2

NAWQA: Cycle 1 and Cycle 2

Since its beginning, the U.S. Geological Survey (USGS) has been one of the primary federal agencies responsible for assessing the quantity and quality of the nation’s surface water and groundwater. In the early 1980s USGS performed and published an assessment of the nation’s water, titled The National Water Summary 1983—Hydrologic Events and Issues (USGS, 1984). After the completion of this document and related congressional testimony in the mid-1980s, USGS scientists concluded that their ability to say something meaningful about the quality of the nation’s waters was limited. Indeed, the USGS resources to assess national water quality were the National Stream Quality Accounting Network1 (NASQAN) and the Hydrologic Benchmark Network,2 which, while nationwide, were sparse and were conducting routine monitoring rather than data analysis. Furthermore, NASQAN and the Hydrologic Benchmark Network reflected water-quality sampling approaches from the early 1970s and 1960s, respectively, and thus did not provide data appropriate to address national water-quality questions of the mid-1980s.

Stimulated by the aforementioned events, the USGS contemplated and envisioned a national water-quality assessment program. Key pieces of this original vision included sampling hydrologeologically meaningful units of study or study units, using multiple scales of investigation to achieve a national picture by piecing together information from the study units, integrated teams of scientists performing the water-quality assessment, a

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1 See http://water.usgs.gov/nasqan/.

2 See http://ny.cf.er.usgs.gov/hbn/.



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2 NAWQA: Cycle 1 and Cycle 2 Since its beginning, the U.S. Geological Survey (USGS) has been one of the primary federal agencies responsible for assessing the quantity and quality of the nation's surface water and groundwater. In the early 1980s USGS performed and published an assessment of the nation's water, titled The National Water Summary 1983--Hydrologic Events and Issues (USGS, 1984). After the completion of this document and related congressional testimony in the mid-1980s, USGS scientists concluded that their ability to say something meaningful about the quality of the nation's waters was limited. Indeed, the USGS resources to assess national water quality were the National Stream Quality Accounting Network1 (NASQAN) and the Hydrologic Benchmark Network,2 which, while nationwide, were sparse and were conducting routine monitoring rather than data analysis. Further- more, NASQAN and the Hydrologic Benchmark Network reflected water- quality sampling approaches from the early 1970s and 1960s, respectively, and thus did not provide data appropriate to address national water-quality questions of the mid-1980s. Stimulated by the aforementioned events, the USGS contemplated and envisioned a national water-quality assessment program. Key pieces of this original vision included sampling hydrologeologically meaningful units of study or study units, using multiple scales of investigation to achieve a national picture by piecing together information from the study units, integrated teams of scientists performing the water-quality assessment, a 1 See http://water.usgs.gov/nasqan/. 2 See http://ny.cf.er.usgs.gov/hbn/. 25

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26 PREPARING FOR THE THIRD DECADE OF THE NAWQA PROGRAM punctuated rotational sampling design, and assessment using established methods (Box 2-1). Shortly after the NRC's Water Science and Technology Board (WSTB) endorsed the original concept of the National Water-Quality Assessment (NAWQA) program (Chapter 1), it convened a colloquium in 1986 to ar- ticulate the necessary elements for a national water-quality assessment pro- gram (NRC, 1987). Colloquium participants endorsed the program concept and also raised new issues for consideration such as whether and how to interface with state regulators, which contaminants would be selected for monitoring, and the need to explore surface water and groundwater inter- actions. For example, the original study unit concept consisted of 123 sepa- rate surface water and groundwater units: 69 surface water-dominated and BOX 2-1 The Original Vision for the NAWQA Program The USGS vision for NAWQA included selecting study units, or hydrologically meaningful pieces of geography (Winter, 2001), in which to monitor water quality. The study units were building blocks for multiple scales of water quality investiga- tion; they served not only as the base level but also as tools for "scaling up" to the bigger, national picture. Consistency between study units would allow the program to make comparable statements about the nation's water quality. Data collection and data analysis for the water quality assessment in each study unit were to be done by a team working together in an integrated group. This team of scientists was to make measurements, understand what these measure- ments meant, and make a statement about water quality in a given study unit. It was thought that sampling and assessment should follow a punctuated, rotational system of study with intense data collection for approximately 3 years followed by a period of analysis and publication, a time of minimal monitoring, and a return to the area to repeat the cycle. NAWQA was envisioned to be a network for data collection defined by geology, hydrology, and land use, rather than a grid or a random sampling strategy. In this way, NAWQA could capture snapshots of both the entire system and "indicator" sites. The design had a strong prejudice toward collecting data in places where USGS had high-quality streamflow data records, in the belief that surface water- quality data are meaningless without considering flow and long-term history. Fi- nally, use of known tools and understanding of processes to monitor the nation's water quality were critical components of the original vision. NAWQA would not deploy untested methods and approaches for analyzing water quality unless on a limited scale. Rather, research and development of methods in other USGS programs would feed the program's activities and assist the program in achieving the goal of assessing the nation's water quality. SOURCE: R. M. Hirsch, personal communication, May 13, 2009.

