Table 1. Average water quality data at individual sampling sites and for all sampling sites during the winter and summer, Clearwater Lake, 1997.

Site	Sample Period During 1977	Number of Samples	Sample Depth m	Depth of Column Sampled m	Secchi Disk Depth m	Turbidity NTU	pH pH units	Total Kjeldahl Nitrogen mg/L	Ammonia- Ammonium Nitrogen mg/L	Un-ionized Ammonia Nitrogen mg/L	Nitrate-Nitrite Nitrogen mg/L	Total Phosphorus mg/L	Dissolved Phosphorus mg/L	Chlorophyll a g/L
WQ1201	February	2	0.55			0.55	8.36	0.36	0.032	0.0007	<0.01	0.015	0.012
WQ1201	July to September	4		2.81	2.5	2.90	8.52	0.25	<0.020		<0.01	0.013	0.006	2.5
WQ1208	February	3	2.03			0.97	8.35	0.46	<0.027	<0.0006	<0.01	0.017	0.011
WQ1208	July to September	4		13.5	6.75	0.91	8.51	0.25	<0.020		<0.01	0.010	0.005	<1.0
WQ1209	February	3	2.03			0.60	8.39	0.30	<0.020	<0.0005	<0.01	0.017	0.014
WQ1214	July to September	4		14.25	7.13	0.98	8.51	0.33	<0.023		<0.01	0.008	0.007	<1.0
WQ1224	July to September	4		11.25	6.5	1.05	8.53	0.25	<0.020		<0.01	0.011	0.005	<1.3
All Sites	February	8	1.66			0.73	8.37	0.38	<0.026	<0.0006	<0.01	0.017	0.012	1.4
All Sites	July to September	16		10.45	5.72	1.46	8.52	0.27	<0.021		<0.01	0.010	0.005
All Sites	February to September	24	1.66a	10.45b	5.72b	1.21	8.47	0.30	<0.022	<0.0006a	<0.01	0.012	0.008	1.4b
All Sites Minus WQ1201	February to September	18	2.03a	13.0b	6.79b	0.91	8.47	0.31	<0.022	<0.0006a	<0.01	0.012	0.008	1.1b

a = Available for 8 February samples only.

b = Available for 16 July to September samples only.

Table 2. Annual averages, Clearwater Lake water quality from 1943 to 1997.

Year	Sample Period	Number of Samples	Secchi Disk Depth m	Turbidity NTU	pH pH units	Total Kjeldahl Nitrogen mg/L	Ammonia- Ammonium Nitrogen mg/L	Un-ionized Ammonia Nitrogen mg/L	Nitrate-Nitrite Nitrogen mg/L	Total Phosphorus mg/L	Dissolved Phosphorus mg/L	Chlorophyll a g/L
1943a	July	2	9.75		7.20
1961	November	1		2	8.18
1962	January to October	9-10		5.0	8.18
1970a	July	4-24	5.36		8.40
1974	June to August	5-11		0.5	8.40				0.060	<0.018d
1988b	February to October	4		0.65	8.14	0.71			<0.150	<0.014
1989c	June	3-50		0.22	8.45	<0.22	0.009	0.0005c	<0.018	0.011
1996a	August			0.91	8.62	<0.26	0.016	0.0022	<0.028	0.033	0.027
1997a	February to September		5.72e	1.21e	8.47	<0.22	<0.022	<0.006	<0.010	0.012	0.008	<1.4

a = Includes samples collected between surface and bottom.

b = Excludes a sample from April 27,1988 in which run-off is suspected.

c = Fifty samples for all perameters except for calculated un-ionized ammonia for only three samples for three sites where temperature was measured.

d = Total phosphorous calculated from total phosphate.

e = Secchi Disk and Turbidity include Site WQ1201 where the total depth is at or near Secchi disk depth. If this data is excluded average Secchi disk depth would be 6.79 m and average turbidity would be 0.98 NTU.

Appendix 1: Water quality data, Clearwater Lake, 1997.

Site	Sample Date	Sample Depth m	Depth of Column Sampled m	Secchi Disk Depth m	Turbidity NTU	pH pH units	Total Kjeldahl Nitrogen mg/L	Ammonia- Ammonium Nitrogen mg/L	Un-ionized Ammonia Nitrogen mg/L	Nitrogen Nitrate-Nitrite mg/L	Total Phosphorus mg/L	Dissolved Phosphorus mg/L	Chlorophyll a g/L
WQ1201	23-Feb-97	0.1			0.76	8.37	0.38	0.032	0.0007	0.01	0.017	0.013
WQ1201	23-Feb-97	1			0.33	8.35	0.34	0.032	0.0007	< 0.01	0.013	0.011
WQ1201	07-Jul-97		3	3	2.0	8.46	0.20	< 0.02		< 0.01	0.016	0.002	< 1
WQ1201	05-Aug-97		3	3	2.1	8.62	0.20	< 0.02		< 0.01	0.017	0.016	< 1
WQ1201	17-Aug-97		3.75	2	3.1	8.52	0.40	< 0.02		< 0.01	0.013	0.003	6
WQ1201	04-Sep-97		1.5	2	4.4	8.5	0.20	< 0.02		< 0.01	0.007	0.002	1
WQ1208	23-Feb-97	0.1			1.1	8.37	0.51	0.022	0.0005	0.01	0.019	0.010
WQ1208	23-Feb-97	1			1.0	8.39	0.32	< 0.02	<0.0005	< 0.01	0.017	0.015
WQ1208	23-Feb-97	5			0.81	8.31	0.55	0.038	0.0008	< 0.01	0.017	0.010
WQ1208	07-Jul-97		16	8	0.51	8.44	0.20	< 0.02		< 0.01	0.011	0.002	< 1
WQ1208	05-Aug-97		17	8.5	1.0	8.56	< 0.2	< 0.02		< 0.01	0.012	0.004	< 1
WQ1208	17-Aug-97		11	5.5	1.2	8.54	0.40	< 0.02		< 0.01	0.012	0.011	1
WQ1208	04-Sep-97		10	5	0.9	8.5	0.20	< 0.02		< 0.01	0.005	0.002	1
WQ1209	23-Feb-97	0.1			1.1	8.39	0.39	< 0.02	<0.0005	0.01	0.021	0.018
WQ1209	23-Feb-97	1			0.23	8.39	0.24	< 0.02	<0.0005	< 0.01	0.015	0.010
WQ1209	23-Feb-97	5			0.48	8.38	0.27	< 0.02	<0.0005	< 0.01	0.014	0.014
WQ1214	07-Jul-97		16	8	0.53	8.45	< 0.2	< 0.02		< 0.01	0.003	0.002	< 1
WQ1214	05-Aug-97		19	9.5	0.7	8.56	< 0.2	0.03		< 0.01	0.013	0.012	< 1
WQ1214	17-Aug-97		12	6	1.5	8.55	0.6	< 0.02		< 0.01	0.011	0.011	1
WQ1214	04-Sep-97		10	5	1.2	8.51	0.3	< 0.02		< 0.01	0.004	0.002	1
WQ1224	07-Jul-97		15	8	1.4	8.46	< 0.2	< 0.02		< 0.01	0.012	0.001	< 1
WQ1224	05-Aug-97		10	8	0.6	8.62	0.20	0.02		< 0.01	0.013	0.013	< 1
WQ1224	17-Aug-97		10	5	0.8	8.51	0.40	< 0.02		< 0.01	0.013	0.002	2
WQ1224	04-Sep-97		10	5	1.4	8.51	0.20	< 0.02		0.01	0.004	0.002	< 1