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environmental information > river & stream WQ monitoring > state network >

Water quality monitoring station

49A190 - Okanogan R @ Oroville

Results that exceed water quality criteria or the usual range of data (since October, 1996)

Results that exceeded water quality standards criteria

The Department of Ecology places limits on how much pollution is allowed in our rivers to protect public health and enjoyment, and to support fish, shellfish, and wildlife (WAC 173-201A). Individual results for temperature, pH, oxygen, fecal coliform bacteria, and metals (where sampled) that are higher than these criteria are listed below. (The standards do not contain criteria for other types of water quality constituents.) This table includes only results from our monthly monitoring program. Results from other monitoring, such as continuous monitoring for temperature, are not evaluated here.

Exceeding a criterion does not necessarily mean the water quality standard has been violated. Often, other �pollution� conditions must exist for a stream segment to be in violation of water quality standards. In some cases, standards require that the source of pollution be human activities rather than natural causes. Also, more than a single result exceeding a criterion may be required.

Washington's Water Quality Standards were amended in November, 2006. Data in the tables below are based on the older standards through 2008. Data collected after 2008 are based on the ammended standards, excluding supplemental temperature criteria. We are currently working on incorporating supplemental temperature criteria into our evaluation procedures.

date	time	units	criterion	result	remark	% exceed
Oxygen
8/3/2009	08:30	mg/L	8	7.6		5
10/6/2008	07:30	mg/L	8	7.4		7
9/10/2007	07:13	mg/L	8	7.9		1
9/14/2004	10:28	mg/L	8	7.4		8
10/7/2003	11:25	mg/L	8	7.3		9
9/10/2002	10:10	mg/L	8	7.9		1
9/5/2001	06:50	mg/L	8	7.9		1
10/13/1998	05:40	mg/L	8	7.3		9
8/11/1998	06:10	mg/L	8	7.8		3
10/15/1996	09:10	mg/L	8	7.2		10
pH
date	time	units	criterion	result	remark	% exceed
9/14/2009	09:00	pH	8.5	9.4		11
7/6/2009	08:45	pH	8.5	8.6		1
6/1/2009	07:45	pH	8.5	8.6		1
9/8/2008	07:30	pH	8.5	8.7		2
8/4/2008	08:15	pH	8.5	8.6		1
9/10/2007	07:13	pH	8.5	8.6		2
8/6/2007	07:40	pH	8.5	8.7		2
7/9/2007	07:25	pH	8.5	8.6		2
9/11/2006	07:10	pH	8.5	8.9		5
8/7/2006	07:45	pH	8.5	8.7		2
7/10/2006	07:30	pH	8.5	8.6		2
5/1/2006	07:40	pH	8.5	8.7		2
3/6/2006	07:35	pH	8.5	8.6		1
8/10/2004	10:27	pH	8.5	8.7		2
7/13/2004	12:14	pH	8.5	8.7		2
6/8/2004	11:24	pH	8.5	8.6		1
9/9/2003	09:21	pH	8.5	8.6		1
6/3/2003	11:31	pH	8.5	8.6		2
5/6/2003	09:45	pH	8.5	8.6		1
8/15/2001	06:45	pH	8.5	8.6		1
7/11/2001	07:30	pH	8.5	8.6		2
6/6/2001	09:00	pH	8.5	8.6		2
9/5/2000	12:35	pH	8.5	8.8		3
8/15/2000	12:05	pH	8.5	9		6
7/11/2000	13:00	pH	8.5	8.9		5
4/4/2000	12:15	pH	8.5	8.6		1
9/7/1999	07:10	pH	8.5	8.6		1
9/8/1998	07:15	pH	8.5	8.7		2
8/11/1998	06:10	pH	8.5	8.8		4
4/7/1998	06:50	pH	8.5	8.7		2
3/10/1998	07:00	pH	8.5	8.6		1
2/10/1998	07:30	pH	8.5	8.6		1
3/11/1997	06:05	pH	8.5	8.6		1
Temperature
date	time	units	criterion	result	remark	% exceed
9/14/2009	09:00	deg C	17.5	18.2		4
8/3/2009	08:30	deg C	17.5	26.6		52
7/6/2009	08:45	deg C	17.5	19.1		9
6/1/2009	07:45	deg C	17.5	20.9		19
9/8/2008	07:30	deg C	18	20.3		13
8/4/2008	08:15	deg C	18	23.1		28
9/10/2007	07:13	deg C	18	19.9		11
8/6/2007	07:40	deg C	18	23.5		31
7/9/2007	07:25	deg C	18	24.2		34
6/5/2007	07:55	deg C	18	21.3		18
9/11/2006	07:10	deg C	18	19.9		11
8/7/2006	07:45	deg C	18	22.4		24
7/10/2006	07:30	deg C	18	24.5		36
9/12/2005	07:00	deg C	18	18.7		4
8/1/2005	06:50	deg C	18	23.1		28
7/11/2005	07:25	deg C	18	19.8		10
9/14/2004	10:28	deg C	18	18.1		1
8/10/2004	10:27	deg C	18	24.3		35
7/13/2004	12:14	deg C	18	22.6		26
6/8/2004	11:24	deg C	18	18.7		4
9/9/2003	09:21	deg C	18	20.6		14
8/5/2003	08:30	deg C	18	22.9		27
7/8/2003	10:29	deg C	18	20.4		13
6/3/2003	11:31	deg C	18	18.8		4
9/10/2002	10:10	deg C	18	19.1		6
8/6/2002	09:57	deg C	18	20		11
7/9/2002	09:10	deg C	18	20.6		14
9/5/2001	06:50	deg C	18	18.6		3
8/15/2001	06:45	deg C	18	26.4		47
7/11/2001	07:30	deg C	18	24.6		37
8/15/2000	12:05	deg C	18	21		17
7/11/2000	13:00	deg C	18	19.5		8
8/3/1999	07:00	deg C	18	21.5		19
6/15/1999	07:25	deg C	18	18.8		4
9/8/1998	07:15	deg C	18	22		22
8/11/1998	06:10	deg C	18	24.3		35
7/14/1998	06:30	deg C	18	21.4		19
9/16/1997	07:00	deg C	18	18.1		1
8/12/1997	07:00	deg C	18	22.7		26
7/15/1997	06:40	deg C	18	21.9		22

