ECONOMICS OF GROUND-WATER QUALITY MONITORING: A SURVEY OF EXPERTS R. R A J A G O P A L
Department of Geography and Civil and Environmental Engineering at the University of lowa and G R A H A M TOBIN
Department of Geography at the University of Minnesota-Duluth
(Received March 1991) Abstract. The cost of a monitoring program can be easily ascertained in terms of the expenditures incurred for such items as personnel, supplies, field visits, instrumentation and laboratory analyses. The benefits of a monitoring program, however, cannot be easily evaluated due to the diversity of objectives for which monitoring programs are initiated and operated. The case study and the results of the follow-up exploratory survey reported in this paper were intended to capture the objective as well as the subjective reasons employed by a group of experts in responding to selected socio-economic questions related to the design of monitoring programs. Ninety-seven individuals, through a formal questionnaire, participated in the survey. They showed definite preferences, although there was some variability in responses due to such factors as residential status, institutional affiliation, education, and the length of professional experience. It was clear that the respondents favored the inclusion of cost-effectiveness criteria in monitoring programs; were ambivalent to the idea of initiating a regulatory program to monitor the wells of a large number of private owners; and if such a program were to be initiated they recommended that individual well owners share the bulk of the financial burden. Preliminary results from such exploratory surveys can lead to the framing of insightful research questions or hypotheses for further evaluation. Confirmatory testing of such questions or hypotheses in real world settings is a valuable area for further research.
Introduction Space, time, and parameter specifications of existing groundwater quality monitoring programs are based on regulatory mandates and guesswork rather than on explicitly stated objectives, statistical measures of precision and cost-effectiveness criteria. The total cost of a monitoring program can be easily ascertained in terms of the component costs of labor, supplies, and equipment. The benefits of monitoring, however, cannot be so easily quantified in terms of dollars and cents. But there are some tangible measures of information that result from a monitoring program which may be of use in the analysis of regulatory and policy decisions pertaining to the protection of public health and the environment. For many such issues, there are no ready-made or instantaneous analyses. The issues are complex and perspectives vary. Rather than going deeper and raising pertinent questions related to the issues, decision-makers often find it convenient to abide by existing monitoring schedules and thus maintain the status quo. Quite often, state-level organizations leave it to the federal government to propose the inclusion of additional parameters, suggest new standards and laboratory methods for measuring them, and prescribe changes in existing monitoring schedules. Environmental Monitoring and Assessment 22: 39-56, 1992. 9 1992 Kluwer Academic Publishers. Printed in the Netherlands.
40
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R. RAJAGOPAL
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Glossary of Selected Terms Finished Water: Water that is piped for human consumption. In many cases such water is also subjected to one or more of several treatment processes. Iowa DNR: The Iowa Department of Natural Resources. Iowa GSB: The Iowa Geological Survey Bureau of the Iowa DNR. MCL: The Maximum Contaminant Level is the maximum permissible level of a contaminant in water which is delivered to any user of a public water supply. There are two types of MCLs, primary and secondary. Primary MCLs are based on potential adverse health effects on humans and are usually enforced. Secondary MCLs are based on levels required to protect public welfare (odor, appearance, etc.) and are usually not enforced. mg I-~: milligrams per liter equals parts per million (ppm). MSIS: The Model State Information System of the Office of Drinking Water of the U.S. EPA, created for the purpose of effectively meeting the provisions of the SDWA (1974). It provides state regulatory officials with data on maximum contaminant level violations, sampling requirements, violations requiring notification, optional sample scheduling, and non-compliance reports. pCi I-k picocuries per liter is a unit of radioactivity measurement. Primary MCL for the combined measurement of 226Ra and 228Ra is 5 pCi 1-~. PWS Systems: Systems that provide piped water for human consumption and have at least 15 service connections or regularly serve an average of at least 25 individuals daily at least 60 days of the year are called Public Water Supply (PWS) Systems. All other systems are referred to as non-PWS Systems. PWS systems used by year-round residents are called community PWS systems and all other PWS systems are called non-community PWS systems. Raw Water: Water that has not been subjected to any man-made alterations by treatment processes. SDWA Act: The Safe Drinking Water Act (1974). In 1974 the Act required the establishment of primary MCLs for 22 contaminants. The 1986 Amendments to this Act requires the establishment of maximum contaminant level goals (MCLGs) for 83 contaminants. USGS: The U.S. Geological Survey of the U.S. Department of the Interior. WATSTORE: The WATer Data STOrage and REtrieval System of the USGS. Data entered into this system have come from a variety of sources, projects, and programs over the last 50 yr. Much of this data has been verified and controlled for physical, chemical, and locational consistency by the USGS. This is the only source of computercoded files containing any significant amount of data on inorganics, trace metals, and radiochemical measurements in untreated Iowa ground water. Issue of Resource Allocation in Monitoring Because of its great quantity, reliability, and consistent biological and chemical quality in
E C O N O M I C S OF G R O U N D - W A T E R Q U A L I T Y M O N I T O R I N G
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any given place, ground water use has steadily increased in the past few decades. As shown in Table I, there are 750 ground water-based community PWS systems and over 230 000 individual wells that supply drinking water to over 2.1 million Iowans, compared to the 74 surface water sources that supply water to over 475 000 Iowans. Each month Iowa DNR, based on monitoring data, prepares a list of PWS systems that have exceeded the MCL for any primary drinking water contaminants listed under the SDWA (1974). Table II is based on 44 such monthly listings. Nitrate, fluoride, and combined radium (226 + 228) constitute an overwhelming majority of incidences that exceed the primary MCL in Iowa (Table II). Limited resources will not permit sampling for many contaminants at the same frequency at all well sites. Given the differences in number and source of supplies, population served by such supplies, and the occurrence and distribution of contaminants in such supplies (as shown in Tables I and II), how should the state go about developing a cost-effective ground water quality monitoring strategy? This is a major resource allocation question or issue of utmost concern in the field of monitoring throughout the United States. The case study reported in this paper and the follow-up exploratory survey were intended to capture the reactions of a group of experts to selected economic questions related to the allocation of resources in monitoring programs. The survey was carried out in the context of groundwater quality monitoring programs in Iowa, but the questions raised are sufficiently generic to be applicable elsewhere. The analysis of participant responses to economic, perceptual, participatory, and policy questions within a structured context form the backbone of this research. As far as we know, no such highly focused analysis of economic issues in ground-water quality TABLE I Iowa population served by source and type of water supply Source and type of water supply
Population
A. Ground water source 750 community PWS systems 236 709 individual wellsa Total
1 394 257 755 102b 2 149 359
47.8 25.9 73.7
475 040
16.3
109 341 2 733 740
3.8 93.8
180 068
6.2
B. Surface water source 74 community PWS systems C. Mixed and other sources 26 comminity PWS systems Total of A, B, and C D. Unaccounted sources 1980 Census Population of Iowa
2 913 808 ~
% Served
100.0
" From the 1980 Census of Population and Housing, Bureau of the Census (1983). h Estimated by multiplying the number of wells by average family size in Iowa, Bureau of the Census (1983).
42
R. R A J A t 3 O P A L A N D G R A H A M TOBIN
TABLE II Descriptive statistical measures of the number of PWS systems exceeding primary drinking water MCLs in
Iowa based on 44 of 106 months betweenMarch 1978and December1986for which the data was available
Contaminant
MCL
Arsenic Barium Fluoride a Nitrate as N
0.05 1.0 1.4-2.4 10.0
Selenium Ra2-~'+Ra22~ Gross alpha
0.01 5.0 15.0
Total ~ of
Total ~ of
(Units)
PWS systems exceeding MCL
incidences exceeding MCL
mg mg mg mg
2 2 69 134
53 33 1888 2012
8 77 17
108 1552 65
I-I 1-I 1-1 1-I
mg 1-I pCi 1-I pCi 1-~
"The fluoride standard varies according to the annual average maximum daily air temperature for the location of the PWS system. In Iowa, it varies between 2.0 and 2.2 mg l-k
monitoring based on expert opinions is available at this time. With careful interpretation, general conclusions for further research can be drawn from survey responses elicited from such a targeted group of experts (Cortner et al., 1984). The paper is organized as follows: first a summary of the survey method, a profile of survey participants (experts), and the limitations of the approach are presented, followed by the text of the case study (with minor editorial revisions) as reviewed by the experts. Analyses and interpretations of the findings of the survey follow with a final section summarizing the conclusions and recommendations of the study. Tabulations of participant responses to the survey questions and the results of exploratory data analyses and various tests of hypotheses are also included.
The Survey and the Participants THE APPROACH TO obtain thoughtful responses from a targeted group of experts to the case study, a mail questionnaire, based on closed- and open-ended questions was prepared. Included were questions related to the tradeoffs between economic and health issues, the protection of public versus private water supplies, and the determination of monitoring priorities in terms of space, time, and compounds. Many were interdisciplinary questions and were posed in a world of incomplete and uncertain information. For this research we surveyed a sample of persons who are or have been actively involved in ground-water protection issues, either by professional practice, occupation, teaching, research, consulting, or community service. In addition, we wanted a majority of our respondents to have lived in the Midwest, in particular Iowa, and hence have experienced issues relevant to this area. We identified and then contacted 150 individuals who we thought would make excellent survey participants. One hundred and twenty experts agreed to respond to the survey.
ECONOMICS
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Each participant was required to read six single-spaced pages of narrative and numerical information related to economic issues in ground-water quality monitoring and then thoughtfully respond to the questionnaire. In the final tally, we obtained 97 completed forms, resulting in an 81% response rate. SURVEY PARTICIPANTPROFILE We postulated that the experts' responses would vary as a function of certain experiential, institutional, educational, and residency characteristics. Therefore, data (as shown in Table III) on such characteristics were elicited from questions directed at: length of groundwater-related experience; institutional affiliation (government, private, or education); level of formal education and subjects studied; and residential status in Iowa. These data were then used to test and explore selected research hypotheses. As shown in Table III, many participants had formally studied subjects related to the field of ground water. They were predominantly people in decision-making, research, teaching, engineering, and farming practice, with a small number from public interest groups, sales and marketing organizations, and enforcement agencies. Over 75% are from government and academic institutions. LIMITATIONS As stated earlier, the survey participants are a select group (purposive sample) of ground water experts and not a random sample from the universe of available experts. In addition, a majority have lived in the Midwest, in particular Iowa, and in some way influence the processes governing ground water protection in the state. Obviously, the results obtained from such a directed survey have serious limitations, and generalization is difficult. On the other hand, findings from such an exploratory survey could provide insights for new hypotheses for further testing. Hence, it is essential that results on preferences reported in this paper be validated with data from real communities that regularly benefit from the use of monitored data.
