JOIN US FOR RESPONSIBLE PERSON TRAINING – 25th APRIL 2023

15 March 2023
Legionella control, Training

Due to recent customer feedback, we have decided to host an additional responsible person training course at our head office in Thornbury on Tuesday 25th April 2023.

Who is the responsible person for legionella?

The responsible person for the control of legionella bacteria is a competent individual that is appointed by the duty holder to take day-to-day responsibility for their organisation’s building.

The course is designed to give site staff a practical understanding of legionnaires’ disease and provide delegates with the confidence, understanding, and knowledge to manage their sites effectively regarding legionella control.

Topics:

Introduction
Background to the disease
Legislation – Health and Safety Law
Identification and risk assessment
Legionella outbreak analysis
Prevention and control
Record keeping / logbook
Who is responsible?
Risk systems
Overview of approved methods of control
The role of the responsible person
Q&A
Test

Each delegate will also receive a certificate for completing the training and course notes to take away with them.

If you would like to join us or have any questions, then please do not hesitate to get in touch.

Call 01454 417 920 Email sales@dantek.co.uk

Legionella control FAQs

14 March 2023
Legionella control, Legionella Risk Assessment, Legionnaires disease

Legionella control FAQs

What is Legionnaires’ Disease?

Legionella control FAQs – Legionnaires’ disease is a potentially fatal pneumonia caused by bacteria called Legionella pneumophila. Exposure to the Legionella bacterium can happen when you inhale contaminated mist or breathe in droplets of water contaminated by the bacteria.

There are many ways to prevent legionnaires’ disease, including routine inspection, temperature monitoring, and maintenance of cooling towers, water tanks, and plumbing systems.

Legionella control FAQs

Who can catch Legionnaires’ disease?

Everyone is potentially susceptible to infection, but some people are at a higher risk e.g. those over 45 years of age, smokers and heavy drinkers, those suffering from chronic respiratory or kidney disease, and people whose immune system is impaired. Symptoms of Legionnaires’ disease may include fever, chills, headache, muscle aches, and tiredness.

Where is legionella found?

Legionella bacteria (legionella pneumophila) are common in natural water courses such as rivers and ponds. Since legionella is widespread in the environment, they may contaminate and grow in man-made water systems such as cooling towers and hot and cold-water services. Spa baths, Jacuzzi’s and hot tubs also provide a potential breeding ground for legionella bacteria as they provide optimum conditions for the bacteria to grow and multiply to sufficient numbers for a system to be colonised.

The bacteria thrives at temperatures between 20 and 45 degrees, particularly if there is a supply of nutrients such as rust, sludge, scale, algae, and other bacteria.

The risk of legionnaires’ disease is increased if water droplets are produced and dispersed in aerosol form for example, in a shower or spa bath.

It is possible to reduce the risk by removing exposure to water droplets and aerosol and by removing the nutrients on which the legionella bacteria feed. This can be done by keeping water systems clean by cleaning and disinfecting cold water storage tanks and showerheads.

How do I the with latest HSE guidance?

The current HSE guidance documents for the legionella control are the L8 Approved Code of Practice and the HSG274 Legionella technical guidance.

The first thing to do is a Legionella Risk Assessment, to consider the risks from legionella that may affect your staff or members of the public, and then take suitable precautions to control and prevent the risk.

Is it a legal requirement to have a legionella risk assessment?

There is a legal duty for employers and landlords to consider the risk legionella bacteria in buildings under your control or management. You must identify and assess the source of risk i.e carry out a legionella risk assessment. Manage the risk. Put in place measures to control or prevent any risks. Keep good records to prove you are taking the appropriate action and to show to external agencies you are following the HSE guidance for legionella control.

What can be used to control legionella bacteria?

Temperature is usually used in hot and cold-water systems, by keeping hot water at above 60 degrees and ensuring it is above 50 degrees at the outlets. Cold water should be kept below 20°c.

There are other methods that can be used if the temperature is not an option, such as copper/silver ionisation and chlorine dioxide. Cooling towers/systems are often treated with biocides. There are other treatment strategies available such as ultraviolet (UV) irradiation.

Do I need to take Legionella samples?

This depends on the risk assessment and control methods being used. In some circumstances it will be required, however, it needs to be done at a UKAS accredited laboratory and will require specialist help. Dantek can provide advice on sample frequency and locations, and what to do if Legionella is detected.

Routine Legionella testing however is not a requirement in domestic hot and cold-water systems. It would only be recommended in hot and cold-water systems due to exceptional circumstances where typical control measures are not working. A full legionella risk assessment would identify the best course of action to reduce the risk.

