sampling point
Rib Below B1386, Gatesbury

Description	RIB BELOW B1386, GATESBURY
Sampling point ID	TH-PLER0479
Type	Freshwater – Unspecified
Status	open
Location	easting northing: 539150 224370 lat lon: 51.900499, 0.021092
Area	Hertfordshire And North London
Sub-Area	L&W Herts & North London
Summary	67 samples taken between 2024 and 2018

Determinands identify a property which can be measured on a sample or the sampling environment, together with the units in which the result of that measurement will be expressed.

15 determinands have been measured at this site

Alky pH 4.5
Ammonia(N)
CHLOROPHYLL
Cond @ 25C
N Oxidised
NH3 un-ion
Nitrate-N
Nitrite-N
O Diss %sat
Orthophospht
Oxygen Diss
Sld Sus@105C
Temp Water
TurbidityNTU
pH

Samples from 1 Jun 2023 to 6 Mar 2024

Notation	Determinand	Units	1 Jun 2023 10:53	4 Jul 2023 11:23	1 Aug 2023 11:23	1 Sep 2023 08:43	2 Oct 2023 08:22	1 Nov 2023 10:30	5 Dec 2023 09:54	8 Jan 2024 08:28	9 Feb 2024 08:33	6 Mar 2024 09:38
0061	pH		7.64	7.37	7.6	7.15	7.53	7.38	7.95	7.91	8.11	7.79
0076	Temperature of Water	°C	11.1	11.8	13.4	11.6	13.1	11.1	6.8	6	8	8.4
0077	Conductivity at 25 C	μs/cm	777	739	743	713	759	744	724	769	476	788
0111	Ammoniacal Nitrogen as N	mg/l	< 0.03	< 0.03	0.033	< 0.03	< 0.03	< 0.03	< 0.03	0.085	0.084	0.21
0116	Nitrogen, Total Oxidised as N	mg/l	9.9	9	8.6	8.3	8.9	9.4	16	11		9.7
0117	Nitrate as N	mg/l	9.88	8.98	8.58	8.28	8.88	9.38	16	11		9.64
0118	Nitrite as N	mg/l	0.022	0.017	0.018	0.016	0.019	0.019	0.012	0.021	0.075	0.061
0119	Ammonia un-ionised as N	mg/l	< 0.00026	< 0.00015	0.00031	< 9.0e-05	< 0.00024	< 0.00014	< 0.00039	0.00094	0.00132	0.00211
0135	Solids, Suspended at 105 C	mg/l	3.6	4.4	3.2	6.5	5.9	5.6	13	5.4	240	7.4
0162	Alkalinity to pH 4.5 as CaCO3	mg/l	290	280	280	270	280	280	250	290	210	290
0180	Orthophosphate, reactive as P	mg/l	0.31	0.32	0.43	0.22	0.42	0.18	0.14	0.18	0.12	0.21
6396	Turbidity	ntu	1.2	< 1	1.6	1.8	3.7	1.9	7.3	4	140	1.8
7887	Chlorophyll : Acetone Extract	μg/l	3.5	1	5.1	2.8	1.2	< 0.5	0.9	< 0.5	1.3	0.67
9901	Oxygen, Dissolved, % Saturation	%	91.4	78.9	86.4	72.1	78.2	75.9	93.5	90.1	96.1	90.8
9924	Oxygen, Dissolved as O2	mg/l	10	8.52	9	7.82	8.2	8.33	11.4	11.2	11.4	10.6