Results that contrast strongly with historical data

Results exceeding the usual range of data (defined as 2 standard deviations beyond the mean value for a station based on data from the same three-month period over the previous six years) are shown below. A certain percentage of results will always be listed in this report. Inclusion here does not necessarily indicate something unique is occurring in the watershed.

date	time	units	result	remark	QMEAN	QSD	QDP
Ammonia-Nitrogen
6/1/2009	07:45	mg/L	0.013		0.01	1.505859E-10	18
3/2/2009	08:00	mg/L	0.029		0.01	1.505859E-10	18
7/7/2008	08:15	mg/L	0.015		0.0105	1.339447E-03	18
4/7/2008	08:00	mg/L	0.013		0.01	1.505859E-10	18
2/11/2008	08:40	mg/L	0.024		0.01	1.505859E-10	18
1/7/2008	08:25	mg/L	0.015		0.01	1.505859E-10	18
9/7/1999	07:10	mg/L	0.032		0.011	0.003	12
8/3/1999	07:00	mg/L	0.033		0.011	0.003	12
7/6/1999	07:00	mg/L	0.027		0.011	0.003	12
12/15/1998	07:20	mg/L	0.046		0.016	0.013	12
10/13/1998	05:40	mg/L	0.234		0.016	0.013	12
10/15/1996	09:10	mg/L	0.054		0.016	0.013	12
Barometric Pressure
date	time	units	result	remark	QMEAN	QSD	QDP
9/14/2009	09:00	mm/Hg	724.916		738.7308	5.270038	18
1/5/2009	07:30	mm/Hg	714.502		737.235	10.72202	18
7/7/2008	08:15	mm/Hg	726.948		739.8738	4.743023	18
4/4/2005	07:35	mm/Hg	725.932		737.4812	5.303378	18
1/3/2005	07:45	mm/Hg	709.676		741.4274	12.61519	18
12/3/2002	09:40	mm/Hg	719.582	J	739.9688	9.381089	18
11/5/2002	08:45	mm/Hg	717.55	J	739.9688	9.381089	18
10/8/2002	10:15	mm/Hg	716.788		739.9688	9.381089	18
Conductivity
date	time	units	result	remark	QMEAN	QSD	QDP
6/1/2009	07:45	umhos/cm	336		307.3889	13.24937	18
5/4/2009	08:00	umhos/cm	343	J	307.3889	13.24937	18
2/2/2009	07:30	umhos/cm	404		318.2222	18.17094	18
5/5/2008	08:00	umhos/cm	335		307.3889	13.24937	18
4/7/2008	08:00	umhos/cm	336		307.3889	13.24937	18
7/8/2003	10:29	umhos/cm	443		254	27.00762	18
12/4/2001	10:15	umhos/cm	320		273.333	18.143	12
11/13/2001	09:40	umhos/cm	316		273.333	18.143	12
9/5/2001	06:50	umhos/cm	314		248.25	16.587	12
8/15/2001	06:45	umhos/cm	301		248.25	16.587	12
7/11/2001	07:30	umhos/cm	308		248.25	16.587	12
6/6/2001	09:00	umhos/cm	302		265.667	16.267	12
5/9/2001	08:50	umhos/cm	303		265.667	16.267	12
4/4/2001	09:05	umhos/cm	303		265.667	16.267	12
11/2/1999	09:35	umhos/cm	235		273.333	18.143	12
10/5/1999	09:15	umhos/cm	315		273.333	18.143	12
5/11/1999	08:50	umhos/cm	308		265.667	16.267	12
8/11/1998	06:10	umhos/cm	213		248.25	16.587	12
