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
Bury New Road Salford CSO Overflow on sewer network Company site name Ashworth Street CSO EA ID / permit UUP00380 · 016993784 Outlet location SJ8346099320 (OS grid reference) · View on Apple Maps WFD catchment Irwell (Croal to Irk) (GB112069061451) 2024 spills / hours 21 / 23 Long-term average 33.6 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 17 hours spilling →	River Irwell	24	17	up 14%	100%
Priestley Clough CSO Overflow on sewer network Company site name PRIESTLY CLOUGH CSO EA ID / permit UUP01578 · 01HYN0028 Outlet location SD7603027270 (OS grid reference) · View on Apple Maps WFD catchment Hyndburn (GB112071065040) 2024 spills / hours 32 / 57 Long-term average 37.7 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement Env Act (SODRP) improvement ongoing Volume & pollution Estimate from 17 hours spilling →	Woodnook Water	15	17	down 53%	100%
Junc Hungerford Road and Laureston Overflow on sewer network Company site name Junction of Hungerford Road and Laureston Avenue CSO EA ID / permit UUP01039 · 01CRE0017 Outlet location SJ7200055500 (OS grid reference) · View on Apple Maps WFD catchment Valley Brook (Englesea Brook to Weaver) (GB112068055310) 2024 spills / hours 18 / 25 Long-term average 18.2 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 17 hours spilling →	Drain, Trib of Valley Brook	14	17	down 22%	100%
Off School Lane CSO (472JI) Overflow on sewer network Company site name Off School Lane CSO EA ID / permit UUP01449 · 01VRY0060 Outlet location SJ6489071570 (OS grid reference) · View on Apple Maps WFD catchment Weaver (Winsford Flashes to Dane) (GB112068060463) 2024 spills / hours 0 / 0.0 Long-term average 0.6 spills a year (monitored since 2021) Investigation Env Act (SODRP) investigation ongoing Improvement Env Act (SODRP) improvement ongoing Volume & pollution Estimate from 17 hours spilling →	Weaver Navigation	3	17	up from 0	94%
Esk Avenue Mirehouse CSO Overflow on sewer network Company site name Esk Avenue Mirehouse CSO EA ID / permit UUP00707 · 017480429 Outlet location NX9788017180 (OS grid reference) · View on Apple Maps WFD catchment Solway Outer South (GB641211630003) 2024 spills / hours 17 / 42 Long-term average 16.6 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 17 hours spilling →	Un-Named Trib of Pow Beck	16	17	down 6%	99%
Black Bull Mh C1 CSO 331EQ Overflow on sewer network Company site name Black Bull Lane M/H C1 EA ID / permit UUP00247 · EPRKB3991VZ Outlet location SD5285631518 (OS grid reference) · View on Apple Maps WFD catchment Savick Brook (GB112071065470) 2024 spills / hours 6 / 19 Long-term average 4.4 spills a year (monitored since 2019) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 17 hours spilling →	Savick Brook	13	17	up 117%	92%
Water Street CSO Overflow on sewer network Company site name Water Street CSO EA ID / permit UUP02038 · EPRSB3793VY Outlet location SJ9351677848 (OS grid reference) · View on Apple Maps WFD catchment Dean (Bollington to Bollin) (GB112069061360) 2024 spills / hours 16 / 13 Long-term average 25.4 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 17 hours spilling →	River Dean	22	17	up 38%	100%
Brook Deans Close CSO Overflow on sewer network Company site name Brook Dean Close (Smithhills Dean Road) Combined Sewer Overflow EA ID / permit UUP00343 · 016982822 Outlet location SD7003011330 (OS grid reference) · View on Apple Maps WFD catchment Astley Brook (Irwell) (GB112069064560) 2024 spills / hours 42 / 60 Long-term average 22.3 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 17 hours spilling →	Dean Brook	6	17	down 86%	100%
Grassendale Combined Sewer Overflow Overflow on sewer network Company site name Grassendale CSO EA ID / permit UUP00831 · 016930985 Outlet location SJ3853084780 (OS grid reference) · View on Apple Maps WFD catchment MERSEY - Transitional (GB531206908100) 2024 spills / hours 17 / 22 Long-term average 18.3 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 17 hours spilling →	River Mersey Estuary	10	17	down 41%	100%