What will a legionella risk assessment cost?

The cost will depend on what assets are on your site and how many buildings. For large sites or multi-site portfolios a site visit by one of our team is the best way to establish exactly how much a risk assessment will cost. However, we are often able to provide a guide price if you know roughly the size and type of building. For example, how many floors, what it is used for, whether there are any cold-water storage tanks, number of calorifiers and if there are any cooling towers. An asset register of plant and equipment can be very helpful in determining how long the on-site assessment will take and therefore the cost.

One of our team would be happy to talk through on the phone any requirements and enquiries.

What do Landlords need to do about Legionella control?

The law clearly states if you are a Landlord and rent out your property then you have a duty under Health and Safety Law to consider the risk posed by Legionella bacteria. The ACoP L8 (3rd edition) also states Landlords must assess the risk from exposure to legionella to their tenants.

In most cases the risk assessment is simple and straight forward, however for more complex systems or if the Landlord is not able / competent to carry out the assessment they can use a specialist Water Treatment Company like Dantek, to carry out the legionella risk assessments and advise on any actions required.

A simple risk assessment will identify if a system is considered a low legionella risk and no further actions are required other than to review the assessment regularly in case anything changes which may affect the risk for example the water system in the building changes.

Examples of low risk systems include;

A small building occupied by people not considered at risk from legionella bacteria.
Where there is enough usage of water per day to ensure the entire system is changed at least once.
Mains fed cold water supplies the entire system, so there are no cold-water storage tanks.
Hot water is fed from combi boilers/ instantaneous heaters or low volume water heater where the hot water is supplied at no less than 50°c
The only outlets at the property are toilets and wash hand basins with no showers present on site.

http://www.hse.gov.uk/legionnaires/legionella-landlords-responsibilities.htm

What is meant by the term water system?

A water system includes all plant and equipment for example all the pipework, pumps, cold water storage tanks, valves, showers, water softeners, chillers, heat exchangers, cooling towers, calorifiers, little used outlets and dead legs, humidifiers, air washes, car washes, indoor fountains and water features.

How do I choose a water hygiene company?

Choosing a water hygiene company with the knowledge and skills to manage and control the risk of legionnaires’ disease at your site is made easier with the help of the Legionella Control Association. The LCA hold a register of members who have met their requirements on an annual basis and have passed their annual audit of systems.

A key factor should be the training of site staff to carry out water hygiene work competently. A provider will be able to demonstrate how their employees are trained and audited to ensure continual compliance with current standards.

The LCA code of conduct sets out the standard of service a client should expect from a water hygiene provider. The code requires a Service Provider to set up an appropriate management system for the control of legionella complying with the latest HSE guidance for the control of legionella bacteria.

How many cases of Legionnaires Disease were there last year?

The figures from 2021 – 2022 are not available yet however between 1^st January – 31^st October 2020 according to a report by Public Health England, there were 254 cases of Legionellosis cases reported in England and Wales.

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/948028/Legionella_Mthly_Rprt-Aggregate_rprt_Jan-Oct20.pdf

If you have any questions in regards to Legionella control FAQs or any other questions, please do not hesitate to call us on 01454 417 920

How much should my Legionella risk assessment cost?

1 February 2023
Legionella control, Legionella Risk Assessment, Legionnaires disease

Legionella risk assessments: We are all faced with the current climbing inflation across products and services that we require. Compliance can be a huge concern, and we all want the best value without compromising the quality and level of service we receive from our suppliers.

This blog will hopefully shed some light on how to get a fair price for your legionella risk assessment and how you can compare your quotes against each other, allowing you to decide what you are confident with.

As a starting point, visit the legionella control association website, https://www.legionellacontrol.org.uk. All approved LCA Members must provide a range of products and services for the control of legionella bacteria in water systems. They would have also demonstrated that they have complied with the LCA Code of Conduct and LCA Service Standards and are committed to helping their customers prevent legionellosis and keep their water systems safe. The website allows you to search a directory of approved contractors within your area.

How much will a Legionella risk assessment cost?

A Legionella risk assessment is a consultancy service that will require a physical visit to your site, and follow-on report writing time to produce your document. For your chosen contractor, to provide an accurate quotation for your site, they will first need to establish how long the report will take to complete. Once this is figured out, multiply the time by a day rate, and bingo! A price.

Estimating how long a survey will take is a fine art, but there are some variables

Ask what the standard day rate is for a surveyor, but be careful, some include administration time some don’t. Ask the question.

