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
Newbiggin (Leven) WwTW Newbg Storm tank at sewage works Sewage works Newbiggin Newbg Company site name NEWBIGGIN WwTW EA ID / permit UUP01382 · 017370051 Outlet location SD2680868949 (OS grid reference) · View on Apple Maps WFD catchment Deep Meadows Beck (GB112073071150) 2024 spills / hours 11 / 0.8 Long-term average 7.6 spills a year (monitored since 2018) Monitor below 90% Telemetry or data archiving failure / issue · Resolved - Aug Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 28 hours spilling →	Deep Meadows Beck	6	28	down 45%	39%
Frankby Close CSO 513MM Overflow on sewer network Company site name Frankby Close CSO EA ID / permit UUP00758 · 01WIR0087 Outlet location SJ2481087060 (OS grid reference) · View on Apple Maps WFD catchment The Birket including Arrowe Brook and Fender (GB112068060530) 2024 spills / hours 36 / 70 Long-term average 29.1 spills a year (monitored since 2018) Investigation No investigation activity in reporting period Improvement Env Act (SODRP) improvement ongoing Volume & pollution Estimate from 28 hours spilling →	Greasby Brook	20	28	down 44%	97%
Blackburn WwTW Storm tank at sewage works Sewage works Blackburn Company site name BLACKBURN WwTW EA ID / permit UUP00250 · 017160024 Outlet location SD6127329311 (OS grid reference) · View on Apple Maps WFD catchment Darwen - conf Roddlesworth to tidal (GB112071065300) Bathing water Southport; St Annes; St. Annes North; Blackpool South Shellfish water Ribble 2024 spills / hours 19 / 138 Long-term average 48.8 spills a year (monitored since 2018) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 28 hours spilling →	River Darwen	19	28	no change	99%
Balle Street Hilton Street CSO Overflow on sewer network Company site name BALLE STREET / HILTON STREET CSO EA ID / permit UUP00172 · 01BBN0127 Outlet location SD6940021610 (OS grid reference) · View on Apple Maps WFD catchment Darwen - headwaters to conf Davy Field Bk (GB112071065240) 2024 spills / hours 49 / 49 Long-term average 62.0 spills a year (monitored since 2020) High-spill reason (company) Not asset maintenance - Hydraulic capacity Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 28 hours spilling →	River Darwen	46	28	down 6%	96%
Zulu Sreet CSO 07032 Overflow on sewer network Company site name Zulu Street CSO EA ID / permit UUP02189 · 016983222 Outlet location SD7288009270 (OS grid reference) · View on Apple Maps WFD catchment Tonge (GB112069064530) 2024 spills / hours 38 / 36 Long-term average 53.4 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement Env Act (SODRP) improvement ongoing Volume & pollution Estimate from 28 hours spilling →	River Tonge	25	28	down 34%	100%
Melling WwTW Inlet overflow at sewage works Sewage works Melling Company site name MELLING WwTW EA ID / permit UUP01280 · 016987034 Outlet location SJ3895098900 (OS grid reference) · View on Apple Maps WFD catchment Alt US Bull Bridge (GB112069061441) 2024 spills / hours 9 / 39 Long-term average 45.0 spills a year (monitored since 2019) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 28 hours spilling →	Unnamed Trib of River Alt	5	28	down 44%	100%
Weaverham STW Inlet overflow at sewage works Sewage works Weaverham Company site name WEAVERHAM WwTW EA ID / permit UUP02064 · 016810113 Outlet location SJ6110475177 (OS grid reference) · View on Apple Maps WFD catchment Weaver (Dane to Frodsham) (GB112068060500) 2024 spills / hours 22 / 39 Long-term average 23.6 spills a year (monitored since 2021) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 28 hours spilling →	Trib of River Weaver	24	28	up 9%	100%
Ester Street Car Park CSO 203DR Overflow on sewer network Company site name Ester Street Car Park CSO EA ID / permit UUP00708 · 016982703 Outlet location SJ5214086050 (OS grid reference) · View on Apple Maps WFD catchment MERSEY - Transitional (GB531206908100) 2024 spills / hours 25 / 41 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 28 hours spilling →	Bowers Brook	15	28	down 40%	100%
