More than 22,000 combined sewer overflows (CSOs) are spilling untreated sewage onto Britain’s beaches and into its rivers and estuaries: 520 beaches are affected, more than 460 of them designated bathing beaches.

Theoretically, CSOs should discharge only in heavy rainfall, and no more than three times a year on bathing beaches. In fact, many of them discharge all the time.

The true scale of the problem remains unknown because there is no comprehensive monitoring and no official record is kept. To help redress this failing, The Sunday Times and the Marine Conservation Society (MCS) invite readers to report any outflow pipes they see discharging dirty water onto a beach.

Here’s how to do it:

1. Go to the Good Beach Guide website, www.goodbeachguide.co.uk

2. Follow the picture link to “Report Pipes Discharging”

3. Using the zoomable satellite map, locate the beach with the CSO that you want to report. The latitude and longitude will be recorded automatically

4. You can then log any details and even upload a photograph

(The MCS will map the information as it receives it, and keep readers informed through dedicated pages on the Good Beach Guide website. The data will then be used to underpin its campaign for government action to force sewage off the beach)

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