Top of the Poops | Constituency - 2025 Data| Ynys Môn

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You're looking at the totals that we have calculated for sewage in Ynys Môn for 2025. It is an estimate, based on very poor quality live data from the Water Companies. This may not align with the 'official' reported sewage values from the water companies, which is reported in April following then end of the year - so 2025 numbers are reported in April 2026.

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Company	Site Name	Receiving Waterway	Overflow Days	Total Duration (hours)	Total Duration (days)
Dwr Cymru Welsh Water	Llanfachraeth WwTW Overflow	River Alaw	318	4,443 h 44m	185.12
Dwr Cymru Welsh Water	Bryngwran WwTW Overflow	Crigyll	161	2,430 h 30m	101.25
Dwr Cymru Welsh Water	Green Terrace Llangaffo Storm Overflow	Unnamed Ditch	83	1,633 h 26m	68.04
Dwr Cymru Welsh Water	Brynsiencyn WwTW Storm Overflow	Menai Strait	101	1,574 h 55m	65.58
Dwr Cymru Welsh Water	Aberffraw WwTW Storm Overflow	Aberffraw Bay	75	1,503 h 30m	62.62
Dwr Cymru Welsh Water	Craig Y Don Storm Overflow	Afon Goch	81	1,469 h 2m	61.21
Dwr Cymru Welsh Water	Menai Llandegfan Storm Overflow	Menai Strait	56	1,233 h 5m	51.38
Dwr Cymru Welsh Water	Holyhead Porth Y Felin Storm Overflow	Unnamed Ditch draining to New Harbour	68	1,183 h 15m	49.29
Dwr Cymru Welsh Water	Talwrn Llangefni Storm Overflow	Unnamed Ditch	55	1,128 h 15m	47
Dwr Cymru Welsh Water	Train Station Gaerwen Storm Overflow	Tributary of Afon Braint	52	1,103 h 15m	45.96
Dwr Cymru Welsh Water	London Road Valley Storm Overflow	Unnamed Watercourse	65	1,056 h 45m	44
Dwr Cymru Welsh Water	Lon Sardis Bodffordd Storm Overflow	Cefni Reservoir Bypass Channel	70	986 h 56m	41.08
Dwr Cymru Welsh Water	Bull Bay Storm Overflow	Bull Bay	66	900 h 30m	37.5
Dwr Cymru Welsh Water	Unknown	Unknown	36	549 h 28m	22.88
Dwr Cymru Welsh Water	Llanfair Pwllgwyngyll WwTW Storm Overflow	Menai Strait	83	480 h 30m	20
Dwr Cymru Welsh Water	Llangaffo WwTW Storm Overflow	Unnamed Stream	72	438 h 30m	18.25
Dwr Cymru Welsh Water	Pont Y Crug Llanddaniel Storm Overflow	Afon Braint	43	430 h 44m	17.92
Dwr Cymru Welsh Water	London Road Valley no.2 Storm Overflow	Unname Watercourse	52	422 h 30m	17.58
Dwr Cymru Welsh Water	Gorsllwyd Llanddona Storm Overflow	Afon Cadnant	39	395 h 8m	16.46
Dwr Cymru Welsh Water	Llanfaelog Storm Overflow	Llyn Maelog	34	382 h 22m	15.92
Dwr Cymru Welsh Water	Copperfield Close Four Mile Bridge Storm Overflow	Holy Island Straits South	29	377 h	15.71
Dwr Cymru Welsh Water	Bae Trearthur Isallt Bach Overflow	Caernarfon Bay North	25	364 h 15m	15.17
Dwr Cymru Welsh Water	Llaneilian Storm Overflow	Coastal Waters	34	362 h 15m	15.08
Dwr Cymru Welsh Water	Rhosybol Gorslwyd Storm Overflow	Unnamed Watercourse	65	351 h	14.62
Dwr Cymru Welsh Water	Llandegfan Menai Bridge Storm Overflow	Afon Cadnant	28	347 h 22m	14.46
Dwr Cymru Welsh Water	Hermon Malltraeth Storm Overflow	Afon Frechwen	27	338 h 28m	14.08
Dwr Cymru Welsh Water	Holyhead Bae Trearthur No2 Storm Overflow	Unnamed Watercourse	27	316 h 59m	13.17
