Ray (Oxon) at gauging station, Grendon Underwood
EA name: RAY ( OXON ) AT G/S, GRENDON UNDERWOOD
Environment Agency sampling point TH-PCHR0042 · Freshwater - rivers · listed as open (“open” does not mean it is sampled now)
These are samples taken on a date, not live readings of the river. Results reach the Environment Agency's archive days to months after the sample is taken, so the newest here may be weeks or months old. FloodRadar does not grade them.
Where and when
- Last sampled
- 3 Mar 2026, 10:377 months ago · time as the Environment Agency records it (UK clock time; the source gives no time zone). Not sampled since, as far as the archive shows: the Environment Agency was asked up to 30 Sep 2026 and had nothing newer.
- Samples banked
- 33 since 16 Oct 2023 Imported periods: 1 Oct 2023 – 30 Sep 2026. Samples outside them are not shown here.
- Latest sample
- River / running surface water Environmental monitoring statutory (EU directives)
- Where
- National Grid 468100, 221100As published, to the nearest 100 m (so up to about 70 m out). Open in a map
- River, by its own name
- Ray
- River, by the map
- River RayPlaced on the river its name gives, 25 m from the line.
- Next gauge downstream
- Lower Arncott On the River Ray · 11 km along the riverBeside Grendon Underwood: too close to say above or below.
- Why it was sampled
- Environmental monitoring statutory (EU directives) (28 samples)
Monitoring (national agency policy) (5 samples)
Main measurements, river water
Dissolved oxygen
% saturation · code 9901 · %
82.9%
Sampled 3 Mar 2026, 7 months ago · 32 results banked
Every result (32)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Mar 2026, 10:37 | 82.9 | 82.9% |
| 5 Feb 2026, 12:33 | 86.8 | 86.8% |
| 5 Jan 2026, 13:44 | 85.5 | 85.5% |
| 18 Dec 2025, 12:43 | 83.3 | 83.3% |
| 20 Nov 2025, 12:10 | 90.8 | 90.8% |
| 22 Oct 2025, 11:38 | 48.6 | 48.6% |
| 12 Sep 2025, 12:50 | 69.2 | 69.2% |
| 22 Aug 2025, 10:09 | 82.6 | 82.6% |
| 28 Jul 2025, 12:36 | 54.8 | 54.8% |
| 12 Jun 2025, 09:58 | 52 | 52% |
| 16 May 2025, 10:18 | 44.2 | 44.2% |
| 25 Apr 2025, 11:09 | 84.8 | 84.8% |
| 14 Mar 2025, 10:26 | 93.5 | 93.5% |
| 25 Feb 2025, 12:09 | 94.5 | 94.5% |
| 31 Jan 2025, 10:22 | 88 | 88% |
| 9 Dec 2024, 09:44 | 80.3 | 80.3% |
| 21 Nov 2024, 12:50 | 90.5 | 90.5% |
| 16 Oct 2024, 13:13 | 87.8 | 87.8% |
| 19 Sep 2024, 10:27 | 57.9 | 57.9% |
| 22 Aug 2024, 11:19 | 73.9 | 73.9% |
| 22 Jul 2024, 11:36 | 50.8 | 50.8% |
| 25 Jun 2024, 10:42 | 51.4 | 51.4% |
| 24 May 2024, 13:10 | 88.5 | 88.5% |
| 24 Apr 2024, 12:11 | 85.4 | 85.4% |
| 19 Mar 2024, 11:04 | 88.5 | 88.5% |
| 23 Feb 2024, 11:11 | 97.7 | 97.7% |