Geography?

Where is the site? Or where are the sites? Travel time is working time, and you pay for it. Ideally, you’ll use someone local if you have a big single site or cluster of buildings, but sometimes this isn’t practical. If you have multiple sites, you can get some great reductions from contractors out of your area allowing you to compare multiple quotes. Also, these are fun for the surveyors. Here at Dantek, we assess nationwide contracts including retail, care homes, and even memorial parks. The attending assessors have a great time traveling across the country.

Once you understand the logistics of getting the surveyor to and from the site, how long will they be there? The two big factors in this debate are what water services do you have? And how hard will they look?

Water Assets and system complexity?

I have seen many different approaches to convey what is on-site, varying from line-item asset registers, and copies of the previous risk assessments to lists of the gross internal areas of properties. The surveyor’s point of view generally stems from, how difficult is this system going to be for me to understand and how many assets will I have to survey. For example, a large modern office block could seem like a big beast but may only have a plant room in the basement, a single wet riser by the lift shaft, toilets and kitchenettes on each floor plus a couple of cleaners cupboards, simple. In contrast, a stately home converted to halls of residence can contain multiple systems and a dog’s breakfast of assets and pipework that would reduce the finest to tears.

Legionella risk assessment – Top tip: Give what information you have, including building use, number of storeys, and location

The industry refers to all hot and cold-water systems for toilets, sinks, showers etc. as domestic systems. These are almost universally included in risk assessments, but what about cooling towers, industrial uses of water, humidifiers, water features, and medical equipment? The survey should cover all water assets in one way or another.

In the industry, we benefit from huge amounts of experience so in talking about your buildings we build a picture of what we are dealing with, by being as honest and open as you can get the most realistic estimate possible.

Begin with the end in mind

The Legionella risk assessment certainly ticks a box for compliance but if done well is a tremendous source of information regarding your water assets. Think about practical outputs, for example, how do you expect to see non-compliances reported? Do you want them separated in a way you could pass to a mechanical contractor or your onsite plumbing team?

Talking to your suppliers about Legionella control in a wider context beyond the risk assessment can pay dividends in understanding how the document could support your efforts to implement a successful control regime later on. You’ll be amazed at what you can get for free during the risk assessment process just by asking, consider;

Do you want accurate schematics drawn in AutoCAD?
Would it be handy if the pipe runs are overlaid on your existing building schematics?
Would you like an electronic copy of the asset register in excel?
Do you want the assets in an electronic logbook?

At the end of the day

All Legionella risk assessment quotes have at their core have an estimation of how long the survey is going to take and the report to produce, as a buyer you should understand and be comfortable that your supplier will do a job that is acceptable to you in the time they have quoted. Industry rates vary from £350.00 to £600.00 per day for a qualified Legionella risk assessor as a guideline.

There are many decent companies out there, and all of them should welcome sensible discussions on the big question – how long is it going to take?

Dantek is a specialist provider of Legionella control services including Legionella risk assessments.

If you have any further questions or would like to speak to one of our sales team, please call us on 01454 417920 or e-mail sales@dantek.co.uk

Keep up to date with our news on Linked in.

https://www.linkedin.com/company/dantek-environmental-services-uk-ltd

Optimizing Legionella Control: The Power of Rental Chlorine Dioxide Units

19 January 2023
Legionella control, Mechanical services, Water Treatment

Rental Chlorine dioxide units

Ensure proper Legionella control in your property with the effective solution of a rental chlorine dioxide unit. When faced with Legionella control issues, this rental unit becomes a powerful tool in your armory, offering numerous benefits.

Rapid Deployment: Rental units can be swiftly deployed, providing a quick response to control issues while other maintenance works are underway.
Cost Savings: Opting for a rental unit eliminates the need for significant capital expenses, making it a cost-effective solution for achieving and maintaining Legionella control.
Safe On-Site Generation: The on-site generation of Chlorine Dioxide ensures safety while effectively combating Legionella, contributing to a secure environment.
Legislative Compliance: Achieve and maintain legislative compliance for Legionella control, meeting the required standards for a safe and hygienic property.
Reduced Running Costs: Experience reduced running costs, especially in terms of hot water temperatures (excluding healthcare), contributing to efficient and economical operation.
Maximum Performance: Benefit from maximum performance through a bespoke system design, tailored to address specific Legionella control needs.
Professional Integration: Ensure smooth integration with the expertise of trained installation and service engineers, guaranteeing optimal performance.
High Purity: The chlorine dioxide generated is of high purity, ensuring its effectiveness in Legionella control.
Compliance with Standards: The chemical regimes used are compliant with BS EN 12671:2009, adhering to industry standards for water treatment.