Suffolk St Combined Sewer Overflow Overflow on sewer network Company site name Suffolk Street CSO EA ID / permit UUP01890 · 016983311 Outlet location SD9084003810 (OS grid reference) · View on Apple Maps WFD catchment Irk (Wince to Irwell) (GB112069061131) 2024 spills / hours 1 / 3.9 Long-term average 5.4 spills a year (monitored since 2020) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 27 hours spilling →	Bower Brook via SWS	26	27	up 2500%	100%
310-314 Chester Road CSO Overflow on sewer network Company site name 310 -314 Chester Road CSO EA ID / permit UUP00037 · 016810821 Outlet location SJ6287371981 (OS grid reference) · View on Apple Maps WFD catchment Cuddington Brook (Source to Crowton Brook) (GB112068060480) 2024 spills / hours 16 / 69 Long-term average 12.5 spills a year (monitored since 2021) Investigation Operational investigation completed Improvement Operational improvement completed Volume & pollution Estimate from 27 hours spilling →	Handforth Brook via SWS	9	27	down 44%	97%
Walkden Rd Holyoake Rd CSO 37045 Overflow on sewer network Company site name Walkden Road/Hoylake Road CSO EA ID / permit UUP02006 · 016983330 Outlet location SD7384002760 (OS grid reference) · View on Apple Maps WFD catchment Folly Brook and Salteye Brook (GB112069061430) 2024 spills / hours 0 / 0.0 Long-term average 43.8 spills a year (monitored since 2019) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 27 hours spilling →	Worsley Brook	19	27	up from 0	100%
Off Bridge St Storm discharge at pumping station Company site name Off Bridge Street PS EA ID / permit UUP01437 · 01CHR0032 Outlet location SD6002021410 (OS grid reference) · View on Apple Maps WFD catchment Lostock US Farington Weir (GB112070064911) 2024 spills / hours 10 / 66 Long-term average 6.5 spills a year (monitored since 2024) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 27 hours spilling →	Kenyon Brook	3	27	down 70%	100%
Croft Close Combined Sewer Overflow Overflow on sewer network Company site name The College CSO EA ID / permit UUP00565 · 01EDE0007 Outlet location NY5534041150 (OS grid reference) · View on Apple Maps WFD catchment Raven Beck (GB102076073840) 2024 spills / hours 47 / 34 Long-term average 50.3 spills a year (monitored since 2020) 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 27 hours spilling →	Raven Beck,Trib of River Eden	43	27	down 9%	96%
Winnington Street CSO 472YM Overflow on sewer network Company site name Winnington Street CSO EA ID / permit UUP02144 · 01VRY0077 Outlet location SJ6567073870 (OS grid reference) · View on Apple Maps WFD catchment Weaver (Dane to Frodsham) (GB112068060500) 2024 spills / hours 14 / 4.0 Long-term average 20.7 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 27 hours spilling →	River Weaver	12	27	down 14%	99%
Carr Clough CSO 091IG Overflow on sewer network Company site name Carr Clough CSO EA ID / permit UUP00407 · 01BRY0044 Outlet location SD8034002600 (OS grid reference) · View on Apple Maps WFD catchment Irwell (Croal to Irk) (GB112069061451) 2024 spills / hours 47 / 40 Long-term average 62.7 spills a year (monitored since 2019) High-spill reason (company) Not asset maintenance - Hydraulic capacity Investigation No investigation activity in reporting period Improvement Env Act (SODRP) improvement ongoing Volume & pollution Estimate from 27 hours spilling →	Prestwich Clough Clvrt Irwell	35	27	down 26%	100%
Stamford New Road CSO Overflow on sewer network Company site name Stamford New Road CSO EA ID / permit UUP01836 · 016892328 Outlet location SJ7739088340 (OS grid reference) · View on Apple Maps WFD catchment Timperley Brook (GB112069061260) 2024 spills / hours 38 / 35 Long-term average 50.2 spills a year (monitored since 2021) Investigation Env Act (SODRP) investigation ongoing, Operational investigation completed Improvement Env Act (SODRP) improvement ongoing, Operational improvement completed Volume & pollution Estimate from 27 hours spilling →	Timperley Brook	28	27	down 26%	100%
