Marske Sewage Treatment Works

Storm overflow run by Northumbrian Water, discharging into North Sea.

Inlet storm overflow at sewage treatment works Bathing water

Linked bathing water: Marske Sands, classified Excellent for 2025. Named in the company’s return to the Environment Agency. A name opens that bathing water’s official profile, with any pollution warning in the season. The classification is the Environment Agency’s for that bathing season, from all its samples there: it is not a reading of the water today, and it does not say what part this overflow played.

Right now
Not discharging
Last discharge ended on (1 day ago).
Times are UK time. Company feed updated 1 min ago

"Not discharging" means the company's monitor reports no discharge right now — not that the water is clean. The feed publishes status only; no discharge volume is measured.

2026 so far
32spills
at least 49 h discharging on 32 days · live feed, before 28 Feb via Top of the Poops, not yet official · 23 discharges whose end the feed did not report (counted, no hours)
2025 official
75spills
531 h · −30% on 2024
Rank in Northumbrian Water
#37
of 1,547 overflows by 2025 spills (1 = most)
Monitor in 2025
99.9% working
Long-term average 99.6 spills a year

Year by year

The Environment Agency's official annual returns, counted the EA's way (12/24-hour spills). 2026 is our own running count, the same way, from the live feed: our own log of it begins on 28 February, and the discharges before that are Top of the Poops' record of the same feed. The feed reports only each overflow's latest discharge, so a discharge it moved past before we saw it end is counted as one spill with no hours: the hours are a floor. The official figure is published next spring.

2024
107 spills · 784 hmonitor 100%
2025
75 spills · 531 hmonitor 99.9%
2026so far
32 spills · at least 49 h

A spill is the EA's 12/24-hour count: the first 12 hours of a discharge count as one, each further 24 hours with discharge as one more. "Monitor" is the share of that year the monitor was working, so a 0 beside a working monitor is a real zero; "no data" means the monitor produced no usable data that year — not zero. Years before 2024 are matched to this site by name and location, because the EA's site IDs changed that year; a monitor figure beside one of them means the outlet's permit confirms the match.

Twin outlet

Northumbrian Water runs another overflow within 300 m that also discharges into North Sea. They share the sewer and the storm, so one outlet's figures are only part of what reaches the water.

0m Marske Sewage Treatment WorksNWL00855Marske Sewage Treatment Works 24spills in 2025

This overflow: 75 spills in 2025. Distances are between the published outlet points.

What the 2025 return says

From Northumbrian Water's annual return to the Environment Agency for this overflow.

High-spill review
Not asset maintenance - Hydraulic capacity
Investigation
Operational investigation ongoing
Improvement work
Operational improvement ongoing
Monitored since
2021
Water body
Tees Coastal

This overflow spilled often enough to trigger the EA's high-spill review; the review line is the company's own stated reason.

Discharges we have recorded

3,052 discharge periods since 1 Jan 2021, 23 whose end the feed never gave. 2,811 of them come from Northumbrian Water's own event-duration-monitoring records (published on Stream, Jan 2021 – Dec 2024); the live feed adds anything after that. The official annual count is the figure to quote.

Show 30 earlier (of 3,052)
StartedEndedDischarge time
2 min
not captured, before not captured
not captured, before not captured
not captured, before not captured
not captured, before 0 min
7 min
7 min
5 min
0 min
1 min
not captured, before 0 min
1 min
3 min
0 min
not captured, before not captured
1 min
2 min
6 min
4 min
2 min
6 min
5 min
6 min
5 min
6 min
9 min
3 min
not captured, before not captured
4 min
not captured, before 0 min

The year figures above use the EA's 12/24-hour counting method, so they are comparable with the official figures; the monitor log's 4,179 raw blocks were merged into 3,052 continuous discharge periods (gaps under 15 min joined).

What the feed showed

FloodRadar's own record of every change of state Northumbrian Water's live feed has shown for this overflow, kept since : 7 states. The feed publishes its status now and its latest discharge, nothing older; the discharges above are read from this. It is here so the figures can be checked.

Show the last 7 states
SeenStatusSinceLatest discharge
Not discharging →
Not discharging →
Discharging → no end yet
Not discharging →
Not discharging →
Not discharging →
Not discharging →

Rain nearby last 30 days

Nearest live rain gauge: Rainfall gauge nr Marske-by-the-Sea, 2.4 km away. Brown shading = when this overflow was discharging; ▼ = a discharge start.

Overflow shading is a timing match, not proof of cause — heavy rain and spills share a trigger. Times come from the water company’s event-duration monitor (site status only; no discharge volume is published).

Where it is

Nearest river gauge
Skinningrove (Kilton Beck) · 8.5 km
Nearest rain gauge
Site reference
NWL00856 · permit 25/06/1015
Coordinates
54.60892, -1.00986

Tell me when this overflow discharges

One message when the company's monitor reports a new discharge here. At most one every 6 hours.

Setting this alert needs JavaScript. The alerts you already have are on your alerts page.

The alert repeats the monitor's status: whether the overflow is discharging, not how much or why. It can only tell you about a discharge that starts after you turn it on.

Concerned about this overflow?

Report pollution you can see or smell to the regulator straight away; the company handles complaints about the overflow itself.

Live status: © Northumbrian Water storm overflow activity data, licensed under CC BY 4.0. Annual spill figures: Environment Agency Event Duration Monitoring return, © Environment Agency copyright and/or database right, Open Government Licence (OGL) v3.0. Storm-overflow spill events: © the respective water company, published on Stream (data.streamwaterdata.co.uk) under CC BY 4.0. Discharges marked "via Top of the Poops", and this year's figures before 28 February, come from Top of the Poops' record of the same company feed, used under CC BY-SA 4.0: the feed's own start and end times as its pages print them, not their derived hours. Times are shown in UK local time. FloodRadar republishes the monitor's status and the EA's figures; it does not measure discharges itself.