CASE STUDY
Economics of Ground-Water Quality Monitoring Introduction Just like any other societal endeavor, water quality monitoring programs can be subjected to analyses and discussions in an economic (cost-benefit and cost-effectiveness) framework. Limited resources will not permit monitoring for many contaminants with the same frequency at every site. Choice of contaminants, site selection, and frequency of sampling should be prioritized. The cost of ground-water quality monitoring in the U.S. is staggering. Consider the sums spent to monitor roughly the 50 000 ground-water-based community water supplies
44
R. RAJAGOPAL AND GRAHAM TOBIN TABLE III
Survey Participant Profile - A total of ninety-seven individuals participated in the survey. All response frequencies are expressed in percentages What is the highest level of education you have obtained? High School 9 Bachelor's 24 Master's 28 Doctorate 27 Other (D.Ed.) I2 2. What are the formal subjects you have studied? (Check up to three in which you believe you have a strong background.) Hydrology/Water Res. 29 Geology 25 Environmental Sciences 23 Planning/Policy 20 Engineering (Env./Chem.) 19 Business Management 15 Chemistry 14 Agronomy 13 Economics 13 Public Health 11 Geography 10 Law 9 Statistics/Biometry 3 Toxicology/Epidemiology 2 Soil Science 2 Computer Science 2 Physics 2 Others 13 3. What is the field of your current professional practice or occupation? (Check up to two) Administration/Management 28 Research 23 Teaching 21 Engineering 14 Policy Analysis 12 Elected Official (Representators/Senators) 11 Farming 11 Enforcement 5 Public Interest Group 5 Sales/Marketing 4 Legal Practice 4 Well Drilling 2 Medical Practice 0 Other 13
4. What is your current institutional affiliation? (Check one.) Government State Federal Local Other
28 16 5 2
Private Sector Farming Well Drilling Dealers/Distributors Chemical Industry Other
6 2 1 1 9
Other University/College Extension Service Public Interest Group
25 5
How many years of professional experience do you have? 0- 2 years 0 2- 5 years 2 5-10 years 15 10-15 years 26 16 or more years 56 How many years of your professional experience have been related to groundwater'?. 0- 2 years 12 2- 5 years 26 5-10 years 22 10-15 years 10 16 or more years 29 Are you or have you been a resident of lowa? Yes 63 No 36 Are you or have you been a resident of one or more of the following midwestern states: Iowa, Illinois, Indiana, Michigan, Ohio, Wisconsin, Minnesota, Nebraska, Missouri, and Kansas? Yes 94 No 5
ECONOMICS
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QUALITY
MONITORING
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in the U.S. For illustration, let us assume that we sample once every three years for the 22 primary drinking water constituents at a cost of $300 a sample. The national cost of such a program will be $ 5 million a year (50 000 • $ 300 for every three years). If we revise this list of 22 constituents with the 83 proposed under the SDWA (1986) amendments at a cost of $1 300 a sample, the national cost will be over $ 21 million a year (50 000 • $1300 for every three years). Many water supplies have more than one well, all of which could be sampled; some of the samples could be replicated for improved quality assurance; sampling frequency could be increased to once or twice a year; and the list of contaminants could be increased to include a range of other compounds not considered earlier. Obviously, all such efforts will cost more money. If we add to these costs the additional burden of ground-water quality monitoring at hazardous waste sites (under RCRA and CERCLA) and other ground-water data collection programs of the U.S. and State Geological Surveys and state health and environmental agencies, the total national cost will be in the range of several hundred million dollars per year. When investing such large sums of money, it is useful to employ an objective resource allocation strategy to maximize the return on monitoring dollars. The strategy should attempt to allocate resources efficiently among the various monitoring components.
Environmental Settings LAND USE AND GEOLOGY One would expect the scope of monitoring activities for a surficial aquifer near a hazardous waste site to be distinctly different from that for a more distant bedrock aquifer. A map of a region or of a state with a clear delineation of past, present, and potential future pollutant generating sites will be of significant value in the spatial allocation of monitoring resources. In addition, information on the composition of wastes stored at different sites will also be of value in the determination of what parameters to monitor. Local land uses should be taken into account in the determination of what parameters to measure in a monitoring program. In intensely cultivated states like Iowa, Illinois, Nebraska, and California, the use of fertilizers and pesticides has played a significant role in increased crop yield. The same farm chemicals are also increasingly found in varying concentrations in shallow aquifers (Hallberg and Hoyer, 1982; Hallberg et al., 1983). Similarly, knowledge of regional or local ambient groundwater quality and the location of underground product or waste storage tanks will be of much value in the design of monitoring programs. The aquifers in a state or a region may not be uniformly distributed and historical sample collection efforts may not exactly correspond with the ground-water availability in aquifers. In some parts of the state, water of potable quality is abundant in shallow units of Quaternary age, while in other areas it is necessary to drill deeper to aquifers of the Cambro-Ordovician age. As might be expected, drillers seek the shallowest source that produces water in adequate quantity and quality. Deeper and otherwise equally suitable sources of ground water are, therefore, underrepresented in the historical samples for
46
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some parts of Iowa. The aquifers from the Quaternary and the Cambro-Ordovician sources provide some of the most highly used and dependable water within Iowa. They also provide good comparative data in terms of man-made sources of impact (nitrate) versus natural sources of impact (fluorides and sulfates) on ground-water resources in Iowa. The mean and standard deviation of nitrate concentration in the shallow Quaternary are respectively over five and three times those found in the deeper Cambro-Ordovician strata (9.8 v s 1.8 mg 1-~for means and 16.5 v s 4.8 mg 1-1for standard deviations), due to the significant influence of nitrogenous fertilizers applied to Iowa farmlands (Rajagopal, 1986a). Mean concentration of fluoride, chloride, and gross alpha measurements in the Quaternary are three to four times smaller than those found in the Cambro-Ordovician aquifers, indicating the influence of natural sources on the quality of water in the deeper rocks (Rajagopal, 1986a). Such differences in water quality characteristics between aquifers illustrate the point that not all aquifers need to be sampled with the same frequency to obtain similar levels of precision in the estimates. HEALTH EFFECTSAND POPULATIONEXPOSURE Currently only 22 contaminants are routinely monitored in public water supplies and have had drinking water standards or MCLs determined for them (U.S. EPA, 1975). The selection of these contaminants has been based on the knowledge of their potential to affect human health adversely. In addition, factors such as the frequency of a contaminant's occurrence in drinking water, the size of exposed populations, the source of the water supply, and the cost of sampling and analysis have also played a role in the determination of the scope and extent of drinking water monitoring programs. A large number of other contaminants are either not being monitored, and/or their health and ecological effects are not known. Clearly, a process is necessary for assessing and ranking a much larger set of contaminants than are currently being monitored in the drinking water environment. Population exposure is one of the most important factors in determining the level of monitoring activities, especially when contamination of drinking water is likely. The monitoring requirements based on population size for public water supplies in Iowa are shown in Tables IV and V. The Iowa Administrative Code (1983, Chapter 41) states that, 'the supplier of water for a community water system and for a non-community water system serving a school shall take coliform density samples at regular time intervals, and in number proportionate to the population served by the system' (as shown in Table IV). Many large urban areas have a significant number of manufacturing operations and waste disposal sites which can make nearby aquifers more vulnerable to contamination. Smaller (often rural) supplies are monitored less frequently than larger (urban) supplies. Occasionally, however, in some site-specific instances, rural supplies may require more extensive monitoring to assess the impact of nitrates and pesticides or naturally occurring contaminants such as fluoride and 226Ra.
ECONOMICS OF GROUND-WATER QUALITY MONITORING
47
TABLE IV Frequency of minimum number of coliform density samples to be taken per month as a function of population served by the system Population served 25 1001 2501 3 301
to to to to
1000 2500 3300 4 100
50001 to
Minimum ~ of samples month 1 2 3 4
54000
60
96001 to l l l 0 0 0
100
450000 to 500000
210
Selected issues in Monitoring PROGRAM INTEGRATION
In the case of PWS sources monitored by Iowa DNR, the Safe Drinking Water Act specifies the parameters as well as the sampling frequency, while the raw water sources sampled by the USGS and the Iowa GSB are analyzed for a variety of parameters to satisfy a number of different goals and objectives. The WATSTORE data files containing raw ground-water quality data and the MSIS data files containing finished ground-water quality data are the only two large, computer-coded data files on Iowa ground-water quality. These two data bases, by themselves, provide significant insights pertaining the distribution of chemicals in different hydrogeological environments and the compliance status of PWS sources (with reference to primary MCLs) in Iowa. Every sample in the raw water-quality (WATSTORE) data base is clearly linked to a locational code (latitude/longitude), which in turn can be linked to an aquifer source of the water's origin. Not all samples in the finished water (MSIS) data base are linked to specific wells, since many PWS sources depend on multiple wells and blend (and/or treat) their water to meet the prescribed water quality standards of the Safe Drinking Water Act. In order to clearly characterize the quality of drinking water as a function of aquifer sources, blending or mixing ratios, and treatment practice, it would be beneficial to collect and analyze a raw water sample from each well at the same time when a finished water sample from the distribution system is collected and analyzed. Such a process would provide raw and finished water quality data, linked to aquifer sources, which are collected at the same place and at the same time. Since both the raw and finished water quality monitoring programs are operated by the newly created DNR, it is now equipped to initiate and manage such program integration activities. SELECTIVE ANALYSES
Ground-water quality in aquifers is often characterized by a study of samples obtained from wells that draw water from the aquifers. Due to physical and financial limitations,
48
R. R A J A G O P A L
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TABLE V Finished water monitoring requirementsfor public water supplies in Iowa Type of water system
Surface water sources samping frequency
Ground water sources sampling frequency
Coliforms (A)
Community Noncommunity
Monthly Quarterly minimum
Monthly Quarterlyminimum
Turbidity (B)
Community Noncommunity
Daily Dailya
Not required Not required
lnorganics (C)
Community Noncummunity
1 yr 3 yr
3 yr 3 yr
Organics (D)
Community
3 yr
Not required
Radionuclides
Community
4 yr
4 yr
Trihalomethanes(E)
Community
Quarterly
Quarterly
Corrosivity (F)
Community
One time only
One time only
Contaminant
Remarks."