Manora Road (Dane Nurseries) CSO Overflow on sewer network Company site name Manora Road (Dane Nurseries) CSO EA ID / permit UUP01250 · 016881776 Outlet location SJ6613073480 (OS grid reference) · View on Apple Maps WFD catchment Dane (Wheelock to Weaver) (GB112068060470) 2024 spills / hours 66 / 105 Long-term average 63.3 spills a year (monitored since 2020) Investigation Operational investigation completed Improvement Operational improvement completed Volume & pollution Estimate from 27 hours spilling →	River Dane	22	27	down 67%	100%
Rudd Avenue CSO Overflow on sewer network Company site name Rudd Avenue SSO EA ID / permit UUP01695 · 016982534 Outlet location SJ5467094920 (OS grid reference) · View on Apple Maps WFD catchment Sankey Brook (Rainford Brook to Mersey) (GB112069061200) 2024 spills / hours 19 / 41 Long-term average 37.2 spills a year (monitored since 2021) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 27 hours spilling →	Sankey Brook	5	27	down 74%	100%
Cotton Hall Street CSO Overflow on sewer network EA ID / permit UUP00548 · 01BBN0117 Outlet location SD6925022850 (OS grid reference) · View on Apple Maps WFD catchment Darwen - headwaters to conf Davy Field Bk (GB112071065240) 2024 spills / hours 50 / 52 Long-term average 54.2 spills a year (monitored since 2021) High-spill reason (company) Not asset maintenance - Hydraulic capacity Investigation No investigation activity in reporting period Improvement Env Act (SODRP) improvement ongoing Volume & pollution Estimate from 27 hours spilling →	Tributary of River Darwen	43	27	down 14%	100%
Gorton Road (Lighting Tower) Overflow on sewer network Company site name Gorton Road CSO EA ID / permit UUP00817 · NPSWQD010710 Outlet location SJ8663197409 (OS grid reference) · View on Apple Maps WFD catchment Irwell / Manchester Ship Canal (Irk to confluence with Upper Mersey) (GB112069061452) 2024 spills / hours 10 / 4.4 Long-term average 14.0 spills a year (monitored since 2020) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 27 hours spilling →	Corn Brook	7	27	down 30%	94%
Holly Street/New Springs CSO Overflow on sewer network Company site name HOLLY STREET / NEW SPRINGS CSO EA ID / permit UUP00977 · 01WIG0015 Outlet location SD5984007060 (OS grid reference) · View on Apple Maps WFD catchment Douglas - Mid (GB112070064780) 2024 spills / hours 23 / 70 Long-term average 22.0 spills a year (monitored since 2021) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 27 hours spilling →	Yellow Brook	10	27	down 57%	100%
Gloucester St CSO Overflow on sewer network Company site name Gloucester street CSO EA ID / permit UUP00810 · 016982786 Outlet location SD6686003290 (OS grid reference) · View on Apple Maps WFD catchment Bedford Brook (GB112069060810) 2024 spills / hours 46 / 433 Long-term average 78.7 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 27 hours spilling →	Collier Brook	3	27	down 93%	100%
Gilsland (Bath House) CSO (101VN) Overflow on sewer network Company site name Gilsland (Bath House) CSO EA ID / permit UUP00791 · 017680314 Outlet location NY6340066530 (OS grid reference) · View on Apple Maps WFD catchment Irthing DS Crammel Linn Waterfall (GB102076073981) 2024 spills / hours 23 / 16 Long-term average 19.8 spills a year (monitored since 2021) Monitor below 90% Sensor failure / issue · Resolved - May Investigation Env Act (SODRP) investigation ongoing Improvement Env Act (SODRP) improvement ongoing Volume & pollution Estimate from 27 hours spilling →	River Irthing	20	27	down 13%	90%
Avenue St Brewery St CSO Overflow on sewer network Company site name Avenue Street/Brewery Street CSO EA ID / permit UUP00161 · 016982673 Outlet location SJ8985090870 (OS grid reference) · View on Apple Maps WFD catchment Goyt (Etherow to Mersey) (GB112069061000) 2024 spills / hours 19 / 38 Long-term average 15.6 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 26 hours spilling →	River Goyt	11	26	down 42%	100%
Chapel St (Temple Sowerby) CSO Overflow on sewer network Company site name Chapel Street (Temple Sowerby) CSO EA ID / permit UUP00446 · 01EDE0013 Outlet location NY6175027321 (OS grid reference) · View on Apple Maps WFD catchment Crowdundle Beck - Lower (GB102076070950) 2024 spills / hours 42 / 61 Long-term average 36.8 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 26 hours spilling →	Birk Sike	27	26	down 36%	100%
