Water Filtration System Upgrade

The Current Filtration System and Setting

Mawdsleys Pump Services were called to inspect a private water system near Sherborne, Dorset.  This water supply is served by a borehole pump delivering to a farmhouse and two cottages. The borehole pump lifts the water to a reservoir, which then gravity feeds the water to the properties, a distance of some 800 metres.

The water quality had been tested by Wessex Water and failed to be within the 2009 Private Water Supplies Regulations on the bacteriological test, in spite of an ultraviolet filter which had been installed in the system between the borehole pump and high-level reservoir.

The Reason for the failed water test

Inspection of the installation revealed that the ultraviolet system was not installed in the ideal position, being between the borehole and the reservoir and up to 800 metres from the point of use. There was an increased risk of contamination from either the reservoir or somewhere in the pipework.

private water supply system


Our recommendation is that the single ultraviolet system be replaced by individual units, sized for each property. This will ensure shortest possible pipe runs to minimise the risk of contamination. Individual treatment will also provide more flexibility and improved performance.

Once installed we will take a sample of water from each property and have it analysed by an independent UKAS Laboratory to ensure the water sample meets the private water supplies regulations.

Find out more about our clean water services