Date: Fri, 25 Apr 1997 17:50:58 -0500 To: nawqa91pc From: "Timothy L Miller, Chief, NAWQA, Reston, VA" (Timothy L. Miller) X-Sender: tlmiller@130.11.51.209 Subject: final Operational SWQ LIP guidelines, 1997 Cc: "Sarahnell L Laible, Secretary, Reston, VA" , "Rosemary Musson, Office Automation Assistant, Reston, VA" , "Walton H Low, Supv Hyd, Boise, ID" , "Jeffrey T Armbruster, Asst. Reg. Hydr.-NAWQA, Norcross, GA" , "Ivan C James II, Asst. Reg. Hydrologist-NAWQA, Denver, CO" , "Michael C Yurewicz, Asst. Reg. Hydrol.-NAWQA, Reston, VA" , "Marc A Sylvester, Asst. Reg. Hydrologist-NAWQA, Menlo Park, CA" , "William G Wilber, National Synthesis Coordinator, Reston, VA" , "Robert S Williams Jr., Hydrologist, Denver, CO" , "Dennis R Helsel, Hydrologist, Denver, CO" , "Martin E Gurtz, Hydrologist, Raleigh, NC" , "Robert J Gilliom, Supv. Hydrologist, Sacramento, CA" , "John S Zogorski, Supervisory Hydrologist, Rapid City, SD" , "O. Lehn Franke, Hydrologist, Denver, CO" , "David K Mueller, Hydrologist, Denver, CO" , "Larry J Puckett, Ecologist, Reston, VA" , "Jonathon C Scott, Hydrologist, Oklahoma City, OK" , "Jeffrey D Stoner, Supervisory Hydrologist, Mounds View, MN" In Reply Refer To: Mail Stop 413 SENT VIA EMAIL MEMORANDUM April 25, 1997 TO: Study-Unit Chiefs, 1991 National Water-Quality Assessment Program FROM: Timothy L. Miller, Chief, National Water-Quality Assessment Program SUBJECT:Operational surface-water quality Low Intensity Phase guidelines, 1997, for the 1991 Study Units REPLY REQUESTED BY MAY 16, 1997 This memorandum issues the 1997 operational surface-water quality Low Intensity Phase (LIP) guidelines for the 1991 Study Units (attachment). The 1997 operational ground-water quality LIP guidelines are forthcoming. Forty-seven LIP sites have been selected (10 Study Unit-wide integrators, 9 sub-basin integrators, 7 urban and 15 agricultural indicator, 6 paired reference sites). For the base interval-sampling frequency, monthly water samples, annual taxa samples, and triennial bottom sediment and tissue samples will be collected for the detection of trends. Additional samples for extreme flow conditions must be justified and approved. The base interval-sampling frequency should begin as soon as practicable in FY1997. The LIP sampling plan and budget should be prepared and submitted to the following individuals by May 16, 1997: nawqanlt@mailrvares.er.usgs.gov, nawqanst@mailrvares.er.usgs.gov, tjlopes, mkoterba, jdmartin, lshelton, sllaible, rmusson wlow, and district management. The allocation of additional funds for 1997 LIP data collection will immediately follow the review and approval of the sampling plan and budget. The submitted plans will be reviewed by the NST, Walton Low, and NLT. NST will provide any review comments of the plans by June 6, 1997. Conference calls among the individual Study Units, ARHN, NST, and Walton Low will be scheduled during mid-June to discuss any unresolved issues regarding the sampling plans and justifications. Please include the Study Unit contact(s) (email ID and telephone number). A Framemaker copy of the guidelines and tables are available via ftp. server: 130.118.149.75 filename: /var/ftp/pub/lip97.fm and lip97tables.fm Attachment cc: ********************************************************************** >>>>>>>>>>>>>>>>>>>>>>>>>>Print in Landscape<<<<<<<<<<<<<<<<<<<<<<<<<< ********************************************************************** OPERATIONAL SURFACE-WATER QUALITY LOW-INTENSITY PHASE GUIDELINES 1997 I. BACKGROUND The primary objective of the Low-Intensity Phase (LIP) is to provide an explicit design that is technically and fiscally prudent and meets the objectives of trends assessment. The objectives of trend assessment are to