(A) Number of samples collected by community systems are based on population served. See Chapter 41 I.A.C. for monitoring schedules. (B) Analysisby nephelometricmethod. aMonitoring frequenciesfor noncummunitysupplies may be reduced by the state. (C) Primary Inorganic Contaminants: Arsenic Cadmium Fluoride M e r c u r y S e l e n i u m Sodiumc Barium C h r o m i u m Lead Nitrateb Silver bNoncommunitywater systems are required to monitor only for nitrate contaminant levels. An MCL for sodium has not been established. (D) Chlorinated Hydrocarbons: Endrin Lindane M e t h o x y c h l o r Toxaphene Chlorophyenoxys 2.4-D 2,4,5-TP (Silvex) (E) Total Trihalomethane (TTHM) monitoring requirement became effectiveJuly 30, 1980. The rules affect only communityPWSsserving10.000or more people. Reductionsin monitoringare possibleafter TTHM levels have been determined. (F) An MCL for corrosivityhas not been established. Source: Iowa Department of Water, Air, and Waste Management, 1983.
any quality characterization of aquifers will have to be necessarily based on the results of sampling. Similarly, any quality characterization of drinking water will have to be based on sampling the water in the distribution system of PWS sources. Due to the variability in cost of analysis a n d the limitation o n available m o n i t o r i n g resources, it will not be feasible to measure all c o n t a m i n a n t s or c o n t a m i n a n t groups to the same degree of frequency in each a n d every sample or site. F o r example, Mills et al. (1980) state that:
usingan estimate of $ 40 for each analysis,the national cost of a separate Radium-228analysisfor each of the roughly 45 000 ground-water supplies in the U.S. would be about $1 800 000. Because this would triple the
ECONOMICS OF GROUND-WATER QUALITY MONITORING
49
total estimated national costs for monitoring radioactivity in community water systems it was not regarded as defensible in terms of the anticipated benefit. For this reason, and in view of the apparent association between the two isotopes, the separate 22~Raanalysis is mandatory only when 226Ra exceeds 3 pCi l-~.
Statistical considerations such as spatial and temporal variability, and correlated behavior of selected contaminants can also help decide the level of sampling intensity in a monitoring program. Such knowledge based on historical field results can be useful in reducing the existing list of contaminants and including those that are not being monitored currently because of lack of funds. Therefore, objective methods based on the economics of sampling, statistical behavior of observed results, and the value of monitored information can be of significant value in selecting contaminants and deciding on the frequency of their measurement in ground water. For example, a recent study by Rajagopal (1986b) has shown that the ambient distributions of nitrate in the Quaternary, and fluoride and sulfate in the CambroOrdovician can be closely estimated by samples of size as small as 50 to a 100. A sample of 1000 measurements, instead of 100, did not lead to a ten-fold reduction in estimation interval. In other words, investments in large numbers of samples do not proportionally increase our parameter-estimation capability regarding the distribution of pollutants in water supplies. In the case of drinking water monitoring, nitrate, fluoride, and combined radium (226 § 228) are the three constituents which have often exceeded the MCLs in Iowa's PWS systems (Waters et al., 1987). Many of the trace metals specified under the Safe Drinking Water Act (U.S. EPA, 1975) are seldom detected in any PWS systems, except at one or two isolated locations. The question is not whether we should continue to monitor such constituents in Iowa's ground water but how often to monitor them. More importantly, due to limited financial resources, not many constituents can be monitored all the time. There may be a lost opportunity in measuring those other chemicals of current concern such as pesticides petroleum derivatives, and synthetic organics in ground water. Therefore, a concerted effort should be made at the state level to analyze and investigate the allocation decisions pertaining to what chemicals to monitor in ground water, and where and how often to monitor them.
Rural Coverage The Safe Drinking Water Act (1974), through periodic monitoring, attempts to ensure the quality of water supplied by public water supply (PWS) systems. The Act at present does not require monitoring non-public water supply systems. Therefore, millions of Americans, including about 740 000 rural Iowans who depend on over 230 000 private wells for drinking water, are not covered by the monitoring provisions of the Safe Drinking Water Act. It would be extremely expensive to initiate a monitoring program to cover all such systems by measuring a large number of constituents. On the other hand, by judiciously selecting possible contaminants and wells based on site-specific knowledge, one can provide valuable advice to rural Iowans regarding the quality of their ground water. The state of Iowa will soon be investing large sums of money to monitor rural wells for
50
R. RAJAGOPAL AND GRAHAM TOB|N
pesticides. Incorporation of many of the concepts discussed in this case study will lead to a cost-effective pesticide monitoring program for rural wells. END OF CASE STUDY
Analysis and Discussion of Survey Results The responses to the questions were, as expected, quite mixed. The responses were further analyzed based on the differences in four selected participant profiles: educational qualification, institutional affiliation, length of professional ground water experience, and residency status. To simultaneously test for the significance of these profile variables on observed responses, standard multivariate modeling methods (analysis of variance using the General Linear and Categorical Models) for the study of cross-classified data were employed (Fienberg, 1980). Only responses and interactions found to be significant at the 0.05 probability level are discussed in this paper. Definition of the four profile variables used to categorize survey participants are as follows:
Educational Qualification: Participants were classified into one of two groups based on the highest level of education attained: Bachelor's degree or lower and Master's degree or higher. Institutional Affiliation: Participants were classified into one of three groups based on their institutional affiliation: governmental institutions, Universities/Colleges/Extension Services, and all other institutions (private sector, non-profit interest groups and others). Professional ground water experience: Participants were classified into one of two groups based on the length of their ground water related professional experience: ten or less years of ground water experience and more than 10 yr of ground water experience. Residency status: Participants were classified into one of two groups based on their residential status: those who are or have been a resident of the state of Iowa and those who are not or have not been a resident of the state of Iowa. In three instances, the residency status explained the observed difference in responses to a question. The other three profile variables, educational qualification, institutional affiliation, and ground water experience, explained the difference in responses to one question each. In three other instances, the interaction effect between variables was found to be significant and even in those cases reliable inference could not be made due to small sample sizes in intersecting cells. THE FINDINGS A summary of participant responses to the survey are presented in Table VI. The responses to the questions were, as expected, quite mixed. The survey questions were framed so as to elicit responses along the following major themes of inquiry: (1) Seriousness of the issue (2) Program Integration, Resource Allocation, and Efficiency, and
ECONOMICS OF GROUND-WATER
QUALITY MONITORING
51
TABLE VI Summary of participant responses to the survey Response frequencies in this table, wherever applicable, are expressed in percentages instead of numeral counts. A total of ninety-seven individuals participated in the survey. N refers to the number responding to the specific question. N 1. How serious is the issue of economic efficiency in water quality monitoring? (Score on a scale of 1 to 5, not an issue to a very serious issue). 2. Since we cannot monitor many contaminants to the same frequency at all sites, how important is it to introduce costeffectiveness criteria in monitoring decisions? (Score on a scale of 1 to 5, least important to most important). 3. All public water supply systems (irrespective of location, population served or depth of well) should be treated the same in monitoring decisions. (Score on a scale of 1 to 5, strongly disagree to strongly agree).
6. Who should pay for monitoring of individual private wells? (Enter a percent figure for each source, with the total equalling 100%). (a) Federal government (b) State government (c) Local government (d) Well owners (e) Others, if any
Max.
3.7
0.9
1.0
5.0
97
4.1
0.8
1.0
5.0
97
2.3
1.3
1.0
5.0
4.4
0.7
2.0
5.0
97
3.3
1.2
1.0
5.0
96 96 95 96 96
6.9 24.0 8.1 57.3 3.8
11.7 24.8 13.7 34.0 16.2
0 0 0 0 0
50 100 50 100 100
3.9
1.0
1.0
5.0
3.8 4.3 3.1
1.0 1.1 1.0
1.0 1.0 1.0
5.0 5.0 5.0
7. To characterize the quality of drinking water as a function of aquifer sources, blending rations and treatment practices, it would be beneficial to collect and analyze a raw water sample from each well at the same time when a finished water sample from the distribution system is collected and analyzed. 96 (Score on a scale of 1 to 5, strongly disagree to strongly agree.) 8. To accomplish the task of integrating (discussed in the previous question) ambient and drinking water quality monitoring programs, the state should: (Rank all the alternatives: least preferred = 1. . . . . most preferred = 5). (a) appoint an advisory committee (b) charge the DNR with the task of integration (c) hire consultant to study the subject
Min.
97
4. Selecting a list of contaminants to monitor in public water supplies should be based exclusively on economics, health effects, and the historical evidence of the distribution of contaminants in water supplies, and not on questions of administrative convenience or political expediency. 96 (Score on scale of 1 to 5, strongly disagree to strongly agree). 5. Federal regulations require the monitoring of public water supplies. Some form of monitoring of individual private wells through regulations is necessary. (Score on a scale of 1 to 5, strongly disagree to strongly agree).
Mean S.D.
96 97 96
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Table VI (Continued) N (d) postponeaction until we hear from other states (e) wait for the federalgovernmentto makesuch a proposition
96 96
Mean S.D. Min. Max. 1.9 1.8
0.9 1.0 1.2 1.0
5.0 5.0
9. Do you have any commentson this case? Percentcommenting= 31 Percentwith no comments-- 69 (3) Regulating and Subsidizing the Monitoring of Individual Private Wells.
