Storm overflow register · United Utilities

Newton Arlosh Newta sewage works: storm overflow spills 2025

Newton Arlosh Newta sewage treatment works, run by United Utilities, has 1 monitored storm overflow discharging to Trib of River Wampool. In 2025 it recorded 81 spills totalling 385 hours, against 93 spills and 437 hours in 2024. By hours spilling, it ranks 127 of 289 United Utilities works, where 1 spilled longest.

Every spill in 2025

Each blue mark is one spill, placed by when it started and sized by how long it lasted. Hover over a mark for the date and duration.

JanFebMarAprMayJunJulAugSepOctNovDecNewton Arlosh WwTW…23 spills, 9.6 h, 1 Jan to 1 Jan24 spills, 15.7 h, 5 Jan to 6 Jan3 spills, 0.4 h, 13 Jan to 13 Jan5 spills, 1.3 h, 23 Jan to 23 Jan27 Jan 2025 13:28 GMT, 5 min3 spills, 0.5 h, 4 Feb to 4 Feb15 May 2025 15:12 GMT, 2 min24 May 2025 01:20 GMT, 14 min4 spills, 0.9 h, 24 May to 24 May17 spills, 4.4 h, 29 May to 30 May5 spills, 1.9 h, 3 Jun to 3 Jun5 Jun 2025 13:43 GMT, 8 min5 spills, 0.5 h, 7 Jun to 7 Jun8 Jun 2025 19:45 GMT, 4 min6 spills, 1.5 h, 9 Jun to 9 Jun18 spills, 10.6 h, 14 Jun to 14 Jun3 spills, 2.1 h, 21 Jun to 21 Jun26 Jun 2025 06:28 GMT, 6 min3 spills, 0.5 h, 27 Jun to 27 Jun4 spills, 1.6 h, 1 Jul to 2 Jul2 spills, 2 h, 5 Jul to 5 Jul2 spills, 0.8 h, 14 Jul to 14 Jul30 spills, 9.7 h, 15 Jul to 15 Jul19 Jul 2025 18:56 GMT, 62 min20 Jul 2025 20:02 GMT, 9 min4 spills, 1 h, 3 Aug to 3 Aug7 spills, 2.1 h, 4 Aug to 4 Aug3 spills, 0.1 h, 28 Aug to 28 Aug6 spills, 2.6 h, 3 Sep to 3 Sep2 spills, 1.2 h, 8 Sep to 8 Sep43 spills, 11.9 h, 11 Sep to 13 Sep20 spills, 3.6 h, 14 Sep to 15 Sep6 spills, 1.7 h, 17 Sep to 17 Sep63 spills, 20 h, 19 Sep to 21 Sep21 Sep 2025 19:31 GMT, 2 min18 spills, 6 h, 3 Oct to 4 Oct2 spills, 0 h, 6 Oct to 6 Oct2 spills, 1.7 h, 27 Oct to 28 Oct2 spills, 0.2 h, 29 Oct to 29 Oct9 spills, 2.3 h, 1 Nov to 1 Nov100 spills, 38.5 h, 3 Nov to 5 Nov2 spills, 0.2 h, 10 Nov to 10 Nov6 spills, 2.5 h, 11 Nov to 11 Nov41 spills, 35.2 h, 12 Nov to 14 Nov5 spills, 2.3 h, 22 Nov to 22 Nov30 spills, 13.1 h, 23 Nov to 24 Nov18 spills, 4.9 h, 27 Nov to 27 Nov2 spills, 33.4 h, 28 Nov to 29 Nov62 spills, 29.2 h, 1 Dec to 3 Dec3 spills, 2.8 h, 6 Dec to 6 Dec69 spills, 35.2 h, 7 Dec to 10 Dec60 spills, 41.6 h, 13 Dec to 16 Dec54 spills, 25.6 h, 17 Dec to 19 Dec

Hours spilling by month, 2025

050100150Jan 2025: 27 hours spillingJanFeb 2025: 0.5 hours spillingFebMar 2025: 0.0 hours spillingMarApr 2025: 0.0 hours spillingAprMay 2025: 5.6 hours spillingMayJun 2025: 17 hours spillingJunJul 2025: 15 hours spillingJulAug 2025: 3.2 hours spillingAugSep 2025: 41 hours spillingSepOct 2025: 8.0 hours spillingOctNov 2025: 132 hours spillingNovDec 2025: 134 hours spillingDec
Hours, measured by the event duration monitor.

Longest single spills

Started (GMT)OverflowDuration
28 Nov 2025, 14:19Newton Arlosh WwTW Newta1.4 days
12 Nov 2025, 23:14Newton Arlosh WwTW Newta21.0 h
4 Nov 2025, 07:42Newton Arlosh WwTW Newta13.2 h
14 Dec 2025, 20:05Newton Arlosh WwTW Newta11.5 h
14 Dec 2025, 00:54Newton Arlosh WwTW Newta10.9 h

Estimated 2025 spill volume and pollution

Estimate, not a measurement. Monitors record how long an overflow spills, not how much. This calculator back-calculates a spill rate from the size of the works, using the Environment Agency's permit formulae, and multiplies it by published storm-sewage concentrations. How it works.

This works serves fewer than 2,000 people, or was not matched to a UWWTD report, so its size is not published. The population equivalent above is a placeholder of 1,000. Enter the population served if you know it.

