Storm overflow register · 2025 annual return

United Utilities storm overflows, 2025

United Utilities reported 2,270 storm overflows in England for 2025. Together they recorded 60,843 spills over 327,452 hours, an average of 26.8 spills per overflow against 20.4 across England. That ranks 9 of 10 companies, where 1 is the fewest spills per overflow. Counting the same overflows in both years, spills were down 23% on 2024.

295 overflows did not spill · 313 spilled more than 60 times · 2,076 had monitors working for 90% of the year or more · 289 sewage treatment works with overflows

Hours spilling by month, 2025

Hours spilling, all United Utilities overflows, from the start/stop records. Spills running across a month end are split between the months.

All United Utilities storm overflows

Sorted by hours spilling. Open an overflow for its permit, location, reasons for high spills and improvement status.

Overflow	Discharges to	Spills 2025	Hours 2025	Spills vs 2024	Monitor uptime
Victoria Rd/Orvietto Avenue CSO Overflow on sewer network Company site name Victoria Road/Orvietto Avenue CSO EA ID / permit UUP01999 · 016993481 Outlet location SJ7844099750 (OS grid reference) · View on Apple Maps WFD catchment Irwell / Manchester Ship Canal (Irk to confluence with Upper Mersey) (GB112069061452) 2024 spills / hours 1 / 0.1 Long-term average 4.7 spills a year (monitored since 2019) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 0.6 hours spilling →	Gilda Brook via SWS	2	0.6	up 100%	100%
Rockliffe Road/River Street CSO Overflow on sewer network Company site name ROCKCLIFFE ROAD / RIVER STREET CSO EA ID / permit UUP01678 · 01ROS0015 Outlet location SD8690022430 (OS grid reference) · View on Apple Maps WFD catchment Irwell (Source to Whitewell Brook) (GB112069064660) 2024 spills / hours 6 / 1.4 Long-term average 4.8 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.6 hours spilling →	River Irwell	3	0.6	down 50%	100%
Trafalgar Street /Ramsey Street CSO Overflow on sewer network Company site name Trafalgar Street/Ramsey Street Combined Sewer Overflow EA ID / permit UUP01962 · NPSWQD010102 Outlet location SD9045013510 (OS grid reference) · View on Apple Maps WFD catchment Roch (Source to Spodden) (GB112069064720) 2024 spills / hours 1 / 0.2 Long-term average 5.8 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.6 hours spilling →	River Roch via SWS	2	0.6	up 100%	100%
Beechwood Road CSO Overflow on sewer network Company site name Beechwood Road CSO EA ID / permit UUP00214 · EPRBP3624GH Outlet location SD6945029050 (OS grid reference) · View on Apple Maps WFD catchment Blakewater (GB112071065310) 2024 spills / hours 1 / 0.6 Long-term average 9.7 spills a year (monitored since 2020) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 0.6 hours spilling →	River Blakewater	3	0.6	up 200%	100%
Notre Dame Gardens CSO Overflow on sewer network EA ID / permit UUP01414 · 01BBN0066 Outlet location SD6910028990 (OS grid reference) · View on Apple Maps WFD catchment Blakewater (GB112071065310) 2024 spills / hours 2 / 1.4 Long-term average 2.2 spills a year (monitored since 2021) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 0.6 hours spilling →	River Blakewater	1	0.6	down 50%	100%
Broomhall SPS Storm discharge at pumping station Company site name Sandford Banks PS EA ID / permit UUP00349 · 016810292 Outlet location SJ6220047200 (OS grid reference) · View on Apple Maps WFD catchment Weaver (Marbury Brook to Barnett Brook) (GB112068055470) 2024 spills / hours 4 / 34 Long-term average 2.5 spills a year (monitored since 2024) Monitor below 90% Sensor failure / issue · Resolved - Nov Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.5 hours spilling →	Trib River Weaver	1	0.5	down 75%	81%
Beechwood Avenue CSO Overflow on sewer network Company site name Beechwood Avenue CSO EA ID / permit UUP00213 · 016982989 Outlet location SJ2905092100 (OS grid reference) · View on Apple Maps WFD catchment The Birket including Arrowe Brook and Fender (GB112068060530) Bathing water Wallasey 2024 spills / hours 1 / 0.1 Long-term average 1.2 spills a year (monitored since 2017) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.5 hours spilling →	Bidston Stream	1	0.5	no change	99%
