Serving parts of North West London and the Home Counties.

Water Quality information in your area

In 2016, we carried out over 186,000 tests on our water. We checked water leaving treatment works, at service reservoirs and at customers’ taps as part of our regulatory monitoring programme. The vast majority of the results complied with the standards set in the Water Supply (Water Quality) Regulations 2000 (as amended), confirming that drinking water quality continues to be of a very high standard. In 2016 our overall compliance performance was 99.97% while our Mean Zonal Compliance, the measure used by The Drinking Water Inspectorate (DWI), was 99.96%.

The Affinity Water area is split into 87 individual Water Supply Zones (WSZ).  Each Zone has its own Regulatory Compliance monitoring programme and reports are available for each of these Zones.  These reports, also known as Schedule 4 reports, are produced annually.  The reports detail the results of all the samples taken in that time period together with a comment if a sample failed to meet the required standard.

To see the report for the results of all samples taken in your WSZ, please enter your post code below.


This information is taken from historic results of monitoring and may be subject to change. This information is provided as a guide only and is subject to our terms and conditions.