Volume, central estimate6,588 m³range 2,624 - 16,540 m³
In litres6.6 millionrange 2.6 million - 16.5 million L
Olympic swimming pools2.6at 2,500 m³ each
Organic load, as people's raw sewage9,882person-days of untreated BOD

Assumed spill rate while spilling: 1.9 - 11.9 L/s (central 4.8 L/s), from a dry-weather flow of 1.9 L/s.

Pollutant releasedLowCentralHighConcentration used (low / typical / high)
BOD₅ (organic load) 105 kg593 kg3,308 kg 40 / 90 / 200 mg/L
Low/high: Europe range, Ellis & Jenkins 2005; typical: UK, Ellis & Jenkins 2005 (both via botturi)
Suspended solids 276 kg2,800 kg11,925 kg 105 / 425 / 721 mg/L
Low/high: Europe range; typical: UK, Ellis & Jenkins 2005 (via botturi)
Ammonium-N 5.0 kg42 kg154 kg 1.9 / 6.3 / 9.3 mg/L
Low: Germany, Brombach 2005; typical/high: Paris range 3.3-9.3 midpoint and top, Gasperi 2012 (via botturi); no UK value found
Total phosphorus 3.1 kg17 kg89 kg 1.2 / 2.6 / 5.4 mg/L
Low/high: Paris, Gasperi 2012; typical: Slovakia (via botturi). UK figure of 10 mg/L treated as an outlier
E. coli 262.4 billion organisms6.6 trillion organisms165.4 trillion organisms 10,000 / 100,000 / 1.0 million per 100 mL
Median range at CSO and retention-tank outlets, Stott et al. 2018 (via botturi); typical = log midpoint

Low combines the low spill rate with low concentrations, and high combines high with high, so the true figure is very likely inside the range. Long spills become more diluted as they go on, so the central figure tends to overstate the load of long events. The calculator does not estimate the effect on the receiving water, which depends on river flow or tide at the time of the spill.

Newton Arlosh WwTW Newta

Inlet overflow at sewage works · discharges to Trib of River Wampool

Spills 2025
81 (385 hours) · down 13% on 2024
Spills 2024
93 (437 hours)
Long-term average
117.9 spills a year (monitored since 2019)
Monitor uptime
100% of the year
High-spill reason (company)
Not asset maintenance - Hydraulic capacity
Investigation
Env Act (SODRP) investigation ongoing
Improvement
No improvement action in reporting period
WFD catchment
SOLWAY (GB530207614700)
Outlet location
NY1909055590 (OS grid reference) · View on Apple Maps
EA ID / permit
UUP01398 · 017570196 · company name: NEWTON ARLOSH WwTW

How the estimate works

  1. Dry-weather flow (DWF) = population × water use per person × (1 + infiltration). Water use is 136.5 L per person per day, England's per-capita consumption for 2024-25 [EA]. Infiltration of groundwater into sewers is taken as 0-40% of that flow [Escritt, via HBF]. The Environment Agency defines DWF as PG + I + E [EA].
  2. Population. The size of each works comes from the load entering it as reported under the Urban Waste Water Treatment Directive, in population equivalents (1 p.e. = 60 g of BOD a day) [UWWTD]. We treat population equivalent as population. That overstates flow where trade effluent adds load, and no official source links the two. Works serving fewer than 2,000 p.e. are not reported, so their size has to be entered by hand.
  3. Low spill rate = DWF. This is the method used by Giakoumis & Voulvoulis (2026), which they note likely underestimates storm loads [G&V].
  4. High spill rate = Formula A − flow to full treatment = (DWF + 1360P) − 3DWF. This is the largest flow the permit expects the storm tanks to handle before it passes on to treatment or overflows [EA]. The central rate is the geometric mean of the low and high rates.
  5. Volume = spill rate × hours spilling, with hours taken from the event duration monitor.
  6. Pollution = volume × published storm-sewage concentrations [Botturi et al.] [US EPA]. Organic load is also shown as person-days of untreated sewage at 60 g of BOD per person per day [UWWTD].

What this cannot tell you. It gives no real flow for any single spill, and no effect on the river or sea, which depends on the flow, tide and the other pressures on the water at the time. It gives no figure for spills from overflows on the sewer network, which serve catchments of unknown size. It is a way to put hours into rough physical terms, not a substitute for flow monitoring.

Sources

  1. EA: Water companies - environmental permits for storm overflows and emergency overflows
  2. EA: Water resources 2024 to 2025 - per capita consumption
  3. HBF: Foul sewer design - historic conventions (citing Escritt 1984 on infiltration)
  4. Giakoumis & Voulvoulis (2026), Environ. Sci.: Water Res. Technol., doi:10.1039/D5EW00860C
  5. Botturi et al. (2021), Crit. Rev. Environ. Sci. Technol. 51:1585 - CSO quality review, Table 2
  6. US EPA (2004) Report to Congress on CSOs and SSOs, chapter 4
  7. Urban Waste Water Treatment Directive, Article 2(6): 1 p.e. = 60 g BOD5/day
  8. Olympic-size swimming pool: 2,500 m³ at the nominal 2 m depth

← All United Utilities works · Contains Environment Agency data licensed under the Open Government Licence v3.0. Spill start and stop times: © Environment Agency copyright and/or database right 2026. All rights reserved. They are water-company data and have not been verified by the Environment Agency. Works size: EEA Waterbase UWWTD. How to read the data.