Samples from 5 Aug 2022 to 22 May 2023

Notation	Determinand	Units	5 Aug 2022 13:33	17 Oct 2022 09:42	21 Oct 2022 13:33	4 Nov 2022 11:07	1 Dec 2022 13:59	19 Jan 2023 12:45	6 Feb 2023 15:41	2 Mar 2023 12:32	27 Apr 2023 13:45	22 May 2023 14:24
0061	pH		7.41	7.73	7.77	7.5	7.52	7.75	7.63	7.86	7.31	7.76
0076	Temperature of Water	°C	14.7	11.8	12.4	10	9.3	7	8.3	8.1	10.2	12.6
0077	Conductivity at 25 C	μs/cm	761	764	608	713	733	808	772	782	692	785
0111	Ammoniacal Nitrogen as N	mg/l	0.046	< 0.03	< 0.03	0.13	< 0.03	0.055	< 0.03	0.039	< 0.03	< 0.03
0116	Nitrogen, Total Oxidised as N	mg/l	8.9	9.6	5.6	19	8.9	11	10	10	8.5	11
0117	Nitrate as N	mg/l	8.88	9.58	5.58	18.9	8.89	11	9.99	9.99	8.5	11
0118	Nitrite as N	mg/l	0.016	0.016	0.023	0.051	0.015	0.03	0.01	0.0094	< 0.004	0.024
0119	Ammonia un-ionised as N	mg/l	0.00031	< 0.00034	< 0.00039	0.00076	< 0.00017	0.00046	< 0.00021	0.00045	< 0.00012	< 0.00038
0135	Solids, Suspended at 105 C	mg/l	86	9.5	9.6	9.4	4.4	14	< 3	11	3.1	8.3
0162	Alkalinity to pH 4.5 as CaCO3	mg/l	280	270	230	200	300	270	270	280	320	270
0180	Orthophosphate, reactive as P	mg/l	0.64	0.76	0.4	0.45	0.21	0.26	0.36	0.34	0.026	0.4
6396	Turbidity	ntu	46	4.3	6.4				1.3	2.9	< 1	1.5
7887	Chlorophyll : Acetone Extract	μg/l	24	6	5.9	3.7	< 0.5	1.2	< 0.5	3.6	0.81	5
9901	Oxygen, Dissolved, % Saturation	%	83.9	74.4	73.3	76.5	73.1	92.3	88	97.1	72.1	102.2
9924	Oxygen, Dissolved as O2	mg/l	8.49	8.04	7.81	8.62	8.37	11.2	10.3	11.5	8.08	10.8

Samples from 26 Oct 2021 to 19 Jul 2022

Notation	Determinand	Units	26 Oct 2021 14:58	5 Nov 2021 08:14	13 Dec 2021 09:07	19 Jan 2022 14:15	3 Feb 2022 14:21	22 Mar 2022 10:00	19 Apr 2022 12:41	3 May 2022 11:16	24 Jun 2022 14:22	19 Jul 2022 11:13
0061	pH		7.72	7.37	7.37	7.61	7.47	7.66	7.72	7.7	7.24	7.57
0076	Temperature of Water	°C	11.8	7.7	9.6	8	9.6	9.4	11	10.8	11.9	16.1
0077	Conductivity at 25 C	μs/cm	762	740	742	786	752	793	777	777	701	763
0111	Ammoniacal Nitrogen as N	mg/l	< 0.03	< 0.03	< 0.03	0.038	0.035	< 0.03	< 0.03	< 0.03	< 0.03	0.047
0116	Nitrogen, Total Oxidised as N	mg/l	9.2	8.5	11	10	10	9.6	9.3	9.6	8	7.9
0117	Nitrate as N	mg/l	9.18	8.49	11	9.97	9.99	9.59	9.28	9.57	8	7.88
0118	Nitrite as N	mg/l	0.019	0.014	0.028	0.027	0.0086	0.012	0.019	0.03	< 0.004	0.02
0119	Ammonia un-ionised as N	mg/l	< 0.00033	< 0.00011	< 0.00013	0.00025	0.00019	< 0.00024	< 0.00031	< 0.00029	< 0.00011	0.00051
0135	Solids, Suspended at 105 C	mg/l	9.3	4.3	6	15	9.2	8.3	4.4	4.8	4.4	7.1
0162	Alkalinity to pH 4.5 as CaCO3	mg/l	280	270	260	290	280	280	280	270	260	280
0180	Orthophosphate, reactive as P	mg/l	0.41	0.24	0.18	0.37	0.32	0.3	0.34	0.47	0.061	0.66
6396	Turbidity	ntu	5.2	1.4	3.3	5.5	5.3	4.3	3		1.1	5
7887	Chlorophyll : Acetone Extract	μg/l	3.4	1.7		2.3	2.4	2.4	8.5	28	1.5	4
9901	Oxygen, Dissolved, % Saturation	%	80.5	77.2	77.2	90.8	80.7	92.6	90.1	92.1	69.4	84.3
9924	Oxygen, Dissolved as O2	mg/l	8.7	9.2	8.78	10.7	9.18	10.6	9.91	10.2	7.48	8.28