| 16 Jan 2024, 12:01 | 91.8 | 91.8% |
| 13 Dec 2023, 11:56 | 81.3 | 81.3% |
| 29 Nov 2023, 09:52 | 80 | 80% |
| 14 Nov 2023, 14:22 | 74.1 | 74.1% |
| 30 Oct 2023, 09:09 | 76.3 | 76.3% |
| 16 Oct 2023, 11:28 | 76.6 | 76.6% |
Dissolved oxygen
as O2 · code 9924 · mg/l
9.75 mg/l
Sampled 3 Mar 2026, 7 months ago · 32 results banked
Every result (32)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Mar 2026, 10:37 | 9.75 | 9.75 mg/l |
| 5 Feb 2026, 12:33 | 10.7 | 10.7 mg/l |
| 5 Jan 2026, 13:44 | 12.2 | 12.2 mg/l |
| 18 Dec 2025, 12:43 | 9.57 | 9.57 mg/l |
| 20 Nov 2025, 12:10 | 11.9 | 11.9 mg/l |
| 22 Oct 2025, 11:38 | 5.31 | 5.31 mg/l |
| 12 Sep 2025, 12:50 | 7.29 | 7.29 mg/l |
| 22 Aug 2025, 10:09 | 8.7 | 8.7 mg/l |
| 28 Jul 2025, 12:36 | 5.27 | 5.27 mg/l |
| 12 Jun 2025, 09:58 | 5.25 | 5.25 mg/l |
| 16 May 2025, 10:18 | 4.94 | 4.94 mg/l |
| 25 Apr 2025, 11:09 | 9.79 | 9.79 mg/l |
| 14 Mar 2025, 10:26 | 12.5 | 12.5 mg/l |
| 25 Feb 2025, 12:09 | 11.2 | 11.2 mg/l |
| 31 Jan 2025, 10:22 | 11.4 | 11.4 mg/l |
| 9 Dec 2024, 09:44 | 9.83 | 9.83 mg/l |
| 21 Nov 2024, 12:50 | 11.8 | 11.8 mg/l |
| 16 Oct 2024, 13:13 | 9.09 | 9.09 mg/l |
| 19 Sep 2024, 10:27 | 5.89 | 5.89 mg/l |
| 22 Aug 2024, 11:19 | 7.37 | 7.37 mg/l |
| 22 Jul 2024, 11:36 | 4.94 | 4.94 mg/l |
| 25 Jun 2024, 10:42 | 4.79 | 4.79 mg/l |
| 24 May 2024, 13:10 | 9.12 | 9.12 mg/l |
| 24 Apr 2024, 12:11 | 10.1 | 10.1 mg/l |
| 19 Mar 2024, 11:04 | 9.83 | 9.83 mg/l |
| 23 Feb 2024, 11:11 | 12.1 | 12.1 mg/l |
| 16 Jan 2024, 12:01 | 12.9 | 12.9 mg/l |
| 13 Dec 2023, 11:56 | 9.76 | 9.76 mg/l |
| 29 Nov 2023, 09:52 | 10.3 | 10.3 mg/l |
| 14 Nov 2023, 14:22 | 8.39 | 8.39 mg/l |
| 30 Oct 2023, 09:09 | 8.54 | 8.54 mg/l |
| 16 Oct 2023, 11:28 | 9.13 | 9.13 mg/l |
Water temperature
code 0076 · °C
8.2 °C
Sampled 3 Mar 2026, 7 months ago · 32 results banked
Every result (32)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Mar 2026, 10:37 | 8.2 | 8.2 °C |
| 5 Feb 2026, 12:33 | 6.3 | 6.3 °C |
| 5 Jan 2026, 13:44 | 0.8 | 0.8 °C |
| 18 Dec 2025, 12:43 | 9.2 | 9.2 °C |
| 20 Nov 2025, 12:10 | 3.9 | 3.9 °C |
| 22 Oct 2025, 11:38 | 11.3 | 11.3 °C |
| 12 Sep 2025, 12:50 | 12.9 | 12.9 °C |
| 22 Aug 2025, 10:09 | 12.9 | 12.9 °C |
| 28 Jul 2025, 12:36 | 17.1 | 17.1 °C |
| 12 Jun 2025, 09:58 | 14.8 | 14.8 °C |
| 16 May 2025, 10:18 | 10.3 | 10.3 °C |
| 25 Apr 2025, 11:09 | 9 | 9 °C |
| 14 Mar 2025, 10:26 | 3.3 | 3.3 °C |
| 25 Feb 2025, 12:09 | 7.8 | 7.8 °C |
| 31 Jan 2025, 10:22 | 4.5 | 4.5 °C |
| 9 Dec 2024, 09:44 | 6.6 | 6.6 °C |
| 21 Nov 2024, 12:50 | 4.3 | 4.3 °C |
| 16 Oct 2024, 13:13 | 13.7 | 13.7 °C |
| 19 Sep 2024, 10:27 | 14.5 | 14.5 °C |
| 22 Aug 2024, 11:19 | 15.4 | 15.4 °C |
