Water Storage Tank Cleaning

Overview

WATER HYGIENE - TANK CLEANING & DISINFECTION

Water Storage Tank Cleaning London. Professional water tank cleaning, chlorination and disinfection services. BS8558 compliant with UKAS laboratory testing. Protect your building's water supply.

Water storage tank cleaning is the professional draining, cleaning, disinfection and recommissioning of cold water storage tanks following BS8558 procedures. Tanks are chlorinated at 50 mg/l minimum free chlorine for a 1-hour contact period, then flushed and refilled. Post-disinfection samples are analysed by UKAS-accredited laboratories. Annual cleaning is recommended under ACoP L8.

• Water Supply (Water Fittings) Regulations 1999

• Hotels & hospitality
• Hospitals & healthcare

• Chlorine Concentration: 50 mg/l minimum (BS8558)
• Contact Period: 1 hour minimum
• Frequency:
  At least annually
• Lab Accreditation: UKAS certified
• Tank Types: GRP, steel, concrete, plastic
• Standard: BS8558:2015

A thorough, documented procedure ensuring your water storage tanks are clean, disinfected, and certified safe.

• Discoloured Water – Brown, yellow, or murky water at outlets indicates sediment or rust contamination.
• Unpleasant Taste or Odour – Unusual taste or smell suggests bacterial contamination or chemical changes.
• Visible Sediment/Biofilm – Sediment, debris, or biofilm visible inside the tank during inspection or at outlets.
• Failed Lab Results – Bacteriological test results exceeding safe limits for Legionella, coliforms, or total viable counts.
• 12+ Months Since Last Clean – Annual cleaning is the minimum recommended frequency.
• Building works near the tank – May introduce dust, debris, or contaminants.

Stored water in tanks and cisterns can become contaminated with sediment, rust, biofilm, and harmful bacteria including Legionella pneumophila. Regular cleaning and disinfection is essential to maintain safe, potable water and comply with ACoP L8 water hygiene regulations.

Our trained engineers follow BS8558 procedures for tank cleaning and chlorination. We drain, clean, inspect, and disinfect your water storage tanks before refilling and testing to confirm bacteriological safety. All work is fully documented with certificates and lab results.

We service all water storage tanks including cold water storage tanks (CWST), hot water calorifiers, header tanks, break tanks, fire suppression tanks, and rainwater harvesting tanks. Whether you have a small loft tank in a residential property or a large sectional GRP tank in a commercial building, we provide the same high standard of service.

Before cleaning, we conduct a thorough inspection of the tank and its installation. This includes checking the structural integrity of the tank body, verifying that the lid is secure, insect-proof, and light-tight, inspecting overflow and vent pipes for screening, checking ball valve operation, verifying insulation condition, and assessing pipework connections. Any defects identified are reported with recommendations for remedial action to bring the installation into compliance with current Water Regulations and WRAS guidelines.

We follow BS8558:2015 procedures for water tank disinfection. After cleaning, the tank is filled and dosed with…