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 \DOCFILES\DATA_ALL.TXT file] WQN DATA FILES The data are provided in two different forms separately on two CD-ROM discs: (1) The "ASCII disc" contains all WQN data in ASCII form, and is readable on any computer capable of reading ISO 9660 standard CD-ROM discs. These data can be searched or accessed through user-supplied software including Web browser (e.g., Mosaic, Netscape Navigator, or Microsoft Internet Explorer), word processor, spreadsheet, statistical analysis programming software, or geographic information systems. [The contents of the ASCII disc are described below] (2) The "DOS disc" can be used to access all WQN data (except for daily streamflow values and selected graphical files associated with the technical memoranda) on a DOS-based computer or under a DOS emulator on another computer (software on this disc is also executable from a Windows operating system). The software supplied on the DOS disc (GSMENU and GSSEARCH) allows the user to browse text files and retrieve and output data according to user-specified criteria. See the DATA_DOS.TXT file for a description of the DOS-accessible data structure. THE WQN ASCII DATA FILES The WQN data base contains water-quality and streamflow data and supporting information identifying and describing the water-quality and streamflow stations, water-quality constituents, and the methods, remarks, laboratories, sample collection agencies, and the measurement accuracy associated with the WQN data. Water-quality and streamflow data approximately span the periods 1973-95 for the National Stream Quality Accounting Network (NASQAN) and 1962-95 for the Hydrologic Benchmark Network (HBN). Estimates of laboratory measurement accuracy of the stream water-quality data based on water reference samples are included in a quality-control data base covering the water years 1985-95 (Oct. 1, 1984 to Sept. 30, 1995). The ASCII forms of the water-quality, streamflow, and ancillary data in the WQN directory are described below. The ASCII (text) form is for the user who may want to use a word processor or data- base package to extract and manipulate the data and transfer it to another program such as a statistics package or spread-sheet. Data in the ASCII form can be read and processed on any computer that can handle a CD-ROM in the ISO 9660 format. HyperText Markup Language (HTML) code is provided on the ASCII disc to allow user access to all of the WQN data through a Web browser. Users may access data in this manner by opening the file INDEX.HTM in the root directory from within a Web browser or by double clicking on the file if the Web browser is associated with the HTM extension. THE WATER-QUALITY AND STREAMFLOW DATA The water-quality and streamflow data are available in ASCII form in the \WQN\WQ directory. The water-quality data include 63 physical, chemical, and biological properties. These data are collectd at 679 stations, and approximately span the period 1973-95 for NASQAN and 1962-95 for HBN. ASCII forms of these data are located in 21 sub-directories corresponding to the major hydrologic regions as defined by the Water Resources Council. Each sub-directory has the name REGIONrr where rr is the first two digits of the hydrologic unit code (HUC) found in the HUCS.TXT file. The FORMATS sub-directory contains the detailed formats and descriptions of the files of water-quality, streamflow, and supporting data in .FMT files. The daily streamflow data are not available on the DOS CD-ROM. ASCII data file names Within each of the 21 regional sub-directories, the water-quality and streamflow data are organized in separate station and parameter files. The name of each file is ssssssss.ttt where ssssssss is the 8-digit USGS station number, and ttt is: ALK for alkalinity, bicarbonate, and carbonate parameters, BIO for biological parameters, DMV for daily mean values of streamflow, MAJ for major dissolved ions, MT1 for dissolved and total trace-element parameters, MT2 for dissolved and total trace-element parameters, MT3 for dissolved and total trace-element parameters, MT4 for dissolved and total trace-element parameters, NUT for nutrients, suspended sediment, and organic carbon, PHY for physical/field parameters including instantaneous flow, and RAD for radiochemical parameters. See WQ_PARM.DAT for a complete listing of constituents associated with each constituent group name. Within each file there is one record for each date and time sampled, except for the daily mean streamflow values, where there is one record for each day of the month (31 records to a calendar year). The water-quality records are sorted by date, time, and ending date (which may be present for some biological data). The instantaneous streamflow recorded at the time of water- quality sampling is stored in each of the water-quality data files, and can be used in cases where water-quality and streamflow pairs are required (e.g., plots of water-quality and flow or