| 22 Jul 2024, 11:36 | 16.6 | 16.6 °C |
| 25 Jun 2024, 10:42 | 18.6 | 18.6 °C |
| 24 May 2024, 13:10 | 13.9 | 13.9 °C |
| 24 Apr 2024, 12:11 | 8 | 8 °C |
| 19 Mar 2024, 11:04 | 10.6 | 10.6 °C |
| 23 Feb 2024, 11:11 | 6.1 | 6.1 °C |
| 16 Jan 2024, 12:01 | 1.3 | 1.3 °C |
| 13 Dec 2023, 11:56 | 7.4 | 7.4 °C |
| 29 Nov 2023, 09:52 | 4.8 | 4.8 °C |
| 14 Nov 2023, 14:22 | 9.8 | 9.8 °C |
| 30 Oct 2023, 09:09 | 10.3 | 10.3 °C |
| 16 Oct 2023, 11:28 | 7.7 | 7.7 °C |
pH
code 0061
7.87
Sampled 3 Mar 2026, 7 months ago · 32 results banked
Every result (32)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Mar 2026, 10:37 | 7.87 | 7.87 |
| 5 Feb 2026, 12:33 | 7.74 | 7.74 |
| 5 Jan 2026, 13:44 | 7.83 | 7.83 |
| 18 Dec 2025, 12:43 | 7.71 | 7.71 |
| 20 Nov 2025, 12:10 | 7.73 | 7.73 |
| 22 Oct 2025, 11:38 | 7.61 | 7.61 |
| 12 Sep 2025, 12:50 | 7.53 | 7.53 |
| 22 Aug 2025, 10:09 | 8.06 | 8.06 |
| 28 Jul 2025, 12:36 | 7.77 | 7.77 |
| 12 Jun 2025, 09:58 | 7.71 | 7.71 |
| 16 May 2025, 10:18 | 7.62 | 7.62 |
| 25 Apr 2025, 11:09 | 7.87 | 7.87 |
| 14 Mar 2025, 10:26 | 8.05 | 8.05 |
| 25 Feb 2025, 12:09 | 7.93 | 7.93 |
| 31 Jan 2025, 10:22 | 7.77 | 7.77 |
| 9 Dec 2024, 09:44 | 7.71 | 7.71 |
| 21 Nov 2024, 12:50 | 7.75 | 7.75 |
| 16 Oct 2024, 13:13 | 7.66 | 7.66 |
| 19 Sep 2024, 10:27 | 7.66 | 7.66 |
| 22 Aug 2024, 11:19 | 7.71 | 7.71 |
| 22 Jul 2024, 11:36 | 7.8 | 7.8 |
| 25 Jun 2024, 10:42 | 7.71 | 7.71 |
| 24 May 2024, 13:10 | 7.94 | 7.94 |
| 24 Apr 2024, 12:11 | 7.96 | 7.96 |
| 19 Mar 2024, 11:04 | 7.83 | 7.83 |
| 23 Feb 2024, 11:11 | 8.05 | 8.05 |
| 16 Jan 2024, 12:01 | 7.88 | 7.88 |
| 13 Dec 2023, 11:56 | 7.67 | 7.67 |
| 29 Nov 2023, 09:52 | 7.7 | 7.7 |
| 14 Nov 2023, 14:22 | 7.5 | 7.5 |
| 30 Oct 2023, 09:09 | 7.57 | 7.57 |
| 16 Oct 2023, 11:28 | 7.7 | 7.7 |
Ammonia
ammoniacal nitrogen as N · code 0111 · mg/l
0.046 mg/l
Sampled 3 Mar 2026, 7 months ago · 32 results banked
Every result (32)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Mar 2026, 10:37 | 0.046 | 0.046 mg/l |
| 5 Feb 2026, 12:33 | <0.03 | below 0.03 mg/l (not detected above this) |
| 5 Jan 2026, 13:44 | 0.068 | 0.068 mg/l |
| 18 Dec 2025, 12:43 | 0.071 | 0.071 mg/l |
| 20 Nov 2025, 12:10 | 0.045 | 0.045 mg/l |
| 22 Oct 2025, 11:38 | <0.03 | below 0.03 mg/l (not detected above this) |
| 12 Sep 2025, 12:50 | <0.03 | below 0.03 mg/l (not detected above this) |
| 22 Aug 2025, 10:09 | <0.03 | below 0.03 mg/l (not detected above this) |
| 28 Jul 2025, 12:36 | 0.43 | 0.43 mg/l |
| 12 Jun 2025, 09:58 | 0.17 | 0.17 mg/l |
| 16 May 2025, 10:18 | 0.22 | 0.22 mg/l |
| 25 Apr 2025, 11:09 | 0.071 | 0.071 mg/l |
| 14 Mar 2025, 10:26 | 0.086 | 0.086 mg/l |
