Storm overflow register · Northumbrian Water

Amble sewage works: storm overflow spills 2025

Amble sewage treatment works, run by Northumbrian Water, has 1 monitored storm overflow discharging to North Sea. In 2025 it recorded 91 spills totalling 522 hours, against 124 spills and 626 hours in 2024. By hours spilling, it ranks 31 of 183 Northumbrian Water 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.

JanFebMarAprMayJunJulAugSepOctNovDecAmble Sewage…24 spills, 6.8 h, 1 Jan to 1 Jan55 spills, 48.9 h, 5 Jan to 7 Jan17 spills, 5.3 h, 26 Jan to 27 Jan3 spills, 0.9 h, 8 Feb to 8 Feb5 spills, 1.8 h, 16 Feb to 16 Feb7 spills, 3.6 h, 20 Feb to 20 Feb7 spills, 1.3 h, 23 Feb to 23 Feb6 spills, 0.8 h, 12 Mar to 12 Mar8 spills, 1.7 h, 22 Mar to 22 Mar12 spills, 4.8 h, 1 May to 1 May7 May 2025 09:38 GMT, 3 min7 spills, 2.7 h, 24 May to 24 May27 May 2025 23:30 GMT, 1 min7 spills, 3.1 h, 29 May to 29 May3 spills, 2.6 h, 8 Jun to 8 Jun12 spills, 0.8 h, 9 Jun to 10 Jun3 spills, 0.3 h, 21 Jun to 21 Jun5 spills, 1.6 h, 22 Jun to 22 Jun3 spills, 0.4 h, 26 Jun to 26 Jun16 spills, 9.9 h, 1 Jul to 2 Jul5 spills, 1.6 h, 7 Jul to 7 Jul8 spills, 3 h, 14 Jul to 14 Jul15 spills, 5.8 h, 19 Jul to 19 Jul4 spills, 1.7 h, 20 Jul to 20 Jul2 spills, 0.2 h, 3 Aug to 3 Aug4 spills, 0.6 h, 4 Aug to 4 Aug5 spills, 1.2 h, 11 Aug to 11 Aug2 spills, 1 h, 31 Aug to 31 Aug11 spills, 4.6 h, 3 Sep to 3 Sep5 spills, 1.5 h, 4 Sep to 4 Sep17 spills, 6.5 h, 10 Sep to 11 Sep22 spills, 8.1 h, 14 Sep to 16 Sep3 spills, 0.4 h, 17 Sep to 17 Sep38 spills, 22.2 h, 20 Sep to 21 Sep2 spills, 0.8 h, 27 Sep to 27 Sep18 spills, 4.7 h, 1 Oct to 1 Oct34 spills, 15.6 h, 2 Oct to 4 Oct6 spills, 1.1 h, 6 Oct to 6 Oct32 spills, 22.8 h, 19 Oct to 20 Oct5 spills, 0.9 h, 23 Oct to 23 Oct29 spills, 11.1 h, 24 Oct to 25 Oct5 spills, 3.5 h, 27 Oct to 28 Oct4 spills, 0.8 h, 31 Oct to 1 Nov25 spills, 9.2 h, 4 Nov to 5 Nov9 Nov 2025 20:02 GMT, 4 min7 spills, 3.4 h, 11 Nov to 11 Nov48 spills, 37.2 h, 13 Nov to 14 Nov4 spills, 0.3 h, 17 Nov to 17 Nov276 spills, 146.6 h, 18 Nov to 28 Nov141 spills, 29.8 h, 29 Nov to 3 Dec389 spills, 78.2 h, 4 Dec to 12 Dec2 spills, 0 h, 15 Dec to 15 Dec5 spills, 0.5 h, 17 Dec to 17 Dec4 spills, 0.1 h, 18 Dec to 18 Dec29 Dec 2025 15:39 GMT, 1 min

Hours spilling by month, 2025

0100200300Jan 2025: 61 hours spillingJanFeb 2025: 7.6 hours spillingFebMar 2025: 2.5 hours spillingMarApr 2025: 0.0 hours spillingAprMay 2025: 11 hours spillingMayJun 2025: 5.6 hours spillingJunJul 2025: 22 hours spillingJulAug 2025: 3.0 hours spillingAugSep 2025: 44 hours spillingSepOct 2025: 60 hours spillingOctNov 2025: 206 hours spillingNovDec 2025: 99 hours spillingDec
Hours, measured by the event duration monitor.

Longest single spills

Started (GMT)OverflowDuration
13 Nov 2025, 01:01Amble Sewage Treatment Works1.2 days
24 Nov 2025, 16:54Amble Sewage Treatment Works1.2 days
23 Nov 2025, 07:47Amble Sewage Treatment Works1.1 days
5 Jan 2025, 17:03Amble Sewage Treatment Works22.0 h
18 Nov 2025, 21:17Amble Sewage Treatment Works18.1 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 estimate8,944 m³range 3,563 - 22,455 m³
In litres8.9 millionrange 3.6 million - 22.5 million L
Olympic swimming pools3.6at 2,500 m³ each
Organic load, as people's raw sewage13,416person-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) 143 kg805 kg4,491 kg 40 / 90 / 200 mg/L
Low/high: Europe range, Ellis & Jenkins 2005; typical: UK, Ellis & Jenkins 2005 (both via botturi)
Suspended solids 374 kg3,801 kg16,190 kg 105 / 425 / 721 mg/L
Low/high: Europe range; typical: UK, Ellis & Jenkins 2005 (via botturi)
Ammonium-N 6.8 kg56 kg209 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 4.3 kg23 kg121 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 356.3 billion organisms8.9 trillion organisms224.5 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.

Amble Sewage Treatment Works

Inlet overflow at sewage works · discharges to North Sea

Spills 2025
91 (522 hours) · down 27% on 2024
Spills 2024
124 (626 hours)
Long-term average
127.0 spills a year (monitored since 2021)
Monitor uptime
100% of the year
High-spill reason (company)
Not Applicable - Ongoing investigation
Investigation
Operational investigation ongoing
Improvement
No improvement action in reporting period
WFD catchment
Northumberland South (GB650301500001)
Outlet location
NU2767004990 (OS grid reference) · View on Apple Maps
EA ID / permit
NWL00049 · 223/0931

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 Northumbrian Water 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.