USGS Scientific Investigations Report 2010–5008 Use of Continuous Monitors and Autosamplers to Predict Unmeasured Water-Quality Constituents in Tributaries of the Tualatin River, Oregon

Table 6. Datasets showing laboratory sample results and summary statistics for scenarios used for calibration and validation of regression models with continuous monitors at Fanno Creek, Durham, Oregon.

[Discharge, turbidity, and specific conductance data were from records at stream gages and continuous monitors. Occasional Clean Water Services samples were collected at higher discharges than shown here, but continuous monitors were not deployed at the time so samples could not be used for this study. Note that USGS uses suspended sediment concentration (SSC) rather than total suspended solids (TSS). SSC and TSS data were combined without adjustment for Scenario 2 and Scenario 3. Abbreviations: FNU, Formazin Nephelometric Unit; n, number of samples (numbers for individual models may vary where missing values or outliers were removed); NWIS, National Water Information System water quality database; USGS, U.S. Geological Survey; ft³/s, cubic foot per second; µS/ cm, microsiemens per centimeter; mg/L, milligram per liter; No./100 mL, colony count per 100 milliliters]

Scenario and summary statistic	Calibration						Validation
Scenario and summary statistic	Discharge (ft³/s)	Turbidity (FNU)	Specific conductance (µS/cm)	Total suspended solids (mg/L)	Total phosphorus (mg/L)	E. coli (No. /100 mL)	Total suspended solids (mg/L)	Total phosphorus (mg/L)	E. coli (No. /100 mL)
Scenario 1	Autosampler (2002–03), n = 54						Clean Water Services ambient monitoring (2001–04), n = 98
Minimum	7.1	5.7	110.0	4.0	0.08	180	2.0	0.08	56
Maximum	134.4	131	245.0	196.0	0.47	10,000	260.0	0.60	12,000
Mean	65.7	47	159.5	51.0	0.19	2,829	16.9	0.15	763
Median	63.9	38	146.0	37.1	0.15	1,300	7.2	0.14	325
Standard deviation	31.0	30	34.7	45.6	0.10	3,174	34.8	0.08	2,020
Scenario 2	Autosampler (2002–03) + USGS NWIS (2001–07), n = 131						Clean Water Services ambient monitoring (2001–04), n = 98
Minimum	1.12	1.4	63.8	0.5	0.08	180	2.0	0.08	56
Maximum	505.0	131	394.0	242.0	0.47	10,000	260.0	0.60	12,000
Mean	49.1	28	187.2	29.9	0.15	2,829	16.9	0.15	763
Median	33.2	17	182.2	12.5	0.14	1,300	7.2	0.14	325
Standard deviation	65.0	29	52.7	40.9	0.07	3,174	34.8	0.08	2,020
Scenario 3	Autosampler peak discharge samples, USGS NWIS high flow 2001–07, Clean Water Services first monthly + high flow, n = 96						Autosampler non-peak discharge samples, USGS non-high flow, Clean Water Services remaining monthly and non-high flow, n = 80
Minimum	1.1	3.9	63.8	2.0	0.08	67	0.5	0.08	56
Maximum	505.0	131	281.0	242.0	0.47	6,300	260.0	0.60	10,000
Mean	57.9	25	177.5	26.3	0.14	824	29.6	0.17	1,565
Median	35.4	17	168.0	13.5	0.13	345	10.0	0.14	520
Standard deviation	80.7	26	48.8	39.4	0.05	1,428	40.7	0.09	2,546