Dantek provides a comprehensive solution, offering a one-stop shop for the provision, installation, and maintenance of chlorine dioxide units. For more information on rental chlorine dioxide unit, contact Dantek at 01454 417 920 or via email at sales@dantek.co.uk. Trust #teamdantek for expert guidance in chlorine dioxide, Legionella control, water treatment, and more. #chlorinedioxide #legionella #watertreatment #legionellacontrol https://dantekenvironmental.co.uk/contact-us/

Join us for a responsible person training course at our head office in Thornbury

17 November 2022
Legionella control, Legionnaires disease, Training

Due to recent customer feedback, we have decided to host the responsible person training course at our head office in Thornbury on Wednesday 18th January 2023.

Who is the responsible person for legionella?

The responsible person for the control of legionella bacteria is a competent individual that is appointed by the duty holder to take day-to-day responsibility for their organisation’s building.

Topics:

Introduction
Background to the disease
Legislation – Health and Safety Law
Identification and risk assessment
Legionella outbreak analysis
Prevention and control
Record keeping / logbook
Who is responsible?
Risk systems
Overview of approved methods of control
The role of the responsible person
Q&A
Test

Each delegate will also receive a certificate for completing the training and course notes to take away with them.

If you would like to join us or have any questions, then please do not hesitate to get in touch.

Call 01454 417 920 Email sales@dantek.co.uk

Water hygiene jobs at Dantek

16 May 2022
Legionella control, Recruitment

This is an excellent opportunity for an experienced Water Hygiene Technician who is looking to progress within an expert team of water treatment professionals. We offer continued technical training, overtime and most importantly a good work-life balance.

The ideal candidate will have at least 2 years experience of in water tank and system cleaning and disinfection, temperature monitoring, showerhead cleaning, sampling, BS8558 flushing and water softener service.

In return, you will receive excellent training and the opportunity to develop your career with a company that values technical expertise and practical skills.

We are looking for candidates with the following:

· 2 years + experience in Water Hygiene / Legionella control industry

· In-depth understanding of the ACoP L8 and HSG274

· Enjoy physical work, lifting and carrying

· GCSE Maths and English grade C and above

· Excellent record keeping and attention to detail

· Full current UK driving Licence

· Based in or around Bristol

Day to day the role includes:

Coldwater storage tank cleaning and disinfection
Temperature Monitoring
Showerhead cleaning and disinfection
Tank inspections
Taking water samples
Calorifier inspections
TMV servicing
LTHW
BS8558 disinfection
Water softener service

It also includes the following more general tasks:

Preparing and completing job sheets and procedure logs
Being responsible for tools and equipment including PPE
Driving to customer sites (circa 25,000 business miles per annum)
Completing on-site logbooks
Maintaining a professional and tidy appearance, both personally and with equipment and van

Package

· Competitive salary depending on experience

· 28 days holiday per annum including bank holidays, accruing one extra day per year from date of second anniversary to a maximum of 33 days.

· Profit related pay bonus scheme

· Sabbatical scheme

· Generous weekend and working away overtime payments

· Sick pay

· Pension

· Private use of company vehicle (Van)

· Full technical training and on-going career progression

Hours – Monday to Friday 40 hours per week

Location – Working at our customer sites, we are looking for people who are flexible and adaptable as the location will change each day. There are also occasions when you will be required to stay away overnight for which overtime is paid.

You will be managed by our fantastic operations team based at our offices in Thornbury.

About Dantek

Dantek is a Thornbury based Water Treatment service company that has built up an enviable reputation since 2003.
Our aim is to ensure our customers comply with the ACOP L8 and HSG274 while managing the water on their sites in the most efficient, safe and cost-effective way possible to reduce the risk of legionella bacteria causing an outbreak of Legionnaires’ disease.

You will be working with a company that believes Legionnaires’ disease is essentially man-made and completely preventable, and people should not be put at risk of contracting this potentially fatal form of pneumonia.

You will have the comfort in knowing the services offered are based on the decades of knowledge held in the company under the steady leadership of Dan Collins (MD) and Martin Kingdon (Technical Director) who are two of the best Legionella professionals in the UK.

You will be part of an excellent, dedicated team of fully trained Water Hygiene Technicians, Legionella Risk Assessors, and plumbers with the support of our capable and experienced office-based team.

Do get in touch to find out more about the role by emailing jobs@dantek.co.uk to request an application form.