6/16/1998	07:40	umhos/cm	222		265.667	16.267	12
10/14/1997	07:00	umhos/cm	227		273.333	18.143	12
Fecal Coliform Bacteria
date	time	units	result	remark	QMEAN	QSD	QDP
8/3/2009	08:30	#/100ml	36	J	12.22222	7.264382	18
2/2/2009	07:30	#/100ml	28		1.176471	0.7276069	17
2/11/2008	08:40	#/100ml	5		1.176471	0.7276069	17
6/5/2007	07:55	#/100ml	30		2.722222	2.10896	18
2/12/2007	07:50	#/100ml	4		1.266667	0.7988086	15
6/6/2005	07:15	#/100ml	26	J	2.722222	2.10896	18
8/15/2001	06:45	#/100ml	37	J	9.75	12.857	12
2/7/2001	09:55	#/100ml	4		1.417	0.9	12
6/15/1999	07:25	#/100ml	6		2.167	1.586	12
8/11/1998	06:10	#/100ml	200		9.75	12.857	12
6/16/1998	07:40	#/100ml	16		2.167	1.586	12
4/15/1997	07:45	#/100ml	6		2.167	1.586	12
Flow
date	time	units	result	remark	QMEAN	QSD	QDP
12/9/1997	07:30	CFS	669		302.778	103.437	9
11/4/1997	07:15	CFS	1170		302.778	103.437	9
10/14/1997	07:00	CFS	1330		302.778	103.437	9
9/16/1997	07:00	CFS	2290		1062.333	576.355	9
8/12/1997	07:00	CFS	2580		1062.333	576.355	9
7/15/1997	06:40	CFS	2610		1062.333	576.355	9
3/11/1997	06:05	CFS	1690		642.778	410.292	9
Nitrate-Nitrite
date	time	units	result	remark	QMEAN	QSD	QDP
2/5/2002	10:02	mg/L	0.01	U	0.066	0.028	12
3/7/2001	09:25	mg/L	0.01	U	0.066	0.028	12
3/16/1999	08:50	mg/L	0.01	U	0.066	0.028	12
2/2/1999	08:05	mg/L	0.173		0.066	0.028	12
1/12/1999	07:40	mg/L	0.156		0.066	0.028	12
12/15/1998	07:20	mg/L	0.105		0.027	0.02	12
3/10/1998	07:00	mg/L	0.01	U	0.066	0.028	12
2/10/1998	07:30	mg/L	0.01	U	0.066	0.028	12
7/15/1997	06:40	mg/L	0.069		0.015	0.017	12
Oxygen
date	time	units	result	remark	QMEAN	QSD	QDP
12/8/2003	11:50	mg/L	12.2		9.767777	1.072148	18
1/7/2003	09:48	mg/L	11.8		13.66556	0.8964126	18
9/5/2000	12:35	mg/L	10.4		8.636	0.361	11
8/15/2000	12:05	mg/L	10.2		8.636	0.361	11
7/11/2000	13:00	mg/L	10.1		8.636	0.361	11
1/4/2000	11:00	mg/L	11.5		14.317	1.289	12
7/6/1999	07:00	mg/L	9.5		8.636	0.361	11
8/11/1998	06:10	mg/L	7.8		8.636	0.361	11
pH
date	time	units	result	remark	QMEAN	QSD	QDP
9/14/2009	09:00	pH	9.4		8.601666	0.1430035	18
10/8/2002	10:15	pH	8.5		8.033334	0.2417339	18
7/9/2002	09:10	pH	8.2		8.608889	0.1839402	18
2/7/2001	09:55	pH	7.9		8.408	0.261	12
1/17/2001	09:30	pH	7.7		8.408	0.261	12
8/15/2000	12:05	pH	9		8.483	0.204	12
7/11/2000	13:00	pH	8.9		8.483	0.204	12
3/7/2000	12:15	pH	7.6		8.408	0.261	12
1/12/1999	07:40	pH	7.3		8.408	0.261	12
12/15/1998	07:20	pH	7.7		8.4	0.3	11
10/13/1998	05:40	pH	7.4		8.4	0.3	11
Phosphorus, Sol Reactive
