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Polluted by sewage 164 times in 2025 lasting 1,117 hours
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Donate NowHere are all the reported sewage overflow totals for Calne in 2025. Sometimes sewage can be being dumped for months at a time.
Reporting refers to how much of the time the monitoring was active. In this place all the declared CSO Combined Sewage Overflow - a device that, when operating, pours combined rainwater & sewage into a waterway s appeared to have monitoring enabled for more than 50% of the year
| Company | Waterway | Site | Sewage Dumps | Duration (Hours) | Reporting % |
|---|---|---|---|---|---|
| Wessex Water | River Marden | ROUGH LEAZE | 23 | 395 | 99.9 |
| Wessex Water | River Marden | CALNE WASTEWATER TREATMENT WORKS | 47 | 299 | 100 |
| Wessex Water | Rivers Brook | COMPTON BASSETT WWTW | 16 | 192 | 100 |
| Wessex Water | Unknown | MOSSES MILL CSO 2 | 44 | 146 | 100 |
| Wessex Water | River Marden | QUEMERFORD BRIDGE CSO | 12 | 45 | 96.7 |
| Wessex Water | River Marden | PATFORD STREET CSO | 10 | 33 | 93.9 |
| Wessex Water | River Marden | THE STRAND CSO | 10 | 4 | 95.1 |
| Wessex Water | Unknown | PATFORD ST/BANK OF RIVER MARDEN CSO | 1 | 0 | 100 |
| Wessex Water | River Marden Via Sws | WOOD STREET COMBINED SEWER OVERFLOW | 1 | 0 | 100 |
| Wessex Water | River Marden Via Sws | MARKET HILL CSO | 0 | 0 | 100 |
| Wessex Water | Unknown | MOSSES MILL CSO 1 | 0 | 0 | 100 |
EDM (Event Duration Monitoring) data and Consented Discharges to Controlled Waters with Conditions from Environment Agency & Data Map Wales, and Scottish Water
Experimental derived data from Thames Water API, Some data may be missing or inaccurate. Live sewage data from Stream Water API
Annual figures up to and including 2025 come from official water company returns. The 2026 figure is our own estimate, derived continuously from the companies' live data feeds.
Uses Environment Agency rainfall data from the real-time data API (Beta) - Rainfall data is delayed by up to two days.
This website is intended to provide an accurate representation of the Environment Agency data. The data is hard to use, and thus some errors may have been made. If you find something that is incorrect, please raise an issue at the GitHub issues page and we'll endeavour to fix it quickly.
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Get in touch if you have queries or want to discuss our data.
press [at] top-of-the-poops.org