TEL: +44 (0) 845 600 6 300

There are a wide range of potential contaminants which can adversely affect water quality and subsequently pose a significant risk to public health.

Water Testing

These include waterborne disease causing pathogens such as:

  • Cryptosporidium
  • E. coli
  • Staphylococcus Aureus
  • Pseudomonas Aeruginosa
  • Legionella bacteria

These waterborne pathogens can be commonly found in and often colonise engineered water systems such as swimming pools, spa baths, drinking water supplies, domestic and process water systems.

The most notable of the waterborne pathogens is Legionella bacteria. Found naturally in soil and water courses, this bacterium is the causative agent of Legionnaires Disease, a progressive and potentially fatal form of pneumonia whereby infection is caused by the inhalation of contaminated water droplets. Sources of the disease are commonly associated with domestic hot and cold water systems and cooling towers, resulting in approximately 250 deaths per annum in the UK.

Pseudomonas Aeruginosa, also found naturally in soil and water courses is becoming increasingly recognised as emerging opportunistic waterborne pathogen and represents a significant risk of fatal infection in Neo Natal and other augmented care facilities within the healthcare sector. The Health Protection Agency has recorded in the region of 3,700 to 4,000 cases per year in the UK.

Both Legionella and Pseduomonas bacteria can proliferate in water systems that are inadequately designed and/or maintained which can result in the occurrence of stagnant water and contamination with organic matter in the form of scale, rust, bio films and sedimentary deposits.

Your Responsibilities and the Law

Current Legislation

  • Health & Safety Act 1974
  • COSHH Regulations 2002
  • Water Supply (Water Fittings) Regulations 1999
  • Water Supply (Water Quality) Regulations 1999

Guidance and Technical Standards

The HSE Approved Code of Practice L8 (4th Edition)

  • Technical Guidance HSG 274 which is in 3 parts:
    HSG 274 Part 1:- The control of legionella bacteria in evaporative cooling systems
    HSG 274 Part 2:- The control of legionella bacteria in hot and cold water systems
    HSG 274 Part 3:- The control of legionella bacteria in other risk systems
  • HTM 04-01 gives advice and guidance on the legal requirements, design applications, maintenance and operation of hot and cold water supply, storage and distribution systems in all types of healthcare premises and has now been revised into 3 parts:
    A, B and C. In addition, there is supplemental document which focuses on performance specification: Thermostatic Mixing Valves (TMV).

    Part A: covers the design, installation and commissioning.
    Part B: covers operational management.
    Part C: focuses on specific additional measures that should be taken to control and minimise the risk of Pseudomonas aeruginosa in augmented care units.

  • BS 8580:2010 Water quality. Risk assessments for Legionella control

The Approved Code of Practice (ACoP L8) ‘The Control of Legionella in Water Systems’ published by the HSC gives detailed guidance to building operators and owners on how to manage and control Legionella bacteria. As a building owner or operator your obligations are as follows;

  • Identify and assess all sources of risk
  • Prepare a written scheme for preventing or controlling the risk
  • Appoint a person to be managerially responsible
  • Implement and manage the precautions
  • Keep records of the precautions implemented

Failure to comply with this legislation and/or any resultant incident or outbreak of the disease can lead to prosecution and criminal conviction.


GRAHAM Environmental Services provide a total water treatment control solution for potable, industrial and waste waters. This includes the prevention of potentially fatal waterborne pathogens, the prevention of scale, corrosion and the maintenance of optimum performance conditions in industrial water systems and the control of waste waters for the protection of the environment.

Our micro biological control services include the installation and maintenance of bespoke water treatment solutions designed to prevent infection from water borne pathogens such as Legionella and Pseudomonas bacteria in a wide range of water systems e.g. domestic hot and cold water systems, drinking water systems, ornamental water features, spa baths and swimming pools humidification systems and cooling towers.

Our industrial water service includes the installation, maintenance and testing of bespoke scale and corrosion control solutions to ensure the safe and efficient operation of plant and equipment critical such as steam boilers, cooling towers, humidification, water softening and closed loop heating and cooling systems.

Our Waste Water service includes the installation, maintenance and testing of pumping, filtration and waste water treatment systems such as interceptors, pH correction and chemical treatment plant to enable clients to optimise and re-use waste waters while also ensuring compliance with strict effluent discharge consent limits.


Current legislation is governed by the:

  • Health & Safety Act 1974
  • COSHH Regulations 2002
  • Environment Act 1995

Failure to comply with this legislation and/or any resultant incident or outbreak of the disease can lead to prosecution and criminal conviction.