USGS Scientific Investigations Report 2013–5001  - Sources and Characteristics of Organic Matter in the Clackamas River, Oregon, Related to the Formation of Disinfection By-Products in Treated Drinking Water 

Table 6. Summary statistics for select streamflow, water quality, optical properties, and disinfection by-products for the upper and lower main-stem Clackamas River, tributaries, and source water, Clackamas River basin, Oregon. 

[Source water includes samples from the Clackamas River Water and City of Lake Oswego drinking-water treatment plants. Abbreviations: n, number of samples; Min, minimum; Max, maximum; nm, namometers; UV, ultraviolet; DBP, disinfection by-product; FP, formation potential; F, filtered; U, unfiltered] 

Abbreviation	Constituent definition,  units	Upper main stem				Tributaries				Lower main stem and source water				Source water
Abbreviation	Constituent definition,  units	n	Min	Median	Max	n	Min	Median	Max	n	Min	Median	Max	n	Min	Median	Max
Flow	Streamflow, in cubic feet per second	20	343	1,720	11,421	15	0	25	422	65	800	2,247	18,142	38	800	2,269	18,142
Temp	Temperature, in degrees Celsius	20	3.8	9.3	13.4	15	8.0	14.8	19.3	62	4.7	11.2	18.4	38	5.4	9.6	18.4
SC	Specifc conductance, in microsemens per centimeter	20	30.0	50.0	82.0	15	32.0	73.0	177.0	62	30.0	50.0	69.0	38	30.0	47.0	69.0
DO	Dissolved oxygen, in milligrams per liter	20	10.5	11.7	13.3	15	9.6	10.3	12.1	62	8.9	11.1	13.0	38	8.9	11.4	12.7
DO%	Percent saturation dissolved oxygen	20	101	104	106	15	96	101	111	62	94	100	112	38	95	100	107
pH	pH, in standard units	20	7.2	7.7	8.0	15	6.8	7.6	8.1	62	7.3	7.6	8.6	38	7.3	7.6	7.8
Turbidity	Turbidity, in formazin nephelometric units	19	0.1	1.7	43	15	0.2	4.1	76.5	62	0.1	1.5	68	38	0.1	1.3	68
Chla (water column)	Chlorophyll-a, in micrograms per liter	20	0.2	0.4	1.0	15	0.4	2.2	7.7	64	0.1	1.1	6.1	37	0.2	1.4	6.1
Chla (benthic)	Chlorophyll-a, in milligrams per square meter	2	52	--	58	10	38	157	304	8	93	201	759	--	--	--	--
SRP	Dissolved phosphate, in milligrams per liter	19	0.010	0.018	0.021	15	0.004	0.031	0.106	64	0.004	0.013	0.030	37	0.004	0.013	0.030
TP	Total phosphorus, in milligrams per liter	18	0.006	0.010	0.033	15	0.009	0.037	0.252	60	0.009	0.010	0.062	36	0.009	0.010	0.062
Si	Dissolved silicate, in milligrams per liter	19	0.7	6.4	9.9	15	2.8	8.5	13.1	64	0.8	6.7	8.9	37	0.9	6.2	8.9
NO3	Dissolved nitrate plus nitrite, in milligrams per liter	19	0.003	0.009	0.025	15	0.059	0.587	1.728	64	0.003	0.026	0.351	37	0.008	0.054	0.351
TPN	Total particulate nitrogen,  in milligrams per liter	20	0.009	0.017	0.036	15	0.005	0.029	0.596	65	0.003	0.029	0.177	38	0.006	0.037	0.177
DOC	Dissolved organic carbon,  in milligrams per liter	20	0.6	1.1	1.9	15	1.2	2.0	7.8	65	0.8	1.2	2.3	38	0.9	1.3	2.2
TPC	Total particulate carbon,  in milligrams per liter	20	0.1	0.2	0.9	15	0.1	0.5	6.3	65	0.1	0.3	2.0	38	0.1	0.3	2.0
TOC	Total organic carbon,  in milligrams per liter	20	0.8	1.3	2.8	15	1.3	2.5	13.5	65	0.9	1.5	3.6	38	1.0	1.5	3.6
% C as POC	Particulate carbon, in percent	20	7	17	33	15	5	20	47	65	5	20	55	38	10	23	55
FDOM	Fluorescence FDOM,  in water Raman units	20	0.02	0.04	0.09	15	0.05	0.14	0.49	65	0.02	0.04	0.12	38	0.03	0.05	0.11
PEAK A	Fluorescence Peak A,  in water Raman units	20	0.03	0.09	0.21	15	0.10	0.33	1.23	65	0.05	0.10	0.25	38	0.07	0.10	0.25
PEAK C	Fluorescence Peak C,  in water Raman units	20	0.02	0.05	0.11	15	0.06	0.19	0.62	65	0.03	0.05	0.14	38	0.04	0.06	0.14