| 25 Feb 2025, 12:09 | 0.039 | 0.039 mg/l |
| 31 Jan 2025, 10:22 | 0.094 | 0.094 mg/l |
| 9 Dec 2024, 09:44 | 0.035 | 0.035 mg/l |
| 21 Nov 2024, 12:50 | 0.2 | 0.2 mg/l |
| 16 Oct 2024, 13:13 | <0.03 | below 0.03 mg/l (not detected above this) |
| 19 Sep 2024, 10:27 | <0.03 | below 0.03 mg/l (not detected above this) |
| 22 Aug 2024, 11:19 | 0.42 | 0.42 mg/l |
| 22 Jul 2024, 11:36 | 0.12 | 0.12 mg/l |
| 25 Jun 2024, 10:42 | 0.25 | 0.25 mg/l |
| 24 May 2024, 13:10 | 0.048 | 0.048 mg/l |
| 24 Apr 2024, 12:11 | 0.096 | 0.096 mg/l |
| 19 Mar 2024, 11:04 | 0.34 | 0.34 mg/l |
| 23 Feb 2024, 11:11 | 0.085 | 0.085 mg/l |
| 16 Jan 2024, 12:01 | 0.11 | 0.11 mg/l |
| 13 Dec 2023, 11:56 | <0.03 | below 0.03 mg/l (not detected above this) |
| 29 Nov 2023, 09:52 | <0.03 | below 0.03 mg/l (not detected above this) |
| 14 Nov 2023, 14:22 | <0.03 | below 0.03 mg/l (not detected above this) |
| 30 Oct 2023, 09:09 | <0.03 | below 0.03 mg/l (not detected above this) |
| 16 Oct 2023, 11:28 | 0.032 | 0.032 mg/l |
Nitrate
as nitrogen (N) · code 0117 · mg/l
2.28 mg/l
Sampled 3 Mar 2026, 7 months ago · 32 results banked
Every result (32)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Mar 2026, 10:37 | 2.28 | 2.28 mg/l |
| 5 Feb 2026, 12:33 | 3.49 | 3.49 mg/l |
| 5 Jan 2026, 13:44 | 4.57 | 4.57 mg/l |
| 18 Dec 2025, 12:43 | 6.18 | 6.18 mg/l |
| 20 Nov 2025, 12:10 | 6.73 | 6.73 mg/l |
| 22 Oct 2025, 11:38 | <0.196 | below 0.196 mg/l (not detected above this) |
| 12 Sep 2025, 12:50 | <0.196 | below 0.196 mg/l (not detected above this) |
| 22 Aug 2025, 10:09 | <0.196 | below 0.196 mg/l (not detected above this) |
| 28 Jul 2025, 12:36 | 0.246 | 0.246 mg/l |
| 12 Jun 2025, 09:58 | 0.54 | 0.54 mg/l |
| 16 May 2025, 10:18 | 0.317 | 0.317 mg/l |
| 25 Apr 2025, 11:09 | 2.18 | 2.18 mg/l |
| 14 Mar 2025, 10:26 | 2.08 | 2.08 mg/l |
| 25 Feb 2025, 12:09 | 2.48 | 2.48 mg/l |
| 31 Jan 2025, 10:22 | 2.68 | 2.68 mg/l |
| 9 Dec 2024, 09:44 | 2.79 | 2.79 mg/l |
| 21 Nov 2024, 12:50 | 4.58 | 4.58 mg/l |
| 16 Oct 2024, 13:13 | 3.29 | 3.29 mg/l |
| 19 Sep 2024, 10:27 | <0.196 | below 0.196 mg/l (not detected above this) |
| 22 Aug 2024, 11:19 | 11.5 | 11.5 mg/l |
| 22 Jul 2024, 11:36 | 0.337 | 0.337 mg/l |
| 25 Jun 2024, 10:42 | 0.173 | 0.173 mg/l |
| 24 May 2024, 13:10 | 2.08 | 2.08 mg/l |
| 24 Apr 2024, 12:11 | 1.58 | 1.58 mg/l |
| 19 Mar 2024, 11:04 | 2.15 | 2.15 mg/l |
| 23 Feb 2024, 11:11 | 1.58 | 1.58 mg/l |
| 16 Jan 2024, 12:01 | 2.89 | 2.89 mg/l |
| 13 Dec 2023, 11:56 | 3.19 | 3.19 mg/l |
| 29 Nov 2023, 09:52 | 4.19 | 4.19 mg/l |
| 14 Nov 2023, 14:22 | 4.88 | 4.88 mg/l |
| 30 Oct 2023, 09:09 | 6.08 | 6.08 mg/l |
| 16 Oct 2023, 11:28 | 7.45 | 7.45 mg/l |
