10 most common water storage tank remedials to achieve L8 compliance

Problem
Positioning the inlet and outlet closely together or on the same side does not allow good cross flow and creates pockets of stagnation where bacteria may proliferate.

Solution
Fit internal sparge pipe and log details of remedial action.

Problem
A damaged lid may allow insect and vermin ingress subsequently contaminating stored water.

Solution
Replace the existing lid and log all details of all remedial action carried out.

Problem
All cold water storage tanks should be in a cool area with adequate access for appropriate monitoring. The CWST should be inspected visually, internally and externally and cleaned and disinfected where necessary.

Solution
Improve access and implement appropriate monitoring. All remedial action must be logged.

Problem
Sediment and debris, including non WRAS approved materials, may provide a nutrient rich harbour for microbiological growth protecting Legionella bacteria from unfavourable temperatures, potentially leading to the CWST and its periphery becoming contaminated.

Solution
Clean and disinfect CWST removing all sediment and possible contaminants. Log all details of remedial action.

This drawing shows a preferential scenario, whereby both calorifiers fitted with open vents discharge to a separate location

Problem
Calorifiers should not vent to a CWST as if the passes the stored cold water temperatures may rise into the bacterial proliferation zone.

Solution
Re-route open vent to a tundish. All details of remedial action must be logged.

Problem
All CWSTs should have an airvent to allow the CWST to breathe as the water level rises and falls. Airvents should be screened to prevent vermin/ insect ingress.

Solution
Install a screened airvent with apertures no greater than 0.65mm, log all details of remedial action.

Problem
An unsecure lid may allow insect and vermin ingress subsequently contaminating stored water.

Solution
Secure and fasten existing lid to tank and log details of all remedial action carried out.

Problem
Unsmooth finished surfaces and scale promote areas of bacterial growth. All cold water storage tanks should reach the appropriate regulation to prevent conditions that may promote bacterial proliferation of contamination of stored water.

Solution
Consideration should be given to replacing CWSTs, logging details of any remedial action.

Problem
Incorrectly configured cold water storage tanks may allow the water to stagnate increasing the risks of bacterial proliferation.

Solution
Configure CWSTs in parallel to provide good flow. All remedial action must be logged.

Problem
All CWSTs over a capacity of 1001 litres must have a warning pipe discharging to a conspicuous location to give an alert that water has reached a predetermined level and may overflow.

Solution
Re-route pipe work to a location visible so that if levels rise warning is given to prevent the CWST overflowing.