London Restaurant Risk Assessment & Remedial Works

Acquiesce Environmental Compliance work within all manner of commercial buildings including schools, colleges, universities, pubs, restaurants, offices, factories, social housing properties and any building with a hot & cold water system.

In Summer 2020, we completed a legionella risk assessment of a restaurant in London. The restaurant was closed due to the COVID-19 pandemic; however the duty holder & owner was eager to have the risk assessment completed, and remedial works carried out ready for re-opening

The building contained a cold water storage tank which hadn’t been inspected previously, and contained low amount of sediment. It was then determined that the cold water tank fed all of the drinking outlets in the building, including water used for cooking. Cold water storage tanks feeding drinking water must be cleaned & disinfected on an annual basis, with sampling carried out 6 monthly to ensure that the quality of water is still safe for building users.

Our assessor also identified unvented hot water storage heaters that couldn’t distribute hot water at correct temperatures. An experienced engineer was sent to site following the assessment to attempt to fix the heaters. We identified that the heaters were beyond repair, and replacement was carried out, ensuring visitors could wash their hands in warm water.

As the building had been closed for a significant period, the cold water tank was cleaned, then dosed with chlorine at 50ppm, ensuring that the PH level of the water was checked, so the correct amount of chemical could be dosed. This was then ‘pulled’ through to all hot & cold outlets in the building, so that the full system was disinfected. Once a satisfactory disinfection period of one hour was achieved, the system was fully flushed through, so that chlorine levels were back down the level supplied to the building

Nottingham Pub/Restaurant Cold Water Tank Replacement

Acquiesce Environmental Compliance work within all manner of commercial buildings including schools, colleges, universities, pubs, restaurants, offices, factories, social housing properties and any building with a hot & cold water system. Often following a legionella risk assessment, we are asked to completed mechanical remedial plumbing services to reduce risks and ensure systems are safe for use by staff, visitors, and residents of commercial buildings.

In Summer 2020, we completed a legionella risk assessment of a pub & restaurant in Nottingham. While conducting the assessment a galvanised cold water storage tank was identified feeding cold water outlets and a water heater in the building. Galvanised cold water storage tanks do not conform to WRAS (Water Regulations Advisory Service) as the material can corrode and impair the quality of water.

Conversion of the system to mains wasn’t possible, as a tank needed to remain in place. Acquiesce Environmental Compliance recommended the removal of the galvanised cold water tank, and replacement with a new GRP tank.

The works were carried out once the pub had closed in the evening and was removed immediately. The new GRP tank was then built in the roof space, pipework shortened and insulated, and finally the tank and system chlorinated to ensure water being supplied to staff & visitors was safe and clean.

The pub re-opened at midday the following day, with safe, clean water for the visits of this Nottingham pub.

Coventry Academy School

Acquiesce Environmental Compliance work with a number of schools, colleges and educational facilities in the West Midlands area, as well as further afield in Warwickshire, Staffordshire, Worcestershire & Gloucestershire to provide legionella risk assessment, monitoring services, sampling, remedial plumbing works, TMV servicing and consultancy.

We received an enquiry from a large Coventry based Academy school. The site had various different types of water systems over a number of buildings, including a chlorine dioxide dosing unit fitted on the incoming mains water supply to the site. Records had indicated that the unit was working correctly and chemical levels at sentinel outlets were correct. Acquiesce Environmental Compliance attended site, and found the chemical containers feeding the unit to be dry, and no detection of chemical at any outlets.  There was no indication of records of why the unit was first installed. Chlorine dioxide units are often fitted in buildings with water systems that have had history of bacterial issues, such as legionella bacteria present. This is often the last resort when remedial works have been completed, disinfections, sampling and a review of the control scheme has taken place.

Acquiesce Environmental Compliance carried out a thorough legionella risk assessment spending nearly a week on the site, identifying any areas of concern within the systems that could contribute to the growth of legionella bacteria.

Once the report was issued, Acquiesce Environmental Compliance compiled a full list of remedial actions including reducing the volume of stored water in the building by either removing cold water tanks, or reducing the volume of those in place. These were completed in a timely fashion. Backflow prevention devices and fittings that matched the requirements of water regulations to prevent poor quality water (such as heating water, water containing chemical fluid etc) flowing back into the town mains supply.

Temperature issues were quickly addressed, and a sampling regime recommended to identify if the primary method for legionella control, temperature, be used rather than secondary disinfection.

After a 4 month sampling regime, and no positive legionella samples, the chlorine dioxide unit, which was now obsolete was removed. Temperature control is now the primary method of legionella control for the school, paired with an extensive flushing regime to flush all infrequently used outlets and ensure that water is kept moving, even during times of the school being closed to pupils & staff, and throughout the COVID-19 lockdown periods.

 

Birmingham based Leisure Centre

We received an enquiry for legionella samples to be taken from a Leisure Centre which had been closed over the Coronavirus lockdown period, and duty holder wished to re-open. Acquiesce Environmental Compliance swiftly attended site to collect samples for analysis in a UKAs accredited laboratory. Upon receiving these results we identified potentially lethal legionella SG1 bacteria within the system. We proceeded to carry out a full legionella risk assessment and through investigation. As soon as the bacteria was identified, point of use filters were fitted to outlets, so that the building could open, and water could safely be used by service users and staff.

During the legionella risk assessment, significant dead legs were identified in the roof void. These lengths of pipework have no outlets and used to feed sinks & wash hand basins. When these have been removed, the plumber has capped off the pipework, leaving a significant risk in the system. These lengths of pipework will contain stagnant water, which will provide an environment suitable for bacterial growth. Once the pipe fills with bacteria, it can then potentially spread into the system. These were quickly removed.

Further into this investigation, we identified an issue with the expansion vessel, which was fed from the hot water return, rather than cold water with no check valve fitted. The vessel had a drain valve fitted to enable regular flushing, however this had been fitted in the wrong place, meaning the entire contents of the unit could not be drained.

When we isolated and drained the unit, the temperature recorded was 34c, which is close to the optimum temperature for bacterial growth of 37c. A decision was made to sample this water. When we received the results, we found SG1 legionella bacteria at 50 x the levels we had in the building. This vessel was then moved to be fed from cold water, the drain valve repositioned, and a check valve fitted to confirm to water regulations. The flushing of this unit was then added to a quarterly regime, as Acquiesce Environmental Compliance was awarded the on-going control scheme monitoring contract for the site, following the excellent work which had been completed.

Following more remedial works, dead end removals, fitting of backflow protection devices, a full hot & cold water system disinfection was carried out. 72 hours after completion of this disinfection, further legionella samples were taken. These come back from our UKAS accredited laboratory all clear. A sampling regime was put in place to check conditions and safety of water supplies for building users & staff. The water system here are now safe for people to use, and a happy customer too! For more on what we do, please call 0121 608 3272 or email info@acquiescecompliance.com