analyze past changes in water quality and to identify, describe, and explain (as possible) current and future changes and trends in water quality (Luoma and others, 1994). The basis of the trend design of NAWQA is the characterization of the temporally-fine but spatially-coarse LIP as a subset of the temporally-coarse but spatially-fine High-Intensity Phase (HIP). One data attribute necessary for a reasonable trend monitoring network is that sampling intervals are fixed rather than event-based (Vecchia and others, 1997). Event-based samples are not useful for trend detection purposes because statistical procedures for including event-based samples in trend estimation are not currently available. Since the draft LIP operational plan by Sylvester (1995), Miller (1995), and the National Leadership Team (1995), continued dialog among the NLT, National Synthesis Team (NST), and the 1991 Study Units have resulted in refinement to the surface-water quality portion of the draft plan. Refinement to the plan focused on three areas: (1) site selection, (2) constituents sampled, and (3) frequency of sample collection. The plan, necessarily, will continually evolve as the NAWQA program gathers and assesses new information on the effectiveness of the LIP design. II. SITE SELECTION The selection of LIP surface-water sites was based on integrator, indicator, and reference sites sampled during the High-Intensity Phase nominated by the 1991 Study Units and the National Synthesis Team (tables 1-5). Table 1.--Low-intensity phase Study Unit Integrator Sites integrating all or most of the study unit (10). SU STAID NAME COMMENTS KM2 CNBR 6805500 PLATTE R AT LOUISVILLE NE basin terminus,HIP IFS,NASQAN2 78149 REDN 5102500 RED R OF THE NO AT EMERSON MAN basin terminus,HIP IFS,past NASQAN 92144 RIOG 8364000 RIO GRANDE AT EL PASO TX basin terminus,HIP BFS,NASQAN2 94946 CONN 1184000 CONNECTICUT R AT THOMPSONVILLE basin terminus,HIP BFS,past NASQAN 25050 LSUS 1578310 L SUSQUEHANNA R AT CONOWINGO MD basin terminus,HIP BFS,DW source,past NASQAN 70189 POTO 1646580 POTOMAC R AT WASH DC basin terminus,HIP BFS,no bst,past NASQAN 29975 WHIT 3374100 WHITE R AT HAZLETON IN basin terminus,HIP IFS,past NASQAN,NASQAN2 29290 SANJ 11303500SAN JOAQUIN R NR VERNALIS CA basin terminus,HIP IFS,past NASQAN 18939 USNK 13154500SNAKE R AT KING HILL ID basin terminus,HIP BFS,past NASQAN,NASQAN2 92941 WILL 14211720WILLAMETTE R AT PORTLAND OR basin terminus,HIP BFS,no bst,NASQAN2 28937 Table 2.--Low-intensity phase Study Unit Integrator Sites integrating a major sub-basin of the study unit (9). SU STAID NAME COMMENTS KM2 SPLT 6754000 S PLATTE R NR KERSEY CO sub-basin,HIP BFS,v S Platte,N Platte,NASQAN2 25144 TRIN 8057410 TRINITY R BEL DALLAS TX sub-basin,HIP BFS 9372 HDSN 1357500 MOHAWK R AT COHOES NY sub-basin,HIP IFS,paired w/Canajoharie Cr 9113 WMIC 4087000 MILWAUKEE R AT MILWAUKEE WI sub-basin,HIP IFS 1852 ACFB 2338000 CHATTAHOOCHEE R NR WHITESBURG GAsub-basin,HIP BFS 6245 ALBE 2089500 NEUSE R AT KINSTON NC sub-basin,HIP BFS,major N&P source 7021 GAFL 2318500 WITHLACOOCHEE R NR QUITMAN GA sub-basin,HIP IFS,paired w/Little R 3864 CCPT 13351000PALOUSE R AT HOOPER WA sub-basin,HIP IFS,ag dominant 6380 NVBR 10350500TRUCKEE R AT CLARK NV sub-basin,HIP BFS,urban dominant 4122 Table 3.--Low-intensity phase Urban Indicator Sites (7). SU STAID NAME COMMENTS KM2 TRIN 8057200 WHITE ROCK CR AT DALLAS TX non-HIP BFS,stable,v Chambers 172 SPLT 6714000 S PLATTE R AT DENVER CO HIP IFS,stable,v Cherry 10009 CONN 1209710 NORWALK R AT WINNIPAUK CT HIP IFS,nps-dominated,v Pequabuck R 85 POTO 1654000 ACCOTINK C NR ANNANDALE VA HIP IFS,v LSUS Cedar Run,NRP sampled 60 WHIT 3353637 L BUCK CR NR INDIANAPOLIS IN HIP IFS,70% developed 45 ACFB 2335870 SOPE CR NR MARIETTA GA HIP IFS,stable,fully developed,v Peachtree 80 NVBR 94196783LAS VEGAS WASH NR LV HIP IFS 2640 Table 4.