Long Marton West STW Inlet overflow at sewage works Sewage works Long Marton West Company site name Long Marton WwTW EA ID / permit UUP02270 · Unpermitted Outlet location NY6638024200 (OS grid reference) · View on Apple Maps WFD catchment Trout Beck (GB102076070930) 2024 spills / hours 24 / 110 Long-term average 21.0 spills a year (monitored since 2024) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 17 hours spilling →	Trout Beck	18	17	down 25%	99%
Singing Clough CSO 071Q8 Overflow on sewer network Company site name Singing Clough CSO EA ID / permit UUP01758 · 01BOL0164 Outlet location SD7513005210 (OS grid reference) · View on Apple Maps WFD catchment Irwell (Croal to Irk) (GB112069061451) 2024 spills / hours 13 / 16 Long-term average 17.6 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 17 hours spilling →	Singing Clough Brook	11	17	down 15%	95%
Kern Mill Lane CSO 122BI Overflow on sewer network Company site name Kem Mill Lane CSO EA ID / permit UUP01059 · 017060027 Outlet location SD5769021680 (OS grid reference) · View on Apple Maps WFD catchment Lostock US Farington Weir (GB112070064911) 2024 spills / hours 41 / 292 Long-term average 36.6 spills a year (monitored since 2019) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 17 hours spilling →	River Lostock	6	17	down 85%	91%
Palmerston St Shrigley Rd 272KZ Overflow on sewer network Company site name Palmerston Street/Shrigley Road CSO EA ID / permit UUP01503 · 01MAC0121 Outlet location SJ9395077990 (OS grid reference) · View on Apple Maps WFD catchment Harrop Brook (GB112069060660) 2024 spills / hours 29 / 23 Long-term average 110.5 spills a year (monitored since 2020) Investigation Operational investigation completed Improvement Env Act (SODRP) improvement ongoing, Operational improvement completed Volume & pollution Estimate from 17 hours spilling →	Harrop Brook	23	17	down 21%	100%
Cuddington Lane CSO (471QL) Overflow on sewer network Company site name Cuddington Lane (adjacent Pipe Bridge) CSO EA ID / permit UUP00587 · 01VRY0053 Outlet location SJ5990072500 (OS grid reference) · View on Apple Maps WFD catchment Cuddington Brook (Source to Crowton Brook) (GB112068060480) 2024 spills / hours 18 / 26 Long-term average 21.6 spills a year (monitored since 2021) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 17 hours spilling →	Cuddington Brook	14	17	down 22%	100%
Lords Street/Liverpool Road CSO Overflow on sewer network Company site name LORDS STREET / LIVERPOOL ROAD CSO EA ID / permit UUP01188 · 01SAL0015 Outlet location SJ7119091820 (OS grid reference) · View on Apple Maps WFD catchment Mersey/ Manchester Ship Canal (Irwell/Manchester Ship Canal to Bollin) (GB112069061011) 2024 spills / hours 7 / 9.8 Long-term average 41.2 spills a year (monitored since 2019) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 16 hours spilling →	Manchester Ship Canal	10	16	up 43%	97%
Simonstone Lane CSO Overflow on sewer network Company site name Simonstone Lane CSO EA ID / permit UUP01757 · EPRSB3396ES Outlet location SD7698033350 (OS grid reference) · View on Apple Maps WFD catchment Calder - Pendle Water to conf Ribble (GB112071065490) 2024 spills / hours 10 / 17 Long-term average 7.4 spills a year (monitored since 2021) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 16 hours spilling →	River Calder	4	16	down 60%	97%
Greengate Combined Sewer Overflow Overflow on sewer network Company site name Greengate CSO EA ID / permit UUP00853 · 016982738 Outlet location SD8847004800 (OS grid reference) · View on Apple Maps WFD catchment Wince Brook (GB112069061120) 2024 spills / hours 31 / 35 Long-term average 34.7 spills a year (monitored since 2020) Investigation Env Act (SODRP) investigation ongoing Improvement Env Act (SODRP) improvement ongoing Volume & pollution Estimate from 16 hours spilling →	Wince Brook	14	16	down 55%	100%