Samples from 9 Dec 2020 to 21 Sep 2021

Notation	Determinand	Units	9 Dec 2020 10:49	5 Jan 2021 09:27	3 Feb 2021 08:37	8 Mar 2021 11:33	13 Apr 2021 11:11	5 May 2021 11:35	1 Jun 2021 13:23	8 Jul 2021 13:30	10 Aug 2021 10:47	21 Sep 2021 09:51
0061	pH		7.88	7.65	7.8	7.38	7.88	7.62	7.7	7.82	7.52	7.68
0076	Temperature of Water	°C	6.6	6.1	7.2	8.8	8	9.5	13.9	13.6	13	11.5
0077	Conductivity at 25 C	μs/cm	829	772	707	768	798	801	786	762	766	772
0111	Ammoniacal Nitrogen as N	mg/l	0.25	0.051	< 0.03	< 0.03	< 0.03	< 0.03	< 0.03	< 0.03	< 0.03	0.037
0116	Nitrogen, Total Oxidised as N	mg/l	15	11	10	10	11	9.8	9.6	9.5	9	9.9
0117	Nitrate as N	mg/l	15	11	9.97	9.98	11	9.77	9.57	9.48	8.98	9.87
0118	Nitrite as N	mg/l	0.044	0.037	0.026	0.021	0.019	0.029	0.032	0.024	0.02	0.034
0119	Ammonia un-ionised as N	mg/l	0.0027	0.00031	< 0.00028	< 0.00012	< 0.00036	< 0.00022	< 0.00037	< 0.00047	< 0.00023	0.00036
0135	Solids, Suspended at 105 C	mg/l	89	11	11	9.3	8.5	4.1	5.9	3.6	14	10
0162	Alkalinity to pH 4.5 as CaCO3	mg/l	230	280	270	270	280	260	290	270	270	280
0180	Orthophosphate, reactive as P	mg/l	0.3	0.25	0.12	0.21	0.35	0.39	0.44	0.4	0.43	0.055
6396	Turbidity	ntu				2.5	2		2	1.3	6.5	5.5
7887	Chlorophyll : Acetone Extract	μg/l	9.1	0.52	0.56	2.3	5.2	9.9	4.8	2.2	18	16
9901	Oxygen, Dissolved, % Saturation	%	90.1	86.5	98.8	87	107.6	107.2	103.1	90.9	84.6	87.3
9924	Oxygen, Dissolved as O2	mg/l	11	10.7	11.9	10.1	12.7	12.2	10.6	9.43	8.89	9.5

Samples from 7 Aug 2019 to 17 Nov 2020

Notation	Determinand	Units	7 Aug 2019 08:00	2 Sep 2019 12:16	3 Oct 2019 13:21	8 Nov 2019 10:06	2 Dec 2019 11:44	8 Jan 2020 10:01	4 Feb 2020 11:02	5 Mar 2020 12:12	5 Mar 2020 12:18	17 Nov 2020 11:41
0061	pH		7.41	7.55	7.62	7.65	7.67	7.62	7.83	7.8	7.8	7.69
0076	Temperature of Water	°C	13.7	12.1	9.7	7	6.2	9.5	7.2	7.4	7.4	11
0077	Conductivity at 25 C	μs/cm	723	712	673	655	774	801	803	822	822	790
0111	Ammoniacal Nitrogen as N	mg/l	< 0.03	< 0.03	0.041	0.041	0.098	0.042	< 0.03	0.14	0.14	0.031
0116	Nitrogen, Total Oxidised as N	mg/l	6.6	5.9	6.5	7.39	9.6	11	9.8	11	11	16
0117	Nitrate as N	mg/l	6.58	5.89	6.48	7.38	9.57	11	9.79	10.9	10.9	16
0118	Nitrite as N	mg/l	0.019	0.01	0.016	0.0139	0.03	0.026	0.012	0.054	0.054	0.05
0119	Ammonia un-ionised as N	mg/l	< 0.00019	< 0.00023	0.00031	0.00027	0.00064	0.00031	< 0.0003	0.00134	0.00134	0.0003
0135	Solids, Suspended at 105 C	mg/l	4.7	5.5	9	6.78	6.9	13	19	15	12	5.8
0162	Alkalinity to pH 4.5 as CaCO3	mg/l	280	280	250	228	280	290	280	270	270	270
0180	Orthophosphate, reactive as P	mg/l	0.57	0.44	0.67	0.749	0.38	0.34	0.33	0.29	0.28	0.23
6396	Turbidity	ntu	4.3	5.1	6.6	6.8	4.5	8.1	9	11	11
7887	Chlorophyll : Acetone Extract	μg/l	3.1	3.6	3	2.5	0.96	0.93	1.9	1.4	1.2	0.61
9901	Oxygen, Dissolved, % Saturation	%	75.7	87.1	79.4	78.4	73.8	84.3	91.3	86.2	86.2	89.6
9924	Oxygen, Dissolved as O2	mg/l	7.83	9.34	9.01	9.5	9.13	9.61	11	10.3	10.3	9.86