Dwr Cymru Welsh Water	Holyhead Bae Trearthur No1 Storm Overflow	Estuarial Waters of the Inland Sea	28	259 h 30m	10.79
Dwr Cymru Welsh Water	Holyhead Turkey Shore Storm Overflow	Old Harbour Holyhead	65	251 h 15m	10.46
Dwr Cymru Welsh Water	Menai Ville Storm Overflow	Menai Strait	47	242 h 45m	10.08
Dwr Cymru Welsh Water	Afon Goch Lon Parys Amlwch Storm Overflow	Afon Goch	37	241 h 30m	10.04
Dwr Cymru Welsh Water	Beaumaris & Llanfaes WwTW Storm Overflow	Menai Strait	37	240 h	10
Dwr Cymru Welsh Water	Menai Bridge Faelog Causeway 1 Overflow	Menai Strait	44	238 h 15m	9.92
Dwr Cymru Welsh Water	Star Gaerwen Storm Overflow	Afon Braint	38	230 h 30m	9.58
Dwr Cymru Welsh Water	Bodedern Main Storm Overflow	River Alaw	26	224 h 45m	9.33
Dwr Cymru Welsh Water	Holyhead Morawelon Storm Overflow	Outer Harbour, Holyhead	35	206 h 30m	8.58
Dwr Cymru Welsh Water	Lon Sardis Storm Overflow	River Cefni	54	203 h 32m	8.46
Dwr Cymru Welsh Water	Newborough WwTW Storm Overflow	Afon Braint	24	180 h	7.5
Dwr Cymru Welsh Water	Holyhead WwTW Overflow	Unnamed Watercourse	50	178 h 45m	7.42
Dwr Cymru Welsh Water	Llanfechell WwTW Storm Overflow	Afon Meddanen	14	171 h 15m	7.12
Dwr Cymru Welsh Water	Gaerwen WwTW Storm Overflow	Afon Cefni	20	166 h 45m	6.92
Dwr Cymru Welsh Water	Prince of Wales Road Storm Overflow	New Harbour, Holyhead	58	166 h 15m	6.92
Dwr Cymru Welsh Water	Ffordd Y Traeth Cemaes Bay Storm Overflow	Cemaes Bay	32	161 h	6.71
Dwr Cymru Welsh Water	Gorad Beach Road Storm Overflow	Estuarial Waters of Afon Alaw	21	158 h 36m	6.58
Dwr Cymru Welsh Water	Fryars Bay Llanfaes Overflow	Menai Strait	27	145 h	6.04
Dwr Cymru Welsh Water	Menai Bridge Suspension Storm Overflow	Menai Strait	51	138 h	5.75
Dwr Cymru Welsh Water	Menai Suspension Bridge No 3 Overflow	Menai Strait	47	131 h 30m	5.46
Dwr Cymru Welsh Water	Benllech WwTW Storm Overflow	Coastal Waters - Benllech	37	113 h	4.71
Dwr Cymru Welsh Water	Llangefni Main Storm Overflow	Afon Cefni	16	112 h	4.67
Dwr Cymru Welsh Water	Amlwch Port Storm Overflow	Coastal Waters - Amlwch Harbour	15	104 h 21m	4.33
Dwr Cymru Welsh Water	Brynsciencyn Overflow	Menai Strait	12	98 h 17m	4.08
Dwr Cymru Welsh Water	Cycle Way Llangefni Storm Overflow	Afon Cefni	40	96 h 30m	4
Dwr Cymru Welsh Water	Unknown	Unknown	16	90 h 57m	3.75
Dwr Cymru Welsh Water	Brynsiencyn Main Storm Overflow	Menai Strait	12	88 h 15m	3.67
Dwr Cymru Welsh Water	Malltraeth WwTW Storm Overflow	Cefni Estuary	22	87 h 45m	3.62
Dwr Cymru Welsh Water	Llangoed Lleiniog Overflow	Menai Strait	27	86 h 57m	3.58
Dwr Cymru Welsh Water	Moelfre Car Park Storm Overflow	Coastal Waters of the Irish Sea	15	55 h 15m	2.29
Dwr Cymru Welsh Water	Llandegfan Rhianfa Overflow	Menai Strait	20	53 h 26m	2.21
Dwr Cymru Welsh Water	Fford Cae Sel Storm Overflow	Drainage Ditch	16	50 h	2.08
Dwr Cymru Welsh Water	Holyhead Hibernia Row Storm Overflow	New Harbour, Holyhead	8	37 h	1.54
Dwr Cymru Welsh Water	Beaumaris West End Overflow	Menai Strait	10	32 h 30m	1.33
Dwr Cymru Welsh Water	Gwalchmai WwTW Storm Overflow	Nant Cwyrtai	23	32 h 28m	1.33