Wrenbury Hall Road SPS Storm discharge at pumping station Company site name Wrenbury Hall Road PS EA ID / permit UUP02181 · 016810369 Outlet location SJ6010048400 (OS grid reference) · View on Apple Maps WFD catchment Weaver (Marbury Brook to Barnett Brook) (GB112068055470) 2024 spills / hours 19 / 26 Long-term average 14.0 spills a year (monitored since 2024) Monitor below 90% Telemetry or data archiving failure / issue · Resolved - Oct Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 16 hours spilling →	Shropshire Union Canal	9	16	down 53%	73%
Opposite No.36 Carr Lane CSO Overflow on sewer network Company site name Opposite 36 Carr Lane CSO EA ID / permit UUP01473 · 01SEF0054 Outlet location SD3302013221 (OS grid reference) · View on Apple Maps WFD catchment Three Pool's Waterway (GB112070064830) Bathing water St Annes; St Annes North; Blackpool South; Blackpool Central; Blackpool North; Southport; Ainsdale Shellfish water Ribble 2024 spills / hours 13 / 15 Long-term average 21.3 spills a year (monitored since 2018) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 16 hours spilling →	Sandy Brook (Tributary of River Alt)	11	16	down 15%	100%
59D Turves Road CSO 432VY Overflow on sewer network Company site name No. 59d Turves Road CSO EA ID / permit UUP00052 · 016982768 Outlet location SJ8684086520 (OS grid reference) · View on Apple Maps WFD catchment Micker Brook (GB112069060940) 2024 spills / hours 4 / 9.2 Long-term average 7.4 spills a year (monitored since 2019) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 16 hours spilling →	Turves Brook, Trib Micker Brk	8	16	up 100%	100%
Ladybridge Lane CSO Overflow on sewer network Company site name Ladybridge Lane CSO EA ID / permit UUP01098 · 016982193 Outlet location SD6843008910 (OS grid reference) · View on Apple Maps WFD catchment Middle Brook (GB112069064540) 2024 spills / hours 11 / 20 Long-term average 12.8 spills a year (monitored since 2021) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 16 hours spilling →	Middle Brook	4	16	down 64%	100%
Leigh SSO Overflow on sewer network Company site name Green Lane Leigh EA ID / permit UUP01129 · 016920277 Outlet location SD6743000380 (OS grid reference) · View on Apple Maps WFD catchment Bedford Brook (GB112069060810) 2024 spills / hours 7 / 9.0 Long-term average 7.5 spills a year (monitored since 2024) Monitor below 90% Sensor failure / issue · Resolved - January after reporting year Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 16 hours spilling →	Pen Leach Brook	8	16	up 14%	80%
Chapel House Road (32014) CSO Overflow on sewer network Company site name Chapel House Road CSO(32014) (PEN0084) EA ID / permit UUP00443 · 017180623 Outlet location SD8646037550 (OS grid reference) · View on Apple Maps WFD catchment Walverden Water (GB112071065130) 2024 spills / hours 16 / 37 Long-term average 25.7 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 16 hours spilling →	Walverden Water	10	16	down 38%	95%
Weaverham STW Storm tank at sewage works Sewage works Weaverham Company site name WEAVERHAM WwTW EA ID / permit UUP02063 · 016810113 Outlet location SJ6110475177 (OS grid reference) · View on Apple Maps WFD catchment Weaver (Dane to Frodsham) (GB112068060500) 2024 spills / hours 15 / 267 Long-term average 16.0 spills a year (monitored since 2021) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 16 hours spilling →	Trib of River Weaver	8	16	down 47%	100%
Brookhouse Green Wastewater Works Inlet overflow at sewage works Sewage works Brookhouse Green Company site name BROOKHOUSE GREEN WwTW X-X MOSS MERE EA ID / permit UUP00346 · 016892175 Outlet location SJ8055061340 (OS grid reference) · View on Apple Maps WFD catchment Arclid Brook (GB112068055430) 2024 spills / hours 3 / 17 Long-term average 11.1 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 16 hours spilling →	Tributary of River Wheelock	6	16	up 100%	100%
