Water Testing
Water testing services, including testing for bacteria in water and laboratory analysis, legionella risk assessments and compliance.
Pulse Water are a water hygiene company that specialises in Legionella services to control the risk of Legionnaires’ disease including an initial ACOP l8 risk assessment, Legionella testing, water tank cleaning, legionella remedial services, water monitoring/remote monitoring and chlorination services. We have over 20 years experience in water safety and all our water sampling is done in accordance with the British Standards BS7592 and HSE guidelines to give you the best possible service.
Testing for Legionella
Legionella testing and water analysis is the process of taking a water sample, in a sterilised bottle (with sodium thiosulphate) for a true reading, before sending the water sample onto our UKAS accredited laboratory for quick analysis and fast results.
The laboratory will identify the presence or absence of Legionella in the water sample collected, along with the bacterial count and Legionella species present. It is important to bear in mind that for accurate results, the water samples must be taken at the right points within the water system and you need to know where to take those Legionella samples from. This means understanding your water system’s design and risk areas. You should also only ever use one sterilised bottle per outlet to avoid mixing samples from two different points.
If you are not sure what to do to meet your legal requirements, then contact us today for specialist Legionella testing guidance. The purpose of testing water samples is to mitigate the risk of Legionnaires’ disease which is a result of the Legionella bacteria growing in the water system and can be fatal so should be taken seriously.
Legionnaires’ Disease
Legionella bacteria can be found in natural environments including ponds, rivers and lakes. The bacteria can also be supplied in small amounts within the mains water supply. Where there is water and the conditions of creating water droplets (aerosols), people using or within the area of these services may be at risk. It is this bacteria found in the water supply which is the cause of Legionnaires’ disease.
Legionnaires’ disease is a form of pneumonia, which can be fatal. The most at risk are the very old and the very young, the ill and smokers to name a few. Legionella bacteria can also cause other, less harmful illness such as Pontiac fever and Lochgoilhead fever, which can affect all people. The main route of infection is through inhalation, by inhaling airborne water droplets that contain Legionella. It cannot be spread from person to person. The majority of cases or outbreaks of the disease have been via domestic water services, evaporative cooling towers, and spa pools.
Conditions and contributing factors to its growth include:
- Temperatures between 20-45°C
- Available nutrients (including sediment, biofilm, algae, scale, rust, material, etc.)
- Presence of biofilm on surfaces of water
- Poor or inadequate management including training and awareness
Water Systems
Regular water sampling is the most effective way to determine water quality and test for the presence of legionella bacteria in your water system. Without testing the water, you are unable to identify water quality and therefore you are unable to determine whether your water management and legionella control is sufficient. With periodic legionella testing, you are able to demonstrate that your water management and legionella control procedures are suitable and the water in your water system is fit for purpose.
All our water samples are tested in UKAS accredited laboratories as standard and we are able to carry out tests on a wide range of microbiological samples and chemical testing services. Below are just some of the water systems that we can test for Legionella:
- Drinking water (including water dispensers and coffee machines)
- Hot and cold water systems
- Coldwater storage tanks
- Hot water cylinders
Water heaters - Dental units
- Swimming pools
- Cooling towers
- Eye showers
- Eyewash units
- Water fountains
- Vending machines
- Closed water systems
- Spa baths
Relevance:
Pulse Water are here to help with:
- Accredited laboratory water testing and analysis: expert water microbiology and water chemistry for Legionella, Pseudomonas, Coliforms, Total Viable Counts (TVCs) and other parameters.
- Chemical make-up of water: laboratory testing and sophisticated test and analysis of potable water, drinking water, process water and wastewater.
- Physical parameters: testing for total and suspended solids and more.
- Metal parameters: testing, analysis and interpretation to determine asset wear, system integrity and water quality.
- Corrosion, scale and contaminants: water testing and analysis to reveal water quality and underlying system parameters and safety.
- Swimming pool and spa water sampling and testing: hygiene analysis, Legionella analysis, environmental organisms growing in pool and distribution water systems, filters and biofilm.
- Monitoring, certification and validation: latest field testing, sampling equipment and advice on appropriate sampling points and frequency. UKAS accreditation water testing and reporting.
Reasons to choose Pulse Water
- Water specialists focused across on-site testing, culture tests, water quality tests, water chemistry and microbiology
- UKAS accredited laboratory network across the UK
- Fully compliant service. City and guilds qualified.