Dwr Cymru Welsh Water	Beaumaris Green Overflow	Estuarial Waters	11	30 h 30m	1.25
Dwr Cymru Welsh Water	Pont y Brenin Overflow	Afon y Brenin	10	30 h 25m	1.25
Dwr Cymru Welsh Water	Beaumaris Green Storm Overflow	Menai Strait	10	30 h	1.25
Dwr Cymru Welsh Water	Unknown	Unknown	18	28 h 15m	1.17
Dwr Cymru Welsh Water	Lon Gardener Valley Overflow	Unnamed Watercourse	6	28 h	1.17
Dwr Cymru Welsh Water	Rhosneigr Overflow	Irish Sea	3	27 h 30m	1.12
Dwr Cymru Welsh Water	Llansadwrn Anglesy Storm Overflow	Afon Cadnant	9	27 h 19m	1.12
Dwr Cymru Welsh Water	Plas Y Ffrwd Rhosybol Storm Overflow	River Alaw	5	24 h 30m	1
Dwr Cymru Welsh Water	Rhosneigr Storm Overflow	Coastal Waters - Irish Sea	3	18 h	0.75
Dwr Cymru Welsh Water	Millbank Storm Overflow	Unnamed Watercourse	10	15 h 56m	0.62
Dwr Cymru Welsh Water	Llangefni WwTW Storm Overflow	Afon Cefni	24	12 h 30m	0.5
Dwr Cymru Welsh Water	Malltraeth Overflow	Afon Cefni	8	5 h 30m	0.21
Dwr Cymru Welsh Water	High Street Malltraeth Storm Overflow	Afon Cefni	6	5 h	0.21
Dwr Cymru Welsh Water	Benllech Old Tidal Tanks Storm Overflow	Coastal Waters - Benllech	3	4 h 29m	0.17
Dwr Cymru Welsh Water	Glyn Garth Overflow	Menai Strait	5	3 h 35m	0.12
Dwr Cymru Welsh Water	Llanfair PG Anglesey No 2 Storm Overflow	Menai Strait	6	1 h 29m	0.04
Dwr Cymru Welsh Water	Malltraeth WwTW Inlet Storm Overflow	Cefni Estuary	1	1 h 13m	0.04
Dwr Cymru Welsh Water	Penrhos Beach Holyhead Storm Overflow	Beddmanarch Bay	1	0 h 45m	0
Dwr Cymru Welsh Water	Pentraeth Tan Y Graig Storm Overflow	River Nodwydd	2	0 h 30m	0
Dwr Cymru Welsh Water	Arosfa Road Dwyran Storm Overflow	Afon Braint	1	0 h 15m	0
Dwr Cymru Welsh Water	Llanerchymedd WwTW Storm Overflow	River Alaw	1	0 h 15m	0
Dwr Cymru Welsh Water	Llansadwrn Anglesey Storm Overflow	Tributary of Afon Cadnant	1	0 h 15m	0
Dwr Cymru Welsh Water	Waterside Holyhead Storm Overflow	New Harbour, Holyhead	0	0 h	0
Dwr Cymru Welsh Water	Menai Bridge Porth Wrach No 2 Overflow	Menai Strait	0	0 h	0
Dwr Cymru Welsh Water	Unknown	Unknown	0	0 h	0
Dwr Cymru Welsh Water	Llanfaes Overflow	Unnamed Watercourse	0	0 h	0
Dwr Cymru Welsh Water	Llangoed Cynlais Overflow	Coastal Waters	0	0 h	0
Dwr Cymru Welsh Water	Lon Fain Dwyran Storm Overflow	River Braint	0	0 h	0
Dwr Cymru Welsh Water	Unknown	Unknown	0	0 h	0
Dwr Cymru Welsh Water	Aberffraw Storm Overflow	River Ffraw	0	0 h	0
Dwr Cymru Welsh Water	Gwalchmai Isaf Storm Overflow	Unnamed Watercourse	0	0 h	0
Dwr Cymru Welsh Water	Gorwelion Road Newlands Beach Storm Overflow	Estuary Afon Alaw	0	0 h	0
Dwr Cymru Welsh Water	Bae Trearthur Lon Isallt Storm Overflow	Adjacent Ditch	0	0 h	0

Ynys Môn - 2025 Sewage

Polluted by sewage 31,574 hours in 2025 - That's 3.65 years

Ynys Môn - 2025 Sewage

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Ynys Môn - 2025 Sewage Polluted by sewage 31,574 hours in 2025 - That's 3.65 years

Ynys Môn - 2025 Sewage

Which Year?

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Constituencies near Ynys Môn

Daily Data

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Ynys Môn - 2025 Sewage

Polluted by sewage 31,574 hours in 2025 - That's 3.65 years