We can design a bespoke programme of L8 Monitoring (Legionella Monitoring) to suit our customers individual needs. Below sets out a typical Monthly L8 Monitoring Programme.

Water Outlets

Where possible, the supplying pipework to the areas that are operating above 20°C after 2 minutes of running should be fully insulated. If the pipework is fully insulated or by insulating the pipework it does not reduce the temperatures, continue to flush weekly. Additionally, consideration should be given to remove the outlets.

Cooling Towers

Ensure cooling towers are visually checked daily for excessive drift, especially in highly populated areas. Also check the treatment chemical levels and plant operation.
Weekly/Monthly/Quarterly Legionella monitoring checks should be carried out by trained operatives, preferably by the site water treatment company.

Heating Systems

Whilst it is not necessary to implement continuous measures with respect to the control of Legionellosis during maintenance, testing and commissioning. This system may be the source of respirable aerosols and suitable precautionary measures should be taken.

Record Keeping

Implement a Control and Monitoring system including a Log Book to record all actions.

Annual Review

An Annual Review of L8 services should be in place in order to ensure that lines of communication are present and that the contract is being carried out satisfactory.

A Typical L8 Legionella monitoring programme and Legionella Risk Assessment carried out by Green Water Services would include the below. Also, please visit our Legionella Control page for further information.

Type of Water System L8 Services Frequency
Hot Water Services Samples to be taken from hot water calorifiers, in order to note condition of drain water Annually
Check temperatures in flow & return calorifiers Monthly
Check temperature up to one minute to see if it has reached 50’C In the sentinel taps Monthly
Visual check on internal surfaces of calorifiers for scale and sludge. Check representative taps for the temperature as above on a rotational basis Annually
Cold Water Services Check tank water temperature remote from ball valve and mains temperature at ball valve Six Monthly
Check that temperature is below 20’C after running water for up to two minutes in the sentinel taps Monthly
Visually inspect cold water storage tanks and carry out remedial work where necessary. Check representative taps for temperature as above on a rotational basis Annually
Shower heads Dismantle, clean and descale shower heads and hoses Quarterly or as necessary
Little-used outlets Flush through & purge to drain, or purge to drain immediately before use, without use of aerosols Weekly
Cooling Towers Carry out clean & disinfection Bi-Annually
Pack removal & clean if practicable Annually
Ultrasonic humidifiers/foggers and water misting systems If equipment fitted with UV lights, check to ensure effectiveness of lamp (check to see if within working life) and clean filters Six-monthly or according to manufacturers instructions
Ensure automatic purge of residual water is functioning As part of machinery shut-down
Clean and Disinfect wetted parts As indicated by risk assessment
Sampling for Legionella As indicated by risk assessment
Spray humidifiers, air washer and wet scrubbers Clean and disinfect spray humidifiers/air washers and make up tanks including all wetted surfaces, descaling as necessary Six Monthly
Confirm the operation of non-chemical water treatment if present Weekly
Water softeners Clean and disinfect resin and and brine tank – check with manufacturers what chemicals can be used to disinfect the resin bed As recommended by manufacturer
Emergency showers and eye-wash sprays Flush through and purge to drain Six monthly or more frequently if recommended by manufacturers
Sprinkler and hose reel systems When witnessing tests of sprinkler blow-sown and hose reels, ensure that there is minimum risk of exposure to aerosols. As directed
Lathe and machine tool coolant systems Clean and disinfect storage and distribution system Six-monthly 
Spa baths Water treatment tests Daily
Specialist monitoring, sampling and callibration Monthly
Check filters – sand filters should be back-washed As directed
Horticultural misting systems Clean and disinfect pipework distribution systems, spray heads and make up tanks including all wetted surfaces, descaling as necessary Annually
Dental equipment Drain down and clean At the end of each working day
Car/bus washes Check filtration and treatment systems, clean and disinfect systems See manufacturers instructions
Indoor fountains and water features Clean and disinfect ponds, spray heads and make up tanks including all wetted surfaces, descaling as necessary Interval depending on condition

Please contact us if you require any further information regarding our L8 risk assessements and Legionella monitoring. We are located in Leeds, Croydon, Swadlincote and Burton-on-Trent, but our services are offered nationwide.

Green Water Services are LCA (Legionella Control Association) certified and comply to the HSG 274 guidance.


Water tank cleaning and tank chlorination

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Designing bespoke L8 Monitoring programmes

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First class Legionella control service

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Risk Assessments

Identify and assessing the risk of exposure to legionella bacteria

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A background to Legionella, the potential risks associated with water systems

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