BS 8558 Water System Chlorination Services

Professional chlorination of new, altered, or recommissioned water systems, delivered in line with BS 8558 to support safe commissioning and documented compliance.

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What BS 8558 Chlorination Is

BS 8558 chlorination is the controlled disinfection of water systems following installation, modification, or recommissioning.

Its purpose is to remove microbiological contamination introduced during construction, maintenance, or shutdown, ensuring the system is safe to use before occupation or handover.

In certain scenarios, chlorination is not optional. It forms part of a duty holder’s responsibility to ensure water systems are hygienic, fit for purpose, and properly commissioned, with records in place to demonstrate compliance.

The outcome is simple:
A clean system, reduced contamination risk, and clear evidence that commissioning has been carried out correctly.

A person wearing white gloves working on a complex network of metal pipes and valves in an industrial or laboratory setting.

When Chlorination Is Required

BS 8558 chlorination is typically required in the following situations:

  • New water mains, tanks, or pipework installations

  • Extensions or alterations to existing water systems

  • Prior to occupation, handover, or re-use of buildings

  • Following maintenance, repairs, or prolonged shutdowns

  • After suspected contamination or failed microbiological results

If any of the above apply, chlorination should be planned as part of system commissioning or re-commissioning.

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Systems We Chlorinate

Flowsafe Compliance carries out chlorination across a wide range of systems, including:

  • Hot and cold water services

  • Boosted water systems

  • Storage tanks and associated distribution pipework

  • Commercial and residential water systems

  • Temporary construction and commissioning water systems

Each system is assessed individually to ensure the method and dosing are appropriate for its size, configuration, and use.

A Controlled, Step-by-Step Method

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    Pre-Service Site Review & System Assessment

    We confirm system layout, volumes, materials, and isolation points to define the correct chlorination approach.

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    System Isolation & Preparation

    The system is prepared, flushed where required, and isolated to ensure controlled dosing and prevent unintended exposure.

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    Chlorine Dosing to Prescribed Concentrations

    Approved disinfectants are introduced at concentrations aligned with BS 8558 guidance.

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    Contact Time Monitoring

    The chlorinated water is held within the system for the required duration to ensure effective disinfection.

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    Neutralisation & Final Flushing

    Following contact time, the system is neutralised and flushed with clean water to restore normal operation.

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    Verification & System Readiness

    Final checks are completed to confirm the system is ready for use or sampling.

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Sampling, Testing & Verification

Where required or specified, microbiological verification can be carried out following chlorination.

This may include:

  • Collection of water samples for microbiological analysis

  • Use of UKAS-accredited laboratories

  • Confirmation that results meet acceptable limits before system use

If results indicate further action is required, we provide clear guidance on next steps without unnecessary alarm.

Clear Records for Compliance and Audit

On completion, documentation is issued to support commissioning and compliance requirements, which may include:

  • BS 8558 chlorination certificate

  • Method statement summary

  • Chlorine dosing and contact time records

  • Test results (where applicable)

  • Audit-ready documentation for handover or inspection

All documentation is quality-checked before issue.

Regulation & Guidance Alignment

Our chlorination services are delivered in alignment with recognised UK water safety guidance, including:

  • BS 8558

  • ACoP L8

  • HSG 274

We apply these standards proportionately, focusing on correct implementation rather than unnecessary box-ticking.

A worker in orange safety gear and a yellow hard hat inspecting large black pipes underneath a building HVAC system with blue piping and metal framework.

Who This Service Is For

This service is commonly used by:

Principal Contractors

supporting commissioning and handover

Commercial Landlords

meeting duty of care obligations

Property & Block Managers

managing shared water systems

Facilities Managers

ensuring systems are safe before use

Building Owners & Site Managers

controlling risk during works

Each role benefits from clear scope, controlled delivery, and documented outcomes.

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Why Use a Specialist Chlorination Provider

Using a competent, specialist provider helps ensure:

  • Correct chemical dosing and contact times

  • Controlled handling of live water systems

  • Reduced risk of recontamination or incomplete disinfection

  • Clear, defensible compliance records

This reduces uncertainty during commissioning and protects those responsible for water safety.

How to Arrange BS 8558 Chlorination

Initial Enquiry

Contact us with basic site and system details.

1

Scope Confirmation & Quotation

We confirm requirements and issue a clear, defined quotation.

2

Scheduled Site Attendance

A qualified engineer attends site to carry out the works.

3

Certification & Reporting

Documentation is issued promptly for your records.

4

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Flowsafe Compliance delivers BS 8558 chlorination with control, clarity, and professional discipline.

Our focus is on correct execution, proportionate compliance, and documentation that stands up to scrutiny, so your water system can be placed into service with confidence.