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 5. Constituents analyzed from water samples collected during stormflows,Tualatin River tributaries, Oregon, May 2002 to September 2004.

[Method number: EPA, U.S. Environmental Protection Agency (1993); SM, Standard Methods (American Public Health Association, 1992). Abbreviations: STORET, U.S. Environmental Protection Agency’s data Storage and Retrieval system; E. coli, Escherichia coli; mg/L, milligram per liter; mL, milliliter]

Parameter (abbreviation)	STORET code	Units	Method number	Reporting level	Analyzing laboratory
Total suspended solids (TSS)	530	mg/L	EPA 160.2	0.2	Clean Water Services
Ammonia nitrogen (NH₃-N)	608	mg/L	EPA 350.1	0.01	Clean Water Services
Total Kjeldahl nitrogen (TKN)	625	mg/L	EPA 351.2	0.1	Clean Water Services
Nitrate plus nitrite nitrogen (NO₃-N)	631	mg/L	EPA 353.1	0.01	Clean Water Services
Total phosphorus (TP)	665	mg/L	EPA 365.4	0.025	Clean Water Services
Soluble reactive phosphorus (SRP)	671	mg/L	EPA 365.1	0.005	Clean Water Services
Chloride (Cl^-)	941	mg/L	EPA 300.3 A	0.1	Clean Water Services
E. coli bacteria	31648	(100 mL)^-1	SM 9213 D	1	Clean Water Services