Tredethy Stream at Helligan
EA name: SSN1096 TREDETHY STREAM AT HELLIGAN
Environment Agency sampling point SW-SSN1096 · 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
- 27 Jul 2026, 14:402 months ago · time as the Environment Agency records it (UK clock time; the source gives no time zone)
- Samples banked
- 6 since 9 Feb 2026 Imported periods: 1 Oct 2023 – 8 Oct 2026. Samples outside them are not shown here.
- Latest sample
- River / running surface water Monitoring (national agency policy)
- Where
- National Grid 206617, 72254As published, to the nearest 1 m. Open in a map
- River, by its own name
- Tredethy Stream
- River, by the map
- An unnamed streamPlaced by position alone (the only river line close by), 6 m from the line.
- Next gauge downstream
- Bodmin Dunmere On the River Camel · 6.4 km along the river
- Why it was sampled
- Monitoring (national agency policy) (6 samples)
Main measurements, river water
Dissolved oxygen
% saturation · code 9901 · %
96.8%
Sampled 27 Jul 2026, 2 months ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 27 Jul 2026, 14:40 | 96.8 | 96.8% |
| 2 Jun 2026, 11:11 | 96.7 | 96.7% |
| 11 May 2026, 10:32 | 105.2 | 105.2% |
| 15 Apr 2026, 14:43 | 99.9 | 99.9% |
| 25 Mar 2026, 09:23 | 100 | 100% |
| 9 Feb 2026, 09:38 | 101.5 | 101.5% |
Dissolved oxygen
as O2 · code 9924 · mg/l
9.49 mg/l
Sampled 27 Jul 2026, 2 months ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 27 Jul 2026, 14:40 | 9.49 | 9.49 mg/l |
| 2 Jun 2026, 11:11 | 10.1 | 10.1 mg/l |
| 11 May 2026, 10:32 | 11.8 | 11.8 mg/l |
| 15 Apr 2026, 14:43 | 10.7 | 10.7 mg/l |
| 25 Mar 2026, 09:23 | 11.7 | 11.7 mg/l |
| 9 Feb 2026, 09:38 | 11.6 | 11.6 mg/l |
Water temperature
code 0076 · °C
16.2 °C
Sampled 27 Jul 2026, 2 months ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 27 Jul 2026, 14:40 | 16.2 | 16.2 °C |
| 2 Jun 2026, 11:11 | 13.2 | 13.2 °C |
| 11 May 2026, 10:32 | 10.1 | 10.1 °C |
| 15 Apr 2026, 14:43 | 12.2 | 12.2 °C |
| 25 Mar 2026, 09:23 | 8.5 | 8.5 °C |
| 9 Feb 2026, 09:38 | 9.4 | 9.4 °C |
pH
code 0061
7.85
Sampled 27 Jul 2026, 2 months ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 27 Jul 2026, 14:40 | 7.85 | 7.85 |
| 2 Jun 2026, 11:11 | 7.9 | 7.9 |
| 11 May 2026, 10:32 | 7.91 | 7.91 |
| 15 Apr 2026, 14:43 | 8.23 | 8.23 |
| 25 Mar 2026, 09:23 | 7.95 | 7.95 |
| 9 Feb 2026, 09:38 | 7.73 | 7.73 |
Ammonia
ammoniacal nitrogen as N · code 0111 · mg/l
below 0.03 mg/l (not detected above this)
Sampled 27 Jul 2026, 2 months ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 27 Jul 2026, 14:40 | <0.03 | below 0.03 mg/l (not detected above this) |
| 2 Jun 2026, 11:11 | <0.03 | below 0.03 mg/l (not detected above this) |
| 11 May 2026, 10:32 | <0.03 | below 0.03 mg/l (not detected above this) |
| 15 Apr 2026, 14:43 | <0.03 | below 0.03 mg/l (not detected above this) |
| 25 Mar 2026, 09:23 | <0.03 | below 0.03 mg/l (not detected above this) |
| 9 Feb 2026, 09:38 | <0.03 | below 0.03 mg/l (not detected above this) |
Nitrate
as nitrogen (N) · code 0117 · mg/l
5.1 mg/l
Sampled 27 Jul 2026, 2 months ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 27 Jul 2026, 14:40 | 5.1 | 5.1 mg/l |
| 2 Jun 2026, 11:11 | 5.1 | 5.1 mg/l |
| 11 May 2026, 10:32 | 5.7 | 5.7 mg/l |
| 15 Apr 2026, 14:43 | 5.6 | 5.6 mg/l |
| 25 Mar 2026, 09:23 | 6.2 | 6.2 mg/l |