Boardshaw Road CSO Overflow on sewer network Company site name Boardshaw Road CSO EA ID / permit UUP00263 · 016950217 Outlet location SD8752006470 (OS grid reference) · View on Apple Maps WFD catchment Irk (Sourtce to Wince Brook) (GB112069061161) 2024 spills / hours 0 / 0.0 Long-term average 2.5 spills a year (monitored since 2020) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 0.5 hours spilling →	Whit Brook, Trib of River Irk	2	0.5	up from 0	100%
Wellington Road CSO Overflow on sewer network EA ID / permit UUP02071 · 01BBN0024 Outlet location SD6729027040 (OS grid reference) · View on Apple Maps WFD catchment Darwen - conf Davy Field Bk to conf Blakewater (GB112071065270) 2024 spills / hours 2 / 0.8 Long-term average 3.2 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.5 hours spilling →	River Darwen	2	0.5	no change	100%
South Street/Pickup Street CSO Overflow on sewer network Company site name SOUTH STREET / PICKUP STREET CSO EA ID / permit UUP01791 · 01ROS0020 Outlet location SD8694022940 (OS grid reference) · View on Apple Maps WFD catchment Irwell (Source to Whitewell Brook) (GB112069064660) 2024 spills / hours 6 / 3.5 Long-term average 5.7 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.5 hours spilling →	River Irwell	4	0.5	down 33%	98%
Schneider Road CSO Overflow on sewer network Company site name Schneider Road CSO EA ID / permit UUP01724 · 017480361 Outlet location SD1958070871 (OS grid reference) · View on Apple Maps WFD catchment Furness Permo-Triassic sandstone aquifers (GB41201G101900) Bathing water Walney West Shore Shellfish water Walney 2024 spills / hours 1 / 0.8 Long-term average 49.9 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement Env Act (SODRP) improvement ongoing Volume & pollution Estimate from 0.5 hours spilling →	Ormsgill Reservoir	3	0.5	up 200%	100%
Lime Street Network Pumping Station Storm discharge at pumping station Company site name Lime Street Wastewater Network Pumping Station EA ID / permit UUP01142 · 017670160 Outlet location NY3999055350 (OS grid reference) · View on Apple Maps WFD catchment Caldew d/s Caldbeck (GB102076073880) 2024 spills / hours 0 / 0.0 Long-term average 22.5 spills a year (monitored since 2020) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 0.5 hours spilling →	River Caldew	1	0.5	up from 0	100%
Stockport Road West CSO Overflow on sewer network Company site name Stockport Road West CSO EA ID / permit UUP01864 · 01STK0012 Outlet location SJ9102091120 (OS grid reference) · View on Apple Maps WFD catchment Goyt (Etherow to Mersey) (GB112069061000) 2024 spills / hours 11 / 103 Long-term average 3.4 spills a year (monitored since 2021) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.5 hours spilling →	River Goyt via SWS	3	0.5	down 73%	100%
Central Avenue CSO Overflow on sewer network Company site name Central Avenue CSO EA ID / permit UUP00434 · 01MAN0008 Outlet location SD8541001790 (OS grid reference) · View on Apple Maps WFD catchment Irk (Wince to Irwell) (GB112069061131) 2024 spills / hours 2 / 0.6 Long-term average 4.5 spills a year (monitored since 2019) Monitor below 90% Sensor failure / issue · Resolved - Aug Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 0.5 hours spilling →	River Irk	2	0.5	no change	73%
Hayton Pumping Station Storm discharge at pumping station Company site name Hayton PS EA ID / permit UUP00926 · 017680324 Outlet location NY5048057930 (OS grid reference) · View on Apple Maps WFD catchment Irthing DS Crammel Linn Waterfall (GB102076073981) 2024 spills / hours 9 / 33 Long-term average 6.3 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.5 hours spilling →	Bye Gill	6	0.5	down 33%	100%