Seriousness of the lssue The respondents rated the issue of economic efficiency in water quality monitoring with a mean score of 3.7 on a scale of 1 to 5, while the importance of introducing costeffectiveness in monitoring decisions was rated higher with a mean score of 4.1 (questions 1 and 2 in Table VI). No significant difference in response between profile groups was noticed, except in the case of question I there was a significant interaction. The issue of economic efficiency was rated higher by nonresident Iowans with advanced education (mean of 3.99) compared to nonresident Iowans without advanced education (mean of 3.36), whereas, it was rated lower by Iowa residents with advanced education (mean of 3.49) compared to Iowa residents without advanced education (mean of 3.73). Four participants provided narrative comments emphasizing the importance of prioritization and economic efficiency in water quality monitoring, They reiterated that testing and monitoring are essential in the development of a strategy for protecting ground-water quality. These activities consume considerable amount of time and money and, therefore, issues related to the efficient allocation of resources to such activities should be of high priority. One participant commented that good well placement and construction practices are essential for the study of such issues and another stated that at present we are on the right track to deal with such issues in monitoring. It is not surprising that most experts consider 'economic efficiency' to be important and that some element of 'cost-effectiveness' be introduced in any monitoring program. However, as later responses show (see below) there is not complete agreement as to the extent to which such criteria influence monitoring decisions.
Program Integration, Resource Allocation and Efficiency When asked whether all public water supply systems should be treated the same in monitoring decisions (question 3), the respondents moderately disagreed with a mean score of 2.3 on a scale of 1 to 5. Consequently, 'experts' generally did not agree with current monitoring practices mandated by federal legislations. In addition, there were significant differences in responses between participant groups. For example, participants with advanced education, those affiliated with universities and colleges, and non-residents of Iowa disagreed more strongly with the statement than their counterparts without aclvanced education, not affiliated with teaching institutions, and Iowa residents. It would seem, therefore, that the better educated, university affiliated, or non-resident Iowans were more likely to question present monitoring practices. Such significant differences in responses highlights the need for further research into the allocation of monitoring dollars
ECONOMICS OF GROUND-WATER
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based on a knowledge of hydrogeology, chemistry, health effects, and population exposure. Responses to question 4 were also not surprising. The experts strongly agreed, mean score of 4.4 in a scale of I to 5, with the notion that contaminant selection for monitoring should be based exclusively on economics, health effects, and historical evidence, and not on administrative convenience or political expediency. However, not all were strongly supportive. One respondent commented that administrative convenience and political expediency are not all bad. In hindsight, we have learned that it would have been interesting to differentiate between the influence of 'economics', 'health effects', and 'historical evidence' on expert opinions. The respondents moderately agreed with the idea of integrating raw and finished water quality monitoring programs with a mean score of 3.9 on a scale of 1 to 5 (question 7). This question being of technical nature, generated a variety of comments. Nine participants provided suggestions on some aspects of the development of a monitoring strategy. The suggestions included that finished water monitoring take into account the detention time of water in the treatment system; that an integrated strategy need not sample finished water with every raw water sample; that high risk criteria, hydrogeochemical knowledge and statistical concepts be used in devising a monitoring strategy; and that surface and ground-water monitoring strategies be integrated. One participant recommended that random sampling of raw and finished water be undertaken, another suggested that raw water be monitored only when a well is suspected of contamination, another pointed out that water quality in a well may vary widely with time and pumping rate, and finally a participant suggested the formation of a national task force to disseminate knowledge pertaining such monitoring data management methodologies. In response to question 8, regarding who should have the responsibility for integrating ambient and drinking water quality monitoring programs, the Iowa Department of Natural Resources received the highest marks. Responses to this question indicate that the survey participants preferred local action rather than waiting for federal initiatives (mean rank of 1.8) or postponing action until success stories are heard from other states (mean rank of 1.9). In one case (question 8e), there was a significant difference in response between resident and nonresident Iowans. Resident Iowans ranked (mean of 2.02) the option of waiting for federal initiatives higher than nonresident Iowans (mean of 1.54). One respondent commented that the assignment of technical responsibility for integrating water quality monitoring programs to DNR should be followed by political action for increased staffing and funding to do the job. Thus, the concept of one responsible agency for monitoring was generally supported by most of the experts.
Regulating and Subsidizing the Monitoring of Individual Private Wells In Iowa, there are over 200000 individual private wells. Creating and operating a regulatory program to monitor the quality of water supplied by these wells would be a major task. Therefore, the survey respondents were somewhat ambivalent with the idea of initiating a regulatory program for the monitoring of water supplies of individual private well owners. Question 5 which dealt with this issue received a mean score of 3.3 on a scale
54
R. R A J A G O P A L
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of I to 5. In general, participants with longer ground water related experience tended to rate this option some what lower than their lesser experienced counterparts. The perceived difficulties of implementing any such monitoring program probably curtailed support for this measure. Regarding the question of who should pay for monitoring individual private wells (question 6), the respondents suggested an average share of 57% of the cost to be borne by well owners, 24% by the state government, 8% by the local government, and 7% by the federal government. There was considerable variation in responses to this question with each 'group' allocated anywhere from 0 to 50 or 100% of the total financial burden (Table VI). Again, only in one case, the residency status of participants explained a statistically significant difference in responses to such allocations. For question 6a, resident Iowans on the average assigned a federal share of 9.02%, whereas, nonresident Iowans assigned a much lower value of 3.34%. Five respondents provided a set of comments stating that a small tax should be levied to finance more monitoring, that the chemical industry should be taxed to support more monitoring, that private wells should be tested at federal government's expense, and that the agency setting the standard should pay for monitoring. Concluding Remarks
This study was intended to capture the reactions of a select group of experts to resource allocation problems faced by almost all state and federal agencies and other organizations that manage water quality monitoring programs. Due to limitations in time and resources, we were able to provide our experts with only a comprehensive (rather than encyclopedic) description of the case at hand. Therefore, this study should be viewed as a search for significant patterns in expert opinions based on incomplete and uncertain information. The major conclusions and recommendations are as follows: - The general consensus of the experts was that the issue of economic efficiencyin water quality monitoring is very important but not an overriding one. The development of a cost-effective strategy to characterize and assess drinking water quality as a function of aquifer source, blending ratio, and treatment practice was favored by many participants. They strongly favored the development of such a strategy based exclusively on economics, health effects, and historical evidence. - The experts also provided several insightful comments pertaining to the technical development of a monitoring strategy and rated Iowa DNR as the most qualified and suitable agency for undertaking such a task. Given the importance of ground water in Iowa, a participant suggested the creation of a state ground water agency for research, education, regulation, and contracting. - Our participants were somewhat ambivalent to the idea of creating a regulatory program to monitor a large number of privately owned individual water supplies. Similarly, they recommended that individual private well owners share a bulk of the financial burden of undertaking such a monitoring program. In general, higher subsidies from governmental sources are recommended for problems of collective entities such as
ECONOMICS OF GROUND-WATER
QUALITY MONITORING
55
PWS systems in comparison to those of individual consumers. - The preferences expressed by an informed population of experts may not necessarily reflect what they or other lay populations would have actually preferred in real world circumstances. Also, significant differences in preferences may exist between groups within an informed population based on factors such as residential status, educational background, institutional affiliation, and ground water related experience. Verification of results presented in this paper with surveys of state or private sector monitoring programs that do not seek federal subsidy is a potential area for further research. - Finally, a few participants noted that if detailed data on analytical costs, sampling costs, and the like were to have been available, their responses would have been much more precise. Unfortunately, we live in an imperfect world with limited resources and will never be able to fully meet the demand for such complete information. Therefore, this case study should be viewed as a search for significant patterns in perceptions based on the responses of a select group of participants who were exposed to incomplete and uncertain information. Acknowledgement
The preparation of this manuscript was made possible by a grant from the Joyce Foundation of Chicago, Illinois, to the Department of Geography at the University of Iowa. The views expressed in this manuscript are those of the authors and do not necessarily reflect the views or policies of the sponsoring organizations. We thank Ping-Chi Li, Ramana Kuchibhatla, and Usha Natarajan of the Department of Geography at the University of Iowa for providing valuable assistance in the conduct of the survey, data compilation, and analysis. References
Cortner, H. J., Gardner, P. D., Taylor, J. G., Carpenter, E. H., Zwolinski, M. J., Daniel, T. C., and Stenberg, K.J.: 1984, 'Uses of Public Opinion Surveys in Resource Planning', The EnvironmentalProfessional6(4), 265-275. Fienberg, S.E.: 1980, The Analysis of Cross-Classified Categorical Data, Second Edition. The MIT Press. Cambridge, Massachusetts, 198 p. Hallberg, G. R. and Hoyer, B. E., 1982, Sinkholes, Hydrogeology, and Ground-Water Qualityin NortheastIowa, Contract Report No. 81-5500-04. Iowa Geological Survey. Iowa City, IA. Hallberg, G. R., Hoyer, B. E., Bettis, E. A., III, and Libra, R. D., 1983,Hydrogeology, WaterQuality, andLand Management in the Big Spring Basin, Clay County, Iowa, Iowa Geological Survey Contract No. 82-5500-2, Iowa City, IA. Iowa Administrative Code. 1983, Chapter 41. Water Supplies, Sate of Iowa, Des Moines, IA. Mills, W. A., Ellett, W. H., and Sullivan, R. E., 1980, 'Monitoring for 228Ra in Water Supplies', Health Physics 39(12), 1003. Rajagopal, R.: 1984, GroundwaterQualityAssessmentfor PublicPolicy in Iowa, First Annual Report (1983-84) to the Joyce Foundation, IL. Department of Geography, University of Iowa. Iowa City, IA. 245p. Rajagopal, R.: 1986a, 'Conceptual Design for a Ground-Water Monitoring Strategy', The Environmental Professionalg(3), 244-264. Rajagopal, R.: 1986b, 'The Effect of Sampling Frequency on Ground-Water Quality Characterization', Ground-Water MonitoringReview 6(4), 65-73, U.S. Department of Commerce: 1983, 1980 Census of Population and Housing, Bureau of the Census,
56
R. RAJAGOPAL AND GRAHAM TOBIN
Washington, D.C. U.S. Environmental Protection Agency: 1975, NationalInterim Primary Drinking WaterRegulations, CFR 40, Parts 141-149, Revised July 1984. Waters, W.P., Rajagopal, R., and Pitchford, A.M., 1987, 'Ground-Water Quality Protection: A Case of Management by Exception', in Proceedingsof the Symposium on Monitoring, Modeling, and Mediating Water Quality, published by the American Water Resources Association, Bethesda, MD, pp. 693-707.