date	time	units	result	remark	QMEAN	QSD	QDP
8/3/2009	08:30	mg/L	0.0034		0.00305	1.543487E-04	18
7/6/2009	08:45	mg/L	0.0046		0.00305	1.543487E-04	18
6/1/2009	07:45	mg/L	0.0078		3.027778E-03	9.582801E-05	18
4/6/2009	07:45	mg/L	0.0036		3.027778E-03	9.582801E-05	18
9/8/2008	07:30	mg/L	0.0051		0.00305	1.543487E-04	18
8/4/2008	08:15	mg/L	0.0049		0.00305	1.543487E-04	18
6/2/2008	08:50	mg/L	0.0055		3.027778E-03	9.582801E-05	18
3/3/2008	08:20	mg/L	0.0051		3.205555E-03	5.556895E-04	18
1/7/2008	08:25	mg/L	0.0067		3.205555E-03	5.556895E-04	18
11/5/2007	07:50	mg/L	0.0056		3.361111E-03	5.007511E-04	18
10/7/2003	11:25	mg/L	0.003	U	4.772222E-03	5.592069E-04	18
9/9/2003	09:21	mg/L	0.003	U	0.0047	7.004201E-04	18
8/5/2003	08:30	mg/L	0.003	U	0.0047	7.004201E-04	18
7/8/2003	10:29	mg/L	0.003	U	0.0047	7.004201E-04	18
12/3/2002	09:40	mg/L	0.0033		4.772222E-03	5.592069E-04	18
10/8/2002	10:15	mg/L	0.003	U	4.772222E-03	5.592069E-04	18
9/10/2002	10:10	mg/L	0.003	U	0.005	7.529297E-11	18
8/6/2002	09:57	mg/L	0.0036		0.005	7.529297E-11	18
7/9/2002	09:10	mg/L	0.003	U	0.005	7.529297E-11	18
6/11/2002	08:42	mg/L	0.003	U	5.166667E-03	7.071068E-04	18
5/7/2002	08:49	mg/L	0.003	U	5.166667E-03	7.071068E-04	18
4/2/2002	10:05	mg/L	0.003	U	5.166667E-03	7.071068E-04	18
3/5/2002	10:20	mg/L	0.003	U	5.333333E-03	9.701425E-04	18
Phosphorus, Total
date	time	units	result	remark	QMEAN	QSD	QDP
12/3/2002	09:40	mg/L	0.018		6.027778E-02	1.225255E-02	17
11/5/2002	08:45	mg/L	0.022		6.027778E-02	1.225255E-02	17
10/8/2002	10:15	mg/L	0.021		6.027778E-02	1.225255E-02	17
7/11/2001	07:30	mg/L	0.029		0.015	0.007	12
7/14/1998	06:30	mg/L	0.03		0.015	0.007	12
12/9/1997	07:30	mg/L	0.034		0.017	0.007	11
11/4/1997	07:15	mg/L	0.042		0.017	0.007	11
10/14/1997	07:00	mg/L	0.055		0.017	0.007	11
9/16/1997	07:00	mg/L	0.029		0.015	0.007	12
6/10/1997	07:00	mg/L	0.062	J	0.021	0.017	12
2/11/1997	07:00	mg/L	0.042		0.017	0.009	12
12/10/1996	07:00	mg/L	0.728		0.017	0.007	11
Suspended Solids
date	time	units	result	remark	QMEAN	QSD	QDP
10/8/2007	07:50	mg/L	7		4.055555	1.392088	18
4/2/2007	07:25	mg/L	13		6	3.289913	18
12/3/2002	09:40	mg/L	6		3.277778	0.95828	18
10/8/2002	10:15	mg/L	6		3.277778	0.95828	18
7/9/2002	09:10	mg/L	16		3.944444	2.879384	18
5/7/2002	08:49	mg/L	10		4.388889	2.768284	18
4/2/2002	10:05	mg/L	10		4.388889	2.768284	18
3/5/2002	10:20	mg/L	18		4.388889	2.681942	18
9/5/2001	06:50	mg/L	7		2.583	0.669	12
8/15/2001	06:45	mg/L	14		2.583	0.669	12
