Delyn polluted by sewage 1,621 times in 2023 - lasting 11,388 hours
- but monitoring was disabled in some locations, so could be more

© OpenStreetMap contributors
Contains OS Data © Crown copyright & database right 2021-2023
© Top of the Poops 2021-2023
✔ means we have experimental daily data since 2023
Totals for Delyn in 2023
55 Sites polluted by Dwr Cymru Welsh Water
1,621 sewage dumps
11,388 h duration
That's 1.32 years! On average 4.4 times a day
Change Over Time

Pollution Summary 2023

Here are all the reported sewage overflow totals for Delyn in 2023. 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 constituency 3 of the total 67 CSO locations had reporting enabled for less than half the year, of which 3 had zero reporting.

Company Waterway Site Sewage Dumps Duration (Hours) Reporting %
Dwr Cymru Welsh Water Unnamed W/C HOLYWELL PEN Y MAES RD/PEN Y M 179 4,079 98.2
Dwr Cymru Welsh Water River Alun Leeswood Transfer SPS 60 738 100
Dwr Cymru Welsh Water Culverted Of Dee MOSTYN DOCKS CAR PARK - SSO 35 698 48.6
Dwr Cymru Welsh Water Gutter Fawr LLANASA PS CSO / EO 58 646 100
Dwr Cymru Welsh Water River Alyn MOLD WwTW 57 612 99.9
Dwr Cymru Welsh Water River Dee MARSH FARM PUMPING STATION 54 450 98.4
Dwr Cymru Welsh Water River Dee Estuary Settled Storm Sewage at Flint WwTW 72 421 100
Dwr Cymru Welsh Water Wheeler Nannerch SPS 126 413 78
Dwr Cymru Welsh Water River Alyn CSO Mynydd Isa Chambers Lane/Mercia Drive Nr 2 102 312 98.7
Dwr Cymru Welsh Water River Alyn CSO at Mynydd Isa Wylfa Hill 70 305 100
Dwr Cymru Welsh Water River Alyn Settled Storm Overflow at Mold Wastewater Treatment Works 37 280 100
Dwr Cymru Welsh Water Nant Y Flint PENTRE HALKYN SPS 23 249 100
Dwr Cymru Welsh Water Ffynnongroew Drain FFYNNON WEST PS 16 215 100
Dwr Cymru Welsh Water S W Sewer MYNYDD ISA WATS DYKE AVE PS 43 177 99.9
Dwr Cymru Welsh Water Holywell Stream GREENFIELD PARENT CSO HOLYWELL 92 174 97.3
Dwr Cymru Welsh Water Northop Brook Northop Wastewater Treatment Works Settled Storm 26 141 17
Dwr Cymru Welsh Water Sw System DISCHARGE B 14 FFORDD DDYFRDWY 12 135 99.8
Dwr Cymru Welsh Water Dee Estuary BAGILLT EAST SPS 18 125 100
Dwr Cymru Welsh Water River Alyn Bridge Inn Pumping Station 11 119 100
Dwr Cymru Welsh Water Unnamed W/C FLINT IN GARDEN 102 MAES GWYN 76 117 99.4
Dwr Cymru Welsh Water River Alyn Mold Football Club Drice CSO 9 116 99.9
Dwr Cymru Welsh Water Surface Water System MYNYDD ISA MOLD ROAD/MERCIA DR CSO 44 97 98
Dwr Cymru Welsh Water Greenfield Valley CSO Adjacent A548 Road Bridge 42 82 100
Dwr Cymru Welsh Water Dee Estuary FLINT BARDYN PS , , 70 76 100
Dwr Cymru Welsh Water New Drain STATION ROAD PS TALACRE 18 74 100
Dwr Cymru Welsh Water Llanerchymor Gutter MOSTYN NEAR FUN SHIP - SSO 19 69 50.8
Dwr Cymru Welsh Water Black Brook Mold Bryn Awelon - CSO 17 63 100
Dwr Cymru Welsh Water Dee Estuary BAGILLT WEST SPS BAGILLT 39 61 99.7
Dwr Cymru Welsh Water Tan Lan Drains CSO at Tanlan Bach Pumping Station 4 45 100
Dwr Cymru Welsh Water River Dee PEN Y MAES PUMPING STATION 23 44 96.1
