial growth on pipe walls.
4. Physical and Chemical Cleaning: Implement a scheduled maintenance program. For tanks, this includes periodic physical scrubbing and draining to remove sediment that feeds biofilm. Follow this with a shock chlorination or another approved disinfectant process, ensuring thorough contact with all surfaces.
5. Material Matters: When installing or replacing pipes and tanks, choose smooth, non-corrosive materials like cross-linked polyethylene (PEX) or lined steel. Rough or corroded surfaces provide ideal anchoring points for biofilm.

A Consistent Regime is Key
There is no single solution. Effective biofilm prevention requires a consistent, multi-pronged approach combining hydraulic management, temperature control, and regular mechanical and chemical cleaning. By implementing these practices, you can break down the pathogen’s stronghold and ensure the integrity of your water system from source to tap.