How Long Island Municipalities Are Fighting the Hidden Enemy in Your Water Lines: Advanced Biofilm Management Protocols

Beneath the surface of Long Island’s water distribution network, a microscopic battle is being waged against one of the most persistent threats to public health: biofilms. These complex communities of bacteria, fungi, and other microorganisms create a protective matrix that can harbor dangerous pathogens like Legionella and E. coli, making traditional cleaning methods ineffective. Biofilm formation in industrial potable water systems presents a multifaceted challenge that has significant implications for both equipment efficiency and human health, with the formation and persistence of these biofilms leading to reduced system efficiency and potential health risks due to microbial‐induced corrosion, contamination and waterborne pathogens.

Understanding the Biofilm Challenge

Biofilm is a dense, slimy layer of microbial colonies that forms on surfaces exposed to water over time, where microbial communities attach to a surface and secrete a sticky matrix known as extracellular polymeric substances (EPS), with this protective layer anchoring the bacteria to pipe walls, filters, and other surfaces – shielding them from disinfectants, heat, and flow. This protective barrier is what makes biofilms so challenging to eliminate from water distribution systems.

Stagnant flow conditions or low flow rates can provide an ideal environment for biofilm formation, as microbes have more time to adhere to surfaces, with the intricacies of the water distribution system, such as dead‐ends or areas with variable pipe materials like iron or PVC, creating niches where biofilms thrive. This is particularly relevant for Long Island’s extensive water infrastructure, which serves millions of residents across Nassau and Suffolk counties.

Advanced Cleaning Protocols Being Implemented

Long Island municipalities have adopted several cutting-edge approaches to combat biofilm contamination:

Air Scouring Technology

The Severn Air Scouring system uses high-volume, high-velocity and low-pressure air to scour clean pipes, where by isolating a section of the water main between an entry point and exit point the section is purged of standing water with high-volume, high-velocity and low-pressure air, with the compressed air, mixing with the water slugs, creating a vortex that travels through the isolated section removing sediment, biofilm and soft mineral scale. This method has proven highly effective, with one Long Island municipality seeing their Hazen-Williams coefficient improve from 67 to 96 after treatment.

Strategic Flushing Programs

MassDEP recommends that all public water suppliers have a routine flushing program, with these programs considered the best way to improve water quality and increase the reliability of the water distribution system, where a proper scouring velocity must be achieved to effectively minimize biofilm. Municipalities typically use one of two options to clean water mains: flushing the main with large quantities of clean water through unidirectional flushing (UDF), or physically passing a “pig” or “swab” through the main.

Enhanced Chemical Treatment

Municipal water utilities attempt to maintain a chlorine residual in the distribution system to discourage microbiological growth, though chlorine in its various forms is a proven disinfectant, it has been shown to be less effective against biofilm bacteria, with higher levels of chlorine for longer contact times necessary to eliminate biofilms.

Multi-Pronged Prevention Strategies

Facilities that proactively manage water chemistry, flow conditions, and monitoring protocols have significantly fewer biofilm growth issues over time, with an effective biofilm prevention strategy including balanced water flow and avoiding dead legs and stagnant zones. For effective biofilm removal from pipes, it is essential to follow a systematic approach with Guardian’s experts conducting a thorough assessment of your water system to identify the risk of biofilm proliferation and the most suitable control technique, with tailored solutions based on the assessment.

Professional Services for Long Island Residents

When municipal efforts aren’t enough and biofilm issues affect individual properties, Long Island residents turn to specialized service providers. Long Island Sewer and Water Main has been serving Nassau and Suffolk County residents for nearly 40 years, offering comprehensive solutions for water line and sewer system maintenance. The team at Long Island Sewer and Water Main is proud to have a fully licensed and insured staff that is ready to assist you with a wide array of services, proudly serving Long Island and NYC home and business owners for almost 40 years, with services ranging from simple water meter checks to complex trenchless water line replacements, available 24/7 to meet your plumbing needs in Suffolk and Nassau Counties.

We are one of the only providers of trenchless sewer and water line services across both Nassau County and Suffolk County, using our trenchless technologies, we are able to provide more efficient, convenient, and cost-effective sewer line services to residents and businesses across Long Island.

The Importance of Regular Monitoring

Heterotrophic plate counts and coliform counts, both of which are routinely run by the municipal water utility, will at least provide an indication of the potential for biofilm formation, with heterotrophic plate count levels in potable water should be <500 CFU/mL, and a direct correlation between heterotrophic plate count and biofilm levels has been demonstrated.

Even with best practices in place, persistent issues – like discoloration, odors, low residuals, or Legionella positives – may signal deeper biofilm contamination in the system, with once biofilm present, eliminating it entirely from water distribution systems difficult – which is why prevention is always the better approach.

Looking Forward

The effective detection and management of biofilms in industrial potable water systems necessitate a multi‐pronged approach. Long Island municipalities continue to invest in advanced technologies and protocols to ensure water safety for their residents. Although there are numerous techniques available to control microbial growth in drinking water, it is not possible to completely eliminate biofilms in DWDSs, therefore, it is crucial to continuously study biofilm formation in the future to better understand the processes behind their formation and control, as well as the effectiveness of different biofilm management approaches to prevent, limit, and control the spread of biofilms within the DWDS.

As biofilm management technology continues to evolve, Long Island residents can expect even more sophisticated approaches to protecting their water supply. The combination of municipal prevention programs and professional remediation services provides a comprehensive defense against this persistent threat to water quality and public health.