Rochdale Road/Wash Lane SSO Overflow on sewer network Company site name Openshaw Park EA ID / permit UUP01674 · 016951425 Outlet location SD8186010590 (OS grid reference) · View on Apple Maps WFD catchment Roch (Spodden to Irwell) (GB112069064600) 2024 spills / hours 33 / 54 Long-term average 16.5 spills a year (monitored since 2020) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 26 hours spilling →	River Roch	25	26	down 24%	100%
Sankey Brook (St Helens) CSO Overflow on sewer network Company site name Sankey Brook (St Helens) CSO EA ID / permit UUP01719 · NPSWQD010822 Outlet location SJ5153096240 (OS grid reference) · View on Apple Maps WFD catchment Rainford Brook (GB112069061240) 2024 spills / hours 26 / 29 Long-term average 25.7 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement Env Act (SODRP) improvement ongoing Volume & pollution Estimate from 26 hours spilling →	Rainford Brook	16	26	down 38%	100%
Tinker Brook CSO (22018) Overflow on sewer network Company site name Tinker Brook CSO EA ID / permit UUP01944 · 017160120 Outlet location SD7416028380 (OS grid reference) · View on Apple Maps WFD catchment Hyndburn Brook - Upper (GB112071065050) 2024 spills / hours 24 / 47 Long-term average 31.8 spills a year (monitored since 2021) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 26 hours spilling →	Tinker Brook	21	26	down 13%	100%
Hapatia Street CSO 074EA Overflow on sewer network Company site name Hypatia Street CSO EA ID / permit UUP00897 · 016983219 Outlet location SD7283009350 (OS grid reference) · View on Apple Maps WFD catchment Tonge (GB112069064530) 2024 spills / hours 3 / 4.3 Long-term average 35.0 spills a year (monitored since 2019) Monitor below 90% Sensor failure / issue · Resolved - Nov Investigation No investigation activity in reporting period Improvement Env Act (SODRP) improvement ongoing Volume & pollution Estimate from 26 hours spilling →	River Tonge	18	26	up 500%	83%
St Michaels Way CSO Overflow on sewer network Company site name St. Michael's Way Combined Sewer Overflow (Site ID 132TH) (CON0039) EA ID / permit UUP01828 · 01CON0039 Outlet location SJ6946066700 (OS grid reference) · View on Apple Maps WFD catchment Wheelock (Fowle Brook to Dane) (GB112068055380) 2024 spills / hours 27 / 12 Long-term average 39.0 spills a year (monitored since 2020) High-spill reason (company) Not asset maintenance - Hydraulic capacity Investigation No investigation activity in reporting period Improvement Env Act (SODRP) improvement ongoing Volume & pollution Estimate from 26 hours spilling →	River Wheelock via SWS	39	26	up 44%	99%
Grimshaw Street CSO Overflow on sewer network Company site name Grimshaw Street Combined Sewer Overflow (Site ID 05033) (BBN0107) EA ID / permit UUP00866 · 017190805 Outlet location SD6978021120 (OS grid reference) · View on Apple Maps WFD catchment Darwen - headwaters to conf Davy Field Bk (GB112071065240) 2024 spills / hours 21 / 31 Long-term average 31.2 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 26 hours spilling →	River Darwen	20	26	down 5%	100%
Balmoral Drive/North Road CSO Overflow on sewer network Company site name Balmoral Drive/North Road CSO EA ID / permit UUP00174 · 01SEF0008 Outlet location SD3715019591 (OS grid reference) · View on Apple Maps WFD catchment Three Pool's Waterway (GB112070064830) Bathing water Southport Shellfish water Ribble 2024 spills / hours 7 / 28 Long-term average 31.8 spills a year (monitored since 2017) Investigation Env Act (SODRP) investigation ongoing, Operational investigation completed Improvement Operational improvement completed Volume & pollution Estimate from 26 hours spilling →	River Ribble	3	26	down 57%	99%
Highfield Avenue CSO Overflow on sewer network Company site name Highfield Avenue CSO EA ID / permit UUP00966 · 016982697 Outlet location SJ5712088130 (OS grid reference) · View on Apple Maps WFD catchment Whittle Brook (Mersey Estuary) (GB112069060990) 2024 spills / hours 7 / 22 Long-term average 9.4 spills a year (monitored since 2021) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 26 hours spilling →	Trib Whittle Brook via SWS	6	26	down 14%	100%
