U.S. GEOLOGICAL SURVEY DIGITAL DATA SERIES 37 Data from Selected U.S. Geological Survey National Stream Water-Quality Monitoring Networks (WQN) [This is the \WQN\WQ\SEAS_DEF.TXT file] A listing of National Stream Quality Accounting Network and Hydrologic Benchmark Network time periods of sample collection for bimonthly and quarterly sampling frequencies [This file appears as Table 3 in the accompanying Open-File Report] _________________________________________________________________ Sample Number Bimonthly frequency Quarterly frequency _________________________________________________________________ 1 October-November October-December 2 December-January January-March 3 February-March April-June 4 April-May July-September 5 June-July 6 August-September _________________________________________________________________