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NAWQA: CYCLE 1 AND CYCLE 2 27 54 groundwater dominated (NRC, 1990). However, as the pilot program progressed, it became apparent to both the National Research Council (NRC) committee and USGS that the separate approach had the potential for missing important surface water-groundwater linkages that could have profound effects on the water quality of both systems. Consequently, the decision was made to consolidate groundwater and surface water study units, although most of the study units were either groundwater or surface water dominated. USGS was authorized by Congress to establish a pilot program in 1986 with seven pilot study units representing a diversity of hydrologic environ- ments and water-quality conditions, four of which were surface water dom- inated (the upper Illinois River basin in Illinois, Wisconsin, and Indiana; the Kentucky River basin in Kentucky; the lower Kansas River basin in Kansas and Nebraska; and the Yakima River basin in Washington) and three of which were groundwater dominated (the Delmarva Peninsula in Delaware, Maryland, and Virginia; the Carson basin in Western Nevada and Eastern California; and the Central Oklahoma aquifer in central Oklahoma) (NRC, 1990). USGS requested the NRC to undertake a 2-year evaluation of the pilot studies in 1987, and the NRC responded with A Review of the USGS National Water Quality Assessment Pilot Program (NRC, 1990). This NRC committee was invited to assist in the evolution and refinement of the NAWQA design as it moved toward full-scale implementation, deliberating on several NAWQA planning documents, issuing an interim report, and visiting the seven pilot study units. The NRC committee was supportive of the NAWQA effort (Box 2-2). The success of the pilot effort led to NAWQA's full-scale implemen- tation in 1991 with the program goals of status, trends over time, and understanding as cornerstones of the program mission--cornerstones that have not changed through the evolution of the program. At the time of its BOX 2-2 Perspective from NRC (1990) "The [NRC] committee is convinced that there is a genuine need for a long-term, large spatial scale national assessment of water quality in the United States. Human health and environmental health are inextricably linked to our nation's water quality. . . . The [NRC] committee is convinced that a national scale, long term water quality assessment is in the best interest of the country." SOURCE: NRC, 1990.

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28 PREPARING FOR THE THIRD DECADE OF THE NAWQA PROGRAM conception, NAWQA was the largest water resources program ever under- taken by USGS (R. J. Gilliom and R. M. Hirsch, personal communication, May 13, 2009). CYCLE 1 OVERVIEW In the first decade of water-quality monitoring (Cycle 1, 1991-2001) NAWQA set out to (1) accumulate high-quality, multidisciplinary, water- quality data and (2) generate a national synthesis of those data focusing on analysis of the highest-priority issues that cuts across the geography and answers the question, "How is the nation's water quality changing?" The program demonstrated considerable progress toward a national water- quality assessment in Cycle 1. For thoroughness and to place this report in context, the committee notes key components of Cycle 1 here. (For a detailed review of Cycle 1 see NRC [2002].) The Study Unit Concept The Cycle 1 study units accounted for 60 to 70 percent of the nation's water use and population served by public water supplies and covered about one-half of the land area of the United States. A broad suite of physi- cal, chemical, and biological constituents was selected based on relevance to water-quality issues and existing analytical methods including measure- ments of: streamflow, pH, temperature, dissolved oxygen, specific conductance, major ions, nutrients, trace elements, organic carbon, pesticides, and volatile organic compounds (VOCs) (NRC, 2002). Also, descriptions of biological communities were made based on different taxonomic groups and habitat conditions (NRC, 2002). A suite of surface water reference sites, a sampling site selected for relatively undisturbed conditions, was built into the surface water network design. At the end of Cycle 1, monitoring at 51 study units plus a study of the High Plains Aqui- fer in the central United States were completed. (The geographic scope of