Phosphate
orthophosphate, reactive, as P · code 0180 · mg/l
0.067 mg/l
Sampled 3 Mar 2026, 7 months ago · 32 results banked
Every result (32)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Mar 2026, 10:37 | 0.067 | 0.067 mg/l |
| 5 Feb 2026, 12:33 | 0.058 | 0.058 mg/l |
| 5 Jan 2026, 13:44 | 0.042 | 0.042 mg/l |
| 18 Dec 2025, 12:43 | 0.073 | 0.073 mg/l |
| 20 Nov 2025, 12:10 | 0.01 | 0.01 mg/l |
| 22 Oct 2025, 11:38 | 0.051 | 0.051 mg/l |
| 12 Sep 2025, 12:50 | 0.047 | 0.047 mg/l |
| 22 Aug 2025, 10:09 | 0.088 | 0.088 mg/l |
| 28 Jul 2025, 12:36 | 0.38 | 0.38 mg/l |
| 12 Jun 2025, 09:58 | 0.12 | 0.12 mg/l |
| 16 May 2025, 10:18 | 0.06 | 0.06 mg/l |
| 25 Apr 2025, 11:09 | 0.061 | 0.061 mg/l |
| 14 Mar 2025, 10:26 | 0.065 | 0.065 mg/l |
| 25 Feb 2025, 12:09 | 0.064 | 0.064 mg/l |
| 31 Jan 2025, 10:22 | 0.084 | 0.084 mg/l |
| 9 Dec 2024, 09:44 | 0.047 | 0.047 mg/l |
| 21 Nov 2024, 12:50 | 0.074 | 0.074 mg/l |
| 16 Oct 2024, 13:13 | 0.056 | 0.056 mg/l |
| 19 Sep 2024, 10:27 | 0.045 | 0.045 mg/l |
| 22 Aug 2024, 11:19 | 1.7 | 1.7 mg/l |
| 22 Jul 2024, 11:36 | 0.18 | 0.18 mg/l |
| 25 Jun 2024, 10:42 | 0.11 | 0.11 mg/l |
| 24 May 2024, 13:10 | 0.025 | 0.025 mg/l |
| 24 Apr 2024, 12:11 | 0.063 | 0.063 mg/l |
| 19 Mar 2024, 11:04 | 0.024 | 0.024 mg/l |
| 23 Feb 2024, 11:11 | 0.038 | 0.038 mg/l |
| 16 Jan 2024, 12:01 | 0.035 | 0.035 mg/l |
| 13 Dec 2023, 11:56 | 0.045 | 0.045 mg/l |
| 29 Nov 2023, 09:52 | 0.039 | 0.039 mg/l |
| 14 Nov 2023, 14:22 | 0.045 | 0.045 mg/l |
| 30 Oct 2023, 09:09 | 0.063 | 0.063 mg/l |
| 16 Oct 2023, 11:28 | 0.066 | 0.066 mg/l |
Conductivity
at 25 °C · code 0077 · µS/cm
728 µS/cm
Sampled 3 Mar 2026, 7 months ago · 32 results banked
Every result (32)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Mar 2026, 10:37 | 728 | 728 µS/cm |
| 5 Feb 2026, 12:33 | 551 | 551 µS/cm |
| 5 Jan 2026, 13:44 | 995 | 995 µS/cm |
| 18 Dec 2025, 12:43 | 1024 | 1024 µS/cm |
| 20 Nov 2025, 12:10 | 2985 | 2985 µS/cm |
| 22 Oct 2025, 11:38 | 1164 | 1164 µS/cm |
| 12 Sep 2025, 12:50 | 1435 | 1435 µS/cm |
| 22 Aug 2025, 10:09 | 1632 | 1632 µS/cm |
| 28 Jul 2025, 12:36 | 1711 | 1711 µS/cm |
| 12 Jun 2025, 09:58 | 1836 | 1836 µS/cm |
| 16 May 2025, 10:18 | 1582 | 1582 µS/cm |
| 25 Apr 2025, 11:09 | 1459 | 1459 µS/cm |
| 14 Mar 2025, 10:26 | 899 | 899 µS/cm |
| 25 Feb 2025, 12:09 | 588 | 588 µS/cm |
| 31 Jan 2025, 10:22 | 795 | 795 µS/cm |
| 9 Dec 2024, 09:44 | 507 | 507 µS/cm |
| 21 Nov 2024, 12:50 | 1376 | 1376 µS/cm |
| 16 Oct 2024, 13:13 | 944 | 944 µS/cm |
| 19 Sep 2024, 10:27 | 2099 | 2099 µS/cm |
| 22 Aug 2024, 11:19 | 3822 | 3822 µS/cm |
| 22 Jul 2024, 11:36 | 1121 | 1121 µS/cm |
