28th Jan 2019

Skid Up to the Challenge

DWI R31 compliant skid mounted water treatment filtration system meets the turbidity challenge set by ageing conventional borehole stations.

Amazon Filters skid mounted or containerised water filtration systems can be deployed quickly off the shelf or custom manufactured for more challenging installations. Here's how we developed a bespoke solution for two ageing water treatment stations.

What Challenges Arise with Ageing Water Treatment Buildings?

1925 GWS Building (A)

A ‘conventional’ borehole station constructed around 1925 with the kind of issues you would expect from a 94+ year old building. The MCC (Motor Control Centre) is housed in a small control building with kiosks for phosphate dosing and UV treatment. Access to the building is limited creating another, but not insignificant, challenge for the Amazon Filters team and the ongoing maintenance of the works.

Chlorination and UV treatment have been used at this site for disinfection, with MSP dosing to reduce plumbosolvency. However, deterioration of unlined pipes and the location of the sample point are believed to be the cause of high turbidity and as a result this station was taken out of service to prevent any further DWI reportable events.

Amazon Filters Skid Assembly



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Grade II Listed GWS Building (B)

The station is a grade II listed building constructed in 1897 with a site-wide tree preservation order. The local city council confirmed that listed building consent would be required to improve the works.

Water is abstracted by duty/standby pumps and UV treated and chlorinated, with MSP dosing to reduce plumbosolvency. The station feeds into a reservoir which supplies the local area or the water is pumped to other local Reservoirs.

Water filtration system at a grade II-listed GWS building

How to Recommission Old Water Treatment Stations to DWI R31 Standards of Supply

The Amazon Filters solution:

  • Filter skid assembly with 3 x filter housings, each taking 40 x 40” cartridge for a total capacity of 5.7 MLD.
  • The restricted access challenge presented at station (B) was overcome by a custom skid design that was able to be easily assembled on site with some pre-assembled sections to make the initial installation as efficient as possible.
  • Differential pressure sensors integrated into the skids to enabling remote monitoring of the system providing alerts when filter cartridges need changing.
  • Horizontal housings with side openings allowing for easy access to the filter cartridges during changeouts.

The project management, design, and manufacture of these custom units was undertaken solely by Amazon Filters providing a cost effective and sustainable solution.

A containerised filtration system inside a clean and tidy warehouse

What Type of Filter is Used to Meet DWI Regulation 31 Standards?

The typical filter used in R31 solutions is the SupaSpun II absolute rated depth filter. These high-performance cartridges excel in dirt holding capacity and give extremely low clean pressure losses as a result of the strictly controlled manufacturing of the fibre matrix.

  • Absolute removal ratings for consistent and reliable performance
  • Graded density structure for maximum dirt holding capacity
  • Increased void volume giving high flow rates and low initial pressure losses
  • Wide chemical compatibility using, polypropylene
  • Range of Absolute ratings (Beta Ratio 5000) from 0.3 to 180µm
  • Thermal bonding process minimises media migration and ensures minimal extractables
  • Identification data embossed on every cartridge

The performance of the SupaSpun II makes it the ideal cartridge for tackling water turbidity but also extremely effective in controlling cryptosporidium and maintaining quality of supply where the groundwater contains oxidised iron.

Get DWI Regulation 31-compliant Solutions with Amazon Filters

The Drinking Water Inspectorate (DWI) Regulation 31 requires that products used in the production of potable water for public supply must be listed on the Secretary of State’s list of approved products – Amazon Filters’ R31 SupaSpun II filters are on this list!

We also offer flexibility and onsite assistance, providing expert support to contractors and water companies to establish the optimum running and most cost-effective solution to suit your budget and site requirements.

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