Dwyfor Meirionnydd polluted by sewage 6,039 times in 2022 - lasting 49,174 hours

© OpenStreetMap contributors
Contains OS Data © Crown copyright & database right 2021-2022
© Top of the Poops 2021-2023
✔ means we have experimental daily data for 2023
Totals for Dwyfor Meirionnydd in 2022
104 Sites polluted by Dwr Cymru Welsh Water
6,039 sewage dumps
49,174 h duration
That's 5.69 years! On average 16.5 times a day

Pollution Summary 2022

Here are all the reported sewage overflow totals for Dwyfor Meirionnydd in 2022. Sometimes sewage can be being dumped for months at a time.

Company Waterway Site Sewage Dumps Duration (Hours) Reporting %
Dwr Cymru Welsh Water River Erch Abererch WwTW Storm Overflow 224 4,298 99.9
Dwr Cymru Welsh Water River Rhyd Hir CSO at Llithfaen WwTW 144 2,672 100
Dwr Cymru Welsh Water River Glaslyn Settled Storm at Beddgelert Waste Water Treatment 157 2,596 100
Dwr Cymru Welsh Water River Erch CSO at Four Crosses STW 238 2,491 100
Dwr Cymru Welsh Water River Goedol BLAENAU FFESTINIOG WWTW (Settled STORM) 146 2,482 100
Dwr Cymru Welsh Water River Llyfni Settled Storm Sewage at Llanllyfni WwTW 175 2,077 84.8
Dwr Cymru Welsh Water Tremadog Bay Criccieth STW CSO to Settled Storm Sewage Tanks 140 2,034 99.8
Dwr Cymru Welsh Water Nant Brisgyll CSO at Llan Ffestiniog Sewage Treatment Works 271 2,010 99.6
Dwr Cymru Welsh Water Coastal Waters FAIRBOURNE WWTW STORM TANKS 91 1,657 100
Dwr Cymru Welsh Water Tyddyn Drain To Coastal Waters TREFOR WWTW 127 1,514 49.55
Dwr Cymru Welsh Water River Glaslyn CSO at Porthmadog Borth-Y-Gest SPS 103 1,316 99.8
Dwr Cymru Welsh Water Mawddach Llanelltyd PS CSO 85 1,283 79.4
Dwr Cymru Welsh Water Cwmllechen BONTDDU STW 106 1,202 100
Dwr Cymru Welsh Water River Wen CSO at Chwilog STW 96 1,187 100
Dwr Cymru Welsh Water Coastal Waters Of Cardigan Bay TYWYN STW MORFA GWYLLT TYWYN 81 1,037 99.8
Dwr Cymru Welsh Water River Rhyd Hir LLANNOR STW (SETTLED STORM) 120 950 100
Dwr Cymru Welsh Water River Geirch NEFYN WWTW 103 919 100
Dwr Cymru Welsh Water River Cedron PENTREFELIN STW 97 870 99.9
Dwr Cymru Welsh Water River Tafarn Helyg GELLILYDAN STW (SETTLED STORM) 110 801 99.6
Dwr Cymru Welsh Water River Llyfni Pontllyfni STW-CSO Pontllyfni 53 725 100
Dwr Cymru Welsh Water River Dee Bala WwTW Storm Tank 89 691 99.4
Dwr Cymru Welsh Water Nant Brisgyll CSO at Llanffestiniog STW 93 659 99.6
Dwr Cymru Welsh Water Estuarial Waters Of River Dwyryd MAENTWROG WWTW 91 657 100
Dwr Cymru Welsh Water Dulas LOWER CORRIS STW 53 641 100
Dwr Cymru Welsh Water Unnamed Stream MYNYTHO STW - STORM OVERFLOW 100 640 91.6
Dwr Cymru Welsh Water River Dwyryd Penrhyndeudraeth CSO 88 616 99.9
Dwr Cymru Welsh Water River Rhyd Hir Settled Storm Overflow at Efailnewydd Wastewater Treatment Works 173 595 99.9
Dwr Cymru Welsh Water River Ceunant Sych CSO at Land Off A496 Manod Blaenau Ffesti 101 554 97.7
Dwr Cymru Welsh Water River Goedol CSO at Land Off Pencefn Road Tanygrisiau 91 531 98.5
Dwr Cymru Welsh Water River Dyfrdwy The Eagles CSO, Llanwchllyn 52 514 99.2
Dwr Cymru Welsh Water River Bowydd CWM BOWYDD SSO BLAENAU FFESTINIOG 90 496 100
Dwr Cymru Welsh Water River Barlwyd LAND OPP GLANLLYN NR OAKLEY SQUARE CSO 97 428 100
Dwr Cymru Welsh Water Llyfni PONTLLYFNI PS 77 425 100
