Water Testing Facilities
Customers that use the range of chemicals that B & V produce to alleviate the problems of scale, corrosion and biological fouling in water systems often require ancillary services that ensure the trouble free application of our chemicals.
Our trained, qualified chemists and microbiologists will carry out the appropriate chemical and microbiological tests in order to advise you on how to maintain the correct water conditions for your application.
Boiler Water Testing
The tests carried out on site using a portable laboratory follow the guidelines as stated in British Standard 2486 and would typically consist of:
- Oxygen scavenger (such as sulphite)
- Total dissolved solids
- Condensate testing
- Quality of water from softener
- Scale inhibitor / dispersant levels
A service report is issued to the client and any remedial action discussed and implemented to ensure that scale and corrosion free conditions are maintained in the boiler and condensate system.
Cooling Water Testing
The tests are carried out on site with a portable laboratory at a minimum of monthly intervals, and would typically consist of:
- Corrosion or scale inhibitor level
- Total dissolved solids
- Levels of oxidising biocide such as Bromine
- Dipslide for biological content
- Water quality from softener etc
- Samples are also taken for Legionella analysis and TVC 30°C.
In order to comply with the requirements of the HSE on the operation of cooling towers, the test results and any remedial actions are discussed with the client and a service report issued and stored in the Cooling Tower Logbook.
Water Services Hygiene & Monitoring
Water hygiene, whether it is for drinking water or for hot and cold water services, is subject to compliance with legislation such as the COSHH Regulations 1999, the Water Supply (Water Quality) Regulations 2001, the Water Supply (Water Fittings) Regulations 1999 and the Approved Code of Practise ‘The Control of Legionella in Water Systems’ L8.
B & V are able to chemically and microbiologically test and examine water systems to ensure that the quality of the water, no matter what it is used for, is fit for the purpose and does not constitute a hazard to health. In addition, for hot and cold water services to comply with L8, the tests should also be part of a complete control programme that will involve temperature monitoring, cleaning and disinfection etc.
Drinking water in workplaces can be provided from a variety of sources such as mains fed taps, private water supplies, vending machines, bottled water dispensers and sometimes from water storage cisterns (tanks). B & V can regularly analyse the microbiological content of drinking water for Total Viable Count (TVC at 22oC and 37oC), coli forms, E. Coli, Pseudomonas auruginosa and also odour, taste and turbity if required. The tests and monitoring to be carried out will also depend upon the delivery method of the water.
There should not be any problems with water supplied from a direct mains water pressure system.
Private Water Supplies
Private water supplies are those that are not provided by a statutory undertaker, that is, a water company, and tend to serve isolated, remote properties, small communities or factories. The source could be from springs, wells, borehole, streams, rivers, lakes or ponds. Private water supplies can pose a threat to health unless they are properly protected and treated. They can become contaminated with bacteria, protozoa, parasites and chemical impurities. These are not necessarily harmful, but there is a chance that the supply could be affected with contaminants that may prove hazardous to some people. Private supplies are more likely to be contaminated because they are more vulnerable to contamination, and are not treated to the same standard as public supplies. They are classified into categories depending on the premises and number of people to which the water is potentially supplied.
All private supplies must be sampled on a regular basis for a range of bacteriological and chemical contaminates and theses tests need to be carried out by the local authority. The frequency of these tests is laid down in the Private Water Supplies Regulations, and varies according to the size of supply. The costs of sampling and analysis are passed on to the person responsible for the supply.
If the supply is contaminated, or is likely to become contaminated, a water treatment system can be installed. There is a range of treatment methods available. Please contact us for advice about which one to choose.
Vending Machines, Bottled Water Coolers & Plumbed in Water Coolers
Vending machines and water cooled dispensers deliver water for hot water drinks machines and for cold water drinking. Many cold water samples from these machines give poor microbiological results, mainly due to poor maintenance of the equipment, especially from the dispensing taps. The advice of the Automatic Vending Association and The Bottled Water Cooler Association should be adopted on cleaning routines to ensure hygienic conditions are maintained. Since the Water Supply Regulations 2001 for the quality of water used for human consumption stipulates that drinking water should contain no micro-organisms which pose a potential danger to human health, whenever Pseudomonas auriginosa, E. Coli or coliforms are detected in a vending machine, it usually indicates that the cleaning of the machines is inadequate and it is recommended that the machine is taken out of the service and cleaned and disinfected before re-introduction. The quality of the water supplied in the bottles for bottled water coolers should be covered by The Natural Mineral Water, Spring Water and Bottled Water Regulations 2003 and as such should be satisfactory, but poor maintenance of the dispensing equipment can contaminate the water.
Drinking water that is supplied from a storage cistern is not recommended as there is more likelihood of contamination. However, the use of a cistern is allowed by the Water Supply (Water Fittings) Regulations 1999 clause 27.2 as long as the water is maintained ‘wholesome’. In order to achieve this, the storage cistern must conform to the physical specification in the regulations, and particular attention should be made to the storage temperature of the water and the inspection and cleanliness of the cistern. The monitoring of the temperature regime of the cold water and the regular clean and disinfection of the cistern and pipework becomes important, and is a service that B & V have a large amount of experience in.
Hot & Cold Water Services
Hot and cold water services are particularly subject to the Health and Safety Commission Approved Code of Practise (ACOP) ‘The Control of Legionella in Water Systems’ (L8).
The first requirement for all hot and cold water services is to assess the risk of exposing the occupants of a building to Legionella. For further details, go to our risk assessment and logbook section.
As well as the microbiological tests that will monitor the efficiency of the control measures, the principle method of control is to monitor the water temperatures at the hot water plant and selected outlets monthly.