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NAWQA: CYCLE 1 AND CYCLE 2 29 the original design was 59 study units, which was adjusted to 51 to account for fiscal restrictions.) The High Plains Aquifer study was a pilot study for a regional approach to a groundwater assessment in the southern High Plains and was added near the end of Cycle 1. In three groups over time, the study units were phased in during Cycle 1: study units 1-20 in 1991, study units 21-36 in 1994, and study units 37-51 in 1997 (Figure 2-1). At the onset, each study unit had a 2-year startup phase with time for planning and analysis of existing data, which was a major effort. At the same time, each study unit was developing li- aison committees with local stakeholders, which became critical to guide how each study unit analysis was carried out and how the results were used to enhance water management. Within each study unit, an integrated group of scientists addressed the three primary objectives by (1) making measurements, (2) evaluating these measurements to understand water quality, and (3) making statements about what is learned and known about a particular study unit. After the 2 year startup, each study unit entered a 3 year intensive data-collection stage. This was followed by a period of data analysis and completion of major reports and then low-level monitoring FIGURE 2-1 Cycle 1 study units (51 plus the High Plains Aquifer) SOURCE: R. J. Gilliom, personal communication, May 17, 2010. Figure 2-1 bitmapped

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30 PREPARING FOR THE THIRD DECADE OF THE NAWQA PROGRAM and assessment activities. Following a short period of retrospective analysis, each study unit would ramp back up and enter the intensive data-collection phase again--10 years after the previous data-collection phase (Figure 2-2). This fixed site design with periodic rotational sampling allowed NAWQA to collect data at regular snapshots in time and document trends. Sampling a total of 505 stream sites and more than 6,000 groundwater wells, each study unit assessment resulted in many individual publications. At the end of 2001, more than 1,000 NAWQA publications were available (NRC, 2002). Also, the study units effectively bridged the environmental system because of a tailored sampling strategy in each study unit (ground- water and/or surface water; the water column and/or bed sediment; pes- ticides and/or nutrients) and a diverse team of scientists working on each assessment. The similar design of each study unit investigation and the use of standard methods made it possible to compare results between different study units, thus enabling multiple scales of investigation or regional and national assessments. These regional and national assessments, referred to as "national syntheses," aggregated water-quality information and also allowed for analysis of important national issues such as, for example, non-point source pollution. FIGURE 2-2The phase in and cycling of NAWQA study units. SOURCE: R. J. Gilliom, personal communication, May 17, 2010. Figure 2-2 Bitmapped

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NAWQA: CYCLE 1 AND CYCLE 2 31 National Synthesis NAWQA phased in national synthesis assessments during Cycle 1, con- ducted by national synthesis teams. These included pesticides and nutrients in 1991, VOCs in 1994, and trace elements and ecology in 1997. Criteria for the selection of these topics considered a combination of understanding stakeholder priorities, capturing appropriate scale (i.e., topics should affect a large area or many small areas), representing persistent and recurring is- sues, importance to the study units that were in place, and complementing other national synthesis topics. NRC (2002) commended NAWQA for its groundbreaking work in these areas during Cycle 1. Environmental Framework NAWQA activities were developed with an "environmental framework" or a broader context through which the data were related to the bigger, envi ronmental picture. This framework, composed of "common natural and human-related factors, such as geology and land use," was used "to com- pare and contrast findings on water quality within and among study units in relation to causative factors and, ultimately, to develop inferences about water quality in areas that have not been sampled" (Gilliom et al., 1995). The environmental framework was reflected in the entire program design from sampling type to the interdisciplinary staffing structure. Application of the environmental framework assisted the program in, for example, choos- ing a drainage basin to study or a set of indicator sites. The environmental framework concept was and is today a touchstone for program efforts. CYCLE 2 The second cycle of water-quality monitoring (Cycle 2) began in 2002 and extends to the end of fiscal year (FY) 2012, slightly past the duration of this committee's review. Per the original design, NAWQA implemented a shift toward trends and understanding as the program moved out of Cycle 1. NAWQA integrated a number of new components as a result of evaluations from the Cycle 2 National Implementation Team (NIT), input from NAWQA personnel who were the primary drivers of the original design, and recommendations from the 2002 NRC report.3 NAWQA inves- tigated select new contaminants and addressed many complexities involved with their environmental occurrence such as seasonal variations, degrada- tion products, and chemical mixtures. These new activities were pursued 3Approximately 80 percent of the 2002 NRC recommendations were implemented by NAWQA, and those that were not were omitted largely because of funding restrictions.

