Note: This presentation requires JavaScript for the links to function properly. You may wish to either enable JavaScript in your browser or go to this alternative page, which does not use JavaScript.

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

Water quality monitoring station

49A070 - Okanogan R @ Malott

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
Fecal Coliform Bacteria (exceeding the ten percent criterion)
6/5/2007	10:00	#/100ml	200	310		55
10/3/2005	10:15	#/100ml	200	210	J	5
Oxygen
date	time	units	criterion	result	remark	% exceed
8/3/2009	10:15	mg/L	8	6.8		15
8/4/2008	10:45	mg/L	8	7.8		3
8/6/2007	10:35	mg/L	8	7.4		7
8/7/2006	09:10	mg/L	8	7.9		1
8/1/2005	08:30	mg/L	8	7.2		9
8/15/2001	08:30	mg/L	8	7.9		1
7/11/2001	09:00	mg/L	8	7.3		8
8/11/1998	08:30	mg/L	8	7.2		10
8/12/1997	08:30	mg/L	8	7.8		3
pH
date	time	units	criterion	result	remark	% exceed
9/11/2006	08:40	pH	8.5	8.6		1
10/7/2003	13:05	pH	8.5	8.6		1
4/13/1999	09:40	pH	8.5	8.6		1
11/3/1998	09:05	pH	8.5	8.6		1
Temperature
date	time	units	criterion	result	remark	% exceed
9/14/2009	10:50	deg C	17.5	19.5		11
8/3/2009	10:15	deg C	17.5	26		49
7/6/2009	10:50	deg C	17.5	22.6		29
9/8/2008	09:25	deg C	18	19.5		8
8/4/2008	10:45	deg C	18	22.4		24
8/6/2007	10:35	deg C	18	23.4		30
7/9/2007	09:55	deg C	18	22.4		24
9/11/2006	08:40	deg C	18	18.5		3
8/7/2006	09:10	deg C	18	21.3		18
7/10/2006	09:00	deg C	18	23		28
8/1/2005	08:30	deg C	18	24.1		34
7/11/2005	09:00	deg C	18	19.4		8
8/10/2004	11:44	deg C	18	23.7		32
7/13/2004	13:39	deg C	18	22.1		23
8/5/2003	10:45	deg C	18	22.7		26
7/8/2003	12:10	deg C	18	22.1		23
9/10/2002	11:30	deg C	18	18.2		1
8/6/2002	11:45	deg C	18	19.3		7
9/5/2001	08:35	deg C	18	18.2		1
8/15/2001	08:30	deg C	18	24.2		34
7/11/2001	09:00	deg C	18	24.7		37
8/15/2000	14:15	deg C	18	20.7		15
8/3/1999	08:40	deg C	18	19.6		9
9/8/1998	10:30	deg C	18	21.8		21
8/11/1998	08:30	deg C	18	21.6		20
7/14/1998	09:00	deg C	18	19.7		9
8/12/1997	08:30	deg C	18	22.1		23
7/15/1997	08:00	deg C	18	18.4		2

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
12/4/2006	09:40	mg/L	0.01	U	2.366667E-02	3.19121E-03	17
11/13/2006	09:55	mg/L	0.01	U	2.366667E-02	3.19121E-03	17
10/2/2006	10:15	mg/L	0.01	U	2.366667E-02	3.19121E-03	17
12/5/2005	10:00	mg/L	0.01	U	2.366667E-02	3.19121E-03	17
11/7/2005	10:35	mg/L	0.01	U	2.366667E-02	3.19121E-03	17
10/3/2005	10:15	mg/L	0.01	U	2.366667E-02	3.19121E-03	17
12/6/2004	09:30	mg/L	0.01	U	2.366667E-02	3.19121E-03	17