Dwr Cymru Welsh Water Caernarfon Bay NEFYN PUMPING STATION 99 421 100
Dwr Cymru Welsh Water River Artro LLANBEDR TERMINAL PS (STORM) 47 386 74
Dwr Cymru Welsh Water Cardigan Bay BARMOUTH WWTW LONG SEA OUTFALL 175 369 99.8
Dwr Cymru Welsh Water River Glaslyn CSO at Beddgelert East Bank Afon Glaslyn 62 358 75.8
Dwr Cymru Welsh Water River Mawddach Penmaenpool PS 56 356 74.8
Dwr Cymru Welsh Water Cyt Bach Surface Watercourse SNOWDON STREET PS 103 348 99.6
Dwr Cymru Welsh Water Tremadog Bay MORFA BYCHAN WWTW 71 321 98.7
Dwr Cymru Welsh Water Unnamed Stream Clynnog Fawr CSO at PS 91 282 96
Dwr Cymru Welsh Water Tremadog Bay CRICCIETH WEST PS , , 33 263 99.4
Dwr Cymru Welsh Water River Blaen-Y-Cae BRYNCIR STW 81 262 99.9
Dwr Cymru Welsh Water River Dwyfor CSO at Garndolbenmaen STW 21 237 100
Dwr Cymru Welsh Water Dwyryd PENRHYNDEUDRAETH OUTFALL-SCREE 28 228 100
Dwr Cymru Welsh Water Tremadog Bay LLANDANWG TERMINAL PS 29 227 99.7
Dwr Cymru Welsh Water River Eden CSO at BRONABER STW 55 211 99.9
Dwr Cymru Welsh Water River Rhydhir LON COB BACH PS PWLLHELI 50 207 99.7
Dwr Cymru Welsh Water Tremadog Bay HARLECH TERMINAL PS (OUTFALL A) 17 206 99.9
Dwr Cymru Welsh Water Dyffryn Main Drain DYFFRYN ARDUDWY WWTW STORM 30 199 100
Dwr Cymru Welsh Water A Stream On Nw Boundary Of The Site CSO at Talsarnau SPS 54 195 100
Dwr Cymru Welsh Water Coastal Waters CRICCIETH EAST PS , , 20 182 96.5
Dwr Cymru Welsh Water Unnamed Stream HARLECH TERMINAL PS (OUTFALL B) 16 161 99.9
Dwr Cymru Welsh Water Tremadog Bay CRICCIETH WEST PS 24 156 99.5
Dwr Cymru Welsh Water River Prysor Trawsfynydd Maesgwindy Est CSO 82 139 99.1
Dwr Cymru Welsh Water River Geirch MORFA NEFYN PUMPING STATION CSO (B) 70 131 95.7
Dwr Cymru Welsh Water Desach ABERDESACH PS 91 118 99.9
Dwr Cymru Welsh Water River Dysynni Abergynolwyn STW (Settled Storm) 39 116 100
Dwr Cymru Welsh Water River Prysor CSO at Trawsfynydd WwTW 13 112 5.8
Dwr Cymru Welsh Water Dysynni Low Level Drainage Cha TYWYN STW MORFA GWYLLT TYWYN , 35 110 99.8
Dwr Cymru Welsh Water Tremadog Bay Llanbedrog SPS 7 109 100
Dwr Cymru Welsh Water River Dyfi ABERDYFI WHARF PS SEAVIEW TERRACE 16 109 100
Dwr Cymru Welsh Water Unnamed Ditch ARTHOG TERRACE SEWAGE PUMPING ST 18 104 99.9
Dwr Cymru Welsh Water River Geirch Edern SPS CSO 29 93 100
Dwr Cymru Welsh Water River Penrhos CSO at Penrhos WwTW 52 91 98.9
Dwr Cymru Welsh Water River Wnion Marian Mawr CSO 57 85 99.8
Dwr Cymru Welsh Water River Wen AFONWEN WWTW PS 20 85 100
Dwr Cymru Welsh Water River Wnion STAYLITTLE LANE CSO 39 71 100
Dwr Cymru Welsh Water Ffos Ddu Marian Mawr Splitter Chamber CSO 17 48 100
Dwr Cymru Welsh Water Coastal Waters - River Daron ABERDARON PS 23 40 100
Dwr Cymru Welsh Water River Y Llan Llanfachreth STW (Storm) CSO 14 39 100
Dwr Cymru Welsh Water Nant Y Cyt CHAPEL STREET/MADOG STREET PORTHM 98 37 98.8
Dwr Cymru Welsh Water Ditch Idris Villas Sewage Pumping Station 21 30 87.6
Dwr Cymru Welsh Water Coastal Waters Llwyngwril SPS 14 30 100
Dwr Cymru Welsh Water Groundwater Via Infiltration System ST MARY'S SEWAGE PUMPING STATION 19 27 100
Dwr Cymru Welsh Water Unnamed Ditch CASTELL PUMPING STATION 5 27 99.9
Dwr Cymru Welsh Water River Henddol FAIRBOURNE PUMPING STATION 6 26 100
Dwr Cymru Welsh Water Cardigan Bay BARMOUTH WWTW OUTFALL TO MLWS 16 25 94.8
