In early March we completed a brand new borehole installation at an education and children’s residential centre in the North East of England.
The new borehole system takes advantage of two e.syboxes in an e.sytwin setup, has a water treatment system and was installed as part of large development incorporating two residential homes and a learning centre for vulnerable children. You can see the pumping plant below:
Borehole and Submersible Pumping Plant
After an initial site visit, desk study and quotation acceptance our drilling team drilled a 150mm diameter borehole to 57 metres into a sandstone aquifer.
A stainless steel submersible pump was installed onto a plastic rising main in suitable lengths for ease of installation and to make future maintenance easier to carry out.
The borehole headworks are fully compliant with the Private Water Supply regulations and comprise of a sealed flange assembly to prevent any potential for surface contamination entering the borehole and above ground. Our engineers completed the headworks with a GRP kiosk designed borehole chamber that is locked down in each corner. This again meets the requirements of the Private Water Supply requirements and is vermin proof.
Raw Water Analysis
After a raw water analysis was undertaken it was discovered the water failed for iron, manganese and turbidity against the drinking water standards. This is very common in borehole water supplies and treatment is readily available.
The water was also hard, which isn’t a health concern but may cause problems with infrastructure in the future due to scale build up. This can lead to inefficiencies and added expense for replacement parts.
Water treatment and treated water analysis
To address the water treatment issues a system was design and installed. It took advantage of the following:
Used to bring iron and manganese out of solution and into suspension quickly, followed by an iron and manganese removal filter utilising Filox media (manganese dioxide).
A water softener is then provided to covert to sodium bicarbonate to assist in prevention of scaling of infrastructure.
The raw water didn’t fail on bacterial content however a precautionary principal to bacterial control was applied. A chlorine dioxide dosing system was also installed to dose into the water storage tank to:
Firstly to provide a residual disinfection for bacteria within the water as it moves through to supply and secondly to assist in preventing biofilm both with the water storage tank and the pipelines in the plant room and throughout the facility.
This dosing was proportional against the pass forward flow rate calculated automatically to a water meter. A 5m3 water storage provides a reservoir of water to meet instantaneous demand and the storage tank is WRAS approved.
Finally a double, duty assist, booster set on variable speed was fitted to pull water from the water storage tank through to delivery. A final precautionary measure of stainless steel UV purifier for point source bacterial control has been provided post the booster set.
The water now passes all water analysis tests and the borehole is fully operational.