--Low-intensity phase Agricultural Indicator Sites (15). SU STAID NAME COMMENTS KM2 CNBR 6800000 MAPLE CR NR NICKERSON NE HIP IFS,long-term WQ&bio data 955 REDN 5082625 TURTLE R NR ARVILLA ND HIP IFS 658 OZRK 7053250 YOCUM CR NR OAK GROVE AR HIP IFS,paired w/N Sylamore 134 HDSN 1349150 CANAJOHARIE CR NR CANAJOHARIE HIP IFS,paired w/Mohawk 155 LSUS 1555400 E MAHANTANGO CR AT KLINGERSTOWN HIP IFS,paired w/Bobs Cr,long-term data,stable 116 POTO 1621050 MUDDY C AT MOUNT CLINTON VA HIP IFS,paired w/Shennandoah R 37 WHIT 39434008SUGAR CR AT NEW PALESTINE IN HIP IFS 246 WMIC 4072050 DUCK CR NR ONEIDA WI HIP IFS,v. NBr Milwaukee R 247 ALBE 2091500 CONTENTNEA CR AT HOOKERTON NC HIP BFS 1909 GAFL 2317797 LITTLE R NR TIFTON GA HIP IFS,paired w/Withlacoochee R 335 CCPT 12471400LIND COULEE WASTEWAY NR WARDEN HIP BFS integrator 1820 SANJ 11272500MERCED R NR STEVINSON CA HIP IFS integrator 3242 SANJ 11274538ORESTIMBA CR NR CROWS LANDING HIP IFS 27 USNK 13092747ROCK CR AB AT TWIN FALLS ID HIP IFS 623 WILL 14201300ZOLLNER CR NR MT ANGEL OR HIP IFS,99% ag,stable,paired w/L Abiqua Cr 39 Table 5.--Low-intensity phase Reference Sites paired with land use indicator (6). SU STAID NAME COMMENTS KM2 OZRK 7060710 N SYLAMORE CR NR FIFTY SIX AR HIP BFS,Benchmark,paired w/Yocum 150 TRIN 8051500 CLEAR CR NR SANGER TX HIP BFS,relative, paired w/White Rock Cr 773 LSUS 1559795 BOBS CR NR PAVIA PA HIP BFS,paired w/E.Mah.,EMAP site,no BS&T 43 ACFB 2337500 SNAKE CR NR WHITESBURG GA HIP BFS,paired w/Sope 92 CCPT 12464770CRAB CR NR RITZVILLE WA HIP IFS,ag relative reference,spring-fed 1188 WILL 14200400L ABIQUA CR NR SCOTTS MILLS OR HIP BFS 25 III. CONSTITUENTS AND SAMPLE COLLECTION FREQUENCY Table 6 lists the base site-sampling frequency and chemical constituents to be sampled. LIP surface-water quality sample collection should commence as soon as practicable in fiscal year 1997. The base interval-sampling frequency for trends is monthly for basin and sub-basin integrator sites (tables 1,2). For the NAWQA LIP/NASQAN2 sites (table 1, 5 sites; table 2, 1 site), additional high-flow samples should be justified and collected. For unusual flow-condition sites, additional samples may be proposed based on individual site stream-flow characteristics. Increases from the base-interval sampling frequency for trends should be proposed, justified, and costs estimated for review and approval. For high-variability sites, continuous specific conductance measurements may be proposed in addition to or in lieu of monthly major ion sample collection. Study Units interested in collecting both continuous specific conductance and monthly major ion data should propose, justify, and estimate costs for review and approval. Water-quality constituents to be sampled monthly at all sites (tables 1-5) include major ions (S2701), nutrients (S2702), and suspended sediment. Pesticides (S2001/2010) will be sampled monthly only at integrator sites. During the LIP, pesticides (S2001/S2010) will be sampled twice per month at agricultural and urban indicator sites during a contiguous 6-month period of each year. Paired reference sites will be sampled once per month during the same contiguous 6-month period as the indicator sites. The 6-month period is the same each year at a particular site, but may vary somewhat among sites. Generally, HIP data should be used to pick the 6-month period centered on the greatest occurrence and concentrations of pesticides for each particular site. These 6-month periods may be adjusted somewhat after all proposed sampling plans are compiled in order to make very similar situations in the same region have the