A Review of the USGS National Water Quality Assessment Pilot Program (1990) / Chapter Skim
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2 NAWQA Design Evaluation
2 NAWQA Design Evaluation
Pages 26-72
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From page 26... ...
This chapter contains an evaluation of the design of the NAWQA program components, including integration of the surface water and ground water study units, how study units were selected, the general exclusion of lakes and estuaries from the study plan, the sampling design program, data collection methods, the choice of chemical and biological constituents, quality assurance/quality control aspects, data management, the analytical framework of the program, and products of the NAWQA program. Integration of Ground Water and Surface Water Description The original concept specified 123 separate surface water and ground water study units: 69 surface water and 54 ground water.
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From page 27... ...
Ground water and surface water interaction is also important in some portions of the Central Oklahoma aquifer study unit; this was known prior to the inception of the pilot project. However, the spatial distribution of this interaction was different from that which was previously believed.
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From page 28... ...
Therefore, in recognition of the important water quality implications of surface water and ground water interactions and the committee's concern that the original NAWQA concept downplayed these implications, the USGS decided in March 1989 to redefine the study units. Instead of the original 123 separate study units, 60 integrated surface water/ground water study units now exist; selection of these new units will be discussed in another section.
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From page 29... ...
. r 29 FIGURE 2.1 Proposed NAWQA study units in the United States.
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From page 30... ...
White River Basin 15. Upper Illinois River Basin 16.
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From page 31... ...
Lakes also interact with other freshwater components of the hydrologic cycle, in that they act as both sources and sinks of various water quality constituents. Thus they can significantly affect downstream surface water or downgradient ground water quality.
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From page 32... ...
However, given the present lack of personnel in the USGS with expertise in the biological and chemical modeling of lakes and estuaries, we believe that the NAWQA program should not be expanded at this juncture to include estuaries. However, we recommend that initially lakes should be considered but only as they affect downstream surface water quality or downgradient ground water quality.
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From page 33... ...
The accounting units are used by the USGS in designing and managing the National Water Data Network. A set of 200 surface water candidate study units (CSUs)
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From page 34... ...
each state contains at least one study unit having at least 30 percent of its area within that state. This exercise yielded two maps: one of surface water study units and one of ground water study units.
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From page 35... ...
Given the large size of approximately eight study units, the combined ground water-surface water nature of these study units, and the USGS's lack of experience in a large study unit, the committee is concerned that NAWQA objectives may not be met in some of the larger units. Summary Study unit selection is generally good; the coverage is broad and represents a variety of hydrologic regions.
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From page 36... ...
These local-scale studies should be useful for examining the interrelationship between surface water and ground water quality. Transects provide very good information about a study unit's physical hydrogeology.
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From page 37... ...
The three ground water pilot project study units are small, 3,000 to 6,050 square miles. Under the revised plan, study units not only will combine both ground water and surface water but also will be 10 to 20 times larger, as large as 60,000 square miles.
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From page 38... ...
The number and timing of synoptic surveys will vary among study units based on the questions being addressed. Studies of selected reaches will be conducted to understand the sources, distribution, and fate of particular water quality constituents in greater detail than is available from either the fixed or synoptic sampling.
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From page 39... ...
Combined Surface- and Ground-Water Study Units The sampling programs described in the previous sections were developed for separate surface water and ground water study units. The study units are now combined, and the USGS needs to reexamine the sampling programs in light of this new organization.
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From page 40... ...
The sampling approach generally seems adequate, although the committee is concerned about the adequacy of regional ground water sampling in the larger study units. The long-term sampling program is a valuable and unique component of NAWQA.
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From page 41... ...
the distribution and location of sampling sites for surface water and ground water; 2. quantification of the interaction between surface water and ground water; and 3.
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From page 42... ...
42 on o a 11 ~ .s' ' tori 7 He Is I Ili ~ i!
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From page 43... ...
The 60 study units will be divided into three groups of 20 selected to provide broad geographic coverage and a range of hydrologic conditions. The program will be staged so that only one group of 20 study units is in the intensive data collection and analysis phase at any given time.
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From page 44... ...
Table 2.3 summaries the general classes of compounds that will be measured in each of the various environmental compartments, i.e., ground water, surface water, bed material, tissues, and suspended sediment. The individual constituents to be measured in the surface and ground water samples are listed in Tables 2.4 to 2.6.
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From page 45... ...
X X Chlorophenoxy herbicides X X R ad i o n u c l i d es X X ~Only detennined in those study units where reconna~ance sa~npling finds occurrence.
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From page 47... ...
NAUSEA Design Evaluation TABLE 2.4 -- continued Compound SEDIMENT SUSPENDED SEDIMENT (ug/L) PERCENT FINER THAN 0.062 mm ORGANIC CARBON WATSTORE Reporting code level 8~0154 70831 CARBON, ORG., DIS.
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From page 49... ...
NAWQA Design Evaluation TABLE 2.5 -- continued 49 Compound GROSS BETA pCi/L as Cs-137 GROSS alpha MAD, BUS.
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From page 50... ...
or schedule number (SH) Properties and major constituents pH Specific conductance Alkalinity Calcium Magnesium Potassium Sodium Chloride Fluoride Sulfate Silica Nutrients Ammonia Nitrite Nitrite and nitrate Kjeldahl nitrogen (ammonia plus organic nitrogen)
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From page 51... ...
or schedule number (SH) Radionuclides Grow alpha Grow beta Radon-~22 Tritium Discolored organic carbon Volatile organic compounds Carbamate insecticides Chlorophenox r-acid herbicides Nitrogen-contaunng pesticides (largely tnasine herbicides)
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From page 52... ...