Grimeford Lane PS 12007 Storm discharge at pumping station Company site name Grimeford Lane PS EA ID / permit UUP02262 · 01CHR0057 Outlet location SD6153912679 (OS grid reference) · View on Apple Maps WFD catchment Douglas - Upper (GB112070064850) 2024 spills / hours 15 / 34 Long-term average 17.8 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 16 hours spilling →	Unnamed tributary of River Douglas	2	16	down 87%	100%
Clifton House Road Pumping Station Storm discharge at pumping station Company site name Clifton House Road (37010) (SAL0145) EA ID / permit UUP00505 · 016940527 Outlet location SD7698004370 (OS grid reference) · View on Apple Maps WFD catchment Irwell (Croal to Irk) (GB112069061451) 2024 spills / hours 4 / 7.7 Long-term average 3.4 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 16 hours spilling →	River Irwell via S.W.	2	16	down 50%	99%
Brook Mill Combined Sewer Overflow Overflow on sewer network Company site name Brook Mill CSO EA ID / permit UUP00345 · 016881909 Outlet location SJ7575060100 (OS grid reference) · View on Apple Maps WFD catchment Arclid Brook (GB112068055430) 2024 spills / hours 17 / 11 Long-term average 16.0 spills a year (monitored since 2020) Monitor below 90% Installation set-up/design issue · Resolved - Sep Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 16 hours spilling →	Clvrtd Section of Brook Mill	13	16	down 24%	72%
St Marys Gate/Cheetham Street CSO Overflow on sewer network Company site name St. Mary's Gate / Cheetham Street CSO EA ID / permit UUP01824 · EPRQB3591EA Outlet location SD8972313686 (OS grid reference) · View on Apple Maps WFD catchment Roch (Source to Spodden) (GB112069064720) 2024 spills / hours 8 / 2.1 Long-term average 18.7 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 16 hours spilling →	Culverted section of Lord Burn a tributary of River Roch	21	16	up 163%	93%
Bridge Street CSO Overflow on sewer network Company site name Bridge Street CSO EA ID / permit UUP02183 · EPRWB3294EP Outlet location SJ7012349593 (OS grid reference) · View on Apple Maps WFD catchment Checkley Brook - Lower (GB112068055240) 2024 spills / hours 2 / 7.9 Long-term average 2.2 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 16 hours spilling →	Wybunbury Brook	9	16	up 350%	95%
28 Tythebarn Street CSO Overflow on sewer network Company site name 28 Tythebarn Street CSO EA ID / permit UUP00027 · NPSWQD010694 Outlet location SD6957022320 (OS grid reference) · View on Apple Maps WFD catchment Darwen - headwaters to conf Davy Field Bk (GB112071065240) 2024 spills / hours 14 / 14 Long-term average 17.3 spills a year (monitored since 2021) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 16 hours spilling →	River Darwen (Sewer)	20	16	up 43%	100%
Broadbottom Pumping Station Storm discharge at pumping station Company site name Broadbottom PS EA ID / permit UUP00331 · 016940167 Outlet location SJ9871093160 (OS grid reference) · View on Apple Maps WFD catchment Etherow (Glossop Brook to Goyt) (GB112069061050) 2024 spills / hours 13 / 12 Long-term average 18.8 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 15 hours spilling →	River Etherow	3	15	down 77%	100%
Chapel House Road CSO (32014) Overflow on sewer network Company site name Chapel House Road CSO EA ID / permit UUP00444 · 01PEN0017 Outlet location SD8646037540 (OS grid reference) · View on Apple Maps WFD catchment Walverden Water (GB112071065130) 2024 spills / hours 17 / 8.6 Long-term average 115.0 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 15 hours spilling →	Walverden Water	27	15	up 59%	98%
New Mill Street CSO Overflow on sewer network Company site name New Mill Street CSO EA ID / permit UUP01379 · EPRWP3723XP Outlet location SD6871828831 (OS grid reference) · View on Apple Maps WFD catchment Blakewater (GB112071065310) 2024 spills / hours 6 / 15 Long-term average 13.4 spills a year (monitored since 2021) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 15 hours spilling →	River Blakewater	4	15	down 33%	100%