Dwr Cymru Welsh Water Marsiandwr TAI TREVOR PS LLANNERCHYMOR 11 37 99.9
Dwr Cymru Welsh Water Pentre Ffwrndan Drain Oakenholt Main SPS 5 30 99.9
Dwr Cymru Welsh Water Pentre Ffwrdan Stream Flint Mountain SPS 8 26 100
Dwr Cymru Welsh Water Estuarial Waters Of River Dee GREENFIELD WWTW (STW) GREENFIELD 26 26 100
Dwr Cymru Welsh Water Dee FLINT DEE COTTAGES PS 13 23 100
Dwr Cymru Welsh Water River Alyn Mold Old St Davids Lane/Bridge St CSO 9 17 99.9
Dwr Cymru Welsh Water River Alyn CSO at Mold Committee's Sewerage System 24 16 100
Dwr Cymru Welsh Water River Alyn Mold Gas Lane CSO 17 15 99.9
Dwr Cymru Welsh Water River Alyn CSO at Mold Gladstone St/Glan Yr Afon Rd 20 14 99.9
Dwr Cymru Welsh Water Unnamed W/C BAGILLT STATION ROAD - SSO 6 8 99.9
Dwr Cymru Welsh Water Nant Brook Via A Ditch Leeswood Bethania SPS 4 6 99.9
Dwr Cymru Welsh Water River Alun Mynydd Isa Chambers lane/Mercia Drive CSO 4 5 99.9
Dwr Cymru Welsh Water Swinchiard Brook FLINT STW (THE MEADOWS) , , 2 4 100
Dwr Cymru Welsh Water River Alyn PONTBLYDDYN NO 1 PUMPING STATION 3 2 100
Dwr Cymru Welsh Water Stream To River Dee BOOT & SHIP PS , , 2 2 100
Dwr Cymru Welsh Water Gutter Fawr ARGOED PS 1 1 100
Dwr Cymru Welsh Water Unnamed W/C GREENFIELD A548 NR ABBEY MILL 4 1 100
Dwr Cymru Welsh Water Unnamed Watercourse Bagillt verge off Manor Drive CSO 2 0 92.4
Dwr Cymru Welsh Water Dolfechlas Brook Rhydymwyn Wastewater Treatment Works Storm Overflow 1 0 99.7
Dwr Cymru Welsh Water Unnamed W/C BAGILLT GREENACRE DRIVE - SSO 1 0 99.8
Dwr Cymru Welsh Water Nant Y Flint Lygan-Y-Wern Pentre Halkyn SPS 2 0 99.9
Dwr Cymru Welsh Water River Alyn Mold Bryn Coch Lane/Lon Y Parc CSO 1 0 99.8
Dwr Cymru Welsh Water Unnamed Watercourse MERLLYN LANE BAGILLT 1 0 99.4
Dwr Cymru Welsh Water Unnamed W/C GWESPYR OLD STW - SSO 1 0 100
Dwr Cymru Welsh Water River Wheeler YSCEIFIOG CSO 1 0 100
Dwr Cymru Welsh Water Maescoed Drain TALACRE STATION ROAD PS 0 0 0
Dwr Cymru Welsh Water River Dee GREENFIELD IND EST NO 1 HOLYWELL 0 0 50.5
Dwr Cymru Welsh Water River Dee Estuary DISCHARGE A 14 FFORDD DDYFRDWY 0 0 90.9
Dwr Cymru Welsh Water Unnamed W/C PEN Y FFORDD ADJ PEN Y FFORDD 0 0 99.1
Dwr Cymru Welsh Water River Alyn Mold Argoed CSO 0 0 99.3
Dwr Cymru Welsh Water River Y Garth SWN Y DWR CSO 0 0 0
Dwr Cymru Welsh Water River Wheeler CROOKED HORN SPS NO 3 BRYNFORD 0 0 0
Dwr Cymru Welsh Water Culverted Of Dee MOSTYN ARMS PS MOSTYN 0 0 100
Dwr Cymru Welsh Water Wepre Brook Northop Hall SPS 0 0 100
Dwr Cymru Welsh Water Surface Water Sewer Northop Hall CSO 0 0 8.7
Dwr Cymru Welsh Water Unnamed W/C HOLYWELL STRAND WALK NR STRAND 0 0 100
Dwr Cymru Welsh Water Unnamed W/C BAGILLT TYDDYN MESHAM LANE - SSO 0 0 37

Data Sources & Accuracy

EDM (Event Duration Monitoring) data and Consented Discharges to Controlled Waters with Conditions from Environment Agency & Data Map Wales

Experimental derived data from Thames Water API, Some data may be missing or inaccurate. This 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.

This project is not associated, approved or endorsed by any of the companies whose logos you see here.