Coronavirus And Legionella Control Testing

Advice for Legionella control during COVID-19 lockdown

16 April 2020
Legionella control, Legionella control during coronavirus crisis, Legionnaires disease

The coronavirus is placing new challenges on our duty of care to minimise the risks from Legionella in our water systems on-site. Further restrictions on movement of people made last night will lead to further reductions in building occupancy increasing the risk of colonisation by Legionella.

We have been advised by the LCA (Legionella control association) & the HSE that all employers still have a duty of care to manage the risks from Legionella. The LCA website states:

“While controls in place may need to be adapted to changing circumstances, duty holders must still be able to demonstrate control of risk to a reasonably practicable level.”

Loss of manpower due to social-distancing and self-isolation of staff could make this difficult. Our objective should be to deploy the resources we have in the best way to achieve the greatest reductions in the overall risk of Legionella becoming established in a building.

Below is a list of actions to be taken which will have the biggest impact in reducing risk in both hot & cold domestic systems and open evaporative cooling tower systems.

2. Domestic Hot & cold water systems

Buildings have already seen a significant decline in building occupancy and this is only likely to become worse. Water systems with dramatically reduced usage can quickly become hazardous if steps are not taken to mitigate this.

It is imperative that:

Flushing regimes are implemented whilst still in even partial operation to keep them from stagnating.
Where a flushing regime cannot be maintained, systems should be formally decommissioned and will need to be recommissioned before being brought back into use.

Actions required to keep domestic water systems safe

Increased flushing regime & monitoring of turnover of water – Carry out building wide flushing of all domestic outlets on a weekly basis as a minimum. (2 minutes of flushing at each outlet on both hot & cold outlets)
Take steps to measure water turnover within the building’s water systems. Estimated water usage can be obtained by taking water meter readings or performing drop testing of tanks.
The above usage information should be used to establish the suitability of the current flushing regime.
Reduce volumes of stored water where possible or as indicated by point 2 above. i.e. Where there are tanks/calorifiers balanced together consider taking some offline.
Increased Legionella sampling – Legionella sampling should be considered to check the effectiveness of the above controls. Contact Dantek for further advice.
Where water is known to be stagnating consider leaving water systems charged with a Hydrogen peroxide and silver biocide (Such as Sanosil) to inhibit microbial growth.
Systems that have been left without sufficient controls will need to be re-commissioned before being brought back into public use. Further guidance regarding re-commissioning is below.

3. Re-commissioning of domestic systems

Short Term – less than 4 weeks

Buildings left unoccupied for less than 4 weeks without the above controls in place.

℃.
℃ & 50℃ respectively.

Long Term – More than 4 weeks

Buildings left unoccupied for over 4 weeks without the above controls in place.

Inspect cold water storage tanks for internal condition and clean if necessary
Flush inlet pipework to cold water storage tanks and check for operation of all float valves.
Open isolation valves on hot water calorifiers.
Reinstate and check operation of secondary HWS circulation pumps.
Open isolation valves on cold water storage tanks and any others which have been isolated as part of the shutdown.
Bring booster sets back online and check they are primed.
Carry out a chemical disinfection of the incoming mains, cold water storage tanks, calorifiers and all associated distribution pipework to all outlets. Dantek Disinfection procedures should be followed.
Switch over any duty/standby pumps on the HWS secondary system.
3 days after the disinfection has been completed, take a representative number of samples and analyse for TVCC and Legionella.

4. Actions to reduce the risks – Open Evaporative Cooling systems

Maintain daily and weekly checks.

Maintain the daily and weekly checks as an absolute minimum to ensure the tower is operating safely. This includes checking the following:
- Dosage and control equipment is on and functioning correctly.
- Adequate chemical stocks are in place
- Control of primary Conductivity is satisfactory
- Control of primary pH is satisfactory
- Dipslide results remain satisfactory
- Visual condition of the towers remains satisfactory.
Dantek will support where possible the maintenance of weekly cooling tower testing. The cooling tower should be shut down if weekly testing can no longer be completed for any reason or if there is a problem that can’t be solved immediately by the weekly testing.
Consider increasing site stock of chemical to mitigate any future delivery issues.
If plant is controlled automatically and there is a risk of reduced demand steps to maintain circulation at all time should be taken.

5. Recommissioning of open evaporative cooling towers shut down:

Cooling towers shut down for less than 1 week

Visually inspect tower sumps, packing and drift and clean if required.
Reinstate dosage and control equipment and check operation of chemical dosage pumps.
Open any isolation valves and bring circulation pumps back online
Check water quality (pH, TDS, Bromine/Chlorine levels) and adjusted so that it is within satisfactory limits.
Once up and running take a dipslide and incubate.

