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url: https://www.eurocovers.eu/glossary/dwi-regulation-31
term: DWI Regulation 31
definition: UK Drinking Water Inspectorate (DWI) approval requirement for non-metallic materials in contact with drinking water under the Water Supply (Water Quality) Regulations.
updated: 2026-05-25
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# DWI Regulation 31

UK Drinking Water Inspectorate (DWI) approval requirement for non-metallic materials in contact with drinking water under the Water Supply (Water Quality) Regulations.

**DWI Regulation 31** is the UK Drinking Water Inspectorate approval requirement for non-metallic
materials in contact with drinking water under the Water Supply (Water Quality) Regulations 2016.
The NSF-61 certified HDPE variant of the hexagonal floating cover satisfies Regulation 31 for
contact with potable water in UK water utility service reservoirs.