Department of Geography and Civil and Environmental Engineering at the University of lowa and G R A H A M TOBIN
Department of Geography at the University of Minnesota-Duluth
(Received March 1991) Abstract. The cost of a monitoring program can be easily ascertained in terms of the expenditures incurred for such items as personnel, supplies, field visits, instrumentation and laboratory analyses. The benefits of a monitoring program, however, cannot be easily evaluated due to the diversity of objectives for which monitoring programs are initiated and operated. The case study and the results of the follow-up exploratory survey reported in this paper were intended to capture the objective as well as the subjective reasons employed by a group of experts in responding to selected socio-economic questions related to the design of monitoring programs. Ninety-seven individuals, through a formal questionnaire, participated in the survey. They showed definite preferences, although there was some variability in responses due to such factors as residential status, institutional affiliation, education, and the length of professional experience. It was clear that the respondents favored the inclusion of cost-effectiveness criteria in monitoring programs; were ambivalent to the idea of initiating a regulatory program to monitor the wells of a large number of private owners; and if such a program were to be initiated they recommended that individual well owners share the bulk of the financial burden. Preliminary results from such exploratory surveys can lead to the framing of insightful research questions or hypotheses for further evaluation. Confirmatory testing of such questions or hypotheses in real world settings is a valuable area for further research.
Introduction Space, time, and parameter specifications of existing groundwater quality monitoring programs are based on regulatory mandates and guesswork rather than on explicitly stated objectives, statistical measures of precision and cost-effectiveness criteria. The total cost of a monitoring program can be easily ascertained in terms of the component costs of labor, supplies, and equipment. The benefits of monitoring, however, cannot be so easily quantified in terms of dollars and cents. But there are some tangible measures of information that result from a monitoring program which may be of use in the analysis of regulatory and policy decisions pertaining to the protection of public health and the environment. For many such issues, there are no ready-made or instantaneous analyses. The issues are complex and perspectives vary. Rather than going deeper and raising pertinent questions related to the issues, decision-makers often find it convenient to abide by existing monitoring schedules and thus maintain the status quo. Quite often, state-level organizations leave it to the federal government to propose the inclusion of additional parameters, suggest new standards and laboratory methods for measuring them, and prescribe changes in existing monitoring schedules. Environmental Monitoring and Assessment 22: 39-56, 1992. 9 1992 Kluwer Academic Publishers. Printed in the Netherlands.
40
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Glossary of Selected Terms Finished Water: Water that is piped for human consumption. In many cases such water is also subjected to one or more of several treatment processes. Iowa DNR: The Iowa Department of Natural Resources. Iowa GSB: The Iowa Geological Survey Bureau of the Iowa DNR. MCL: The Maximum Contaminant Level is the maximum permissible level of a contaminant in water which is delivered to any user of a public water supply. There are two types of MCLs, primary and secondary. Primary MCLs are based on potential adverse health effects on humans and are usually enforced. Secondary MCLs are based on levels required to protect public welfare (odor, appearance, etc.) and are usually not enforced. mg I-~: milligrams per liter equals parts per million (ppm). MSIS: The Model State Information System of the Office of Drinking Water of the U.S. EPA, created for the purpose of effectively meeting the provisions of the SDWA (1974). It provides state regulatory officials with data on maximum contaminant level violations, sampling requirements, violations requiring notification, optional sample scheduling, and non-compliance reports. pCi I-k picocuries per liter is a unit of radioactivity measurement. Primary MCL for the combined measurement of 226Ra and 228Ra is 5 pCi 1-~. PWS Systems: Systems that provide piped water for human consumption and have at least 15 service connections or regularly serve an average of at least 25 individuals daily at least 60 days of the year are called Public Water Supply (PWS) Systems. All other systems are referred to as non-PWS Systems. PWS systems used by year-round residents are called community PWS systems and all other PWS systems are called non-community PWS systems. Raw Water: Water that has not been subjected to any man-made alterations by treatment processes. SDWA Act: The Safe Drinking Water Act (1974). In 1974 the Act required the establishment of primary MCLs for 22 contaminants. The 1986 Amendments to this Act requires the establishment of maximum contaminant level goals (MCLGs) for 83 contaminants. USGS: The U.S. Geological Survey of the U.S. Department of the Interior. WATSTORE: The WATer Data STOrage and REtrieval System of the USGS. Data entered into this system have come from a variety of sources, projects, and programs over the last 50 yr. Much of this data has been verified and controlled for physical, chemical, and locational consistency by the USGS. This is the only source of computercoded files containing any significant amount of data on inorganics, trace metals, and radiochemical measurements in untreated Iowa ground water. Issue of Resource Allocation in Monitoring Because of its great quantity, reliability, and consistent biological and chemical quality in
E C O N O M I C S OF G R O U N D - W A T E R Q U A L I T Y M O N I T O R I N G
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any given place, ground water use has steadily increased in the past few decades. As shown in Table I, there are 750 ground water-based community PWS systems and over 230 000 individual wells that supply drinking water to over 2.1 million Iowans, compared to the 74 surface water sources that supply water to over 475 000 Iowans. Each month Iowa DNR, based on monitoring data, prepares a list of PWS systems that have exceeded the MCL for any primary drinking water contaminants listed under the SDWA (1974). Table II is based on 44 such monthly listings. Nitrate, fluoride, and combined radium (226 + 228) constitute an overwhelming majority of incidences that exceed the primary MCL in Iowa (Table II). Limited resources will not permit sampling for many contaminants at the same frequency at all well sites. Given the differences in number and source of supplies, population served by such supplies, and the occurrence and distribution of contaminants in such supplies (as shown in Tables I and II), how should the state go about developing a cost-effective ground water quality monitoring strategy? This is a major resource allocation question or issue of utmost concern in the field of monitoring throughout the United States. The case study reported in this paper and the follow-up exploratory survey were intended to capture the reactions of a group of experts to selected economic questions related to the allocation of resources in monitoring programs. The survey was carried out in the context of groundwater quality monitoring programs in Iowa, but the questions raised are sufficiently generic to be applicable elsewhere. The analysis of participant responses to economic, perceptual, participatory, and policy questions within a structured context form the backbone of this research. As far as we know, no such highly focused analysis of economic issues in ground-water quality TABLE I Iowa population served by source and type of water supply Source and type of water supply
Population
A. Ground water source 750 community PWS systems 236 709 individual wellsa Total
1 394 257 755 102b 2 149 359
47.8 25.9 73.7
475 040
16.3
109 341 2 733 740
3.8 93.8
180 068
6.2
B. Surface water source 74 community PWS systems C. Mixed and other sources 26 comminity PWS systems Total of A, B, and C D. Unaccounted sources 1980 Census Population of Iowa
2 913 808 ~
% Served
100.0
" From the 1980 Census of Population and Housing, Bureau of the Census (1983). h Estimated by multiplying the number of wells by average family size in Iowa, Bureau of the Census (1983).
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R. R A J A t 3 O P A L A N D G R A H A M TOBIN
TABLE II Descriptive statistical measures of the number of PWS systems exceeding primary drinking water MCLs in
Iowa based on 44 of 106 months betweenMarch 1978and December1986for which the data was available
Contaminant
MCL
Arsenic Barium Fluoride a Nitrate as N
0.05 1.0 1.4-2.4 10.0
Selenium Ra2-~'+Ra22~ Gross alpha
0.01 5.0 15.0
Total ~ of
Total ~ of
(Units)
PWS systems exceeding MCL
incidences exceeding MCL
mg mg mg mg
2 2 69 134
53 33 1888 2012
8 77 17
108 1552 65
I-I 1-I 1-1 1-I
mg 1-I pCi 1-I pCi 1-~
"The fluoride standard varies according to the annual average maximum daily air temperature for the location of the PWS system. In Iowa, it varies between 2.0 and 2.2 mg l-k
monitoring based on expert opinions is available at this time. With careful interpretation, general conclusions for further research can be drawn from survey responses elicited from such a targeted group of experts (Cortner et al., 1984). The paper is organized as follows: first a summary of the survey method, a profile of survey participants (experts), and the limitations of the approach are presented, followed by the text of the case study (with minor editorial revisions) as reviewed by the experts. Analyses and interpretations of the findings of the survey follow with a final section summarizing the conclusions and recommendations of the study. Tabulations of participant responses to the survey questions and the results of exploratory data analyses and various tests of hypotheses are also included.
The Survey and the Participants THE APPROACH TO obtain thoughtful responses from a targeted group of experts to the case study, a mail questionnaire, based on closed- and open-ended questions was prepared. Included were questions related to the tradeoffs between economic and health issues, the protection of public versus private water supplies, and the determination of monitoring priorities in terms of space, time, and compounds. Many were interdisciplinary questions and were posed in a world of incomplete and uncertain information. For this research we surveyed a sample of persons who are or have been actively involved in ground-water protection issues, either by professional practice, occupation, teaching, research, consulting, or community service. In addition, we wanted a majority of our respondents to have lived in the Midwest, in particular Iowa, and hence have experienced issues relevant to this area. We identified and then contacted 150 individuals who we thought would make excellent survey participants. One hundred and twenty experts agreed to respond to the survey.