Cooling towers shut down for more than 1 week and less than 4 weeks

The below should be carried out with w water treatment Engineer in attendance.
Visually inspect tower sumps, packing and drift and clean if required.
Reinstate dosage and control equipment and check operation of chemical dosage pumps.
Check controller settings ad operation.
Open any isolation valves and bring circulation pumps back online
Check water quality (pH, TDS, Bromine/Chlorine levels) and adjusted so that it is within satisfactory limits.
Once up and running take a dipslide and Legionella sample.

Cooling towers shut down for more than 4 weeks

Carry out full cleaning and disinfection of cooling towers systems as per Dantek Method statement
Reinstate dosage and control equipment and check operation of chemical dosage pumps.
Open any isolation valves and bring circulation pumps back online
Check water quality (pH, TDS, Bromine/Chlorine levels) and adjusted so that it is within satisfactory limits.
Once up and running take a dipslide and incubate.

LTHW And Chilled Pipework Connections To An Office FCU

Closed hot and cold water circulating systems within large buildings

4 February 2020
Legionella control, Water Treatment

Closed hot and cold water circulating systems within large buildings : Controlling the office environment is paramount to maintaining a happy and productive workforce. One important factor is the ability of the building’s systems to control the temperature of the workspace.

Most of the time, these hidden heroes work away in the background, keeping the temperature ‘just right’, like Goldilocks’ porridge. Happy days!

But when a hot and cold-water circulating system fails, everybody notices. The complaints come pouring in and solutions are needed fast; a loss of control of temperature within the working space is a leading cause for complaints and quickly becomes a major priority for the building management, so it makes sense to have robust maintenance regimes in place.

Circulating hot or cold-water systems

A common, cost-effective and efficient way of achieving a comfortable temperature year-round is by maintaining circulating hot and cold-water systems, usually in the form of a centralised LTHW (low temperature hot water system), and a chilled water system. LTHW and chilled systems are circulated through the office areas where they often feed fan coil units, providing the heat exchange location.

What is a Fan Coil Unit? (The technical bit)

Fan coil units are essentially a box mounted into the ceiling void. As well as containing a fan, the unit also has two heat exchange surfaces, one connected to the chilled system and the other to the LTHW system.

Air is moved by the fan from the ceiling void across either the heating or cooling coil before being distributed back into the office areas via multiple ducted air supplies.

The rate at which the heat can be added or removed from the environment is proportional to the difference in temperature at the heat exchange surface and the flow rate of air across it. Large temperature differences at the heat exchange surface, can achieve big changes in the temperature of air flowing across it. Likewise, the temperature differences at the heat exchanger surface, on the water side, are directly proportional to the temperature that the water system is maintained at and the rate of flow through the heat exchanger.

As with most plant in large commercial buildings, these water systems can be highly complex with a large variety of flow control devices. Some control flow locally, using temperature or pressure and others are connected to the building’s BMS (Building Management System).

When the system fails

Like any complex system, these units can fail from time to time. Water quality is often assumed to be the culprit, although there can be other causes (poor design, lack of maintenance or inadequate commissioning, for example). It’s true that water quality can deteriorate over time, leading to reductions in flow within the system and reduced temperature control in the work environment. That’s why on-going prophylactic water treatment maintenance of such systems is essential.

If your system fails and water quality is determined to be the cause, you will want a specialist water treatment contractor such as Dantek to flush the system. In my next post, I will explain the process and offer some advice on the best ways to manage it and get your building’s ambient temperature back to ‘just right’!

Please contact Dantek for further information on how we can help guide you through a successful flushing project within your building.

Temperature control and legionella bacteria prevention

20 November 2019
Legionella control

What is legionella bacteria?

Legionella is a bacteria found naturally in water such as rivers and ponds. Given favourable conditions and nutrients to grow, legionella bacteria can colonise man-made water systems. For an outbreak of legionniares’ disease to occur the bacteria must be disseminated in aerosol form and inhaled by a susceptible person. Legionnaires’ disease is a man-made problem and one which is preventable by following the latest HSE guidance.

What temperature kills legionella bacteria?

As with all living things the conditions need to be right for survival and growth to occur and with legionella bacteria temperature is one of the key factors in determining the correct conditions. There are no known cases of Legionnaires’ disease from natural watercourses such as rivers or streams which in the Uk are typically less than 20°c.
In man-made systems, legionella bacteria require the right conditions to grow and multiply and a vital condition is the temperature must be between 20°c and 45°c. If the temperature is below 20°c legionella bacteria will lie dormant and when temperatures are above 60°c the bacteria is killed off.