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32 PREPARING FOR THE THIRD DECADE OF THE NAWQA PROGRAM through program components such as Topical Studies and the Source Water Quality Assessment, discussed in the following pages. However, because of limited funding NAWQA was unable to pursue the following recommen- dations from the NRC report (2002): sample lakes and reservoirs that are important sources of water supply; enhance sediment monitoring, enhance interpretation, and make sediment a topic of a national synthesis team; and add pharmaceuticals, high production volume chemicals, and waterborne pathogens and microbial indicator organisms to the list of contaminants monitored in Cycle 2. The program also continued to assess the current water quality of the nation through standardized data collection, in concert with the goal of assessing long-term water-quality trends. Planned activities were grouped into 12 themes:4 1.resources 2.drinking water sources 3.contaminants 4.trends in status 5.response to agricultural management 6.response to urbanization 7.sources of contaminants 8.transport to and within groundwater 9.transport to and within streams 10.groundwater and surface water interactions 11.effects on aquatic biota 12.extrapolation Each theme correlated to NAWQA's goal of status (themes 1-3), trends (themes 4-6), and understanding (themes 7-12). In Cycle 1, NAWQA focused 80 percent of program resources on the status effort, continuing to establish the nation's baseline water-quality condition. This was reduced to 20 percent of available resources in Cycle 2, although NAWQA did enhance the status activities with the Source Water Quality Assessments, an examination of the drinking water in communi- ties across the United States, corresponding to status theme 2 (Delzer and Hamilton, 2007). The program placed an increased emphasis on trends (40 percent of program resources) and understanding (40 percent of program resources) through planned topical studies with a source, fate, and trans- port perspective (Figure 2-3). This shift in design at the onset of Cycle 2 along with several years of flat funding required beginning Cycle 2 with 42 study units, instead of the 4 Items 1 and 3 (resources and contaminants) were not pursued in Cycle 2 because of limited funding.

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NAWQA: CYCLE 1 AND CYCLE 2 33 100 90 Cycle 1 80 Cycle 2 % Program Resources 70 60 50 40 30 20 10 0 Status Trends Understanding FIGURE 2-3Shift from status (Cycle 1) to trends and understanding (Cycle 2). SOURCE: G. Rowe, personal communication, May 13, 2009. Figure 2-3 51 monitored in Cycle 1 (Figure 2-4). NAWQA conducted a detailed analy- sis to determine which study units should be discontinued or consolidated and which were the most representative study units. Discontinued study units include those in Hawaii (the Oahu Study Unit), Alaska (the Cook Inlet Basin Study Unit), and the Lower Susquehanna basin in Pennsylvania (the Lower Susquehanna River Basin Study Unit). For example, the decision was made to discontinue the Hawaii study unit because of low population density relative to water use in comparison with other study units. Low population density or low water use criteria drove the discontinuance of most of the other study units as well. As Cycle 2 progressed, perhaps the most notable design change began in 2004. The program transitioned away from the study unit focus and moved to a larger-scale regional design for status and trends assessment because of limited resources. The regional design retained a core of status and trends monitoring still conducted within the study units, but de- emphasized the role of more detailed study unit investigations and their individual teams and liaison committees. Status and trends data analysis and modeling, as well as program products, were shifted to teams orga- nized by 8 Major River Basins (MRBs) and 19 Principal Aquifers (PAs) (Figures 2-5 and 2-6). The MRB and PA regions are similar in concept to the role of study units as the building blocks of Cycle 1, but on a larger scale that collectively includes the conterminous United States, albeit at lower resolution. Cor-

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NAWQA study units are reduced and consolidated 34 PREPARING FOR THE THIRD DECADE OF THE NAWQA PROGRAM for the second cycle of assessment 1991 to 2001 PUGT CCPT NROK YAKI WILL REDN NECB CONN WMIC YELL UMIS HDSN USNK CHEY DELR GRSL ALMN SACR NPLT EIWA LINJ CNBR UIRB LERI LSUS NVBR LIRB POTO SPLT MIAM UCOL KANS WHIT DLMV SANJ KANA NVBR UARK KNTY ALBE MARK OZRK CACI UTEN LTEN SANT SANA CAZB RIOG MISE SHPL MOBL TRIN ACFB Study Units-- GAFL Assessment schedule ACAD 199195 OAHU SCTX 199498 SOFL 19972001 Not scheduled COOK High Plains Regional Ground Water Study, 1999-2004 Study units in the second cycle In the second cycle of studies, the NAWQA Program will focus on 42 of the Nation's most important 2001 to 2012 river-basin and aquifer systems. The geographic scope of the origi- nal design (59 study units) has PUGT been adjusted to accommodate budget reductions. A systematic CCYK NROK process was used to eliminate 13 WILL REDN NECB CONN study units and combine 8 into WMIC UMIS 4 study units. Geographic areas YELL HDSN USNK were selected to represent a wide CHEY DELR range of important hydrologic GRSL NPLT EIWA ALMN LSUS LINJ SACR CNBR LERI environments and priority eco- NVBR UIRB logical resources; critical contami- UCOL SPLT LIRB WHMI SANJ KANS nant sources, including agricultural, NVBR UARK KNTY KANA PODL urban, and natural sources; and MARK OZRK ALBE a high percentage of population CACI TENN served by municipal water supply SOCA RIOG MISE SANT CAZB and irrigated agriculture. The 59 SHPL MOBL TRIN original study units covered about ACFB 65 percent of water used for drink- GAFL ing and irrigation; the reduced set ACAD of 42 study units still accounts SCTX SOFL for more than 60 percent of those OAHU Study Units-- water uses. This adjusted national Assessment schedule study design supports the goal Scheduled to begin in fiscal year 2001 COOK of extrapolating directly measured Scheduled to begin in fiscal year 2004 water-quality conditions to unmon- Scheduled to begin in fiscal year 2007 itored, comparable areas in other Discontinued parts of the Nation. High Plains Regional Ground Water Study, 19992004 Two study units combined FIGURE 2-4 The planned reduction and consolidation of study units at the onset of Cycle 2. Discontinued study units are shown in yellow. See Gilliom et al. (2001) for study unit designation. SOURCE: Gilliom et al., 2001. responding to the study unit redesign, monitoring for specific conductance and temperature ceased, and pesticide monitoring at reference sites was discontinued. Also, the role of study unit liaison committees was reduced, which in turn reduced the degree of local stakeholder input to NAWQA (see Chapter 5 for further discussion).