Depth of well Water level Depth to top and bottom of each open integral Depth to top and bottom of each geohydrologic unit Rated pump capacity Type of lift Date of well construction Method of construction Type of finish Type of surface seal Casing material Sampling method Primary reason for well selection (with or without regard to known or suspected local problem areas) Occurrence of various land uses and local features such as gas stations and septic tanks within a 100 ft and 1/4 mi radius of the sampling well Predominant land use within 100 ft radius of the sampling well Predominant land use within 1/4 mi radius of the sampling well Percent of total area within a 1/4 mi radius of the well that consists of predominant land use Known occurrences of major changes in land use near the well within the last decade Local agricultural practices Source: Hirsch et al., 1988.
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From page 53... ...
, and attention was given to complementing the other programs rather than duplicating their analyses. In general, the suites of synthetic organic compounds to be measured in surface water will be different than those for ground water.
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From page 54... ...
This flexibility will also enable the NAWQA program to detect emerging water quality issues rather than focus on the classical or current water quality constituents. In order to evaluate those emerging water quality problems, the USGS should consider a library archive of spectroscopic data, such as ultraviolet (UV)
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From page 55... ...
cold within surface waters of the study unit and to relate them to patterns of land use and waste management practices. The techniques for doing this have been described in a' protocol (Appendix B
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From page 56... ...
=33) proposes a core set of a few measurements using similar approaches in all study units at sites similarly selected.
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From page 57... ...
Monthly sampling at selected fixed stations in addition to that done during synoptic surveys is recommended. To date NAWQA has collected data concerning fecal contamination in only one study unit during one synoptic survey (Appendix B
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From page 58... ...
Equally important is devising protocols to guide study units in selecting how many and which samples are to be archived. Archiving samples is costly; hence researchers at sampling sites must be judicious in their choices of samples to archive.
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From page 59... ...
The extent to which modeling and understanding will be limited will depend on local conditions and could be anticipated by the early application of models in the study unit. Summary Fecal contamination will be assessed using the E
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From page 60... ...
cold and fecal coliform tests at a limited number of fixed-station sites in study units where fecal contamination is a potential problem. The procedures for analysis of contaminants in tissues appear adequate to provide an assessment of tissue contamination that fills a void in existing tissue monitoring programs.
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From page 61... ...
Each team prepared a report summarizing their findings from the review. The reviews were thorough and followed the quality assurance checklist for surface-water projects or the checklist for ground water projects.
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From page 62... ...
The QA program assures that technically sound procedures will be used in the NAWQA program. The reviews demonstrated that the proposed QA/QC program is working in the study units.
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From page 63... ...
The committee would like to see more coordination of the NAWQA program with other agencies, especially in such areas as uniformity of water quality parameters monitored and more consistent sampling and analytical techniques. The NAWQA program has the advantage over EPA's 305(b)
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From page 64... ...
. In addition to the sanitary water quality data, the ecological survey is documenting the current status of the biological community (fish and invertebrate distribution data and tissue sampling for bioaccumulation)
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From page 65... ...
The integration of surface water and ground water studies provides sorely needed opportunities to understand the important interactions between surface and ground waters. The USGS is ideally suited to conduct a process-oriented assessment of our nation's waters.
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From page 66... ...
Critique An important feature that appears to be lacking from the overall NAWQA program, particularly the regional pilot studies, is the quantitative and analytical framework that identifies the principal cause and effect relationships. While this issue has been qualitatively addressed in NAWQA documents and in comments by USGS personnel, its quantitative definition, which is essential for decisionmaking, appears to be inadequate at this stage.
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From page 67... ...
Of particular importance is the large-scale flow modeling that was undertaken by the USGS in the RASA program. These models should provide a framework for ground water modeling in many of the NAWQA study units (and in fact, have been used this way to some extent in the pilot studies)
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From page 68... ...
A midcourse mode' evaluation should be built into the assessment cycle so that corrections can be made in sufficient time. Over the long term, the USGS should be developing a coherent strategy for water quality modeling in the context of a large spatial scale assessment, addressing such issues as scale, model complexity, and surface and ground water interactions.
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From page 69... ...
The retrospective reports available for review focus on compiling available existing data from federal, state, and local agencies, evaluating the suitability of these data for NAWQA study unit activities, and presenting a preliminary spatial analysis of water quality conditions in the study unit via mapping, summary statistics, and descriptive text. They also contain background material of the study unit, its natural and cultural features, and its hydrologic systems.
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From page 70... ...
the retrospective reports make no attempt to identify and assess available studies of water quality processes in the study units or available water quality models that have been developed for all portions of the study units. If the goal of NAWQA is indeed to improve our understanding of water quality processes on the studyunit, regional, and national scales, it is imperative that information on sources and previous investigations of processes be included within the concept of a retrospective report.
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From page 71... ...
Committee-Initiated Case Study Description In order to obtain a sharper focus on how a cause and effect analysis would be conducted under the NAWQA program, the committee recommended that the USGS conduct a special study of the effect of changes in wastewater treatment on trends in the downstream water quality of the Illinois River. Wastewater treatment was selected as the problem area owing to the large federal investment in these facilities The Illinois River Basin was selected as the study area because ~t Is relatively simple from a hydrologic point of view and an extensive long-term data base already exists.
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From page 72... ...
Summary The USGS should immediately intensify its cause and effect assessment activities and provide complete case studies and a coherent national methodology for doing cause and effect assessments. This initial effort should utilize all available data and not be restricted to data generated by the NAWQA monitoring program.
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