Denver Avenue Alton Street CSO Overflow on sewer network Company site name DENVER AVENUE / ALTON STREET CSO EA ID / permit UUP00633 · 01CRE0034 Outlet location SJ6990055340 (OS grid reference) · View on Apple Maps WFD catchment Valley Brook (Englesea Brook to Weaver) (GB112068055310) 2024 spills / hours 18 / 13 Long-term average 14.0 spills a year (monitored since 2019) Investigation Operational investigation completed Improvement Operational improvement completed Volume & pollution Estimate from 15 hours spilling →	Valley Brook	12	15	down 33%	100%
329 Barton Road CSO Overflow on sewer network Company site name Barton Road CSO EA ID / permit UUP00038 · 016892359 Outlet location SJ7886095300 (OS grid reference) · View on Apple Maps WFD catchment Irwell / Manchester Ship Canal (Irk to confluence with Upper Mersey) (GB112069061452) 2024 spills / hours 17 / 17 Long-term average 35.3 spills a year (monitored since 2020) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 15 hours spilling →	Bent Lanes Brook/Longford Broo	19	15	up 12%	100%
Cop Lane CSO Overflow on sewer network Company site name Cop Lane CSO EA ID / permit UUP00537 · 017190853 Outlet location SD5223028130 (OS grid reference) · View on Apple Maps WFD catchment RIBBLE - transitional (GB531207112400) Bathing water St Annes 2024 spills / hours 5 / 9.3 Long-term average 3.4 spills a year (monitored since 2017) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 15 hours spilling →	Tributary of the River Ribble, via a surface water sewer	1	15	down 80%	100%
Clapham Wastewater Treatment Works Storm tank at sewage works Sewage works Clapham Company site name Clapham WwTW EA ID / permit UUP00492 · EPREP3526XK Outlet location SD7372967616 (OS grid reference) · View on Apple Maps WFD catchment Clapham Beck (GB112072071840) 2024 spills / hours 3 / 84 Long-term average 15.0 spills a year (monitored since 2021) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 15 hours spilling →	River Wenning	3	15	no change	100%
Cleveland Rd Delaunay Rd CSO 288NJ Overflow on sewer network Company site name Cleveland/Delauney's Road CSO EA ID / permit UUP00500 · 01MAN0078 Outlet location SD8505102790 (OS grid reference) · View on Apple Maps WFD catchment Irk (Wince to Irwell) (GB112069061131) 2024 spills / hours 29 / 21 Long-term average 52.9 spills a year (monitored since 2019) High-spill reason (company) Not asset maintenance - Hydraulic capacity Investigation Env Act (SODRP) investigation ongoing Improvement Env Act (SODRP) improvement ongoing Volume & pollution Estimate from 15 hours spilling →	River Irk	31	15	up 7%	100%
Fairhurst Drive SPS Storm discharge at pumping station Company site name Fairhurst Drive PS EA ID / permit UUP02289 · 017021060 Outlet location SD4871911042 (OS grid reference) · View on Apple Maps WFD catchment Douglas - Lower (GB112070064820) 2024 spills / hours – / – Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 15 hours spilling →	River Douglas	3	15		99%
Prestwich Golf Course CSO 093IR Overflow on sewer network Company site name Prestwich Golf Course CSO EA ID / permit UUP01576 · 016983241 Outlet location SD8150002170 (OS grid reference) · View on Apple Maps WFD catchment Irwell (Croal to Irk) (GB112069061451) 2024 spills / hours 12 / 18 Long-term average 12.9 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 15 hours spilling →	Singleton Brook	8	15	down 33%	100%
Barton Lane Combined Sewer Overflow Overflow on sewer network Company site name Barton Lane/Fountain Street CSO EA ID / permit UUP00198 · 016982648 Outlet location SJ7677097680 (OS grid reference) · View on Apple Maps WFD catchment Irwell / Manchester Ship Canal (Irk to confluence with Upper Mersey) (GB112069061452) 2024 spills / hours 12 / 18 Long-term average 10.5 spills a year (monitored since 2020) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 15 hours spilling →	Manchester Ship Canal via SWS	8	15	down 33%	100%