- Over 20 years experience in the industry.
- Nationwide Coverage With engineers located all across the UK, we’re never too far away.
- Expert support across Healthcare Water, Yeast and Mould Sample Analysis, Sulphate Reducing Bacteria Analysis, Suspended Solids Analysis, Potable Water Analysis, Effluent Water Analysis, BSRIA Closed System Analysis for BG50, Metals Analysis and much more
Common questions
Refer to HSG 274 Part 2, page 40 onwards.
Legionella testing is recommended when:
- A water system is being treated with biocides and water is stored or distributed at low temperatures
- There is a lack of confidence in the water system integrity and degree of water quality control
- In accordance with the Water Hygiene Risk Assessment, if temperature control and disinfectant concentrations are sporadic and not being consistently achieved. Once the water system is brought back under control to establish and demonstrate a satisfactory ‘baseline’ in accordance with ACoP L8.
- There is a high risk population or critical exposure (eg hospital, healthcare premises, clinical or laboratory usage, swimming or spa pool usage, care home setting as well as public or commercial duty of care – HM Prison, public buildings, commercial offices, private landlord properties and so-on).
Property owners or managers are also required to test for Legionella across both hot and cold water systems, in systems where dead legs occur, sites containing cold water storage systems and cooling towers.
It rather depends on what you are using water for on your site and what your concerns initially are.
Sites with patient care plans will typically test for; Legionella bacteria, Coliforms, E-coli, Total Viable Count (TVC), Pseudomonas aeruginosa, Other Pseudomonas species and Staphyococcus aureus.
Sites with boreholes, wells or natural springs or in close proximity to farmland where concern may exist about contamination, will want to test for E-coli and Coliform as well as TVC to help determine water quality. Sites concerned about metals and heavy metals in their drinking water, will need to abide by regulations which are explicit about what constitutes wholesome drinking water.
Refer to The Drinking Water Inspectorate for Water Quality in England & Wales, Scotland and N Ireland as appropriate.
For sites using water treatment, there are also a range of chemical tests to detect scale, corrosion potential, strange taste, odour, staining and so-on.
The Pool Water Treatment Advisory Group Code of Practice (PWTAG) provides pool and spa operators with a detailed plan to ensure their pool water meets quality standards that provide a healthy experience for swimmers and bathers. All operators are required to work to the following general guidance. More specific parameters relate to bath load, operating levels, and water temperature maintained (swimming or bathing).
MICROBIOLOGICAL ANALYSIS
Total Viable Count / Aerobic Colony Count (TVC)
TVC at 37oC (24-hour incubation) reveals if the filtration systems are working satisfactorily. This should not exceed 100 cfu/ml.
Escherichia coli (E-coli)
This should be absent from a 100ml sample. Detection indicates human or animal faeces contamination.
Coliforms
Coliforms are related to E-coli. They should be absent in 100ml. Less than 10 cfu/100ml is acceptable provided it does not occur in consecutive samples, there is zero E-coli, ACC is below 10 cfu/ml and the residual disinfectant and pH values are within recommended ranges.
Pseudomanas aruginosa
This is a pathogen capable of growing in water at low temperatures especially in filters, deck level transfer channels, balance tanks, flexible polymetric tubing, pool covers and backwash systems. It should be absent in a 100ml sample. If detected between 10-50 cfu/ml, repeat water sampling and analysis whilst maintaining the free chlorine and pH values. If a count above 50 cfu/ml is detected, the pool / spa should immediately be closed and thoroughly decontaminated.
CHEMICAL TESTING OF POOL WATER
When disinfection and pH are not automatically monitored and controlled, daily manual testing is required (but refer to the Risk Assessment for frequency). Pool water samples for chemical analysis should be taken from a depth of 100-300mm.
Free chlorine levels
These values require validation by satisfactory bacteriological water quality standards. For pools using hypochlorite, assuming the pH value is 7.2, the free chlorine levels should be maintained at 1mg/l or below with an absolute minimum of 0.5mg/l. This assumes the pool has satisfactory microbiological monitoring results. The use of secondary disinfection (UV or ozone) can help minimise the free chlorine levels. These values can only be achieved where the pool is designed, engineered and operated well with effective pre-swim hygiene and is not overloaded.