PEAK M	Fluorescence Peak M,  in water Raman units	20	0.01	0.04	0.08	15	0.05	0.15	0.60	65	0.03	0.04	0.12	38	0.03	0.05	0.12
PEAK D	Fluorescence Peak D,  in water Raman units	20	0.01	0.03	0.06	15	0.03	0.08	0.30	65	0.01	0.03	0.08	38	0.02	0.03	0.07
PEAK B	Fluorescence Peak B,  in water Raman units	20	0.02	0.03	0.12	15	0.03	0.09	0.52	65	0.02	0.04	0.10	38	0.02	0.04	0.10
PEAK T	Fluorescence Peak T,  in water Raman units	20	0.02	0.04	0.10	15	0.04	0.10	0.57	65	0.02	0.04	0.14	38	0.03	0.04	0.14
PEAK N	Fluorescence Peak N,  in water Raman units	20	0.01	0.03	0.07	15	0.04	0.14	0.56	65	0.02	0.04	0.13	38	0.03	0.04	0.13
FI	Fluorescence Index, unitless	20	1.33	1.38	1.46	15	1.39	1.44	1.50	65	1.31	1.38	1.45	38	1.34	1.38	1.45
HIX	Humic Index, unitless	20	2.13	3.49	6.08	15	2.10	4.71	7.52	65	2.36	3.68	5.32	38	2.36	3.69	4.75
C1 Loading	Component 1, in fluorescence maximum values	20	0.01	0.04	0.09	15	0.04	0.14	0.94	65	0.02	0.04	0.17	38	0.03	0.05	0.17
C2 Loading	Component 2, in fluorescence maximum values	20	0.01	0.03	0.08	15	0.04	0.09	0.35	65	0.02	0.03	0.10	38	0.02	0.04	0.10
C3 Loading	Component 3, in fluorescence maximum values	20	0.02	0.05	0.12	15	0.06	0.18	0.59	65	0.03	0.05	0.14	38	0.04	0.06	0.14
C4 Loading	Component 4, in fluorescence maximum values	20	0.02	0.04	0.10	15	0.05	0.16	0.52	65	0.03	0.05	0.12	38	0.03	0.05	0.12
C5 Loading	Component 5, in fluorescence maximum values	20	0.01	0.03	0.09	15	0.02	0.08	0.56	65	0.02	0.03	0.10	38	0.02	0.03	0.10
Total C Loading	Total component, in fluorescence maximum values	20	0.08	0.18	0.45	15	0.24	0.72	2.81	65	0.13	0.21	0.57	38	0.15	0.22	0.57
% C1	Percentage of component 1	20	13	19	22	15	16	22	41	65	17	21	33	38	18	21	33
% C2	Percentage of component 2	20	13	16	20	15	11	14	18	65	11	16	21	38	11	17	19
% C3	Percentage of component 3	20	20	26	29	15	19	25	29	65	16	25	30	38	19	26	28
% C4	Percentage of component 4	20	18	22	25	15	17	22	26	65	18	22	24	38	18	23	24
% C5	Percentage of component 5	20	8.3	17	31	15	5.4	12	30	65	5.7	16	27	38	8.2	15	23
S_275-295	Spectral Slope for  275-295 nm, in per nm	20	0.01	0.01	0.02	15	0.01	0.01	0.01	65	0.01	0.01	0.02	38	0.01	0.01	0.02
S_290-350	Spectral Slope for  290-350 nm, in per nm	20	0.01	0.01	0.02	15	0.01	0.01	0.02	65	0.01	0.01	0.03	38	0.01	0.01	0.03
S_350-400	Spectral Slope for  350-400 nm, in per nm	19	0.01	0.01	0.02	15	0.01	0.01	0.01	63	0.01	0.01	0.02	37	0.01	0.01	0.02
SR	Spectral Slope Ratio, unitless	19	0.67	0.96	1.50	15	0.78	0.92	1.23	63	0.71	0.98	2.05	37	0.71	0.98	2.05
A₂₅₄	Absorbance at 254 nm,  in per centimeter	20	0.01	0.03	0.07	15	0.03	0.05	0.39	65	0.01	0.03	0.10	38	0.01	0.03	0.10
SUVA	Specific UV absorbance at  254 liters per milligram per meter	20	1.43	2.60	4.06	15	2.00	2.88	4.03	65	1.64	2.64	4.41	38	2.00	2.73	4.41
THMFP-F	DBPFP for total trihalomethanes, in milligrams per liter (filtered)	5	0.055	0.096	0.130	15	0.113	0.198	0.595	20	0.091	0.134	0.158	8	0.119	0.145	0.156
HAAFP-F	DBPFP for total haloacetic acids, in milligrams per liter (filtered)	5	0.010	0.015	0.059	15	0.030	0.071	0.637	20	0.016	0.026	0.076	8	0.020	0.031	0.064
THMFP-U	DBPFP for total trihalomethanes, in milligrams per liter (unfiltered)	5	0.063	0.083	0.123	15	0.116	0.194	0.956	20	0.096	0.148	0.237	8	0.140	0.166	0.223
HAAFP-U	DBPFP for total haloacetic acids, in milligrams per liter (unfiltered)	5	0.013	0.038	0.096	15	0.036	0.087	0.929	20	0.021	0.040	0.154	8	0.025	0.044	0.154