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NAWQA: CYCLE 1 AND CYCLE 2 35 FIGURE 2-5 Eight large geographical regions or Major River Basins that were the basis of NAWQA's status and trends assessment in the latter portion of Cycle 2 (2006-2012). SOURCE: Crawford et al., 2006. Figure 205 Bitmapped NAWQA expanded efforts toward modeling in Cycle 2, to allow the program to extrapolate water-quality conditions across the country in ar- eas not sampled by the program. This began in 2002 with an assessment of nutrient conditions in six large regions across the country using the SPAtially Referenced Regressions on Watershed Attributes (SPARROW) model (Smith et al., 2003). Later, mid-Cycle 2, the shift from study units to MRBs and PAs was considered an opportune time to begin developing planned regional-scale water-quality models. For example, a regional-scale SPARROW model was developed for the southeastern United States (Hoos and McMahon, 2009). NAWQA increased efforts to communicate and disseminate its prod- ucts and information. NAWQA moved from dissemination through paper reports in Cycle 1 to a multimedia in Cycle 2. Communication strategies were created for each major report, and more web-based dissemination and decision-support tools were initiated to reach a variety of audiences. Components of the enhanced communication effort included5: 5 NAWQA leadership, personal communication, May 9, 2009.

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42 PREPARING FOR THE THIRD DECADE OF THE NAWQA PROGRAM NAWQA's Source Water Quality Assessments (SWQA) examined drink- ing water quality of community water systems across the United States by comparing compounds in raw ambient water collected at a supply well or surface-water intake prior to treatment (i.e., "source water") to compounds in the finished water supplied to the community (Delzer and Hamilton, 2007). The assessment focused on 280 unregulated organic compounds with a focus on VOCs and pesticides. Carter et al. (2007) provide infor- mation on the design and analytical methods used in the SWQA. While a diverse group of compounds were present in source water, the major- ity of the compounds assessed were present only at low concentrations (<< 1 ppb). Compounds detected in source water were often in finished water, although compounds detected in finished water were below human- health benchmarks if one existed. Mixtures of compounds were commonly detected in both. Capstone products were released in 2008 and 2009 (Hopple et al., 2009; Kingsbury et al., 2008). Understanding Activities The understanding component of NAWQA was carried out in Cycle 2 through five hypothesis-driven topical studies. The conceptual approach of these studies was to understand contaminant source, fate and transport, and impacts on humans and aquatic ecosystems. NAWQA took a mass balance approach to the studies, understanding that a mass balance of water and a mass balance of constituents go hand in hand (i.e., scientists should understand how water is flowing through the system in order to eventually understand the effects of contaminants). NAWQA integrated the use of models into a few of the topical studies. With each topical study, NAWQA adhered to the concept of a national program with a focus on a national understanding of water-quality problems. In each of the five topi- cal studies, NAWQA probed multiple locations, scales, and gradients (i.e., multiple climate, landscape settings, hydrology, crops, land use settings, and atmospheric deposition settings). The topical studies were nested within the study units of Cycle 1, using knowledge gained in Cycle 1: Topical Study 1: Agrochemical Sources, Transport, and Fate10 Topical Study 2: Effects of Nutrient Enrichment in Stream Ecosystems11 Topical Study 3: Mercury Cycling in Stream Ecosystems12 10 See http://pubs.usgs.gov/fs/2004/3098/. 11 See http://wa.water.usgs.gov/neet/. 12 See http://water.usgs.gov/nawqa/mercury/.