Bromley Road CSO Overflow on sewer network Company site name Bromley Road CSO EA ID / permit UUP00339 · 016892195 Outlet location SJ8670063170 (OS grid reference) · View on Apple Maps WFD catchment Dane (Cow Brook to Wheelock) (GB112068060190) 2024 spills / hours 19 / 4.1 Long-term average 16.2 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement Env Act (SODRP) improvement ongoing Volume & pollution Estimate from 0.5 hours spilling →	River Dane via SWS	2	0.5	down 89%	99%
Linethwaite Pumping Station Storm discharge at pumping station Company site name Linethwaite PS EA ID / permit UUP01149 · 017480475 Outlet location NX9917014000 (OS grid reference) · View on Apple Maps WFD catchment Pow Beck (South West Lakes) (GB112074069990) Bathing water St Bees 2024 spills / hours 1 / 0.2 Long-term average 7.3 spills a year (monitored since 2018) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.5 hours spilling →	Needless Beck	1	0.5	no change	100%
Edleston Road No 2 CSO Overflow on sewer network Company site name Edleston Road No 2 CSO EA ID / permit UUP00691 · 016892253 Outlet location SJ7052055320 (OS grid reference) · View on Apple Maps WFD catchment Valley Brook (Englesea Brook to Weaver) (GB112068055310) 2024 spills / hours 0 / 0.0 Long-term average 1.7 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.4 hours spilling →	Valley Brook	2	0.4	up from 0	99%
The CSO at Main Street Overflow on sewer network Company site name The CSO at Main Street EA ID / permit UUP01917 · 017580276 Outlet location NY0711628810 (OS grid reference) · View on Apple Maps WFD catchment Marron (GB112075070540) 2024 spills / hours 1 / 0.4 Long-term average 2.9 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.4 hours spilling →	Townsend Beck	4	0.4	up 300%	97%
Cross Street CSO Overflow on sewer network Company site name Cross Street CSO EA ID / permit UUP00572 · 016982777 Outlet location SD6149004420 (OS grid reference) · View on Apple Maps WFD catchment Hey/Borsdane Brook (GB112069064520) 2024 spills / hours 0 / 0.0 Long-term average 4.0 spills a year (monitored since 2020) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 0.4 hours spilling →	Culvrtd Section Hockery Brook	1	0.4	up from 0	99%
103 Brinksway/Lark Hill Overflow on sewer network Company site name 103 Brinksway/Lark Hill CSO EA ID / permit UUP00004 · 016982676 Outlet location SJ8845089970 (OS grid reference) · View on Apple Maps WFD catchment Mersey (upstream of Manchester Ship Canal) (GB112069061030) 2024 spills / hours 4 / 0.4 Long-term average 4.5 spills a year (monitored since 2024) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 0.4 hours spilling →	River Mersey	5	0.4	up 25%	100%
Lightbounds Rd Lvaine Ave CSO 072CO Overflow on sewer network Company site name LIGHTBOUNDS ROAD / LOUVAINE AVENUE CSO EA ID / permit UUP01139 · 01BOL0070 Outlet location SD6888011330 (OS grid reference) · View on Apple Maps WFD catchment Astley Brook (Irwell) (GB112069064560) 2024 spills / hours 1 / 0.2 Long-term average 6.7 spills a year (monitored since 2018) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.4 hours spilling →	Astley Brook	2	0.4	up 100%	97%
Mill Lane CSO 425E6 Overflow on sewer network Company site name Mill Lane CSO EA ID / permit UUP01312 · 01STH0049 Outlet location SJ5928395291 (OS grid reference) · View on Apple Maps WFD catchment Millingford (Newton) Brook (GB112068055360) 2024 spills / hours 3 / 17 Long-term average 29.0 spills a year (monitored since 2021) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.4 hours spilling →	Newton Brook	2	0.4	down 33%	100%
Lightfoot Lane PS Storm discharge at pumping station Company site name Lightfoot Lane PS EA ID / permit UUP01140 · 01PRE0081 Outlet location SD5115033320 (OS grid reference) · View on Apple Maps WFD catchment Woodplumpton Brook (GB112072065760) 2024 spills / hours 0 / 0.0 Long-term average 0.5 spills a year (monitored since 2024) Monitor below 90% Sensor failure / issue · Resolved - Nov Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.4 hours spilling →	Unamed Trib Woodplumpton Brook	1	0.4	up from 0	80%