Dwr Cymru Welsh Water River Glaslyn BORTH Y GES PS 32 24 100
Dwr Cymru Welsh Water Unnamed Ditch GLASFRYN TERRACE STW ARTHOG 5 24 98.6
Dwr Cymru Welsh Water Glaslyn Estuary Within Glaslyn PORTHMADOG STW STORM STORAGE PORT 10 23 96.6
Dwr Cymru Welsh Water Un-Named Stream PORTHMADOG - LOMBARD STREET SS 39 23 73
Dwr Cymru Welsh Water River Prysor CSO at Trawsfynydd Near Bron Gwyndy 14 16 78.8
Dwr Cymru Welsh Water River Cyll-Y-Felin CSO at Aberdaron WwTW 2 15 100
Dwr Cymru Welsh Water Mawddach Estuary BARMOUTH HARBOUR PUMPING STATION 9 9 100
Dwr Cymru Welsh Water Dulas North Minffordd St CSO, Corris 4 8 99.9
Dwr Cymru Welsh Water Unnamed Stream Trefor CSO 21 8 99.7
Dwr Cymru Welsh Water Un-Named Watercourse BRYNCOCH SEWAGE PUMPING STATION 3 7 100
Dwr Cymru Welsh Water Stream Leading To Cyt Stre TREMADOG SSO 6 6 100
Dwr Cymru Welsh Water Un-Named Watercourse LLANERCH CSO 20 6 98.1
Dwr Cymru Welsh Water River Bowydd Blaenau Ffestiniog WWTW Settled Storm (B) 4 5 100
Dwr Cymru Welsh Water Unnamed Stream CSO Rear Of Prysor Filling Station Traw 10 4 100
Dwr Cymru Welsh Water River Mawddach Dolgellau Main PS 2 2 100
Dwr Cymru Welsh Water Tremadog Bay CSO ON SEWER (CRICCIETH BEACH) 2 2 93.8
Dwr Cymru Welsh Water Glaslyn Estuary PORTHMADOG STW STORM STORAGE PORT 3 2 99.6
Dwr Cymru Welsh Water Barlwyd BLAENAU FFESTINIOG NO2 5 2 50
Dwr Cymru Welsh Water River Dysynni Abergynolwyn SPS 6 2 100
Dwr Cymru Welsh Water River Mawddach Llanelltyd CSO 7 2 98.9
Dwr Cymru Welsh Water Unnamed Stream FRIOG SEWAGE PUMPING STATION 3 2 99.8
Dwr Cymru Welsh Water River Bowydd Blaenau Ffestiniog CSO No 3 2 0 100
Dwr Cymru Welsh Water Mawddach MAWDDACH CRESCENT PUMPING STATION 1 0 99.8
Dwr Cymru Welsh Water River Dwyryd Harlech Rum Hole CSO 2 0 99.8
Dwr Cymru Welsh Water Esturial Waters River Erch GLAN Y DON PS PWLLHELI 1 0 96.1
Dwr Cymru Welsh Water Esturial Waters Of River Erch GIMBLET ROCK TIDAL TANK CSO 1 0 99.9
Dwr Cymru Welsh Water Groundwater Via Infiltration System WESLEYAN TERRACE SEWAGE PUMPING ST 0 0 100
Dwr Cymru Welsh Water River Dwyfawr LLANYSTUMDWY PUMPING STATION 0 0 100
Dwr Cymru Welsh Water Angell Aberangell No1 PS 0 0 0
Dwr Cymru Welsh Water Tremadog Bay CSO at Llandanwg SPS 0 0 100
Dwr Cymru Welsh Water River Glaslyn AMMANDA TERRACE BORTH Y GEST PORTHM 0 0 37.3
Dwr Cymru Welsh Water Tremadog Bay CRICCIETH EAST PS 0 0 0
Dwr Cymru Welsh Water River Soch Estuary ABERSOCH HARBOUR PUMPING STATION 0 0 100
Dwr Cymru Welsh Water River Dwyryd MAENTWROG CSO 0 0 0
Dwr Cymru Welsh Water River Rhyd Hir Estuary Y MAES CSO 0 0 100
Dwr Cymru Welsh Water River Erch BRIDGE GARAGE PWLLHELI 0 0 100
Dwr Cymru Welsh Water River Geirch NEFYN WWTW (CONT. S/WATER OUTFALL) 0 0 0
Dwr Cymru Welsh Water Un-Named Stream MORFA BYCHAN WWTW 0 0 98.7
Dwr Cymru Welsh Water Unnamed Culvert To River Artro Llanbedr CSO 0 0 99.4
Dwr Cymru Welsh Water Nant Y Cyt BAKERS LANE/CHANDLERS PLACE PORTH 0 0 100
Dwr Cymru Welsh Water Unnamed Stream HARLECH OUTSIDE LAUNDRY 0 0 0
Dwr Cymru Welsh Water River Dwyfawr Llanystumdwy (W Porthmadog) A (Settled Storm) 0 0 0
Dwr Cymru Welsh Water River Glaslyn BRITANNIA PS 0 0 78.4
Dwr Cymru Welsh Water Esturial Waters Of River Erch MORFA GARREG PS PWLLHELI 0 0 99.9

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.