B & V are able to carry out this monitoring where maintenance personnel do not have the time or resources available. Since this monitoring is only one of the HSE requirements to control the proliferation of Legionella, it should be part of a complete management system that is covered by our risk assessments and logbook system.
In some premises it may be necessary to implement additional treatment in order to control bacterial levels within a system. B & V Water Treatment have extensive experience of selecting the appropriate additional treatment methods for such problematic systems. Although there are other treatment solutions which we can put forward to customers in a proposal as appropriate, the most effective control measure is often chlorine dioxide dosing.
Microbiological Water Quality Testing
Microbial tests for water quality are carried out in an independent UKAS approved laboratory, and only dipslide tests are carried out on site. These laboratory tests fall into the following categories:
Tests for Drinking Water Quality
TVC at 22oC is considered a good temperature for growth or organisms naturally present in the soil and cold water. 37oC is chosen because bacteria which may affect humans will grow best at this temperature. There is no evidence of harmful nature of the general bacterial population that grows at 22oC and 37oC, hence why the Drinking Directive has not set limits on these measures. The microbiological count at 22oC or 37oC in UK mains water arriving at a premises is usually less than 100 cfu per ml. However, micro-organisms tend to stick to, and then grow inside, tubing (more to plastic than metal) forming a biofilm; their preferred state. A number of factors will adversely affect the count in water: Low usage of water (allowing a long time in the pipe), high temperature, dead legs, poor cleaning regimes and storage tanks will all tend to increase the count.
Total Viable Count at 22°C and 37°C
A Total Viable Count (TVC) at 22°c and 37°c is the basic test for drinking water quality. Absolute numbers for acceptable counts are not defined; rather, the results should be monitored over a certain period in order to identify significant changes in total viable count.
Total and Faecal Coliforms Including Escherica Coli
Coliforms are a group of environmental bacteria that have originated from the intestines of animals. They can generally grow in the environment also, and are known as indicator organisms i.e. they are used as a guideline of possible contamination. Coliforms are sensitive to disinfection and should be absent in 100ml of sample.
Escherichia Coli (E. Coli) / Faecal Coliforms
E. coli itself is a coliform bacteria. Again it is used as an indicator organism, but E. coli does not live for very long in water so is an indication of recent contamination. The E. coli species found in water are generally harmless bacteria but are used as an indication of the possibility of other similar bacteria being present which may cause problems. Acceptable levels not detected in 100ml.
Pseudomonas ssp. Including Pseudomonas Aeruginosa
In certain systems it may be appropriate to test for Pseudomonas spp in water systems. Pseudomonas ssp. are common environmental organisms. However, they can easily colonise water systems and produce biofilms which can affect the taste and colour of the water. Pseudomonas aeruginosa is an opportunistic pathogen which may in some instances cause infections.
There may be a requirement to test for Legionella spp in hot and cold down water services. There is also specific requirement under L8 to identify water systems which may pose a risk. Such water systems, including cooling towers must be tested for Legionella spp.
Legionnaires Disease Bacteria, Including Serotyping
The presence of Legionella in buildings and cooling tower systems presents a serious risk to human health. As a result, there are strict guidelines for a testing regime for Legionella and other related organisms. The testing will confirm the absence or presence of Legionella in a water sample, and will also provide the serotype of the organism isolated.
Total Viable Count at 30°C
A TVC at 30°c is a useful test to determine the overall levels of bacteria contamination in a water supply. Whilst not suitable for drinking water, it is an essential test in relation to Legionella testing to ensure the TVC falls within the recommended guidelines for the control of Legionella.
Test for Bacterial Contamination in Closed Circuit Systems
All or an appropriate selection of the following tests are required for closed industrial heating or chilled water systems. The bacteria described can cause many problems including the formation of biofilm and corrosion if left untreated.
Total Viable Count
BSRIA guidelines require the testing of TVC at 22°C and 37°C following pre-commision cleaning of a closed circuit system. Testing of TVC at 30oC is equally acceptable for on-going monitoring of total bacterial levels in a closed circuit system.
Nitrite Reducing Bacteria
Organisms in this group are capable of using nitrite and nitrite containing compounds as an energy source. As many closed circuit corrosion inhibitors are based on, or contain nitrite as part of the corrosion inhibition, the presence of high numbers of these bacteria can be problematic in closed circuits. The action of these organisms can break down the Nitrite present and lead to loss of inhibitor and therefore corrosion in a closed circuit system.
Pseudomonas ssp. Including Pseudomonas Aeruginosa
Pseudomonas ssp. are common environmental organisms. However, they can easily colonise water systems, including closed heating and chilled circuits, by forming thick biofilms which can inhibit heat transfer and cause blockages of pipe work.
Sulphate Reducing Bacteria
These bacteria are capable of breaking down sulphate to sulphide and Sulphuric acid with the resulting problems of under deposit corrosion of pipework.
Most water systems are in continuous use, so it is rare to be able to inspect the internal condition of pipework and equipment for the efficiency of corrosion inhibitor chemicals. One of the more common methods employed are as follows:
Weight Loss Coupons
One of the most commonly used methods for internal corrosion and erosion monitoring is to use weight loss coupons. The coupons are carefully machined small bars, made of the same material as the pipework or equipment being monitored. They are accurately weighed and then exposed to the process for a period by being inserted into an external ‘rack’, or layout of 1 in. piping to the main circulating loop. When it is removed, carefully cleaned and re-weighed, the change in weight is used to calculate the metal loss that may then be expressed as an annualised rate of loss (mils or millimetres per year). Typically, the external rack is configured to allow the simultaneous testing of two of four corrosion coupons of similar or different metals as the water navigates the standard zig zag piping configuration.