Samples from 3 Oct 2018 to 3 Jul 2019

Notation	Determinand	Units	3 Oct 2018 11:26	2 Nov 2018 13:17	27 Nov 2018 13:09	2 Jan 2019 12:30	5 Feb 2019 13:23	1 Mar 2019 11:32	10 Apr 2019 13:11	3 May 2019 11:07	3 Jun 2019 10:14	3 Jul 2019 11:49
0061	pH		7.6	7.57	7.68	7.88	7.93	7.68	7.73	7.62	7.61	7.54
0076	Temperature of Water	°C	11.5	8.7	7.7	7.5	6.1	9.1	10.4	10.5	12.7	13.1
0077	Conductivity at 25 C	μs/cm	742	752	759	769	848	766	754	755	752	750
0111	Ammoniacal Nitrogen as N	mg/l	< 0.03	0.052	0.041	< 0.03	0.079	< 0.03	< 0.03	< 0.03	0.055	0.032
0116	Nitrogen, Total Oxidised as N	mg/l	8.6	10.1	8.86	8.02	22.2	9.12	8.27	8.23	8.84	8
0117	Nitrate as N	mg/l	8.58	10.1	8.83	7.99	22.1	9.1	8.26	8.22	8.8	7.98
0118	Nitrite as N	mg/l	0.0163	0.0402	0.0323	0.0285	0.0564	0.0153	0.011	0.0093	0.0447	0.022
0119	Ammonia un-ionised as N	mg/l	< 0.00025	0.00032	0.0003	< 0.00035	0.00092	< 0.00025	< 0.00031	< 0.00024	0.0005	0.00026
0135	Solids, Suspended at 105 C	mg/l	7.02	5.53	10.4	7.68	13.6	5.58	10.7	9.8	4.2	< 3
0162	Alkalinity to pH 4.5 as CaCO3	mg/l	283	283	280	286	228	273	269	269	277	270
0180	Orthophosphate, reactive as P	mg/l	0.463	0.814	0.595	0.508	0.27	0.529	0.375	0.244	0.74	0.67
6396	Turbidity	ntu	2.2	2.9	10.4	6.3	38.6	10.6	3.1	4.8	3.4	7.5
7887	Chlorophyll : Acetone Extract	μg/l	7.3	2.1	3.1	1.1	2.3	3.3	9.8	47	4.2	4.4
9901	Oxygen, Dissolved, % Saturation	%	84.9	79.2	104.1	83.4	93.9	91.8	111.1	91.2	86.5	84.2
9924	Oxygen, Dissolved as O2	mg/l	9.23	9.21	12.4	9.98	11.6	10.6	12.4	10.2	9.15	8.83

Samples from 6 Mar 2018 to 5 Sep 2018

Notation	Determinand	Units	6 Mar 2018 14:42	4 Apr 2018 10:55	25 May 2018 13:21	28 Jun 2018 09:50	17 Jul 2018 13:25	9 Aug 2018 14:09	5 Sep 2018 12:44
0061	pH		7.66	7.97	7.3	7.68	7.58	7.7	7.76
0076	Temperature of Water	°C	8.5	8.1	12.3	12.7	13.9	13.6	13
0077	Conductivity at 25 C	μs/cm	803	773	764	760	738	747	746
0111	Ammoniacal Nitrogen as N	mg/l	< 0.03	0.059	< 0.03	< 0.03	< 0.03	0.037	< 0.03
0116	Nitrogen, Total Oxidised as N	mg/l	9.85	12.6	9.72	8.52	8.92	7.79	8.35
0117	Nitrate as N	mg/l	9.82	12.6	9.69	8.5	8.9	7.77	8.33
0118	Nitrite as N	mg/l	0.0323	0.0233	0.0341	0.0227	0.0197	0.0203	0.0166
0119	Ammonia un-ionised as N	mg/l	< 0.00023	0.00087	< 0.00013	< 0.00032	< 0.00028	0.00045	< 0.0004
0135	Solids, Suspended at 105 C	mg/l	4.6	12.3	3.82	5.92	5.75	5.6	4.93
0162	Alkalinity to pH 4.5 as CaCO3	mg/l	272	283	271	274	276	269	281
0180	Orthophosphate, reactive as P	mg/l	0.251	0.127	0.408	0.353	0.43	0.396	0.468
6396	Turbidity	ntu	2.7	6.8	3.7	4.6	1.5	3.1	3.9
7887	Chlorophyll : Acetone Extract	μg/l	2	2.5	3.1	3.5	2.6	4.4	7.2
9901	Oxygen, Dissolved, % Saturation	%	93.8	90.1	102.1	84.3	88.5	89.3	87.7
9924	Oxygen, Dissolved as O2	mg/l	11	10.6	10.9	8.92	9.12	9.26	9.22