| 25 Jun 2024, 10:42 | 1012 | 1012 µS/cm |
| 24 May 2024, 13:10 | 658 | 658 µS/cm |
| 24 Apr 2024, 12:11 | 1339 | 1339 µS/cm |
| 19 Mar 2024, 11:04 | 1196 | 1196 µS/cm |
| 23 Feb 2024, 11:11 | 558 | 558 µS/cm |
| 16 Jan 2024, 12:01 | 735 | 735 µS/cm |
| 13 Dec 2023, 11:56 | 523 | 523 µS/cm |
| 29 Nov 2023, 09:52 | 765 | 765 µS/cm |
| 14 Nov 2023, 14:22 | 619 | 619 µS/cm |
| 30 Oct 2023, 09:09 | 1024 | 1024 µS/cm |
| 16 Oct 2023, 11:28 | 1030 | 1030 µS/cm |
Everything measured here
60 determinands, each kept by its code, unit and sample material: results in different units or on different materials are never mixed. A “below” result is under the laboratory's detection limit, not zero.
Show all 60 rows
| Determinand | Material | Results | First – last | Latest result |
|---|---|---|---|---|
| Oxygen, Dissolved, % Saturation 9901 | River water | 32 | Oct 2023 – Mar 2026 | 82.9% 3 Mar 2026 |
| Oxygen, Dissolved as O2 9924 | River water | 32 | Oct 2023 – Mar 2026 | 9.75 mg/l 3 Mar 2026 |
| Temperature of Water 0076 | River water | 32 | Oct 2023 – Mar 2026 | 8.2 °C 3 Mar 2026 |
| pH 0061 | River water | 32 | Oct 2023 – Mar 2026 | 7.87 3 Mar 2026 |
| Ammoniacal Nitrogen as N 0111 | River water | 32 | Oct 2023 – Mar 2026 | 0.046 mg/l 3 Mar 2026 |
| Nitrate as N 0117 | River water | 32 | Oct 2023 – Mar 2026 | 2.28 mg/l 3 Mar 2026 |
| Orthophosphate, reactive as P 0180 | River water | 32 | Oct 2023 – Mar 2026 | 0.067 mg/l 3 Mar 2026 |
| Conductivity at 25 C 0077 | River water | 32 | Oct 2023 – Mar 2026 | 728 µS/cm 3 Mar 2026 |
| 11-chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (F-53B Minor) 2993 | River water | 4 | Apr 2024 – Mar 2025 | below 0.001 µg/l 14 Mar 2025 |
| 2-(N-Ethylperfluorooctanesulfonamido)acetic acid (B) 2942 | River water | 4 | Apr 2024 – Mar 2025 | below 0.001 µg/l 14 Mar 2025 |
| 2-(N-Ethylperfluorooctanesulfonamido)acetic acid (L) 2991 | River water | 4 | Apr 2024 – Mar 2025 | below 0.001 µg/l 14 Mar 2025 |
| 2-(N-Methylperfluorooctanesulfonamido)acetic acid (B) 2943 | River water | 4 | Apr 2024 – Mar 2025 | below 0.002 µg/l 14 Mar 2025 |
| 2-(N-Methylperfluorooctanesulfonamido)acetic acid (L) 2990 | River water | 4 | Apr 2024 – Mar 2025 | below 0.0005 µg/l 14 Mar 2025 |
| 2H,2H,3H,3H-Perfluorooctanoic acid 2989 | River water | 4 | Apr 2024 – Mar 2025 | below 0.001 µg/l 14 Mar 2025 |
| 3-Perfluoroheptylpropanoic acid 2925 | River water | 4 | Apr 2024 – Mar 2025 | below 0.0005 µg/l 14 Mar 2025 |
| 3:3 Fluorotelomer carboxylic acid 2926 | River water | 4 | Apr 2024 – Mar 2025 | below 0.004 µg/l 14 Mar 2025 |
| 4,8-Dioxa-3H-perfluorononanoic acid (ADONA) 2988 | River water | 4 | Apr 2024 – Mar 2025 | below 0.005 µg/l 14 Mar 2025 |