10/4/2004	08:50	mg/L	0.01	U	2.366667E-02	3.19121E-03	17
12/8/2003	13:54	mg/L	0.01	U	2.366667E-02	3.19121E-03	17
11/4/2003	12:25	mg/L	0.01	U	2.366667E-02	3.19121E-03	17
10/7/2003	13:05	mg/L	0.01	U	2.366667E-02	3.19121E-03	17
12/3/2002	11:10	mg/L	0.01	U	2.366667E-02	3.19121E-03	17
11/5/2002	11:01	mg/L	0.01	U	2.366667E-02	3.19121E-03	17
10/8/2002	11:24	mg/L	0.01	U	2.366667E-02	3.19121E-03	17
10/5/1999	10:50	mg/L	0.023		0.01	0	18
9/7/1999	08:50	mg/L	0.036		0.011	0.003	18
8/3/1999	08:40	mg/L	0.024		0.011	0.003	18
7/6/1999	08:40	mg/L	0.029		0.011	0.003	18
5/11/1999	10:10	mg/L	0.031		0.012	0.004	18
12/15/1998	09:55	mg/L	0.013		0.01	0	18
10/13/1998	09:40	mg/L	0.24		0.01	0	18
6/16/1998	09:30	mg/L	0.032		0.012	0.004	18
Barometric Pressure
date	time	units	result	remark	QMEAN	QSD	QDP
9/14/2009	10:50	mm/Hg	724.408		739.267	5.406611	18
7/7/2008	10:30	mm/Hg	727.202		740.7064	4.756096	18
1/7/2008	10:20	mm/Hg	721.106		740.0036	7.999877	15
4/10/2006	09:15	mm/Hg	728.218		739.7633	5.385864	18
6/6/2005	08:45	mm/Hg	726.694		739.7633	5.385864	18
4/4/2005	09:00	mm/Hg	724.408		739.7633	5.385864	18
2/10/2004	12:46	mm/Hg	756.92		740.1042	7.473023	17
12/3/2002	11:10	mm/Hg	721.868	J	741.5642	9.126153	18
11/5/2002	11:01	mm/Hg	717.804	J	741.5642	9.126153	18
10/8/2002	11:24	mm/Hg	716.026		741.5642	9.126153	18
4/2/2002	11:47	mm/Hg	748.538		736.7447	5.756864	18
Conductivity
date	time	units	result	remark	QMEAN	QSD	QDP
4/6/2009	09:20	umhos/cm	317		158.2222	61.84759	18
4/7/2008	10:10	umhos/cm	311		158.2222	61.84759	18
11/13/2006	09:55	umhos/cm	147		279.5555	41.17141	18
3/14/2005	08:50	umhos/cm	179		277.1176	30.39918	17
2/7/2005	09:10	umhos/cm	208		277.1176	30.39918	17
6/11/2002	10:10	umhos/cm	13.7		176.9444	72.65913	18
9/5/2001	08:35	umhos/cm	348		225.056	45.355	18
4/4/2001	10:30	umhos/cm	303		156.333	50.29	18
4/4/2000	14:05	umhos/cm	261		156.333	50.29	18
10/5/1999	10:50	umhos/cm	347		245.889	44.443	18
7/6/1999	08:40	umhos/cm	124		225.056	45.355	18
4/13/1999	09:40	umhos/cm	321		156.333	50.29	18
9/8/1998	10:30	umhos/cm	322		225.056	45.355	18
Fecal Coliform Bacteria
date	time	units	result	remark	QMEAN	QSD	QDP
6/5/2007	10:00	#/100ml	310		28.77778	27.91912	18
10/2/2006	10:15	#/100ml	31		10.88235	7.663896	17
5/1/2006	09:05	#/100ml	86		28.77778	27.91912	18
1/9/2006	09:45	#/100ml	16		3.2	3.38484	15
10/3/2005	10:15	#/100ml	210	J	10.88235	7.663896	17
2/7/2005	09:10	#/100ml	24	J	3.2	3.38484	15
1/3/2005	09:30	#/100ml	22		3.2	3.38484	15