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NAWQA: CYCLE 1 AND CYCLE 2 43 Topical Study 4: Effects of Urbanization on Stream Ecosystems13 Topical Study 5: Contaminant Transport and Public Supply Wells14 The topical studies produced a variety of interesting findings, published in methods papers, comprehensive journal article series, and USGS reports. Due, in part, to an underestimation of the amount of work associated with these efforts, some topical studies progressed further than others during Cycle 2. For example, the mercury study (Topical Study 3) documented methylmercury concentrations across the United States and observed that the highest levels of methylmercury in fish are found in the southeastern United States and in mined areas in the western United States (Scudder et al., 2009). (Methylmercury is the most toxic form of mercury in the en- vironment and is readily taken up by aquatic organisms.) NAWQA noted that major urban centers are experiencing a significant increase in mercury deposition. Finally, because of biogeochemical properties of methylmercury, concentrations of the contaminant in streams are driven by wetland density and dissolved organic carbon concentration (Figure 2-9). Monitoring . . . to Monitoring and Modeling . . . to the User In Cycle 2, NAWQA moved from monitoring to monitoring and model- ing water quality of the nation's groundwater, surface water, and ecology at all scales (i.e., using deterministic models at smaller scales and statistical regression at large scales). The NAWQA Cycle 2 modeling approach is to use monitoring data and stream network to probe water quality from the regional and national to the local scales. Modeling efforts amplify the program goals through (1) extrapolation of water-quality conditions to unmonitored areas to facilitate a "national assessment" and (2) forecast- ing of conditions and simulation of the effects of changes in influencing factors (test scenarios). As Cycle 2 draws to a close, the modeling efforts are improving understanding of the factors (sources, transport, etc.) that influence water quality. The goal of one of NAWQA's first exercises in modeling was to predict groundwater vulnerability to nitrate contamination at the national scale. The program showed this vulnerability based on monitoring data, fertilizer data, and soil characteristics, which were integrated into a model called GWAVA (Ground-WAter Vulnerability Assessment). In the southeastern United States NAWQA reported lower concentrations of nitrogen where de- nitrification is promoted compared to the central plains (Nebraska), where the United States has high fertilizer use, gravel and sand, fast transport, and 13 See http://water.usgs.gov/nawqa/urban/. 14 See http://oh.water.usgs.gov/tanc/NAWQATANC.htm.

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44 PREPARING FOR THE THIRD DECADE OF THE NAWQA PROGRAM FIGURE 2-9 Increasing concentrations of mean methylmercury in U.S. streams with increased wetland density and mean dissolved organic carbon. Once deposited in wetlands, mercury is converted to methylmercury. Dissolved organic carbon binds strongly to mercury keeping mercury in the aquatic zone and available for uptake by organisms. SOURCE: USGS, 2009a. lack of denitification (Nolan and Hitt, 2006). EPA uses this information to help prioritize monitoring and better assess its regulatory efforts. During Cycle 2 NAWQA developed empirical models to probe hydro- logic alteration nationwide as well as the connection between hydrologic alteration and the structure of macroinvertebrates and fish assemblages. NAWQA successfully modeled ecologically important flow metrics under a "natural" or "minimally disturbed" flow regime using geospatial data and a reference condition approach. This opened the possibility of quantifica- tion of hydrologic alteration across the United States (Figure 2-10). Using geospatial models and NAWQA data, Carlisle et al. (2011) demonstrated that diminished magnitude of flows was the best predictor of impairment of macroinvertebrate and fish assemblages nationally. NAWQA integrated macroinvertebrate data (collected by NAWQA and the EPA Wadeable Stream Assessment15) to expand the scope of a model assessment of biologi- cal condition in streams in the western United States (Carlisle and Hawkins, 2008). These studies are the foundational material for a USGS Circular summarizing findings on aquatic communities across the United States prepared by the Ecological National Synthesis Project, planned for 2012. 15 See http://water.epa.gov/type/rsl/monitoring/streamsurvey/index.cfm.

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NAWQA: CYCLE 1 AND CYCLE 2 45 FIGURE 2-10Alteration of minimum and maximum streamflow magnitudes at 2,888 sites monitored from 1980 to 2007. "Inflated" condition indicates that ob- served average magnitudes exceeded expected reference magnitudes. "Diminished" condition indicates that observed average magnitudes were less than expected reference magnitudes. SOURCE: Reprinted, with permission, from Carlisle et al., 2011. 2011 by Ecological Society of America.