Charles St Princess St CSO 28116 Overflow on sewer network Company site name Charles Street/Princess Street CSO EA ID / permit UUP00450 · 01MAN0166 Outlet location SJ8433097510 (OS grid reference) · View on Apple Maps WFD catchment Medlock (Lumb Brook to Irwell) (GB112069061152) 2024 spills / hours 8 / 1.6 Long-term average 17.9 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 26 hours spilling →	River Medlock	17	26	up 113%	99%
Tbc Overflow on sewer network Company site name The Crescent CSO (383KE) EA ID / permit UUP02242 · Permit applied for Outlet location SD3751019433 (OS grid reference) · View on Apple Maps WFD catchment Three Pool's Waterway (GB112070064830) 2024 spills / hours 10 / 27 Long-term average 8.0 spills a year (monitored since 2024) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 25 hours spilling →	Three Pool's Waterway	6	25	down 40%	100%
Bredbury Uid CSO Tank Overflow on sewer network Company site name BREDBURY UID CSO EA ID / permit UUP00307 · NPSWQD010894 Outlet location SJ9208991712 (OS grid reference) · View on Apple Maps WFD catchment Goyt (Etherow to Mersey) (GB112069061000) 2024 spills / hours 5 / 8.7 Long-term average 5.0 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 25 hours spilling →	Crookilley Brook via A SWS	5	25	no change	94%
Boarshaw Road CSO Overflow on sewer network EA ID / permit UUP00264 · 01ROC0013 Outlet location SD8759006660 (OS grid reference) · View on Apple Maps WFD catchment Irk (Sourtce to Wince Brook) (GB112069061161) 2024 spills / hours 32 / 24 Long-term average 55.0 spills a year (monitored since 2020) 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 25 hours spilling →	Whit Brook	32	25	no change	99%
Cumberland Street CSO Overflow on sewer network Company site name Cumberland Street CSO EA ID / permit UUP00593 · NPSWQD010680 Outlet location SD6887027440 (OS grid reference) · View on Apple Maps WFD catchment Blakewater (GB112071065310) 2024 spills / hours 56 / 110 Long-term average 55.7 spills a year (monitored since 2020) Investigation Env Act (SODRP) investigation ongoing Improvement Env Act (SODRP) improvement ongoing Volume & pollution Estimate from 25 hours spilling →	Queens Park Culvert via SWS	25	25	down 55%	100%
Sudell Road CSO Overflow on sewer network Company site name Sudell Road CSO EA ID / permit UUP01888 · 017180464 Outlet location SD6980022200 (OS grid reference) · View on Apple Maps WFD catchment Darwen - headwaters to conf Davy Field Bk (GB112071065240) 2024 spills / hours 19 / 28 Long-term average 25.2 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 25 hours spilling →	Trib River Darwen	26	25	up 37%	100%
Great Clowes CSO 37048 SAL0080 Overflow on sewer network Company site name Great Clowes Street/Sussex Street CSO EA ID / permit UUP00839 · 016993788 Outlet location SJ8290099370 (OS grid reference) · View on Apple Maps WFD catchment Irwell (Croal to Irk) (GB112069061451) 2024 spills / hours 69 / 66 Long-term average 69.6 spills a year (monitored since 2018) High-spill reason (company) Not asset maintenance - Hydraulic capacity Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 25 hours spilling →	River Irwell	35	25	down 49%	100%
Bryn Road Overflow on sewer network Company site name Bryn Road CSO EA ID / permit UUP00356 · 01WIG0104 Outlet location SJ5857098960 (OS grid reference) · View on Apple Maps WFD catchment Millingford (Newton) Brook (GB112069061220) 2024 spills / hours 42 / 29 Long-term average 48.2 spills a year (monitored since 2019) High-spill reason (company) Not asset maintenance - Hydraulic capacity Investigation Operational investigation completed Improvement Operational improvement completed Volume & pollution Estimate from 25 hours spilling →	Millingford Brook	32	25	down 24%	100%