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Each participant was required to read six single-spaced pages of narrative and numerical information related to economic issues in ground-water quality monitoring and then thoughtfully respond to the questionnaire. In the final tally, we obtained 97 completed forms, resulting in an 81% response rate. SURVEY PARTICIPANTPROFILE We postulated that the experts' responses would vary as a function of certain experiential, institutional, educational, and residency characteristics. Therefore, data (as shown in Table III) on such characteristics were elicited from questions directed at: length of groundwater-related experience; institutional affiliation (government, private, or education); level of formal education and subjects studied; and residential status in Iowa. These data were then used to test and explore selected research hypotheses. As shown in Table III, many participants had formally studied subjects related to the field of ground water. They were predominantly people in decision-making, research, teaching, engineering, and farming practice, with a small number from public interest groups, sales and marketing organizations, and enforcement agencies. Over 75% are from government and academic institutions. LIMITATIONS As stated earlier, the survey participants are a select group (purposive sample) of ground water experts and not a random sample from the universe of available experts. In addition, a majority have lived in the Midwest, in particular Iowa, and in some way influence the processes governing ground water protection in the state. Obviously, the results obtained from such a directed survey have serious limitations, and generalization is difficult. On the other hand, findings from such an exploratory survey could provide insights for new hypotheses for further testing. Hence, it is essential that results on preferences reported in this paper be validated with data from real communities that regularly benefit from the use of monitored data.
CASE STUDY
Economics of Ground-Water Quality Monitoring Introduction Just like any other societal endeavor, water quality monitoring programs can be subjected to analyses and discussions in an economic (cost-benefit and cost-effectiveness) framework. Limited resources will not permit monitoring for many contaminants with the same frequency at every site. Choice of contaminants, site selection, and frequency of sampling should be prioritized. The cost of ground-water quality monitoring in the U.S. is staggering. Consider the sums spent to monitor roughly the 50 000 ground-water-based community water supplies
44
R. RAJAGOPAL AND GRAHAM TOBIN TABLE III
Survey Participant Profile - A total of ninety-seven individuals participated in the survey. All response frequencies are expressed in percentages What is the highest level of education you have obtained? High School 9 Bachelor's 24 Master's 28 Doctorate 27 Other (D.Ed.) I2 2. What are the formal subjects you have studied? (Check up to three in which you believe you have a strong background.) Hydrology/Water Res. 29 Geology 25 Environmental Sciences 23 Planning/Policy 20 Engineering (Env./Chem.) 19 Business Management 15 Chemistry 14 Agronomy 13 Economics 13 Public Health 11 Geography 10 Law 9 Statistics/Biometry 3 Toxicology/Epidemiology 2 Soil Science 2 Computer Science 2 Physics 2 Others 13 3. What is the field of your current professional practice or occupation? (Check up to two) Administration/Management 28 Research 23 Teaching 21 Engineering 14 Policy Analysis 12 Elected Official (Representators/Senators) 11 Farming 11 Enforcement 5 Public Interest Group 5 Sales/Marketing 4 Legal Practice 4 Well Drilling 2 Medical Practice 0 Other 13
4. What is your current institutional affiliation? (Check one.) Government State Federal Local Other
28 16 5 2
Private Sector Farming Well Drilling Dealers/Distributors Chemical Industry Other
6 2 1 1 9
Other University/College Extension Service Public Interest Group
25 5
How many years of professional experience do you have? 0- 2 years 0 2- 5 years 2 5-10 years 15 10-15 years 26 16 or more years 56 How many years of your professional experience have been related to groundwater'?. 0- 2 years 12 2- 5 years 26 5-10 years 22 10-15 years 10 16 or more years 29 Are you or have you been a resident of lowa? Yes 63 No 36 Are you or have you been a resident of one or more of the following midwestern states: Iowa, Illinois, Indiana, Michigan, Ohio, Wisconsin, Minnesota, Nebraska, Missouri, and Kansas? Yes 94 No 5
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in the U.S. For illustration, let us assume that we sample once every three years for the 22 primary drinking water constituents at a cost of $300 a sample. The national cost of such a program will be $ 5 million a year (50 000 • $ 300 for every three years). If we revise this list of 22 constituents with the 83 proposed under the SDWA (1986) amendments at a cost of $1 300 a sample, the national cost will be over $ 21 million a year (50 000 • $1300 for every three years). Many water supplies have more than one well, all of which could be sampled; some of the samples could be replicated for improved quality assurance; sampling frequency could be increased to once or twice a year; and the list of contaminants could be increased to include a range of other compounds not considered earlier. Obviously, all such efforts will cost more money. If we add to these costs the additional burden of ground-water quality monitoring at hazardous waste sites (under RCRA and CERCLA) and other ground-water data collection programs of the U.S. and State Geological Surveys and state health and environmental agencies, the total national cost will be in the range of several hundred million dollars per year. When investing such large sums of money, it is useful to employ an objective resource allocation strategy to maximize the return on monitoring dollars. The strategy should attempt to allocate resources efficiently among the various monitoring components.
Environmental Settings LAND USE AND GEOLOGY One would expect the scope of monitoring activities for a surficial aquifer near a hazardous waste site to be distinctly different from that for a more distant bedrock aquifer. A map of a region or of a state with a clear delineation of past, present, and potential future pollutant generating sites will be of significant value in the spatial allocation of monitoring resources. In addition, information on the composition of wastes stored at different sites will also be of value in the determination of what parameters to monitor. Local land uses should be taken into account in the determination of what parameters to measure in a monitoring program. In intensely cultivated states like Iowa, Illinois, Nebraska, and California, the use of fertilizers and pesticides has played a significant role in increased crop yield. The same farm chemicals are also increasingly found in varying concentrations in shallow aquifers (Hallberg and Hoyer, 1982; Hallberg et al., 1983). Similarly, knowledge of regional or local ambient groundwater quality and the location of underground product or waste storage tanks will be of much value in the design of monitoring programs. The aquifers in a state or a region may not be uniformly distributed and historical sample collection efforts may not exactly correspond with the ground-water availability in aquifers. In some parts of the state, water of potable quality is abundant in shallow units of Quaternary age, while in other areas it is necessary to drill deeper to aquifers of the Cambro-Ordovician age. As might be expected, drillers seek the shallowest source that produces water in adequate quantity and quality. Deeper and otherwise equally suitable sources of ground water are, therefore, underrepresented in the historical samples for
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some parts of Iowa. The aquifers from the Quaternary and the Cambro-Ordovician sources provide some of the most highly used and dependable water within Iowa. They also provide good comparative data in terms of man-made sources of impact (nitrate) versus natural sources of impact (fluorides and sulfates) on ground-water resources in Iowa. The mean and standard deviation of nitrate concentration in the shallow Quaternary are respectively over five and three times those found in the deeper Cambro-Ordovician strata (9.8 v s 1.8 mg 1-~for means and 16.5 v s 4.8 mg 1-1for standard deviations), due to the significant influence of nitrogenous fertilizers applied to Iowa farmlands (Rajagopal, 1986a). Mean concentration of fluoride, chloride, and gross alpha measurements in the Quaternary are three to four times smaller than those found in the Cambro-Ordovician aquifers, indicating the influence of natural sources on the quality of water in the deeper rocks (Rajagopal, 1986a). Such differences in water quality characteristics between aquifers illustrate the point that not all aquifers need to be sampled with the same frequency to obtain similar levels of precision in the estimates. HEALTH EFFECTSAND POPULATIONEXPOSURE Currently only 22 contaminants are routinely monitored in public water supplies and have had drinking water standards or MCLs determined for them (U.S. EPA, 1975). The selection of these contaminants has been based on the knowledge of their potential to affect human health adversely. In addition, factors such as the frequency of a contaminant's occurrence in drinking water, the size of exposed populations, the source of the water supply, and the cost of sampling and analysis have also played a role in the determination of the scope and extent of drinking water monitoring programs. A large number of other contaminants are either not being monitored, and/or their health and ecological effects are not known. Clearly, a process is necessary for assessing and ranking a much larger set of contaminants than are currently being monitored in the drinking water environment. Population exposure is one of the most important factors in determining the level of monitoring activities, especially when contamination of drinking water is likely. The monitoring requirements based on population size for public water supplies in Iowa are shown in Tables IV and V. The Iowa Administrative Code (1983, Chapter 41) states that, 'the supplier of water for a community water system and for a non-community water system serving a school shall take coliform density samples at regular time intervals, and in number proportionate to the population served by the system' (as shown in Table IV). Many large urban areas have a significant number of manufacturing operations and waste disposal sites which can make nearby aquifers more vulnerable to contamination. Smaller (often rural) supplies are monitored less frequently than larger (urban) supplies. Occasionally, however, in some site-specific instances, rural supplies may require more extensive monitoring to assess the impact of nitrates and pesticides or naturally occurring contaminants such as fluoride and 226Ra.
ECONOMICS OF GROUND-WATER QUALITY MONITORING
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TABLE IV Frequency of minimum number of coliform density samples to be taken per month as a function of population served by the system Population served 25 1001 2501 3 301
to to to to
1000 2500 3300 4 100
50001 to
Minimum ~ of samples month 1 2 3 4
54000
60
96001 to l l l 0 0 0
100
450000 to 500000
210
Selected issues in Monitoring PROGRAM INTEGRATION
In the case of PWS sources monitored by Iowa DNR, the Safe Drinking Water Act specifies the parameters as well as the sampling frequency, while the raw water sources sampled by the USGS and the Iowa GSB are analyzed for a variety of parameters to satisfy a number of different goals and objectives. The WATSTORE data files containing raw ground-water quality data and the MSIS data files containing finished ground-water quality data are the only two large, computer-coded data files on Iowa ground-water quality. These two data bases, by themselves, provide significant insights pertaining the distribution of chemicals in different hydrogeological environments and the compliance status of PWS sources (with reference to primary MCLs) in Iowa. Every sample in the raw water-quality (WATSTORE) data base is clearly linked to a locational code (latitude/longitude), which in turn can be linked to an aquifer source of the water's origin. Not all samples in the finished water (MSIS) data base are linked to specific wells, since many PWS sources depend on multiple wells and blend (and/or treat) their water to meet the prescribed water quality standards of the Safe Drinking Water Act. In order to clearly characterize the quality of drinking water as a function of aquifer sources, blending or mixing ratios, and treatment practice, it would be beneficial to collect and analyze a raw water sample from each well at the same time when a finished water sample from the distribution system is collected and analyzed. Such a process would provide raw and finished water quality data, linked to aquifer sources, which are collected at the same place and at the same time. Since both the raw and finished water quality monitoring programs are operated by the newly created DNR, it is now equipped to initiate and manage such program integration activities. SELECTIVE ANALYSES
Ground-water quality in aquifers is often characterized by a study of samples obtained from wells that draw water from the aquifers. Due to physical and financial limitations,
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TABLE V Finished water monitoring requirementsfor public water supplies in Iowa Type of water system
Surface water sources samping frequency
Ground water sources sampling frequency
Coliforms (A)
Community Noncommunity
Monthly Quarterly minimum
Monthly Quarterlyminimum
Turbidity (B)
Community Noncommunity
Daily Dailya
Not required Not required
lnorganics (C)
Community Noncummunity
1 yr 3 yr
3 yr 3 yr
Organics (D)
Community
3 yr
Not required
Radionuclides
Community
4 yr
4 yr
Trihalomethanes(E)
Community
Quarterly
Quarterly
Corrosivity (F)
Community
One time only
One time only
Contaminant
Remarks."