computations of flow-adjusted concentrations). See the WQ.FMT and DMV.FMT files in the \WQN\WQ\FORMATS sub-directory for details of the water-quality and streamflow file layouts. ANCILLARY DATA The ancillary data provides information on the history and characteristics of the national networks and information on the water-quality constituents, stations, methods, agencies, laboratories, and laboratory measurement accuracy associated with the WQN stream water-quality data. The data files listed below that provide information on the stations and constituents will be useful for most searches. The other ancillary data can assist in the proper use and interpretation of WQN water-quality data. The FORMATS sub-directory contains .FMT files giving the detailed formats and descriptions of many of the files described in this section. Station Information Files WQ_STAS.DAT list the identifying number, name, and other attributes of the 679 national network stations. [file location: \WQN\WQ] WQ_RELOC.DAT list 48 NASQAN water-quality stations that were relocated during their period of record. This information may be useful for identifying station records suitable for merging. [file location: \WQN\WQ] WQ_MVNET.DAT list 2 stations that have belonged to both national networks (NASQAN and Benchmark) during their periods of operation. [file location: \WQN\WQ] WQ_FLOW.DAT contains information on the availability of streamflow records for each of the 679 water-quality stations. Alternate streamflow gaging stations or relocated NASQAN stations are identified in 79 cases where data are not available at the water-quality sites. These streamflow data can be used with the water-quality data to derive estimates of flux or load. Note that the streamflow at NASQAN site 01096550 can be determined from the streamflow of two upstream gaging sites, 01100000 and 01099500 [contact the USGS New England District office for details; see the file CONTACTS.TXT for instructions]. [file location: \WQN\WQ] FLOWSTAS.DAT list the attributes of 61 stations that serve as alternate streamflow gaging stations for the water-quality sites. [file location: \WQN\WQ] Water-Quality Measurement-Related Files WQ_PARM.DAT list 121 physical, chemical, and biological constituents for which stream water-quality data are available. Their units of measure, chemical expression, and unique five digit parameter code are provided. This file references filtered and unfiltered substances as "dissolved" and "total" constituents, respectively. [file location: \WQN\WQ] WQ_PARM2.DAT contains the list of 121 physical, chemical, and biological constituents available on CD-ROM with the current USGS parameter-code expressions. This file includes references to "dissolved" substances as filtered, and "total" as unfiltered, whole-water. [file location: \WQN\WQ] WQ_PARM.TXT contains a list of the 63 water properties for which data are available on the CD-ROM and their approximate sampling frequencies. [file location: \WQN\WQ] ALK_PARM.TXT contains the applicable parameter/method codes and dates used to compile national network alkalinity, bicarbonate, and carbonate data on the CD-ROM. [file location: \WQN\WQ] WQ_DEFS.TXT explains the total constituent analyses performed on WQN samples. The total form reflects different characteristics of the analytical methods and the water-suspended sediment mixture of the samples. [file location: \WQN\WQ] SEAS_DEF.TXT contains NASQAN and HBN time periods of sample collection for bimonthly and quarterly sampling frequencies. [file location: \WQN\WQ] AGENCIES.DAT list the govenmental and private organizations responsible for sample collection of the stream water- quality data at WQN stations. These codes were frequently reported in the data base beginning in the early 1980s. Non-USGS agencies may have periodically collected data at WQN sites as part of local investigations. [file location: \WQN\WQ] LABS.DAT list the governmental and private organizations responsible for laboratory analysis of the stream water-quality data at WQN stations. These codes were frequently reported in the data base beginning in the early 1980s. Non-USGS laboratories may have periodically analyzed samples collected as part of local investigations conducted at WQN sites. [file location: \WQN\WQ] METHODS.DAT defines the laboratory analytical method codes corresponding to the values of stream water quality. These codes are reported beginning in 1985. Descriptive information is given for 209 laboratory methods used to analyze 76 of the 121 water-quality constituents (other analytical methods not listed in this file may have been used to analyze some of these constituents; information on these methods was unavailable at the time of CD-ROM production). The remaining 46 constituents include 17 laboratory-analyzed parameters for which codes were unavailable at the time of production of the CD-ROM, 27 field parameters, and 2 computed parameters. The 17 constituents include 1 trace element, 4 