South of Blackley New Road CSO Overflow on sewer network Company site name BLACKLEY NEW ROAD CSO EA ID / permit UUP01783 · 01MAN0111 Outlet location SD8390003150 (OS grid reference) · View on Apple Maps WFD catchment Irk (Wince to Irwell) (GB112069061131) 2024 spills / hours 39 / 27 Long-term average 61.5 spills a year (monitored since 2019) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 15 hours spilling →	River Irk	17	15	down 56%	92%
Cross Lane Sandside Rd CSO LAK0110 Overflow on sewer network Company site name Cross Lane/Sandside Road Combined Sewer Overflow EA ID / permit UUP02204 · EPRJB3894WW Outlet location SD3016877538 (OS grid reference) · View on Apple Maps WFD catchment Dragley Beck (GB112073071160) 2024 spills / hours 0 / 0.0 Long-term average 2.0 spills a year (monitored since 2024) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 15 hours spilling →	Carter Pool	4	15	up from 0	99%
Powis Road CSO 332MG PRE0025 Overflow on sewer network Company site name Powis Road CSO EA ID / permit UUP01569 · 017160321 Outlet location SD5140229892 (OS grid reference) · View on Apple Maps WFD catchment RIBBLE_Transitional (GB531207112400) Bathing water Southport; St Annes; St. Annes North; Blackpool South Shellfish water Ribble 2024 spills / hours 3 / 2.6 Long-term average 2.1 spills a year (monitored since 2018) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 15 hours spilling →	Chain Caul Culvert	2	15	down 33%	100%
Burnley Rd E/Booth St CSO Overflow on sewer network Company site name Burnley Road East/Booth Street CSO EA ID / permit UUP00366 · 01ROS0041 Outlet location SD8339021940 (OS grid reference) · View on Apple Maps WFD catchment Whitewell Brook (GB112069064670) 2024 spills / hours 22 / 13 Long-term average 11.8 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 15 hours spilling →	Whitewell Brook	13	15	down 41%	100%
Atherton Rd Detention Tank Overflow on sewer network Company site name Atherton Road Detention Tank EA ID / permit UUP00155 · 016983228 Outlet location SD6256003670 (OS grid reference) · View on Apple Maps WFD catchment Hey/Borsdane Brook (GB112069064520) 2024 spills / hours 11 / 24 Long-term average 8.5 spills a year (monitored since 2020) Investigation Env Act (SODRP) investigation ongoing, Operational investigation completed Improvement Operational improvement completed Volume & pollution Estimate from 15 hours spilling →	Dog Pool Brook	5	15	down 55%	100%
High Street/Moors Lane CSO Overflow on sewer network Company site name High Street/Moors Lane CSO EA ID / permit UUP00962 · 01VRY0059 Outlet location SJ5140078190 (OS grid reference) · View on Apple Maps WFD catchment Weaver (Dane to Frodsham) (GB112068060500) 2024 spills / hours 29 / 21 Long-term average 87.4 spills a year (monitored since 2017) Investigation No investigation activity in reporting period Improvement Env Act (SODRP) improvement ongoing Volume & pollution Estimate from 15 hours spilling →	Main Drain (Trib River Weaver)	18	15	down 38%	100%
Landgate SPS Storm discharge at pumping station Company site name Landgate PS EA ID / permit UUP01104 · 017020034 Outlet location SD5715001450 (OS grid reference) · View on Apple Maps WFD catchment Poolstock Brook (GB112070061610) 2024 spills / hours 2 / 1.0 Long-term average 3.0 spills a year (monitored since 2024) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 15 hours spilling →	Park Brook	4	15	up 100%	100%
Flag Lane N0 2 CSO 165JH Overflow on sewer network Company site name FLAG LANE No1 CSO EA ID / permit UUP00742 · 01CRE0036 Outlet location SJ7003055320 (OS grid reference) · View on Apple Maps WFD catchment Valley Brook (Englesea Brook to Weaver) (GB112068055310) 2024 spills / hours 24 / 19 Long-term average 22.2 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 15 hours spilling →	Valley Brook	23	15	down 4%	100%

Sewage treatment works

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

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