| 9 Feb 2026, 09:38 | 6.2 | 6.2 mg/l |
Phosphate
orthophosphate, reactive, as P · code 0180 · mg/l
0.041 mg/l
Sampled 27 Jul 2026, 2 months ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 27 Jul 2026, 14:40 | 0.041 | 0.041 mg/l |
| 2 Jun 2026, 11:11 | 0.03 | 0.03 mg/l |
| 11 May 2026, 10:32 | 0.021 | 0.021 mg/l |
| 15 Apr 2026, 14:43 | 0.028 | 0.028 mg/l |
| 25 Mar 2026, 09:23 | 0.013 | 0.013 mg/l |
| 9 Feb 2026, 09:38 | 0.024 | 0.024 mg/l |
Conductivity
at 25 °C · code 0077 · µS/cm
273 µS/cm
Sampled 27 Jul 2026, 2 months ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 27 Jul 2026, 14:40 | 273 | 273 µS/cm |
| 2 Jun 2026, 11:11 | 251 | 251 µS/cm |
| 11 May 2026, 10:32 | 265 | 265 µS/cm |
| 15 Apr 2026, 14:43 | 261 | 261 µS/cm |
| 25 Mar 2026, 09:23 | 258 | 258 µS/cm |
| 9 Feb 2026, 09:38 | 249 | 249 µS/cm |
Everything measured here
23 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 23 rows
| Determinand | Material | Results | First – last | Latest result |
|---|---|---|---|---|
| Oxygen, Dissolved, % Saturation 9901 | River water | 6 | Feb 2026 – Jul 2026 | 96.8% 27 Jul 2026 |
| Oxygen, Dissolved as O2 9924 | River water | 6 | Feb 2026 – Jul 2026 | 9.49 mg/l 27 Jul 2026 |
| Temperature of Water 0076 | River water | 6 | Feb 2026 – Jul 2026 | 16.2 °C 27 Jul 2026 |
| pH 0061 | River water | 6 | Feb 2026 – Jul 2026 | 7.85 27 Jul 2026 |
| Ammoniacal Nitrogen as N 0111 | River water | 6 | Feb 2026 – Jul 2026 | below 0.03 mg/l 27 Jul 2026 |
| Nitrate as N 0117 | River water | 6 | Feb 2026 – Jul 2026 | 5.1 mg/l 27 Jul 2026 |
| Orthophosphate, reactive as P 0180 | River water | 6 | Feb 2026 – Jul 2026 | 0.041 mg/l 27 Jul 2026 |
| Conductivity at 25 C 0077 | River water | 6 | Feb 2026 – Jul 2026 | 273 µS/cm 27 Jul 2026 |
| Alkalinity to pH 4.5 as CaCO3 0162 | River water | 6 | Feb 2026 – Jul 2026 | 61 mg/l 27 Jul 2026 |
| Aminomethylphosphonic acid 7125 | River water | 3 | Feb 2026 – Apr 2026 | below 0.1 µg/l 15 Apr 2026 |
| Ammonia un-ionised as N 0119 | River water | 6 | Feb 2026 – Jul 2026 | below 0.00061 mg/l 27 Jul 2026 |
| Carbon, Organic, Dissolved as C :- {DOC} 0301 | River water | 6 | Feb 2026 – Jul 2026 | 1.1 mg/l 27 Jul 2026 |
| Chloride 0172 | River water | 6 | Feb 2026 – Jul 2026 | 24 mg/l 27 Jul 2026 |
| Flow Type 2896 | River water | 6 | Feb 2026 – Jul 2026 | Moderate Flow 27 Jul 2026 |
| GCMS Screen : Target Based multi-residue screening : Semi Quantitative 4994 | River water | 1 | May 2026 – May 2026 | 1 text result 11 May 2026 |
| Glyphosate 3007 | River water | 3 | Feb 2026 – Apr 2026 | below 0.1 µg/l 15 Apr 2026 |
| LCMS Screen : Semi Quantitative 7299 | River water | 2 | Mar 2026 – Jun 2026 | 1 text result 2 Jun 2026 |
| Nitrite as N 0118 | River water | 6 | Feb 2026 – Jul 2026 | below 0.004 mg/l 27 Jul 2026 |
| Nitrogen, Total as N 9686 | River water | 6 | Feb 2026 – Jul 2026 | 5.3 mg/l 27 Jul 2026 |
| Nitrogen, Total Oxidised as N 0116 | River water | 6 | Feb 2026 – Jul 2026 | 5.1 mg/l 27 Jul 2026 |
| Phosphorus, Total as P 0348 | River water | 6 | Feb 2026 – Jul 2026 | 0.043 mg/l 27 Jul 2026 |
| Silica, reactive as SiO2 0182 | River water | 6 | Feb 2026 – Jul 2026 | 4.9 mg/l 27 Jul 2026 |
| Solids, Suspended at 105 C 0135 | River water | 6 | Feb 2026 – Jul 2026 | 5.4 mg/l 27 Jul 2026 |
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.