same 6-month period. Study Units interested in collecting monthly SOC/DOC (S2075) should propose, justify, and estimate costs for review and approval. Biological data collection include ANNUAL single-reach assessments of fish, invertebrate, and algal communities (RTH and QMH; DTH must be justified), and Level I habitat characterization. Tissue collections for organic compounds (S2101) and trace elements (S2200), and bed sediment for organic compounds (S2500) and trace elements (S2400) should be completed once every 3 years (triennial) beginning in 1997 and again in 2000. Continuous water temperature should be collected at all selected LIP sites. Table 6.--Base site-sampling and data collection frequency. Study Unit Sub-Basin Agricultural Urban Paired Integrator1/ Integrator1/ Indicator2/ Indicator2/ Reference3/ Major ions monthly monthly monthly monthly monthly (S2701) Nutrients monthly monthly monthly monthly monthly (S2702) Pesticides monthly monthly 2 per mo 2 per mo 1 per mo (S2001/2010) for 6 mo for 6 mo for 6 mo Suspended monthly monthly monthly monthly monthly Sediment QA/QC scheduled scheduled scheduled scheduled scheduled Taxa annually annually annually annually annually fish/alg/inv BS&T triennially triennially triennially triennially triennially (S2101/2200) (S2500/2400) 1/--NAWQA/NASQAN2 sites, add additional high-flow samples 2/--unusual or variant flow conditions, add additional samples 3/--sample 1 per month during same 6 months as the paired indicator site IV. LIP SAMPLING PLAN The purpose for the LIP surface-water quality (SWQ) site sampling plan is to document the environmental setting, HIP sample summary, and LIP sampling schedule for each LIP site. The plan should document unusual hydrologic and other conditions that may affect water-quality conditions and also any proposed increases to the base sampling frequency and constituents. An example plan is given below. 1. An overview of the study-unit LIP/HIP relation and why the LIP sites were chosen. 2. Monthly-mean hydrograph for the historic period of discharge record and 1991-present (or previous HIP period) and a flow- duration hydrograph showing past HIP and proposed sampling periods. The hydrographs provide insight to streamflow variability and the adequacy of the frequency of sample collection and constituents to be sampled. For urban and agricultural indicator sites, prepare a graph showing average monthly total herbicide and insecticide concentrations for one year overlayed with the proposed 6-month pesticide sampling period. 3. Site description for each LIP SWQ site. The intent of the description is to report hydrologic conditions that may affect stream water quality and support any proposed increases from the base sampling frequency. Table 7 is an example table listing site descriptive components. Table 7.--USNK LIP SWQ site description. 13154500 13092747 BASIN SNAKE R AT ROCK CR AT CHARACTERISTICS KING HILL,ID TWIN FALLS,ID Latitude, longitude 430008 1151206 423347 1142942 Area, square miles 35800 241 Percent of Study Unit 100 0.006 Geology Quaternary/Tertiary Quaternary/Tertiary sedimentary, volcanics sedimentary, volcanics Physiographic province Columbia Plateau Columbia Plateau Ecoregion Snake R Basin/ Snake R Basin/ High Desert High Desert Percent agricultural land use 21 24 Crop Group wheat grains>50 wheat grains potatoes>10 alfalfa>20 Percent urban residential land use 0.29 1.05 Water use,Mgal/d,1995 irrigation 12684 - public supply 71 - domestic supply 18 - industrial 165 - Population 1990 425000 53580 1995 469000 59480 Environmental stable agriculture stable agriculture influences highly regulated rapid population growth streamflow highly regulated conversion of streamflow irrigation methods conversion of irrigation methods LIP site pair none none 4. High Intensity Phase sample summary for each LIP SWQ site. This information will help determine what and when sampling was completed and whether particular flow conditions should be sampled, in addition to the routine monthly sampling. Table 8 is an example table listing site sample information from the HIP. Table 8.