How hot does water have to be to control legionella bacteria?

Temperature is the most straight forward, cheapest and the most common way in which Legionella bacteria is controlled in domestic hot and cold-water systems.

Hot water must be stored in hot water cylinders or calorifiers at 60°C or higher to ensure if legionella bacteria were to enter a given water system it would be killed off and not be able to grow and colonise a system.

Hot water should achieve no less than 50°C (55° in health care premises) at the outlets within one minute of running the tap/outlet.

The monthly check of the temperature on the flow of a calorifier must be 60°c. The temperature of the return pipe must also reach no less than 50°c to ensure the entire system temperature will prevent legionella bacteria from growing.

Direct fired (gas) water heaters are considered to be a lower risk as the volume of stored water is often less than in calorifiers and the temperature is distributed more evenly in the cylinder with less stratification.

How hot do point of use water heaters need to be to control legionella?

POU’s with storage of no more than 15 litres must be checked to ensure they operate between 50° and 60°c. It is important to ensure all POU’s have a high turnover of water so it is not providing a stagnant area of the system.

Can legionella survive in cold water?

Cold water should be stored and distributed at below 20°C within 2 minutes of running the cold taps. Ensuring water is stored at below the level in which legionella bacteria can grow, ensures the system is kept safe and reduces the risk of legionnaires’ disease. At temperatures below 20°, c legionella bacteria will lie dormant.

How to check water temperatures for legionella control?

In non-circulating systems the temperature must be taken at the sentinel outlets monthly which are those nearest and furthest from the calorifier and also at long pipe runs to ensure temperatures are above 50°c.

In addition to the above for circulating systems the temperature at the return pipework needs to be recorded to ensure the entire system is achieving 50°c minimum.

Temperatures also need to be recorded on subordinate loops on a quarterly basis, it is important to check subordinate loops as there can often be an issue on a long leg, where it takes more than a minute for temperatures to rise, therefore providing a potential legionella risk.

A legionella risk assessment will set out the location where temperatures checks need to take place and will ensure high-risk areas are monitored for example where there are high-risk users.

Where can temperature issues occur within a hot and cold water system?

There are specific areas within hot and cold water systems were temperature can be a risk and allow legionella bacteria can grow. These include the bottom of calorifiers/water storage vessels where the incoming cold water enters and mixes with the stored hot water reducing the temperature of the water at the bottom of the vessel where debris and sediment collect. A shunt pump can be installed to reduce the risk of stratification and uneven temperature within the calorfier.

Dead legs in pipework, little used outlets can also provide favourable temperature conditions for legionella bacteria as the stagnated water temperature can rise to above 20°C. Regular weekly flushing of little used outlets can reduce the risk of legionella bacteria growing in the system.

If the incoming mains temperature is above 20°c or there are areas within the cold water system which are exposed to heat gain this can also lead to the right conditions for legionella bacteria to grow. Insulating pipework to reduce the risk of thermal gain will reduce the risk of the water temperature increasing.

What temperatures checks are needed on cold water storage tanks

The incoming mains and the stored water in the tank need to be measured to make sure they are both less than 20°C. Every 6 months the temperature must be taken at the ball-valve and a record kept of the results. It is good practice to carry this out both in summer and winter to ensure the stored water remains within the guidelines even when the ambient temperature is higher in summer months. The average groundwater temperature in the UK is 12°c however during particularly warm summers the mains water can be above the desired 20°c, if this were to occur then the risk assessment would need to be reviewed and control measures put in place as appropriate.

Cold water storage tanks must be well insulated to protect the stored water from changes in the ambient air temperature.

The sentinel (nearest and furthest) cold water outlets for example taps and showers need to be checked on a monthly basis to check they are less than 20°c after running the outlet for 2 minutes. It is also important to check a representative sample of taps on a rotational basis this helps to make sure the supply of cold water remains at a temperature that will not support the growth of legionella bacteria. A monitoring contract will establish the schedule of representative taps to ensure the entire system will be checked over a specified period of time.

What sort of thermometers are used for legionella monitoring?

Surface probe thermometers are used to record the temperature of water within pipework and a submersible probe used for recording the temperature of running water from outlets.

How do TMV’s affect temperature monitoring for legionella control?

