Cold Water Storage Vessel Cleaning & Chlorination Services

Professional inspection, cleaning, and disinfection of cold water storage vessels to control contamination risk and support compliant water system management.

What a Cold Water Storage Vessel Is

Cold water storage vessels (CWSVs), sometimes referred to as tanks or cisterns, store potable water before distribution throughout a building.

Because water is held rather than continuously refreshed, these vessels are vulnerable to:

  • Temperature rise

  • Sediment build-up

  • Microbiological contamination

If not maintained correctly, they can become one of the highest-risk components within a water system.

Routine inspection, cleaning, and chlorination are essential to maintain water quality and system integrity.

Why Cold Water Storage Vessels Require Cleaning & Chlorination

Over time, storage vessels can accumulate debris and contamination that compromise water quality.

Common issues include:

  • Sediment and biofilm build-up

  • Increased water temperatures due to poor insulation or location

  • Contamination from damaged lids, vents, or screens

  • Microbiological growth, including Legionella risk

  • Degraded coatings or structural defects

Cleaning and chlorination remove contamination and restore hygienic conditions within the vessel.

When Cleaning & Chlorination Is Typically Required

Cold water storage vessel cleaning and disinfection is commonly required:

  • As part of routine planned maintenance

  • Following Legionella risk assessment recommendations

  • After system contamination or failed samples

  • When vessels show visible sediment or fouling

  • After repair, modification, or prolonged shutdown

  • Prior to recommissioning or change of use

Frequency should be determined by risk assessment findings and system condition.

A Controlled, Compliant Method

Pre-Service Inspection & Risk Review

We assess vessel condition, access, and system configuration.

Mechanical Cleaning

Internal surfaces are cleaned using appropriate methods for the vessel type.

Internal Inspection & Debris Removal

Sediment, scale, and visible contamination are removed.

Isolation & Controlled Drain-Down

The vessel is isolated and drained in a controlled manner to prevent contamination.

Chlorination & Disinfection

Approved disinfectants are applied at prescribed concentrations.

Final Rinse & Refill

The vessel is flushed, refilled, and returned to service.

Chlorination & Disinfection Control

Chlorination is carried out using approved chemicals and controlled dosing.

This ensures:

  • Effective disinfection of internal surfaces

  • Control of residual contamination

  • Compatibility with vessel materials

Contact times and concentrations are managed carefully to ensure effective treatment without damage.

How to Arrange Vessel Cleaning & Chlorination


Initial Enquiry

Contact us to discuss vessel size, location, and system details.

1


Scope Confirmation & Quotation

We confirm access requirements and issue a clear quotation.

2


Scheduled Site Attendance

A qualified engineer carries out the works safely and efficiently.

3


Reporting & Aftercare Guidance

Documentation is issued with guidance on review and maintenance.

4


Audit-Ready Records

On completion, documentation typically includes:

  • Service report detailing works undertaken

  • Inspection findings and observations

  • Chlorination records and dosing information

  • Sampling results (where applicable)

  • Recommendations for ongoing management

All documentation is suitable for audits, inspections, and compliance review.


Who This Service Is For

This service is commonly used by:

  • Facilities and estates managers

  • Property and block managers

  • Commercial landlords

  • Healthcare and education providers

  • Hospitality operators

  • Duty holders responsible for water safety

It supports both operational reliability and regulatory compliance.

Flowsafe Compliance delivers cold water storage vessel cleaning and chlorination with controlled methodology, appropriate chemical use, and clear documentation.

Our focus is on reducing contamination risk, protecting water quality, and supporting ongoing compliance — ensuring storage vessels remain a controlled component of your water system.