--USNK High Intensity Phase sample summary. No. of 13154500 samples No. of Snake River fixed Period of samples Period of at King Hill ID interval Record high-flow Record Major Ions S2701 36 Mar93-Jun95 6 Apr-May,94-95 QA/QC-blanks 5 QA/QC-replicates 5 Nutrients S2702 36 Mar93-Jun95 6 Apr-May,94-95 QA/QC-blanks 5 QA/QC-replicates 5 DOC/SOC S2075 36 Mar93-Jun95 6 Apr-May,94-95 QA/QC-blanks 5 QA/QC-replicates 5 Pesticides S2001 12 Mar93-Jun95 6 Apr-May,94-95 S2050 12 QA/QC-blanks 5 QA/QC-replicates 5 QA/QC-spikes 5 Suspended Sediment 36 Mar93-Jun95 6 Apr-May,94-95 QA/QC-blanks 5 QA/QC-replicates 5 Water temperature cont Mar-Sep,93-95 Specific conductance cont Mar-Sep,93-95 Taxa fish 3 Aug,93-95 macroinvertebrate 3 Aug,93-95 algae 3 Aug,93-95 Bed Sediment 3 Aug,93-95 ********** Table 8.--USNK High Intensity Phase sample summary--continued. No. of 13092747 samples No. of Rock Creek at fixed Period of samples Period of Twin Falls, ID interval Record high-flow Record Major Ions S2701 36 Mar93-Jun95 6 Apr-May,94-95 QA/QC-blanks 5 QA/QC-replicates 5 Nutrients S2702 36 Mar93-Jun95 6 Apr-May,94-95 QA/QC-blanks 5 QA/QC-replicates 5 DOC/SOC S2075 36 Mar93-Jun95 6 Apr-May,94-95 QA/QC-blanks 5 QA/QC-replicates 5 Pesticides S2001 20 Mar93-Jun95 6 Apr-May,94-95 S2050 20 QA/QC-blanks 5 QA/QC-replicates 5 QA/QC-spikes SusSed 36 Mar93-Jun95 6 Apr-May,94-95 QA/QC-blanks 5 QA/QC-replicates 5 Water temperature cont Mar-Sep,93-95 Specific conductance cont Mar-Sep,93-95 Taxa fish 3 Aug,93-95 macroinvertebrate 3 Aug,93-95 algae 3 Aug,93-95 Bed Sediment 3 Aug,93-95 5. Schedule of LIP sample collection. Table 9.--USNK sampling plan, FY1997, 13154500 Snake River at King Hill Id, Integrator Maj Ion Nutri Pest Month Week S2701 S2702 S2001 SusSed QA/QC Oct 2 0 0 0 0 0 Nov 2 0 0 0 0 0 Dec 2 0 0 0 0 0 Jan 2 0 0 0 0 0 Feb 2 0 0 0 0 0 Mar 2 0 0 0 0 0 Apr 2 0 0 0 0 0 May 2,4* 1 1 1 1 inorg repl,blk Jun 2,4* 1 1 1 1 0 Jul 2 1 1 1 1 org repl,blk,spk Aug 2 1 1 1 1 0 Sep 2 1 1 1 1 0 * - NO pesticide sample Table 9.--USNK sampling plan, FY1997, 13092747 Rock Creek at Twin Falls, ID, Ag Indicator--continued. Maj Ion Nutri Pest Month Week S2701 S2702 S2001 SusSed QA/QC Oct 2 0 0 0 0 0 Nov 2 0 0 0 0 0 Dec 2 0 0 0 0 0 Jan 2 0 0 0 0 0 Feb 2 0 0 0 0 0 Mar 2 0 0 0 0 0 Apr 2 0 0 0 0 0 May 2,4# 1 1 1 1 inorg repl,blk Jun 2,4# 1 1 1 1 org rep,blk,spk Jul 2,4# 1 1 1 1 0 Aug 2,4# 1 1 1 1 0 Sep 2,4# 1 1 1 1 0 # - pesticide sample ONLY V. QUALITY ASSURANCE/QUALITY CONTROL The objective of the QA/QC plan for the LIP is to evaluate sampling bias and variability in relation to changes or trends in environmental data. QC samples for surface-water chemistry should be collected and managed in accordance with NAWQA protocols (Miller, 1996). For FY97, the minimum number of surface-water QC samples collected in each LIP study unit should include: (1) at least one field blank for each analytical schedule (and for VOCs, if sampled, at least one cannister blank); (2) at least one replicate sample for each schedule; and (3) at least one set of duplicate spiked samples for each pesticide and VOC schedule. Subsequent QC sampling should be scheduled according to guidance in Miller (1996). Scheduling of QC sample collection might need to be modified in the future, subject to a national review of the suitability of the temporal distribution of QC data. VI. ESTIMATED FY97 and FY98 GROSS