| 4:2 Fluorotelomer sulfonic acid 2987 | River water | 4 | Apr 2024 – Mar 2025 | below 0.0005 µg/l 14 Mar 2025 |
| 6:2 Fluorotelomer sulfonic acid 2984 | River water | 4 | Apr 2024 – Mar 2025 | below 0.001 µg/l 14 Mar 2025 |
| 8:2 Fluorotelomer sulfonic acid 2983 | River water | 4 | Apr 2024 – Mar 2025 | below 0.001 µg/l 14 Mar 2025 |
| 9-chlorohexadecafluoro-3-oxanonane-1-sulfonic acid 2982 | River water | 4 | Apr 2024 – Mar 2025 | below 0.0005 µg/l 14 Mar 2025 |
| Alkalinity to pH 4.5 as CaCO3 0162 | River water | 32 | Oct 2023 – Mar 2026 | 210 mg/l 3 Mar 2026 |
| Ammonia un-ionised as N 0119 | River water | 32 | Oct 2023 – Mar 2026 | 0.00055 mg/l 3 Mar 2026 |
| BOD : 5 Day ATU 0085 | River water | 29 | Oct 2023 – Mar 2026 | below 1 mg/l 3 Mar 2026 |
| Hexafluoropropylene oxide dimer acid (Gen X) 2981 | River water | 4 | Apr 2024 – Mar 2025 | below 0.001 µg/l 14 Mar 2025 |
| N-Ethylperfluorooctanesulfonamide 2977 | River water | 4 | Apr 2024 – Mar 2025 | below 0.002 µg/l 14 Mar 2025 |
| N-methylperfluorooctanesulfonamide 2975 | River water | 4 | Apr 2024 – Mar 2025 | below 0.002 µg/l 14 Mar 2025 |
| Nitrite as N 0118 | River water | 32 | Oct 2023 – Mar 2026 | 0.022 mg/l 3 Mar 2026 |
| Nitrogen, Total Oxidised as N 0116 | River water | 32 | Oct 2023 – Mar 2026 | 2.3 mg/l 3 Mar 2026 |
| Perfluoro(2-ethoxyethane)sulfonic acid 2924 | River water | 4 | Apr 2024 – Mar 2025 | below 0.0005 µg/l 14 Mar 2025 |
| Perfluoro(4-methoxybutanoic) acid 2923 | River water | 4 | Apr 2024 – Mar 2025 | below 0.0005 µg/l 14 Mar 2025 |
| Perfluoro-3,6-dioxaheptanoic acid 2922 | River water | 4 | Apr 2024 – Mar 2025 | below 0.0005 µg/l 14 Mar 2025 |
| Perfluoro-3-methoxypropanoic acid 2921 | River water | 4 | Apr 2024 – Mar 2025 | below 0.0005 µg/l 14 Mar 2025 |
| Perfluoro-4-ethylcyclohexanesulfonic acid 2973 | River water | 4 | Apr 2024 – Mar 2025 | below 0.0005 µg/l 14 Mar 2025 |
| Perfluorobutanesulfonic acid 2972 | River water | 4 | Apr 2024 – Mar 2025 | 0.003 µg/l 14 Mar 2025 |
| Perfluorobutanoic acid 2995 | River water | 4 | Apr 2024 – Mar 2025 | 0.0043 µg/l 14 Mar 2025 |
| Perfluorobutylsulfonamide (perfluorobutane sulfonamide) 2970 | River water | 4 | Apr 2024 – Mar 2025 | 0.00055 µg/l 14 Mar 2025 |
| Perfluorodecanesulfonic acid 2969 | River water | 4 | Apr 2024 – Mar 2025 | below 0.002 µg/l 14 Mar 2025 |
| Perfluorodecanoic acid 8892 | River water | 4 | Apr 2024 – Mar 2025 | below 0.002 µg/l 14 Mar 2025 |
| Perfluorododecane sulfonic acid 2968 | River water | 4 | Apr 2024 – Mar 2025 | below 0.005 µg/l 14 Mar 2025 |