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46 PREPARING FOR THE THIRD DECADE OF THE NAWQA PROGRAM The SPARROW16 model is NAWQA's most popular and visible regres- sion model.17 The SPARROW model is a watershed based model designed to predict patterns in water quality, concentration, and amount of constitu- ents, across spatial extents ranging from entire regions of the United States to smaller watersheds. The model is perhaps best known for contributing to understanding of key parameters that affect hypoxia in the Gulf of Mexico by determining nutrient load to the Gulf and pinpointing which watersheds or which of the 31 state drainage basins are the greatest contributors. Specifically, the SPARROW effort highlighted that nine states18 making up one-third of the Mississippi River drainage area contribute 75 percent of the nitrogen and phosphorus to the Gulf (Alexander et al., 2008). This study also filled gaps in the understanding on the sources of phosphorus in the Gulf; phosphorus associated with animal manure contributes almost as much phosphorus as cultivated crops (37 versus 43 percent) (Alexander et al., 2008). Currently NAWQA is in the process of developing fine-scale, regional water-quality models in each MRB. Nutrients are the focus of these mod- eling efforts, except in the arid southwest, where dissolved solids are of greater importance. To do this, NAWQA is using local ancillary data and refining the SPARROW model to reflect the unique environmental condi- tions and smaller scale of each MRB. At this time, models have been devel- oped for six of the eight MRBs. Regional models for the remaining basins, California and the Southwest, are planned for the future. The preliminary findings from this effort show the promise of future regional SPARROW modeling of water-quality conditions in the United States. The October 2011 issue of the Journal of American Water Resources Association pro- vides a featured collection of articles on the regional SPARROW effort.19 NAWQA is exploring uncertainty in all the modeling efforts, i.e., as- sociating uncertainty with all the estimates the program produces. For example, Robertson et al. (2009) examined approximately 800 watersheds in the Mississippi River basin and assigned a ranking that indicated whether nutrient yields from the basin were among the highest delivering of nutri- ents contributing to hypoxia in the northern Gulf of Mexico (Figure 2-11, top). This involved a robust statistical procedure applied to the results from a previous application of SPARROW to identify the top 150 watersheds. Once identified, scientists incorporated information on confidence intervals 16 See http://water.usgs.gov/nawqa/sparrow/. 17 Development of SPARROW was initiated by the Branch Systems Analysis working on new and emerging technical issues and techniques used within the former Water Resources Division. The branch was dissolved in the late 1990s because of funding shortfalls, and the individuals developing SPARROW joined NAWQA and continued their work. 18 Illinois, Iowa, Indiana, Missouri, Arkansas, Kentucky, Tennessee, Ohio, and Mississippi. 19 See http://onlinelibrary.wiley.com/doi/10.1111/jawr.2011.47.issue-5/issuetoc.

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NAWQA: CYCLE 1 AND CYCLE 2 47 FIGURE 2-11Map showing Total Nitrogen and Total Phosphorus (as delivered incremental yield) from the top 150 contributing watersheds (top). Map showing the certainty of placement within the top 150 contributing watersheds for Total Nitrogen and Total Phosphorus (bottom). SOURCE: Reprinted, with permission, from Robertson et al. 2009. 2009Figure 2-11 by John Wiley & Sons. Bitmapped of these model predictions estimating the probability that these watersheds are among those that have the highest nutrient yields to the Gulf (Figure 2-11, bottom). This was a SPARROW spin-off project and was EPA driven. This information has important management implications for the Midwest and is being used by EPA to target non-point source pollution in those watersheds. NAWQA is offering the use of monitoring and modeling tools to the user, an effort that will extend into Cycle 3. Although these efforts are still in their infancy, they represent a significant step forward for NAWQA and the user community. For example, the Watershed Regression for Pes- ticides models, referred to as WARP models, predict specific concentration statistics for a given pesticide in the United States. These models establish linkages between pesticides measured at NAWQA surface water sampling sites to variety of factors (pesticide use, soil characteristics, hydrology, and