(A) Number of samples collected by community systems are based on population served. See Chapter 41 I.A.C. for monitoring schedules. (B) Analysisby nephelometricmethod. aMonitoring frequenciesfor noncummunitysupplies may be reduced by the state. (C) Primary Inorganic Contaminants: Arsenic Cadmium Fluoride M e r c u r y S e l e n i u m Sodiumc Barium C h r o m i u m Lead Nitrateb Silver bNoncommunitywater systems are required to monitor only for nitrate contaminant levels. An MCL for sodium has not been established. (D) Chlorinated Hydrocarbons: Endrin Lindane M e t h o x y c h l o r Toxaphene Chlorophyenoxys 2.4-D 2,4,5-TP (Silvex) (E) Total Trihalomethane (TTHM) monitoring requirement became effectiveJuly 30, 1980. The rules affect only communityPWSsserving10.000or more people. Reductionsin monitoringare possibleafter TTHM levels have been determined. (F) An MCL for corrosivityhas not been established. Source: Iowa Department of Water, Air, and Waste Management, 1983.
any quality characterization of aquifers will have to be necessarily based on the results of sampling. Similarly, any quality characterization of drinking water will have to be based on sampling the water in the distribution system of PWS sources. Due to the variability in cost of analysis a n d the limitation o n available m o n i t o r i n g resources, it will not be feasible to measure all c o n t a m i n a n t s or c o n t a m i n a n t groups to the same degree of frequency in each a n d every sample or site. F o r example, Mills et al. (1980) state that:
usingan estimate of $ 40 for each analysis,the national cost of a separate Radium-228analysisfor each of the roughly 45 000 ground-water supplies in the U.S. would be about $1 800 000. Because this would triple the
ECONOMICS OF GROUND-WATER QUALITY MONITORING
49
total estimated national costs for monitoring radioactivity in community water systems it was not regarded as defensible in terms of the anticipated benefit. For this reason, and in view of the apparent association between the two isotopes, the separate 22~Raanalysis is mandatory only when 226Ra exceeds 3 pCi l-~.
Statistical considerations such as spatial and temporal variability, and correlated behavior of selected contaminants can also help decide the level of sampling intensity in a monitoring program. Such knowledge based on historical field results can be useful in reducing the existing list of contaminants and including those that are not being monitored currently because of lack of funds. Therefore, objective methods based on the economics of sampling, statistical behavior of observed results, and the value of monitored information can be of significant value in selecting contaminants and deciding on the frequency of their measurement in ground water. For example, a recent study by Rajagopal (1986b) has shown that the ambient distributions of nitrate in the Quaternary, and fluoride and sulfate in the CambroOrdovician can be closely estimated by samples of size as small as 50 to a 100. A sample of 1000 measurements, instead of 100, did not lead to a ten-fold reduction in estimation interval. In other words, investments in large numbers of samples do not proportionally increase our parameter-estimation capability regarding the distribution of pollutants in water supplies. In the case of drinking water monitoring, nitrate, fluoride, and combined radium (226 § 228) are the three constituents which have often exceeded the MCLs in Iowa's PWS systems (Waters et al., 1987). Many of the trace metals specified under the Safe Drinking Water Act (U.S. EPA, 1975) are seldom detected in any PWS systems, except at one or two isolated locations. The question is not whether we should continue to monitor such constituents in Iowa's ground water but how often to monitor them. More importantly, due to limited financial resources, not many constituents can be monitored all the time. There may be a lost opportunity in measuring those other chemicals of current concern such as pesticides petroleum derivatives, and synthetic organics in ground water. Therefore, a concerted effort should be made at the state level to analyze and investigate the allocation decisions pertaining to what chemicals to monitor in ground water, and where and how often to monitor them.
Rural Coverage The Safe Drinking Water Act (1974), through periodic monitoring, attempts to ensure the quality of water supplied by public water supply (PWS) systems. The Act at present does not require monitoring non-public water supply systems. Therefore, millions of Americans, including about 740 000 rural Iowans who depend on over 230 000 private wells for drinking water, are not covered by the monitoring provisions of the Safe Drinking Water Act. It would be extremely expensive to initiate a monitoring program to cover all such systems by measuring a large number of constituents. On the other hand, by judiciously selecting possible contaminants and wells based on site-specific knowledge, one can provide valuable advice to rural Iowans regarding the quality of their ground water. The state of Iowa will soon be investing large sums of money to monitor rural wells for
50
R. RAJAGOPAL AND GRAHAM TOB|N
pesticides. Incorporation of many of the concepts discussed in this case study will lead to a cost-effective pesticide monitoring program for rural wells. END OF CASE STUDY
Analysis and Discussion of Survey Results The responses to the questions were, as expected, quite mixed. The responses were further analyzed based on the differences in four selected participant profiles: educational qualification, institutional affiliation, length of professional ground water experience, and residency status. To simultaneously test for the significance of these profile variables on observed responses, standard multivariate modeling methods (analysis of variance using the General Linear and Categorical Models) for the study of cross-classified data were employed (Fienberg, 1980). Only responses and interactions found to be significant at the 0.05 probability level are discussed in this paper. Definition of the four profile variables used to categorize survey participants are as follows:
Educational Qualification: Participants were classified into one of two groups based on the highest level of education attained: Bachelor's degree or lower and Master's degree or higher. Institutional Affiliation: Participants were classified into one of three groups based on their institutional affiliation: governmental institutions, Universities/Colleges/Extension Services, and all other institutions (private sector, non-profit interest groups and others). Professional ground water experience: Participants were classified into one of two groups based on the length of their ground water related professional experience: ten or less years of ground water experience and more than 10 yr of ground water experience. Residency status: Participants were classified into one of two groups based on their residential status: those who are or have been a resident of the state of Iowa and those who are not or have not been a resident of the state of Iowa. In three instances, the residency status explained the observed difference in responses to a question. The other three profile variables, educational qualification, institutional affiliation, and ground water experience, explained the difference in responses to one question each. In three other instances, the interaction effect between variables was found to be significant and even in those cases reliable inference could not be made due to small sample sizes in intersecting cells. THE FINDINGS A summary of participant responses to the survey are presented in Table VI. The responses to the questions were, as expected, quite mixed. The survey questions were framed so as to elicit responses along the following major themes of inquiry: (1) Seriousness of the issue (2) Program Integration, Resource Allocation, and Efficiency, and
ECONOMICS OF GROUND-WATER
QUALITY MONITORING
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TABLE VI Summary of participant responses to the survey Response frequencies in this table, wherever applicable, are expressed in percentages instead of numeral counts. A total of ninety-seven individuals participated in the survey. N refers to the number responding to the specific question. N 1. How serious is the issue of economic efficiency in water quality monitoring? (Score on a scale of 1 to 5, not an issue to a very serious issue). 2. Since we cannot monitor many contaminants to the same frequency at all sites, how important is it to introduce costeffectiveness criteria in monitoring decisions? (Score on a scale of 1 to 5, least important to most important). 3. All public water supply systems (irrespective of location, population served or depth of well) should be treated the same in monitoring decisions. (Score on a scale of 1 to 5, strongly disagree to strongly agree).
6. Who should pay for monitoring of individual private wells? (Enter a percent figure for each source, with the total equalling 100%). (a) Federal government (b) State government (c) Local government (d) Well owners (e) Others, if any
Max.
3.7
0.9
1.0
5.0
97
4.1
0.8
1.0
5.0
97
2.3
1.3
1.0
5.0
4.4
0.7
2.0
5.0
97
3.3
1.2
1.0
5.0
96 96 95 96 96
6.9 24.0 8.1 57.3 3.8
11.7 24.8 13.7 34.0 16.2
0 0 0 0 0
50 100 50 100 100
3.9
1.0
1.0
5.0
3.8 4.3 3.1
1.0 1.1 1.0
1.0 1.0 1.0
5.0 5.0 5.0
7. To characterize the quality of drinking water as a function of aquifer sources, blending rations and treatment practices, it would be beneficial to collect and analyze a raw water sample from each well at the same time when a finished water sample from the distribution system is collected and analyzed. 96 (Score on a scale of 1 to 5, strongly disagree to strongly agree.) 8. To accomplish the task of integrating (discussed in the previous question) ambient and drinking water quality monitoring programs, the state should: (Rank all the alternatives: least preferred = 1. . . . . most preferred = 5). (a) appoint an advisory committee (b) charge the DNR with the task of integration (c) hire consultant to study the subject
Min.
97
4. Selecting a list of contaminants to monitor in public water supplies should be based exclusively on economics, health effects, and the historical evidence of the distribution of contaminants in water supplies, and not on questions of administrative convenience or political expediency. 96 (Score on scale of 1 to 5, strongly disagree to strongly agree). 5. Federal regulations require the monitoring of public water supplies. Some form of monitoring of individual private wells through regulations is necessary. (Score on a scale of 1 to 5, strongly disagree to strongly agree).
