River Purwell A505 Road Bridge Hitchin
EA name: R.PURWELL A505 RD.BR. HITCHIN
Environment Agency sampling point AN-13M24 · 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 Sep 2026, 11:1328 days ago · time as the Environment Agency records it (UK clock time; the source gives no time zone)
- Samples banked
- 6 since 17 Apr 2026 Imported periods: 1 Oct 2023 – 30 Sep 2026. Samples outside them are not shown here.
- Latest sample
- River / running surface water Monitoring (national agency policy)
- Where
- National Grid 519780, 229970As published, to the nearest 10 m. Open in a map
- River, by its own name
- Purwell
- River, by the map
- River PurwellPlaced on the river its name gives, 16 m from the line.
- Next gauge downstream
- Arlesey On the River Hiz · 11 km along the riverARLESEY GS 11 km along the river
- Why it was sampled
- Monitoring (national agency policy) (6 samples)
Main measurements, river water
Dissolved oxygen
% saturation · code 9901 · %
82%
Sampled 3 Sep 2026, 28 days ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Sep 2026, 11:13 | 82 | 82% |
| 3 Aug 2026, 11:09 | 88.2 | 88.2% |
| 6 Jul 2026, 12:05 | 90.4 | 90.4% |
| 4 Jun 2026, 11:30 | 82.4 | 82.4% |
| 1 May 2026, 12:49 | 95 | 95% |
| 17 Apr 2026, 08:12 | 87.5 | 87.5% |
Dissolved oxygen
as O2 · code 9924 · mg/l
8.32 mg/l
Sampled 3 Sep 2026, 28 days ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Sep 2026, 11:13 | 8.32 | 8.32 mg/l |
| 3 Aug 2026, 11:09 | 8.89 | 8.89 mg/l |
| 6 Jul 2026, 12:05 | 8.88 | 8.88 mg/l |
| 4 Jun 2026, 11:30 | 8.6 | 8.6 mg/l |
| 1 May 2026, 12:49 | 9.92 | 9.92 mg/l |
| 17 Apr 2026, 08:12 | 9.65 | 9.65 mg/l |
Water temperature
code 0076 · °C
14.6 °C
Sampled 3 Sep 2026, 28 days ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Sep 2026, 11:13 | 14.6 | 14.6 °C |
| 3 Aug 2026, 11:09 | 14.9 | 14.9 °C |
| 6 Jul 2026, 12:05 | 16.1 | 16.1 °C |
| 4 Jun 2026, 11:30 | 13.3 | 13.3 °C |
| 1 May 2026, 12:49 | 13.3 | 13.3 °C |
| 17 Apr 2026, 08:12 | 10.9 | 10.9 °C |
pH
code 0061
7.52
Sampled 3 Sep 2026, 28 days ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Sep 2026, 11:13 | 7.52 | 7.52 |
| 3 Aug 2026, 11:09 | 7.91 | 7.91 |
| 6 Jul 2026, 12:05 | 7.92 | 7.92 |
| 4 Jun 2026, 11:30 | 7.71 | 7.71 |
| 1 May 2026, 12:49 | 7.65 | 7.65 |
| 17 Apr 2026, 08:12 | 7.65 | 7.65 |
Ammonia
ammoniacal nitrogen as N · code 0111 · mg/l
below 0.03 mg/l (not detected above this)
Sampled 3 Sep 2026, 28 days ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Sep 2026, 11:13 | <0.03 | below 0.03 mg/l (not detected above this) |
| 3 Aug 2026, 11:09 | <0.03 | below 0.03 mg/l (not detected above this) |
| 6 Jul 2026, 12:05 | <0.03 | below 0.03 mg/l (not detected above this) |