Burton St nr Dalton St CSO 281HX Overflow on sewer network Company site name Burton Street near Dalton Street CSO EA ID / permit UUP00376 · 016982622 Outlet location SJ8486099630 (OS grid reference) · View on Apple Maps WFD catchment Irk (Wince to Irwell) (GB112069061131) 2024 spills / hours 0 / 0.0 Long-term average 8.9 spills a year (monitored since 2019) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 0.4 hours spilling →	River Irk	2	0.4	up from 0	100%
Hawthorn Crescent CSO Overflow on sewer network Company site name Hawthorn Crescent CSO EA ID / permit UUP00921 · NPSWQD010099 Outlet location SD4948029980 (OS grid reference) · View on Apple Maps WFD catchment RIBBLE_Transitional (GB531207112400) Bathing water St Annes Shellfish water Ribble 2024 spills / hours 12 / 4.7 Long-term average 12.3 spills a year (monitored since 2018) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.4 hours spilling →	River Ribble	3	0.4	down 75%	99%
134 Burnley Road CSO Overflow on sewer network Company site name 134 Burnley Road CSO EA ID / permit UUP00007 · 017180606 Outlet location SD8457035940 (OS grid reference) · View on Apple Maps WFD catchment Calder - Pendle Water to conf Ribble (GB112071065490) 2024 spills / hours 3 / 0.2 Long-term average 17.0 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.4 hours spilling →	Pendle Water via Culvert	4	0.4	up 33%	100%
Windsor Grove Overflow on sewer network Company site name Windsor Grove CSO EA ID / permit UUP02142 · 01HAL0126 Outlet location SJ5176782097 (OS grid reference) · View on Apple Maps WFD catchment Bridgewater Canal (GB71210001) 2024 spills / hours 8 / 1.6 Long-term average 61.0 spills a year (monitored since 2016) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.4 hours spilling →	Willow Brook	2	0.4	down 75%	99%
Limbrick Pumping Station Storm discharge at pumping station Company site name Limbrick Pumping Station (12024) (CHR0030) EA ID / permit UUP01141 · 01CHR0030 Outlet location SD6003016340 (OS grid reference) · View on Apple Maps WFD catchment Yarrow US Big Lodge Water (GB112070064951) 2024 spills / hours 5 / 0.6 Long-term average 11.7 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.4 hours spilling →	River Yarrow	2	0.4	down 60%	100%
Mount Street/Greek Street CSO Overflow on sewer network Company site name MOUNT STREET / GREEK STREET CSO EA ID / permit UUP01359 · 01MAN0187 Outlet location SJ8453097390 (OS grid reference) · View on Apple Maps WFD catchment Medlock (Lumb Brook to Irwell) (GB112069061152) 2024 spills / hours 1 / 0.2 Long-term average 4.5 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.4 hours spilling →	River Medlock	2	0.4	up 100%	96%
Church Street West CSO Overflow on sewer network Company site name Church Street West CSO EA ID / permit UUP00485 · 016993584 Outlet location SD7662010460 (OS grid reference) · View on Apple Maps WFD catchment Irwell (Roch to Croal) (GB112069060840) 2024 spills / hours 3 / 1.6 Long-term average 2.9 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.4 hours spilling →	Unnamed Pond	1	0.4	down 67%	100%
Moricambe Park PS 02540 Storm discharge at pumping station Company site name Moricambe Park PS EA ID / permit UUP01341 · 017580248 Outlet location NY1282055840 (OS grid reference) · View on Apple Maps WFD catchment SOLWAY (GB530207614700) Bathing water Silloth 2024 spills / hours 5 / 0.5 Long-term average 11.4 spills a year (monitored since 2017) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 0.3 hours spilling →	Great Gutter Estuarine Water	1	0.3	down 80%	100%
Standedge Rd Diggle SSO Overflow on sewer network Company site name Standedge Road SSO EA ID / permit UUP01841 · 016982528 Outlet location SD9985006900 (OS grid reference) · View on Apple Maps WFD catchment Tame (Source to Chew Brook) (GB112069064741) 2024 spills / hours 2 / 0.8 Long-term average 1.5 spills a year (monitored since 2024) Monitor below 90% Sensor failure / issue · Resolved - Sep Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.3 hours spilling →	Diggle Brook	1	0.3	down 50%	83%