9/5/2000	12:35	mg/L	5		2.583	0.669	12
8/15/2000	12:05	mg/L	5		2.583	0.669	12
4/4/2000	12:15	mg/L	15		4.25	1.422	12
7/6/1999	07:00	mg/L	4		2.583	0.669	12
3/16/1999	08:50	mg/L	12		3.833	2.167	12
9/8/1998	07:15	mg/L	1		2.583	0.669	12
8/11/1998	06:10	mg/L	4	U	2.583	0.669	12
7/14/1998	06:30	mg/L	4	U	2.583	0.669	12
8/12/1997	07:00	mg/L	4		2.583	0.669	12
1/14/1997	07:15	mg/L	9		3.833	2.167	12
Temperature
date	time	units	result	remark	QMEAN	QSD	QDP
8/3/2009	08:30	deg C	26.6		21.37778	2.048401	18
2/2/2009	07:30	deg C	7.7		2.338889	1.275626	18
3/9/2004	11:42	deg C	5		1.794444	1.449329	18
10/7/2003	11:25	deg C	17.6		8.772223	4.192824	18
8/15/2001	06:45	deg C	26.4		20.717	1.818	12
7/11/2001	07:30	deg C	24.6		20.717	1.818	12
3/7/2001	09:25	deg C	4.8		1.55	1.088	12
7/6/1999	07:00	deg C	16.9		20.717	1.818	12
1/13/1998	07:25	deg C	-0.8		1.55	1.088	12
Total Persulf Nitrogen
date	time	units	result	remark	QMEAN	QSD	QDP
10/8/2007	07:50	mg/L	0.313		0.2398333	2.915325E-02	18
1/13/2004	11:45	mg/L	1.26		0.2299444	6.931978E-02	18
3/7/2001	09:25	mg/L	0.122		0.253	0.05	9
1/17/2001	09:30	mg/L	0.113		0.253	0.05	9
12/6/2000	10:00	mg/L	0.135		0.265	0.057	9
10/4/2000	09:15	mg/L	0.107		0.265	0.057	9
10/5/1999	09:15	mg/L	0.062		0.265	0.057	9
2/2/1999	08:05	mg/L	0.354		0.253	0.05	9
1/12/1999	07:40	mg/L	0.367		0.253	0.05	9
12/15/1998	07:20	mg/L	0.393		0.265	0.057	9
Turbidity
date	time	units	result	remark	QMEAN	QSD	QDP
12/1/2008	07:00	NTU	3.8		1.75	0.4047512	18
11/3/2008	07:15	NTU	4.5		1.75	0.4047512	18
5/5/2008	08:00	NTU	4.7		2.505556	0.9071431	18
11/5/2007	07:50	NTU	2.8		1.75	0.4047512	18
10/8/2007	07:50	NTU	3.9		1.75	0.4047512	18
8/6/2007	07:40	NTU	7.8		2.977778	1.992502	18
10/4/2004	07:15	NTU	2.3		1.511111	0.3924117	18
10/8/2002	10:15	NTU	2.8		1.455556	0.2594615	18
7/9/2002	09:10	NTU	6.3		2.127778	1.911207	18
3/5/2002	10:20	NTU	5.7		1.411111	0.5367537	18
9/5/2001	06:50	NTU	4.4		1.425	0.411	12
8/15/2001	06:45	NTU	9.1		1.425	0.411	12
8/15/2000	12:05	NTU	2.7		1.425	0.411	12
5/2/2000	11:45	NTU	3.2		1.617	0.49	12
4/4/2000	12:15	NTU	23		1.617	0.49	12

Note: QMEAN, QSD, and QDP are the quarterly mean, standard deviation, and number of data points for the last six years, where available, for the station shown.

Washington State Department of Ecology

Data users please read disclaimer.

Questions or comments on content may be sent to Dave Hallock
Questions or comments on presentation may be sent to Steve Barrett.