| Perfluorododecanoic acid 8894 | River water | 4 | Apr 2024 – Mar 2025 | below 0.002 µg/l 14 Mar 2025 |
| Perfluoroheptanesulfonic acid 2967 | River water | 4 | Apr 2024 – Mar 2025 | below 0.0005 µg/l 14 Mar 2025 |
| Perfluoroheptanoic acid 8889 | River water | 4 | Apr 2024 – Mar 2025 | below 0.001 µg/l 14 Mar 2025 |
| Perfluorohexanesulfonamide 2965 | River water | 4 | Apr 2024 – Mar 2025 | below 0.0005 µg/l 14 Mar 2025 |
| Perfluorohexanesulfonic acid (B) 2944 | River water | 4 | Apr 2024 – Mar 2025 | below 0.0005 µg/l 14 Mar 2025 |
| Perfluorohexanesulfonic acid (L) 2964 | River water | 4 | Apr 2024 – Mar 2025 | below 0.0005 µg/l 14 Mar 2025 |
| Perfluorohexanoic acid 8888 | River water | 4 | Apr 2024 – Mar 2025 | 0.0015 µg/l 14 Mar 2025 |
| Perfluorononanesulfonic acid 2963 | River water | 4 | Apr 2024 – Mar 2025 | below 0.0005 µg/l 14 Mar 2025 |
| Perfluorononanoic acid 8891 | River water | 4 | Apr 2024 – Mar 2025 | below 0.001 µg/l 14 Mar 2025 |
| Perfluorooctadecanoic acid 2962 | River water | 4 | Apr 2024 – Mar 2025 | below 0.002 µg/l 14 Mar 2025 |
| Perfluorooctanesulfonamide 2961 | River water | 4 | Apr 2024 – Mar 2025 | below 0.001 µg/l 14 Mar 2025 |
| Perfluorooctanesulfonic acid (branched) 2960 | River water | 4 | Apr 2024 – Mar 2025 | 0.00055 µg/l 14 Mar 2025 |
| Perfluorooctanesulfonic acid (linear) 2959 | River water | 4 | Apr 2024 – Mar 2025 | below 0.0005 µg/l 14 Mar 2025 |
| Perfluorooctanoic acid 8890 | River water | 4 | Apr 2024 – Mar 2025 | 0.001 µg/l 14 Mar 2025 |
| Perfluoropentanesulfonic acid 2957 | River water | 4 | Apr 2024 – Mar 2025 | below 0.0005 µg/l 14 Mar 2025 |
| Perfluoropentanoic acid 8887 | River water | 4 | Apr 2024 – Mar 2025 | 0.0021 µg/l 14 Mar 2025 |
| Perfluorotetradecanoic acid 8895 | River water | 4 | Apr 2024 – Mar 2025 | below 0.006 µg/l 14 Mar 2025 |
| Perfluorotridecanoic acid 2955 | River water | 4 | Apr 2024 – Mar 2025 | below 0.005 µg/l 14 Mar 2025 |
| Perfluoroundecane sulfonic acid 2953 | River water | 4 | Apr 2024 – Mar 2025 | below 0.004 µg/l 14 Mar 2025 |
| Perfluoroundecanoic acid 8893 | River water | 4 | Apr 2024 – Mar 2025 | below 0.002 µg/l 14 Mar 2025 |
FloodRadar does not grade these results: there is no overall score, and official river classifications are a separate dataset. A sample taken downstream of an overflow does not by itself show where anything in it came from. River connections and distances are traced on OS Open Rivers (edition 2026-04), which leaves out many small channels.
Water samples: Environment Agency Water Quality Archive, © Environment Agency and/or database right 2026, Open Government Licence v3.0.
Contains OS data © Crown copyright and database rights 2026.