Willaston Relief Sewer Overflow on sewer network Company site name Willaston Relief Sewer EA ID / permit UUP02133 · 016810794 Outlet location SJ3412078180 (OS grid reference) · View on Apple Maps WFD catchment Dibbinsdale Brook and Clatter Brook (GB112068060270) 2024 spills / hours 2 / 1.1 Long-term average 1.5 spills a year (monitored since 2024) Monitor below 90% Sensor failure / issue · Resolved - Sep Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 0.3 hours spilling →	Trib Dibbinsdale Brook	1	0.3	down 50%	85%
Manor Road CSO (052ER) Overflow on sewer network Company site name MANOR ROAD CSO EA ID / permit UUP01247 · 01BBN0068 Outlet location SD6701027830 (OS grid reference) · View on Apple Maps WFD catchment Blakewater (GB112071065310) 2024 spills / hours 1 / 0.2 Long-term average 2.6 spills a year (monitored since 2021) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 0.3 hours spilling →	River Blakewater	3	0.3	up 200%	97%
Whalley Range/Grace Street CSO Overflow on sewer network Company site name Whalley Range CSO EA ID / permit UUP02101 · 01BBN0049 Outlet location SD6873028890 (OS grid reference) · View on Apple Maps WFD catchment Blakewater (GB112071065310) 2024 spills / hours 4 / 0.4 Long-term average 3.0 spills a year (monitored since 2020) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 0.3 hours spilling →	River Blakewater	3	0.3	down 25%	100%
Whalley Range/Millham Street CSO Overflow on sewer network Company site name WHALLEY RANGE / MILLHAM STREET CSO EA ID / permit UUP02102 · 01BBN0048 Outlet location SD6862028780 (OS grid reference) · View on Apple Maps WFD catchment Blakewater (GB112071065310) 2024 spills / hours 4 / 0.4 Long-term average 6.0 spills a year (monitored since 2020) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 0.3 hours spilling →	River Blakewater via SWS	3	0.3	down 25%	100%
Waterside Combined Sewer Overflow Overflow on sewer network Company site name Waterside CSO EA ID / permit UUP02050 · 016982850 Outlet location SJ9810086400 (OS grid reference) · View on Apple Maps WFD catchment Goyt (Sett to Etherow) (GB112069060960) 2024 spills / hours 2 / 0.5 Long-term average 9.9 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.3 hours spilling →	River Goyt	1	0.3	down 50%	97%
Dane Avenue/Wheatclose Road CSO Overflow on sewer network Company site name Dane Avenue/Wheatclose Road CSO EA ID / permit UUP00605 · 017480444 Outlet location SD2194069334 (OS grid reference) · View on Apple Maps WFD catchment Mill Beck (Poaka Beck) (GB112074069790) Bathing water Walney West Shore Shellfish water Walney; Roosebeck 2024 spills / hours – / – Long-term average 18.5 spills a year (monitored since 2018) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 0.3 hours spilling →	Mill Beck	1	0.3		100%
Tbc Overflow on sewer network Company site name Waygreen Cottages CSO (399KS) EA ID / permit UUP02283 · Permit applied for Outlet location SD3286985685 (OS grid reference) · View on Apple Maps WFD catchment Leven (GB112073071420) 2024 spills / hours 0 / 0.0 Long-term average 0.5 spills a year (monitored since 2024) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.3 hours spilling →	Wear Beck	1	0.3	up from 0	99%
Belmont WwTW Inlet overflow at sewage works Sewage works Belmont Company site name BELMONT WwTW EA ID / permit UUP00220 · 016950031 Outlet location SD6833015750 (OS grid reference) · View on Apple Maps WFD catchment Eagley Brook (GB112069064570) 2024 spills / hours 0 / 0.0 Long-term average 1.1 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.3 hours spilling →	Eagley Brook	2	0.3	up from 0	100%
Battery Lane CSO Overflow on sewer network Company site name Battery Lane CSO EA ID / permit UUP00203 · 016930972 Outlet location SJ3320092000 (OS grid reference) · View on Apple Maps WFD catchment MERSEY - Transitional (GB531206908100) Bathing water Wallasey Shellfish water North Wirral (East) 2024 spills / hours 10 / 2.2 Long-term average 4.9 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.3 hours spilling →	The Mersey Estuary	2	0.3	down 80%	100%