COSTS, LIP SURFACE-WATER QUALITY For consistency and to facilitate review and integration of Study Unit budgets at Regional and National levels, please provide study unit budget tables that are consistent with AIS management categories of each District and mapped to the default district management categories. Study units are requested to develop budget salary, NWQL, and burden estimates in AIS. Tracking of NWQL sample flow will be accomplished periodically from each District and study unit AIS master budget. Budget assumptions, overhead rates, and other explanations should be discussed and footnoted. For AIS-derived budgets, a copy of an AIS "Project Budget Summary by Account By Management Category" and "Management Category: OC. LABORATORY-CENTRAL LAB, Detailed" should be provided (via ftp and/or hard copy). For spreadsheet-derived budgets, please provide the name of the spreadsheet software and a TAB-DELIMITED output filename. Finally, please provide the ftp address from which the file(s) may be obtained by anonymous ftp. FY97 and FY98 table should be provided. Table 10 list the budget descriptions. Table 10.--Estimated FY97 and FY98 costs, LIP surface-water quality. SWQ ECO SWQ ECO CAT CATEGORY NAME DESCRIPTION OR DEFINITION 97 97 98 98 AC Overtime Overtime AS1 Salaries 1 SU core personnel only & awards AS2 Salaries 2 Non-SU personnel (or see P.) C Travel Travel excluding NTC training DD,FP Postage&freight USPS,FedEx,UPS,truck DG,DI Vehicles Vehicles, GSA & Interior G Printing Report printing & reproduction HD Contracts Contract services, burdened HZ Contracts Contract services, non-burdened K Training District, NTC, & other training L Supplies Supplies, non-Ocala M,MZ Equipment Equipment,computers,&software N Miscellaneous Miscellaneous expenses OCL NWQL NWQL analytical & taxonomic OOL Non-NWQL Contract lab, if any P Reimbursements Intra/inter-WRD SV (Q O&M,field office,Ocala,&sediment lab) T Subtotal NET TOTAL U District burden ((T-OCL)/(1-(U+V rates))*U rate)+ (OCL/(1-(.1+V rate))*.1) V Hdqtr burden ((T-OCL/(1-U+V rates))*V rate)+ (OCL/(1-(.1+V rate))*V rate) TOTAL GROSS TOTAL VII. REFERENCES CITED Luoma, S.N., Hsieh, P.A., Betancourt, J.L., Cayan, D., Hill, M.C., Robertson, D.M., Vecchia, A.V., Wagner, B.J., and Helsel, D.R., 1994, Guidelines for the Determination of Water Quality Trends in the National Water Quality Assessment Program: U.S. Geological Survey Report of the Committee, October 9, 1994, 35 p. Miller, T.L., 1995, Guidance on preparation of fiscal year (FY) 1996 work plans for study units started in FY 1991: U.S. Geological Survey electronic memorandum from the Acting Chief, National Water-Quality Assessment Program, October 16, 1995, 12 p. Miller, T.L., 1996, Quality-control plan for National Water-Quality Assessment (NAWQA) program surface-water sites: U.S. Geological Survey memorandum from the Acting Chief, National Water-Quality Assessment Program, May 15, 1996, 2 p.; attachment, 14 p. (ftp://srv1rvares.er.usgs.gov/pub/nawqa, as 'qcplan.0596.fm) National Leadership Team, 1995, Low-intensity phase sampling guidance: U.S. Geological Survey electronic memorandum from National Leadership Team, National Water Quality Assessment Program, October 24, 1995, 4 p. Sylvester, M.A., 1995, Draft operational plan for trends component of NAWQA: U.S. Geological Survey electronic memorandum from Assistant Regional Hydrologist for NAWQA, June 1, 1995, 11 p. Vecchia,A.V.,Jr., Wiche,G.J., and Berkas,W.R., 1997, Evaluation of sampling procedures for monitoring trends in surface water quality for the NAWQA program: Report to the NAWQA National Leadership Team, U.S. Geological Survey, January 6, 1997, 73 p. ************************************************************************