9/14/2004	12:43	#/100ml	200		46.44444	39.88251	18
9/9/2003	11:12	#/100ml	170		43.33333	26.39073	18
8/15/2001	08:30	#/100ml	97	J	41.556	23.385	18
6/15/1999	09:10	#/100ml	80		29.056	22.349	18
Flow
date	time	units	result	remark	QMEAN	QSD	QDP
7/6/1999	08:40	CFS	9080		2126.733	1408.056	15
7/15/1997	08:00	CFS	7170		2126.733	1408.056	15
6/10/1997	08:30	CFS	16100		6351.333	4486.752	15
2/11/1997	08:30	CFS	3250		1556.75	700.693	12
Hardness
date	time	units	result	remark	QMEAN	QSD	QDP
4/7/2008	10:10	mg/L	134		71.66666	28.21869	6
Nitrate+Nitrite-Nitrogen
date	time	units	result	remark	QMEAN	QSD	QDP
6/1/2009	09:30	mg/L	0.03		1.377778E-02	4.89364E-03	18
4/6/2009	09:20	mg/L	0.026		1.377778E-02	4.89364E-03	18
6/2/2008	11:50	mg/L	0.031		1.377778E-02	4.89364E-03	18
12/4/2006	09:40	mg/L	0.138		4.622222E-02	3.752263E-02	18
Nitrate-Nitrite
date	time	units	result	remark	QMEAN	QSD	QDP
4/4/2001	10:30	mg/L	0.031		0.014	0.007	18
2/2/1999	09:45	mg/L	0.135		0.064	0.029	14
1/12/1999	09:30	mg/L	0.158		0.064	0.029	14
12/15/1998	09:55	mg/L	0.15		0.055	0.033	18
8/12/1997	08:30	mg/L	0.091		0.024	0.021	18
4/15/1997	09:05	mg/L	0.036		0.014	0.007	18
Oxygen
date	time	units	result	remark	QMEAN	QSD	QDP
8/3/2009	10:15	mg/L	6.8		8.458236	0.5823147	17
8/1/2005	08:30	mg/L	7.2		8.760555	0.6794502	18
6/6/2005	08:45	mg/L	9.2		10.54	0.5438101	18
3/14/2005	08:50	mg/L	11.5		12.93529	0.6991076	17
3/9/2004	13:30	mg/L	11.5		12.86588	0.584648	17
2/10/2004	12:46	mg/L	14.1		12.86588	0.584648	17
7/6/1999	08:40	mg/L	10.4		8.544	0.665	18
8/11/1998	08:30	mg/L	7.2		8.544	0.665	18
6/10/1997	08:30	mg/L	8.5		10.217	0.826	18
pH
date	time	units	result	remark	QMEAN	QSD	QDP
5/4/2004	13:13	pH	7.5		8.187058	0.2023199	16
7/9/2002	11:15	pH	7.8		8.272223	0.2056998	18
11/2/1999	10:50	pH	7.6		8.194	0.236	17
7/6/1999	08:40	pH	7.7		8.283	0.176	18
4/13/1999	09:40	pH	8.6		8.006	0.269	18
6/10/1997	08:30	pH	7.4		8.006	0.269	18
Phosphorus, Sol Reactive
date	time	units	result	remark	QMEAN	QSD	QDP
4/7/2008	10:10	mg/L	0.012		4.833333E-03	1.888666E-03	18
12/4/2006	09:40	mg/L	0.015		4.766667E-03	9.523964E-04	18
11/13/2006	09:55	mg/L	0.0091		4.766667E-03	9.523964E-04	18
4/10/2006	09:15	mg/L	0.011		5.327778E-03	2.153193E-03	18
11/1/2004	09:40	mg/L	0.003		5.072222E-03	6.007893E-04	18
9/14/2004	12:43	mg/L	0.003	U	5.277778E-03	9.926527E-04	18
12/8/2003	13:54	mg/L	0.003	U	5.072222E-03	6.007893E-04	18
11/4/2003	12:25	mg/L	0.0031		5.072222E-03	6.007893E-04	18
10/7/2003	13:05	mg/L	0.0034		5.011111E-03	5.497474E-04	18