| 4 Jun 2026, 11:30 | <0.03 | below 0.03 mg/l (not detected above this) |
| 1 May 2026, 12:49 | <0.03 | below 0.03 mg/l (not detected above this) |
| 17 Apr 2026, 08:12 | <0.03 | below 0.03 mg/l (not detected above this) |
Nitrate
as nitrogen (N) · code 0117 · mg/l
5.89 mg/l
Sampled 3 Sep 2026, 28 days ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Sep 2026, 11:13 | 5.89 | 5.89 mg/l |
| 3 Aug 2026, 11:09 | 6.09 | 6.09 mg/l |
| 6 Jul 2026, 12:05 | 6.18 | 6.18 mg/l |
| 4 Jun 2026, 11:30 | 4.68 | 4.68 mg/l |
| 1 May 2026, 12:49 | 5.79 | 5.79 mg/l |
| 17 Apr 2026, 08:12 | 6.38 | 6.38 mg/l |
Phosphate
orthophosphate, reactive, as P · code 0180 · mg/l
0.04 mg/l
Sampled 3 Sep 2026, 28 days ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Sep 2026, 11:13 | 0.04 | 0.04 mg/l |
| 3 Aug 2026, 11:09 | 0.034 | 0.034 mg/l |
| 6 Jul 2026, 12:05 | 0.031 | 0.031 mg/l |
| 4 Jun 2026, 11:30 | 0.039 | 0.039 mg/l |
| 1 May 2026, 12:49 | 0.03 | 0.03 mg/l |
| 17 Apr 2026, 08:12 | 0.028 | 0.028 mg/l |
Conductivity
at 25 °C · code 0077 · µS/cm
735 µS/cm
Sampled 3 Sep 2026, 28 days ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Sep 2026, 11:13 | 735 | 735 µS/cm |
| 3 Aug 2026, 11:09 | 746 | 746 µS/cm |
| 6 Jul 2026, 12:05 | 735 | 735 µS/cm |
| 4 Jun 2026, 11:30 | 693 | 693 µS/cm |
| 1 May 2026, 12:49 | 720 | 720 µS/cm |
| 17 Apr 2026, 08:12 | 721 | 721 µS/cm |
Everything measured here
12 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 12 rows
| Determinand | Material | Results | First – last | Latest result |
|---|---|---|---|---|
| Oxygen, Dissolved, % Saturation 9901 | River water | 6 | Apr 2026 – Sep 2026 | 82% 3 Sep 2026 |
| Oxygen, Dissolved as O2 9924 | River water | 6 | Apr 2026 – Sep 2026 | 8.32 mg/l 3 Sep 2026 |
| Temperature of Water 0076 | River water | 6 | Apr 2026 – Sep 2026 | 14.6 °C 3 Sep 2026 |
| pH 0061 | River water | 6 | Apr 2026 – Sep 2026 | 7.52 3 Sep 2026 |
| Ammoniacal Nitrogen as N 0111 | River water | 6 | Apr 2026 – Sep 2026 | below 0.03 mg/l 3 Sep 2026 |
| Nitrate as N 0117 | River water | 6 | Apr 2026 – Sep 2026 | 5.89 mg/l 3 Sep 2026 |
| Orthophosphate, reactive as P 0180 | River water | 6 | Apr 2026 – Sep 2026 | 0.04 mg/l 3 Sep 2026 |
| Conductivity at 25 C 0077 | River water | 6 | Apr 2026 – Sep 2026 | 735 µS/cm 3 Sep 2026 |
| Alkalinity to pH 4.5 as CaCO3 0162 | River water | 6 | Apr 2026 – Sep 2026 | 250 mg/l 3 Sep 2026 |
| Ammonia un-ionised as N 0119 | River water | 6 | Apr 2026 – Sep 2026 | below 0.00026 mg/l 3 Sep 2026 |
| Nitrite as N 0118 | River water | 6 | Apr 2026 – Sep 2026 | 0.01 mg/l 3 Sep 2026 |
| Nitrogen, Total Oxidised as N 0116 | River water | 6 | Apr 2026 – Sep 2026 | 5.9 mg/l 3 Sep 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.