radiochemicals, and 12 biological constituents (these predated the use of method codes). Although method codes are reported in the water-quality data base for the 27 field and 2 computed parameters, these codes are not officially supported by the USGS. [file location: \WQN\WQ] REMARKS.DAT contains definitions for remark codes corresponding to the values of stream water quality at WQN stations. [file location: \WQN\WQ] Quality-Assurance/Quality-Control Files QA_FLD.TXT gives a summary of important changes in national network field methods, constituent coverage, and field sample contamination that may affect the use and interpretation of WQN stream water-quality data. [file location: \WQN\QASURE] QW_LAB.TXT gives a summary of important changes in national network laboratory methods, reporting conventions, and field sample contamination that may affect the use and interpretation of WQN stream water-quality data. [file location: \WQN\QASURE] QA_MEMOS.TXT gives a brief summary of 60 USGS water-quality memoranda cited in QA_FLD.TXT and QA_LAB.TXT and describing changes in methods, constituent coverage, and sample contamination that may affect the use and interpretation of WQN stream water-quality data. The 60 memoranda are listed separately as text documents in the same directory. [file location: \WQN\QASURE] Graphical files associated with seven of the water-quality memoranda are located in a sub-directory \GRAPHICS in both GIF and PostScript (PS) formats. Refer to the 1ST_READ.ME file in this sub-directory for a listing of the figure and table names. BSP_PARM.DAT list 34 dissolved chemical constituents for which Blind Sample Program (BSP) reference sample data are available. The BSP data can be used to estimate the laboratory measurement bias and variability associated with national network stream water-quality data for selected constituents for water years 1985-95 (Oct. 1, 1994 to Sept. 30, 1995). [file location: \WQN\BSP] BSP_METH.DAT contains a listing of the laboratory analytical methods and years for the 34 dissolved chemical constituents for which BSP data were selected. These analytical methods were used for national network stream water-quality data for the years and constituents indicated. [file location: \WQN\BSP] BSP Data Files: The estimates of BSP laboratory measurement error and variability for 34 constituents for water years 1985-95 are organized in separate files by constituent group. Measurement error data from which the bias can be estimated appear in the file BIAS.ttt, and laboratory measurement variability data appear in the file VAR.ttt, where ttt is: MJ1 for major dissolved ions, MJ2 for major dissolved ions, NUT for nutrients, MT1 for dissolved trace-element parameters, MT2 for dissolved trace-element parameters, MT3 for dissolved trace-element parameters, and MT4 for dissolved trace-element parameters. BSP_PARM.DAT identifies the constituents belonging to each constituent group. [file location: \WQN\BSP] WQN Report and Supplementary Data REPORT.TXT is the accompanying USGS report that describes the history and characteristics of the WQN data including the stream water-quality data and the BSP reference sample data. This report also describes statistical methods for using the BSP reference sample data to evaluate the accuracy of the network stream water-quality observations. The tables and figures for the report are located in the same sub-directory in the files TABLE#.TXT (# = 1 to 9) FIG#.XX (# = 1 to 8), respectively, where XX is PS for the PostScript format and GIF for the GIF format. [The accompanying report is entitled "Data from Selected U.S. Geological Survey National Stream Water Quality Monitoring Networks (WQN) on CD-ROM" by R.B. Alexander, A.S. Ludtke, K.K. Fitzgerald, and T.L. Schertz, U.S. Geological Survey Open-File Report 96-337.] [file location: \REPORT] BIBLIO.TXT is a bibiliography of publication on national network field and laboratory methods, historical information on the networks, summaries and interpretations of network data at the national, regional, and local levels, and statistical and computer software methods that have been developed for use with data having characteristics similar to those of the national network data. [file location: \REPORT] Hydrologic Unit and State Geographic Information Files (not accessible from GSMENU on the DOS disc) STATES.DAT gives the correspondence between the state codes used in the STATIONS.DAT file and the state names. [file location: \WQN\WQ] HUCS.TXT gives an explanation of hydrologic units, regions, sub-regions, accounting units, cataloging units, and hydrologic unit codes (HUC). [file location: \WQN\WQ] HUC_NAME.TXT gives the full description of all the hydrologic units. [file location: \WQN\WQ] HUC_AREA.DAT gives the drainage area of the hydrologic units by region, subregion, accounting unit, and cataloging unit. [file location: \WQN\WQ] SREGIONS.DAT gives the names of the hydrologic regions and subregions. [file location: \WQN\WQ]