Thermostatic mixer valves blend hot and cold water to produce water at the outlet which avoids the risk of scalding this is usually between 38°c and 46°c. It is important to ensure the pipework downstream of the TMV is as short as possible to reduce the legionella risk. A surface probe thermometer must be used to ensure the temperature of the hot water is at least 50°c prior to the TMV.

For recording temperatures can I use a paper based or electronic logbook?

It is vital to keep good records of all temperature monitoring. It will identify where and if there are any issues and also an indication of trends. A paper based logbook is adequate however we encourage customers to adopt our cloud based electronic log book as there is immediate reporting functionality to allow smart decisions and prompt actions to be taken. The electronic log book is available for free to all our contract customers. Click the following link for more information on monitoring contracts

Can temperature monitoring for legionella control be carried out in-house?

Yes, however, the person taking the temperatures must be trained and competent to carry out the tasks and must understand the importance and significance of the findings. Correct records must be held to allow trends and patterns to be assessed if necessary. Dantek offer site specific training to allow individuals to carry out temperature monitoring. This practical site specific training in legionella control can help customers to reduce costs while also ensuring the legionella risk is controlled.

For more information

Managing legionella in hot and cold water systems

Legionella control case study at a large boarding school

9 October 2019
Legionella control, Legionella Risk Assessment, Legionnaires disease, Tank cleaning and disinfection, Water Treatment

Dantek have provided legionella control services to Marlborough College for a number of years, below is a case study about how we work together to ensure ACoP L8 compliance and the safety of the students and staff.

Since its establishment in 1843 by a group of Church of England clergymen at the Castle Inn at Marlborough, Marlborough College has never been frightened of change.

In its recent history, numerous academic initiatives have been fostered at the College including, Business Studies, SMP Maths, Combined Science, Pre-U examination syllabuses and the teaching of Arabic and Chinese. In 1968 Marlborough was one of the first of the traditional boys’ boarding schools to admit girls into the Sixth Form.

In 1989, the College became fully co-educational with the admission of girls into the Lower School and with the establishment of the first of the all-girl boarding houses.

Today the College caters for 936 pupils (of which just over 40% are girls) and the great majority of whom (98%) are boarders. The remaining four “Out-College” houses accommodate 13-16-year-old boys, plus a mixed Sixth Form of both girls and boys.

School size: 201-500 employees

Based at: Marlborough, Wiltshire

The support Dantek provides

As a school, Marlborough College provides care for a large group of students most of which board on site, this means that they must adhere to strict health and safety guidelines. One of these areas is the need to protect students and staff from potential Legionella infection. Dantek has worked with the school for many years ensuring they comply with all regulations thus providing a safe environment for their students to thrive in.

As part of their on-going activity, Dantek engineers monitor the water quality, carry out remedial work and run regular testing and Legionella risk assessments. The College compliance team benefit from using Dantek’s electronic logbook which saves time and helps them keep on top of the various requirements. Dantek has provided a long-standing service to the college and act as part of their team which supports the quality of environment and interaction required by the College.

What does the client say?

We caught up with Kelvin Neale, M&E and Energy Manager at Marlborough College to find out how he views working with Dantek;

How did you hear of Dantek?

I have worked at Marlborough College for 8 months so Dantek were already in place when I joined. However, I did work with Dantek through another employer. I can certainly say that Dantek are known for their sound reputation in the industry.

What are the most important elements you look for in a contractor?

The most important elements for me are timely communication and a conscientious, effective manner. Due to the nature of the work Dantek provide, I also look for clear paperwork and accurate paper trial. We do consider the price, but it is not the only factor. When it comes to compliance, we must make sure we are choosing the right supplier who has the knowledge and systems which we require.

What do you like about working with Dantek?

I am very happy with their work in general. Three things stand up for me in particular:

All engineers are professionals and knowledgeable, DBS checked and employed directly. They will always provide a service that goes beyond their contractual requirements and nothing we ask is ever an issue.
The level of knowledge and expertise the company holds is impressive, they clearly know their stuff. I am also very impressed with the fact that on the rare occasion when they come across something they don’t know; they will go away to research for the right solution. It really demonstrates how competent they are and allows me to trust their advice implicitly.
The electronic logbook is helpful and saves me a lot of time. It means I always have the data I need available to me and we never miss any tests and activities we need to complete.

How do they stand out against the competition?

As mentioned before, Dantek has a strong reputation in the industry. I think the main elements that make them stand out for me are as follows:

The concise and timely completion of every job
The electronic logbook which allows me to stay on top of compliance requirements, documentation and paperwork
The level of knowledge and expertise they demonstrate about water treatment and legionella control

Marlborough College Case Study (PDF)