Cecil Road/Ashley Road CSO Overflow on sewer network Company site name Cecil Road/Ashley Road CSO EA ID / permit UUP00432 · 01TRA0012 Outlet location SJ7682085960 (OS grid reference) · View on Apple Maps WFD catchment Bollin (Ashley Mill to Manchester Ship Canal) (GB112069061382) 2024 spills / hours 0 / 0.0 Long-term average 0.2 spills a year (monitored since 2021) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.3 hours spilling →	Trib of River Bollin via SWS	1	0.3	up from 0	100%
Chapel Green Road/Bridgewater St Overflow on sewer network Company site name Chapel Green Road/Bridgewater Street CSO EA ID / permit UUP00441 · 01WIG0060 Outlet location SD6199004420 (OS grid reference) · View on Apple Maps WFD catchment Hey/Borsdane Brook (GB112069064520) 2024 spills / hours 0 / 0.0 Long-term average 0.5 spills a year (monitored since 2024) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 0.3 hours spilling →	Borsdane Brook	1	0.3	up from 0	100%
Manchester Rd CSO (363F2) Overflow on sewer network Company site name Manchester Road (Bent Street) CSO EA ID / permit UUP01229 · 01ROS0038 Outlet location SD7937022010 (OS grid reference) · View on Apple Maps WFD catchment Irwell (Cowpe Bk to Rossendale STW) (GB112069064641) 2024 spills / hours 2 / 0.9 Long-term average 1.2 spills a year (monitored since 2021) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.3 hours spilling →	Culverted Langwood Brook	2	0.3	no change	100%
Junction of Graver Ln Elsma Rd CSO Overflow on sewer network Company site name Junction of GRAVER LANE and ELSMA ROAD CSO EA ID / permit UUP01044 · 01MAN0104 Outlet location SJ8896099500 (OS grid reference) · View on Apple Maps WFD catchment Medlock (Lumb Brook to Irwell) (GB112069061152) 2024 spills / hours 0 / 0.0 Long-term average 1.7 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.3 hours spilling →	Berry Brow Culvert	1	0.3	up from 0	100%
Footpath nr Cross St CSO Overflow on sewer network Company site name Footpath Near Cross Street CSO EA ID / permit UUP00750 · 017190822 Outlet location SD6975021230 (OS grid reference) · View on Apple Maps WFD catchment Darwen - headwaters to conf Davy Field Bk (GB112071065240) 2024 spills / hours 2 / 2.6 Long-term average 1.8 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.3 hours spilling →	River Darwen	3	0.3	up 50%	100%
95 Mill Lane (St. Helens) CSO Overflow on sewer network Company site name 95 Mill Lane (St.Helens) CSO EA ID / permit UUP01315 · 016982531 Outlet location SJ5279792612 (OS grid reference) · View on Apple Maps WFD catchment Sutton Brook (GB112069061170) 2024 spills / hours 3 / 1.6 Long-term average 2.3 spills a year (monitored since 2020) Monitor below 90% Power failure / issue · Resolved - Jul Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.3 hours spilling →	Sutton Mill Brook via Surface water sewer	1	0.3	down 67%	72%
Bridgeman Park CSO Overflow on sewer network Company site name Bridgeman Park Combined Sewer Overflow EA ID / permit UUP00321 · 016982924 Outlet location SD7228008810 (OS grid reference) · View on Apple Maps WFD catchment Middle Brook (GB112069064540) 2024 spills / hours 0 / 0.0 Long-term average 10.0 spills a year (monitored since 2021) Monitor below 90% Sensor failure / issue · Resolved - Nov Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.3 hours spilling →	River Croal	1	0.3	up from 0	89%
Limeside Road/Fox Mill CSO Overflow on sewer network Company site name Limeside Road/Fox Mill CSO EA ID / permit UUP01145 · 01OLD0075 Outlet location SD9116001882 (OS grid reference) · View on Apple Maps WFD catchment Irk (Wince to Irwell) (GB112069061131) 2024 spills / hours 21 / 36 Long-term average 10.3 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.3 hours spilling →	Moston Brook via SWS	2	0.3	down 90%	100%

Sewage treatment works

Storm tanks and inlet overflows at each United Utilities sewage works. The figures are 2025 spills.

← All water companies · Contains Environment Agency data licensed under the Open Government Licence v3.0. How to read the data.