Upper limits
Free chlorine levels above 3mg/l should not be present in any pool using hypochlorite. If this is exceeded, dosing should be reduced. If dosing has gone wrong and free chlorine reaches 5mg/l, chlorination should be stopped immediately. If free chlorine continues to rise, bathing should cease until the fault has been resolved and the residual free chlorine is under control.
Combined chlorine levels
The level of combined chlorine residuals should be as low as possible. Combined chlorine levels should be less than half the free chlorine, and no more than 1mg/l irrespective of the level of free chlorine. If the ratio of combined chlorine to free chlorine is unsatisfactory, some correction may need to be applied.
pH value
The pH values for the pool water should be maintained within the range recommended for the disinfectant being used. But a pH value of between 7.2 and 7.4 should be the target when using chlorine-based disinfectants. At levels above this range the free chlorine will not be so effective and may need to be increased.
Alkalinity
To ensure effective coagulation and a stable pH when using acidic disinfectants, alkalinity in pool water should be maintained at a level between 80 and 200mg/l (measured as CaCO3). Alkalinity measurements should be taken weekly, using commercially available alkalinity test kits and using appropriate tablets. Dilution or dilute acid should be used to lower the levels of alkalinity in the pool water.
Calcium hardness
Pool water should be maintained for bather comfort, and the grout in the pool should withstand that water. Ideally calcium hardness should be maintained between 75 and 150mg/l as CaCO3. However, in areas with a hard water supply this cannot be practically achieved. It is therefore very important that water treatment chemicals do not further increase the calcium hardness values over and above that in the hard water make up supply. Calcium hardness concentrations greater than 300mg/l may result in the deposition of scale causing sudden changes in temperature and pH. Calcium hardness measurements should be taken weekly, using commercially available test kits with the appropriate tablets.
Total dissolved solids (TDS)
Dissolved solids are destructive at high levels and should never be allowed to rise more than 1,000mg/l greater the level in the source water. The TDS concentration should be reduced by dilution if necessary and should be measured weekly, using a commercially available electronic meter that has been calibrated against a commercially available standard.
Sulphates
Sulphate levels should be maintained below 360mg/l and should be measured once a week using a commercially available test kit.
Balanced water
It is important to maintain the water in balance and this is usually achieved when the pH is properly controlled. Alkalinity, Calcium hardness, TDS and temperature are also factors. The Langelier index is a formula that brings together all these factors. It makes sense to calculate Langelier weekly when measuring Alkalinity, Calcium hardness and TDS.
Water is tested for metals to ensure drinking water is of high quality, to confirm limits prohibited in wastewater are being met, or to establish scale potential in water for example.
DRINKING WATER METALS TESTING
In accordance with The Water Supply Regulations (2010), you should test at point of supply (sentinels / taps) to the following maximum limits:
- Lead (Pb) 10 µg/l
- Boron (B) 1.0 mg/l
- Chromium (Cr) 50 µg/l
- Mercury (Hg) 1.0 µg/l
- Arsenic (As) 10 µg/l
- Cadmium (Vd) 5.0 µg/l
- Copper (Cu) 2.0 mg/l
- Antimony (Sb) 5.0 µg/l
- Nickel (Ni) 20 µg/l
- Selenium (Se) 10 µg/l
- Aluminium (Al) 200 µg/l
- Manganese (Mn) 50 µg/l
- Iron (Fe) 200 µg/l
- Sodium (N) 200 mg/l
WASTEWATER METALS TESTING
Some industries can be heavy users of water in their operating and manufacturing processes. They are required to adhere to strict limits on what is discharged within their effluent water including metal content. We can test and advise on the following:
- Barium
- Lead
- Copper
- Molybdenum
- Antimony
- Selenium
- Zinc
- Chromium
- Mercury
- Arsenic
- Cadmium
SCALING METALS TESTING
You can establish the scaling potential of water by testing and analysing metal content. In particular for:
- Magnesium
- Calcium
- Strontium
- Barium
At Pulse Water, we test for chemical and microbial parameters which provide insights in to metals in water.
Closed systems (circuits) should be tested for three parameters. We provide ongoing diagnosis for all:
- System Integrity – Dissolved Oxygen, Pressure, Temperature, Water Make-up
- Water Characteristics – Conductivity, pH, Microbiological Risk
- Corrosion – Galvanic Currents, Crevice Corrosion