Peel Hall Drive CSO Overflow on sewer network Company site name Peel Hall Drive CSO EA ID / permit UUP01525 · 01BRY0004 Outlet location SD7898014680 (OS grid reference) · View on Apple Maps WFD catchment Irwell (Rossendale STW to Roch) (GB112069064620) 2024 spills / hours 61 / 85 Long-term average 84.6 spills a year (monitored since 2017) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 25 hours spilling →	River Irwell	13	25	down 79%	97%
Blackshaw Lane CSO 072FW Overflow on sewer network Company site name Blackshaw Lane CSO EA ID / permit UUP00255 · 01BOL0104 Outlet location SD7020008690 (OS grid reference) · View on Apple Maps WFD catchment Middle Brook (GB112069064540) 2024 spills / hours 15 / 10 Long-term average 50.9 spills a year (monitored since 2018) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 25 hours spilling →	Middle Brook (River Croal)	15	25	no change	99%
Torkington Road CSO Overflow on sewer network Company site name Torkington Road CSO EA ID / permit UUP01951 · 016982664 Outlet location SJ9338087070 (OS grid reference) · View on Apple Maps WFD catchment Poise Brook (GB112069060950) 2024 spills / hours 0 / 0.0 Long-term average 0.8 spills a year (monitored since 2021) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 25 hours spilling →	Trib of Ocherley Brook	2	25	up from 0	98%
Bull Beck Brookhouse CSO Overflow on sewer network Company site name Bull Beck Brookhouse Combined Sewer Overflow (Site ID 251HH) (LAN0089) EA ID / permit UUP00362 · 017280284 Outlet location SD5408064800 (OS grid reference) · View on Apple Maps WFD catchment Lune - conf Wenning to tidal (GB112072065980) 2024 spills / hours 7 / 15 Long-term average 6.1 spills a year (monitored since 2018) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 25 hours spilling →	Bull Beck	9	25	up 29%	97%
Lynton Avenue CSO Overflow on sewer network Company site name Lynton Avenue CSO EA ID / permit UUP01214 · 01WIG0005 Outlet location SD5624006710 (OS grid reference) · View on Apple Maps WFD catchment Douglas - Lower (GB112070064820) 2024 spills / hours 16 / 17 Long-term average 22.0 spills a year (monitored since 2024) Investigation Env Act (SODRP) investigation ongoing Improvement Env Act (SODRP) improvement ongoing Volume & pollution Estimate from 25 hours spilling →	Culverted Trib. River Douglas	28	25	up 75%	99%
Heaton Moor CSO 431YX Overflow on sewer network Company site name Heaton Moor CSO EA ID / permit UUP00934 · 016982679 Outlet location SJ8596090050 (OS grid reference) · View on Apple Maps WFD catchment Mersey (upstream of Manchester Ship Canal) (GB112069061030) 2024 spills / hours 13 / 24 Long-term average 10.8 spills a year (monitored since 2018) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 25 hours spilling →	River Mersey	17	25	up 31%	97%
Frederick Road CSO (371UV) Overflow on sewer network Company site name Frederick Road CSO EA ID / permit UUP00760 · 016940467 Outlet location SJ8216099790 (OS grid reference) · View on Apple Maps WFD catchment Irwell (Croal to Irk) (GB112069061451) 2024 spills / hours 11 / 24 Long-term average 17.6 spills a year (monitored since 2021) Investigation Operational investigation completed Improvement Operational improvement completed Volume & pollution Estimate from 24 hours spilling →	River Irwell	10	24	down 9%	96%
Gambrel Bank Road CSO 441U7 Overflow on sewer network Company site name Gambrel Bank Road CSO EA ID / permit UUP00771 · 01TAM0050 Outlet location SD9374000740 (OS grid reference) · View on Apple Maps WFD catchment Medlock (Source to Lumb Brook) (GB112069061151) 2024 spills / hours 15 / 14 Long-term average 14.2 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 24 hours spilling →	Downshaw Brook	22	24	up 47%	100%
Priory Road CSO 392MO Storm discharge at pumping station Company site name Priory Road, Ulverston EA ID / permit UUP01586 · 01LAK0005 Outlet location SD2973076700 (OS grid reference) · View on Apple Maps WFD catchment LEVEN - transitional (GB531207311900) 2024 spills / hours 18 / 40 Long-term average 23.5 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 24 hours spilling →	Trib Carter Pool	24	24	up 33%	99%

Sewage treatment works

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

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