Menu Close

What is Chlorination? – An In-Depth Look at Water Disinfection

What is Chlorination? – Explore the process of chlorination with PTS and its vital role in providing safe, disinfected water.

What is Chlorination? - An In-Depth Look at Water Disinfection

    In Need of Chlorination Services? – >>

    In the United Kingdom, we often take clean drinking water for granted. However, providing safe potable water involves meticulous treatment processes.

    At Pipe Testing Services (PTS), we understand the importance of water disinfection. This guide delves into chlorination, exploring its history, mechanisms, and vital role in safeguarding public health.

    Expert Support for All Your Needs

    In addition to water main repair and replacement chlorination, PTS offers a comprehensive suite of specialised pipeline services:

    At PTS, our seasoned professionals collaborate closely with you to develop tailored solutions that place the utmost emphasis on safety protocols, regulatory compliance, and optimised efficiency across the full scope of your pipeline project needs. Explore the comprehensive suite of specialised services we offer above to learn how we can provide a customised approach that exceeds your project requirements while upholding the highest standards of quality and best practices.

    The Necessity of Water Disinfection

    Water from natural sources like rivers, lakes and wells may harbour microorganisms. While many are harmless, some pathogens can cause severe waterborne illnesses. Consuming water contaminated with pathogens like those causing cholera, typhoid or dysentery can be potentially life-threatening. Thus, disinfecting drinking water is crucial to eliminate disease-causing microbes.

    The Chlorination Process Explained

    It’s a widely-used disinfection method that involves treating water with chlorine-based compounds. The chlorine damages the cell membrane of microorganisms. Once inside, it disrupts respiration and DNA activity, effectively killing the cell. This tried-and-tested technique has been employed for over a century due to its efficacy and cost-effectiveness.

    The Origins of Chlorination

    Though initially proposed in Sweden in the 1740s, the idea didn’t gain traction until the 1830s. At that time, chlorine was used to remove unpleasant odours from water. Unknowingly, this process also killed microorganisms present. By 1890, the link between waterborne pathogens and disease was established. The UK began routinely chlorinating drinking water, with the practice quickly spreading worldwide.

    chlorination of water main repair and replacement.
    chlorinating and sampling for SLP Client - ongoing work including chlorination services and pressure testing.

    Not only are we Chlorination experts, but we’re also Legionella Contractors – take a look at our page here to learn more about Chlorination and Legionella Control | Pipe Testing Services

    Why Choose Chlorination?

    Numerous studies validate chlorine’s effectiveness against bacteria and viruses. While some protozoan cysts resist chlorination, it remains highly potent against most water contaminants. The key advantages include:

    When is Chlorination Performed?

    Chlorination can occur at various stages, with distinct benefits:


    Adding chlorine to raw water entering the treatment plant eliminates algae and organisms. This prevents fouling, odours and contamination of systems like pipes and filters.

    Disinfecting water after sedimentation but before filtration controls microbial growth and oxidises dissolved solids for easy removal.

    In most UK treatment plants, a final chlorine dose disinfects filtered water before distribution. This ensures safe residual levels during transportation to homes and businesses.

    When chlorine dissolves in water, it forms hypochlorous acid and hypochlorite ions – the active disinfecting agents. Their relative concentrations depend on the water’s pH. Acidic conditions favour more potent hypochlorous acid.

    ‘Free chlorine’ refers to these two compounds, while ‘combined chlorine’ forms from reactions with ammonia – a less effective disinfectant.

    The chlorine demand is the amount required to remove impurities before free chlorine forms. Factors like ammonia levels impact this breakpoint. Insufficient chlorine leads to incomplete disinfection, underscoring precise dosing’s importance.

    Prioritising Chlorination Safety

    At PTS, we adhere to stringent chlorination protocols to uphold worker and environmental safety. Our expert technicians undergo comprehensive training annually, supplemented by regular toolbox talks. We utilise specialised PPE like SCBAs, chemical suits and decontamination equipment when handling chlorine.

    Through rigorous procedures encompassing storage, application, exposure control and disposal, we ensure regulatory compliance. This minimises acute and chronic chlorine hazards while preventing environmental releases.

    You can read more here about Chlorination Safety Protocols and PPE for Water System Disinfection on our dedicated page.

    Chlorination FAQs

    What are the advantages of chlorination over other disinfection methods?

    Several key benefits, including; its proven effectiveness against most waterborne pathogens, cost-efficiency, rapid large-scale treatment capabilities, and compatibility with multiple stages of the water treatment process. Its long-standing use worldwide attests to its versatility and reliability.

    Chlorine damages the cell membrane of microbes, allowing it to penetrate the cell interior. Once inside, it disrupts vital processes like respiration and DNA replication, effectively killing the organism. This multi-pronged attack mechanism makes chlorine highly potent against a wide range of pathogens.

    Chlorine is a highly reactive oxidising agent that can cause severe respiratory issues, eye injuries, and chemical burns upon exposure. Proper PPE like SCBAs, chemical suits, and decontamination equipment are essential for mitigating these hazards during chlorination work.

    We adhere to stringent chlorination protocols encompassing safe handling, storage, application, exposure control, and disposal procedures. Routine hazard assessments, specialised training, PPE enforcement, and regulatory compliance underpin our comprehensive approach to chlorination safety.

    Discharged chlorinated water can harm aquatic life and ecosystems. PTS implements dechlorination measures to neutralise residual chlorine before any discharges, preventing ecological damage. We also have robust spill containment and mitigation plans to avert environmental releases.

    The chlorine demand depends on factors like the type and concentration of contaminants, pH levels, and presence of ammonia or other interfering substances. Precise dosing calculations based on water quality analysis ensure adequate free chlorine levels for complete disinfection.

    While chlorine is highly effective against most bacteria, viruses, and many other microbes, some protozoan cysts like Cryptosporidium are resistant to chlorination. An integrated multi-barrier approach combining chlorination with other techniques like filtration may be required for comprehensive disinfection.

     Following chlorination, we conduct extensive sampling and analysis to verify residual chlorine concentrations are within safe, potable water standards. Thorough flushing is performed before reintegrating the treated system to eliminate any exceedances.

    Absolutely. PTS offers specialised chlorination services for new main installations, commissioning projects, as well as repair and replacement works on existing water distribution networks. Our flexible solutions cater to all phases of a system’s lifecycle.

    Trust PTS for Comprehensive Chlorination Expertise

    When it comes to safe, compliant water disinfection through chlorination, trust the professionals at PTS. Our team’s in-depth knowledge, rigorous training, and meticulous adherence to protocols ensure your chlorination needs are met with uncompromising standards.

    Contact us today to leverage our specialised chlorination services and solutions across all your water system projects. At PTS, we can handle any chlorination job – and we operate nationwide, across the whole of the UK! So don’t hesitate to get in contact for a personalised quote.

    Phone – 01922 451646

    Email –

    Address – Unit 27 Birchbrook Industrial Estate, Shenstone, Lichfield, Staffs, WS14 0DJ

    Experience industry-leading chlorination proficiency backed by an unwavering commitment to safety, regulatory compliance, and reliable disinfection results nationwide.