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48 PREPARING FOR THE THIRD DECADE OF THE NAWQA PROGRAM climate) that affect pesticides in streams. One of the first completed WARP models was for the pesticide atrazine (Larson and Gilliom, 2001), which was improved during Cycle 2 (Larson et al., 2004). Today, the atrazine WARP model and associated data are available for public use on the web.20 The user can visit a website and see estimates of atrazine concentrations in an area or basin along with the error and uncertainty associated with that estimate. NAWQA scientists are planning to bring other pesticide data to the web in a similar fashion. Another example of bringing modeling and monitoring activities to the user, the SPARROW Decision Support System provides online ac- cess to SPARROW models that can be used to predict long-term average water-quality conditions and source contributions by stream reach and catchment and to evaluate management source-reduction scenarios (Booth et al., 2011).21 (For additional information see Box 4-1.) Also, USGS and EPA are working together to provide interested parties with a web service to assist in integrating large water-quality databases.22 Users can go into the USGS website and retrieve data from the National Water Information System, which includes water-quality data from NAWQA, in a common format and go to the state EPA data (STORET) and retrieve data formatted in the same way. CURRENT STATUS Using the FY2011 appropriations for USGS as the metric, NAWQA's budget of $62.9 million was approximately one-third of the appropriation for water-related programs at USGS (the former Water Resources Discipline area). Although the allocation of the budget evolves with programmatic design, in FY2010 the majority of NAWQA's budget was used for program activities (for example, status and trends networks) versus program man- agement or support of broader USGS efforts (Figure 2-12). The appropria- tions in actual or nominal dollars for NAWQA have been flat since the late 1990s or declining when adjusted for inflation (Figure 2-13). This has been consistent with the overall budget and staffing trends of water-related programs at USGS over the past 16 years, which are flat or declining (NRC, 2009). NAWQA is visible to the public via the data and interpretive delivery systems the program strives to make publicly available, and the program has a record of scientific achievement since its inception (NRC, 1990, 2002, 2009, 2010, 2011a; USGS, 2010). NAWQA has produced approximately 20 See http://infotrek.er.usgs.gov/warp/. 21 See http://cida.usgs.gov/sparrow/. 22 See http://qwwebservices.usgs.gov/.

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NAWQA: CYCLE 1 AND CYCLE 2 49 All Status and Trends 35.7% FIGURE 2-12 NAWQA funding by category in FY2009. Total appropriation for FY2010 was approximately $66.5 million. "Science Support" represents funds allocated for Bureau Science support (approximately 5 percent), the National Re- Figure 2-12 search Program (approximately 34 percent), and Water Mission Area Technical Bitmapped support (approximately 61 percent). The last supports the Office of Water Qual- ity, the National Water Quality Laboratory including the Methods Research and Development Program, which develops new analytical methods, and the Branch of Quality Systems. "Technical Support" represents funds allocated to support the Hydrologic Systems Team, which provides modeling support to all components and includes the national SPARROW team and Data Synthesis Team, which provides data management support for NAWQA including the Data Warehouse and BioData database. "Management and Communication" represents funds allocated to sup- port the NAWQA National Leadership Team and its support staff and NAWQA Communications staff. SOURCE: NAWQA National Leadership Team, personal communication, May 13, 2009. 1,900 reports during its 20-year history, a publication every 4.2 days on average, a value which, while not an indicator of quality, provides a sense of the quantity of work produced over the history of the program. (M. Larsen, personal communication, May 13, 2009). If released products are the metric (those already released and to be released), NAWQA has mined approximately one-third of the Cycle 1 data (NAWQA leadership, personal

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50 PREPARING FOR THE THIRD DECADE OF THE NAWQA PROGRAM FIGURE 2-13 NAWQA appropriations history in nominal or non-inflation adjusted U.S. dollars (USD) and constant 1986 USD. Inflation was calculated using the Con- sumer Price Index inflation factor, and base year is an average across 1982-1984 and indexed at 100. SOURCE: FY appropriationsFigure 2-13 from NAWQA leadership, personal communication, August 2011. Bitmapped Quality of info 56 40 4 Clarity 48 46 5 Level of technical 49 45 5 detail Usefulness 37 51 13 Overall quality 47 49 4 0% 25% 50% 75% 100% Percentages Very satisfied Satisfied Dissatisfied FIGURE 2-14 A Customer Satisfaction Survey, conducted in 2010, indicates user satisfaction with NAWQA information. SOURCE: USGS, personal communication. Figure 2-14

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NAWQA: CYCLE 1 AND CYCLE 2 51 communication, May 9, 2009), a value that, although not an indicator of quality, provides a sense of the quantity of work produced over the history of the program. A Customer Satisfaction Survey, conducted in 2010,23 indi- cates that the majority of NAWQA users are either satisfied or very satisfied with NAWQA information (Figure 2-14). The Statement of Task charges the committee to conduct an assess- ment of NAWQA's accomplishments. In response, the committee notes 10 representative accomplishments of NAWQA in Chapter 3 to answer the Statement of Task. 23 The 2010 NAWQA Customer Satisfaction Survey, referenced several times in this report, was conducted by the USGS Office of Budget, Planning, and Integration. It was conducted in July and August of 2010 and consisted of a random sample of 500 persons from the NAWQA stakeholder database. The response rate to the survey was 37 percent.

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