9/9/2003	11:12	mg/L	0.007		5.177778E-03	8.868686E-04	18
9/10/2002	11:30	mg/L	0.0035		5.222222E-03	7.320845E-04	18
10/9/2001	11:00	mg/L	0.0033	J	0.008	0.002	17
Phosphorus, Total
date	time	units	result	remark	QMEAN	QSD	QDP
12/3/2002	11:10	mg/L	0.017		6.816667E-02	1.164171E-02	17
11/5/2002	11:01	mg/L	0.023		6.816667E-02	1.164171E-02	17
10/8/2002	11:24	mg/L	0.019		6.816667E-02	1.164171E-02	17
8/3/1999	08:40	mg/L	0.038		0.018	0.009	18
7/6/1999	08:40	mg/L	0.061		0.018	0.009	18
9/8/1998	10:30	mg/L	0.054		0.018	0.009	18
11/4/1997	08:35	mg/L	0.052		0.016	0.007	17
10/14/1997	09:40	mg/L	0.046		0.016	0.007	17
9/16/1997	08:30	mg/L	0.04		0.018	0.009	18
5/13/1997	09:00	mg/L	0.241		0.06	0.055	18
12/10/1996	08:45	mg/L	0.867		0.016	0.007	17
Suspended Solids
date	time	units	result	remark	QMEAN	QSD	QDP
6/1/2009	09:30	mg/L	178		51.22222	42.82599	18
7/7/2008	10:30	mg/L	30		6.611111	7.252901	18
6/5/2007	10:00	mg/L	140		39.88889	35.18002	18
11/13/2006	09:55	mg/L	36		3.277778	2.13667	18
12/5/2005	10:00	mg/L	25		3.277778	2.13667	18
2/7/2005	09:10	mg/L	21		4.294117	3.40523	17
5/4/2004	13:13	mg/L	150		34.61111	24.69374	18
7/6/1999	08:40	mg/L	46		10.611	9.531	18
5/13/1997	09:00	mg/L	153		52.833	43.454	18
Temperature
date	time	units	result	remark	QMEAN	QSD	QDP
8/3/2009	10:15	deg C	26		20.37222	2.603348	18
6/6/2005	08:45	deg C	15.3		11.02222	2.011893	18
3/9/2004	13:30	deg C	9.1		2.370588	2.059965	17
10/7/2003	13:05	deg C	16.5		5.966667	3.718475	18
10/8/2002	11:24	deg C	13.8		5.966667	3.718475	18
7/11/2001	09:00	deg C	24.7		19.35	2.544	18
7/6/1999	08:40	deg C	12.7		19.35	2.544	18
Total Persulf Nitrogen
date	time	units	result	remark	QMEAN	QSD	QDP
3/7/2001	10:40	mg/L	0.102		0.22	0.032	10
2/7/2001	11:35	mg/L	0.117		0.22	0.032	10
1/17/2001	10:50	mg/L	0.127		0.22	0.032	10
11/8/2000	10:30	mg/L	0.062		0.195	0.062	12
3/16/1999	09:25	mg/L	0.32		0.22	0.032	10
2/2/1999	09:45	mg/L	0.301		0.22	0.032	10
12/15/1998	09:55	mg/L	0.362		0.195	0.062	12
2/10/1998	08:55	mg/L	0.341		0.22	0.032	10
Turbidity
date	time	units	result	remark	QMEAN	QSD	QDP
6/1/2009	09:30	NTU	75		20.01111	23.05803	18
7/9/2007	09:55	NTU	12		3.144444	3.762543	18
6/5/2007	10:00	NTU	85		15.11111	16.70368	18
11/13/2006	09:55	NTU	24		1.588889	1.194541	18
5/4/2004	13:13	NTU	75		11.76667	8.060433	18
7/9/2002	11:15	NTU	14		3.472222	3.232156	18
7/6/1999	08:40	NTU	12		3.072	2.161	18
5/13/1997	09:00	NTU	65		18.3	18.208	18

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.