Mean S.D.
96 97 96
52
R. R A J A G O P A L
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TOBIN
Table VI (Continued) N (d) postponeaction until we hear from other states (e) wait for the federalgovernmentto makesuch a proposition
96 96
Mean S.D. Min. Max. 1.9 1.8
0.9 1.0 1.2 1.0
5.0 5.0
9. Do you have any commentson this case? Percentcommenting= 31 Percentwith no comments-- 69 (3) Regulating and Subsidizing the Monitoring of Individual Private Wells.
Seriousness of the lssue The respondents rated the issue of economic efficiency in water quality monitoring with a mean score of 3.7 on a scale of 1 to 5, while the importance of introducing costeffectiveness in monitoring decisions was rated higher with a mean score of 4.1 (questions 1 and 2 in Table VI). No significant difference in response between profile groups was noticed, except in the case of question I there was a significant interaction. The issue of economic efficiency was rated higher by nonresident Iowans with advanced education (mean of 3.99) compared to nonresident Iowans without advanced education (mean of 3.36), whereas, it was rated lower by Iowa residents with advanced education (mean of 3.49) compared to Iowa residents without advanced education (mean of 3.73). Four participants provided narrative comments emphasizing the importance of prioritization and economic efficiency in water quality monitoring, They reiterated that testing and monitoring are essential in the development of a strategy for protecting ground-water quality. These activities consume considerable amount of time and money and, therefore, issues related to the efficient allocation of resources to such activities should be of high priority. One participant commented that good well placement and construction practices are essential for the study of such issues and another stated that at present we are on the right track to deal with such issues in monitoring. It is not surprising that most experts consider 'economic efficiency' to be important and that some element of 'cost-effectiveness' be introduced in any monitoring program. However, as later responses show (see below) there is not complete agreement as to the extent to which such criteria influence monitoring decisions.
Program Integration, Resource Allocation and Efficiency When asked whether all public water supply systems should be treated the same in monitoring decisions (question 3), the respondents moderately disagreed with a mean score of 2.3 on a scale of 1 to 5. Consequently, 'experts' generally did not agree with current monitoring practices mandated by federal legislations. In addition, there were significant differences in responses between participant groups. For example, participants with advanced education, those affiliated with universities and colleges, and non-residents of Iowa disagreed more strongly with the statement than their counterparts without aclvanced education, not affiliated with teaching institutions, and Iowa residents. It would seem, therefore, that the better educated, university affiliated, or non-resident Iowans were more likely to question present monitoring practices. Such significant differences in responses highlights the need for further research into the allocation of monitoring dollars
ECONOMICS OF GROUND-WATER
QUALITY MONITORING
53
based on a knowledge of hydrogeology, chemistry, health effects, and population exposure. Responses to question 4 were also not surprising. The experts strongly agreed, mean score of 4.4 in a scale of I to 5, with the notion that contaminant selection for monitoring should be based exclusively on economics, health effects, and historical evidence, and not on administrative convenience or political expediency. However, not all were strongly supportive. One respondent commented that administrative convenience and political expediency are not all bad. In hindsight, we have learned that it would have been interesting to differentiate between the influence of 'economics', 'health effects', and 'historical evidence' on expert opinions. The respondents moderately agreed with the idea of integrating raw and finished water quality monitoring programs with a mean score of 3.9 on a scale of 1 to 5 (question 7). This question being of technical nature, generated a variety of comments. Nine participants provided suggestions on some aspects of the development of a monitoring strategy. The suggestions included that finished water monitoring take into account the detention time of water in the treatment system; that an integrated strategy need not sample finished water with every raw water sample; that high risk criteria, hydrogeochemical knowledge and statistical concepts be used in devising a monitoring strategy; and that surface and ground-water monitoring strategies be integrated. One participant recommended that random sampling of raw and finished water be undertaken, another suggested that raw water be monitored only when a well is suspected of contamination, another pointed out that water quality in a well may vary widely with time and pumping rate, and finally a participant suggested the formation of a national task force to disseminate knowledge pertaining such monitoring data management methodologies. In response to question 8, regarding who should have the responsibility for integrating ambient and drinking water quality monitoring programs, the Iowa Department of Natural Resources received the highest marks. Responses to this question indicate that the survey participants preferred local action rather than waiting for federal initiatives (mean rank of 1.8) or postponing action until success stories are heard from other states (mean rank of 1.9). In one case (question 8e), there was a significant difference in response between resident and nonresident Iowans. Resident Iowans ranked (mean of 2.02) the option of waiting for federal initiatives higher than nonresident Iowans (mean of 1.54). One respondent commented that the assignment of technical responsibility for integrating water quality monitoring programs to DNR should be followed by political action for increased staffing and funding to do the job. Thus, the concept of one responsible agency for monitoring was generally supported by most of the experts.
Regulating and Subsidizing the Monitoring of Individual Private Wells In Iowa, there are over 200000 individual private wells. Creating and operating a regulatory program to monitor the quality of water supplied by these wells would be a major task. Therefore, the survey respondents were somewhat ambivalent with the idea of initiating a regulatory program for the monitoring of water supplies of individual private well owners. Question 5 which dealt with this issue received a mean score of 3.3 on a scale
54
R. R A J A G O P A L
AND GRAHAM
TOBIN
of I to 5. In general, participants with longer ground water related experience tended to rate this option some what lower than their lesser experienced counterparts. The perceived difficulties of implementing any such monitoring program probably curtailed support for this measure. Regarding the question of who should pay for monitoring individual private wells (question 6), the respondents suggested an average share of 57% of the cost to be borne by well owners, 24% by the state government, 8% by the local government, and 7% by the federal government. There was considerable variation in responses to this question with each 'group' allocated anywhere from 0 to 50 or 100% of the total financial burden (Table VI). Again, only in one case, the residency status of participants explained a statistically significant difference in responses to such allocations. For question 6a, resident Iowans on the average assigned a federal share of 9.02%, whereas, nonresident Iowans assigned a much lower value of 3.34%. Five respondents provided a set of comments stating that a small tax should be levied to finance more monitoring, that the chemical industry should be taxed to support more monitoring, that private wells should be tested at federal government's expense, and that the agency setting the standard should pay for monitoring. Concluding Remarks
This study was intended to capture the reactions of a select group of experts to resource allocation problems faced by almost all state and federal agencies and other organizations that manage water quality monitoring programs. Due to limitations in time and resources, we were able to provide our experts with only a comprehensive (rather than encyclopedic) description of the case at hand. Therefore, this study should be viewed as a search for significant patterns in expert opinions based on incomplete and uncertain information. The major conclusions and recommendations are as follows: - The general consensus of the experts was that the issue of economic efficiencyin water quality monitoring is very important but not an overriding one. The development of a cost-effective strategy to characterize and assess drinking water quality as a function of aquifer source, blending ratio, and treatment practice was favored by many participants. They strongly favored the development of such a strategy based exclusively on economics, health effects, and historical evidence. - The experts also provided several insightful comments pertaining to the technical development of a monitoring strategy and rated Iowa DNR as the most qualified and suitable agency for undertaking such a task. Given the importance of ground water in Iowa, a participant suggested the creation of a state ground water agency for research, education, regulation, and contracting. - Our participants were somewhat ambivalent to the idea of creating a regulatory program to monitor a large number of privately owned individual water supplies. Similarly, they recommended that individual private well owners share a bulk of the financial burden of undertaking such a monitoring program. In general, higher subsidies from governmental sources are recommended for problems of collective entities such as
ECONOMICS OF GROUND-WATER
QUALITY MONITORING
55
PWS systems in comparison to those of individual consumers. - The preferences expressed by an informed population of experts may not necessarily reflect what they or other lay populations would have actually preferred in real world circumstances. Also, significant differences in preferences may exist between groups within an informed population based on factors such as residential status, educational background, institutional affiliation, and ground water related experience. Verification of results presented in this paper with surveys of state or private sector monitoring programs that do not seek federal subsidy is a potential area for further research. - Finally, a few participants noted that if detailed data on analytical costs, sampling costs, and the like were to have been available, their responses would have been much more precise. Unfortunately, we live in an imperfect world with limited resources and will never be able to fully meet the demand for such complete information. Therefore, this case study should be viewed as a search for significant patterns in perceptions based on the responses of a select group of participants who were exposed to incomplete and uncertain information. Acknowledgement
The preparation of this manuscript was made possible by a grant from the Joyce Foundation of Chicago, Illinois, to the Department of Geography at the University of Iowa. The views expressed in this manuscript are those of the authors and do not necessarily reflect the views or policies of the sponsoring organizations. We thank Ping-Chi Li, Ramana Kuchibhatla, and Usha Natarajan of the Department of Geography at the University of Iowa for providing valuable assistance in the conduct of the survey, data compilation, and analysis. References
Cortner, H. J., Gardner, P. D., Taylor, J. G., Carpenter, E. H., Zwolinski, M. J., Daniel, T. C., and Stenberg, K.J.: 1984, 'Uses of Public Opinion Surveys in Resource Planning', The EnvironmentalProfessional6(4), 265-275. Fienberg, S.E.: 1980, The Analysis of Cross-Classified Categorical Data, Second Edition. The MIT Press. Cambridge, Massachusetts, 198 p. Hallberg, G. R. and Hoyer, B. E., 1982, Sinkholes, Hydrogeology, and Ground-Water Qualityin NortheastIowa, Contract Report No. 81-5500-04. Iowa Geological Survey. Iowa City, IA. Hallberg, G. R., Hoyer, B. E., Bettis, E. A., III, and Libra, R. D., 1983,Hydrogeology, WaterQuality, andLand Management in the Big Spring Basin, Clay County, Iowa, Iowa Geological Survey Contract No. 82-5500-2, Iowa City, IA. Iowa Administrative Code. 1983, Chapter 41. Water Supplies, Sate of Iowa, Des Moines, IA. Mills, W. A., Ellett, W. H., and Sullivan, R. E., 1980, 'Monitoring for 228Ra in Water Supplies', Health Physics 39(12), 1003. Rajagopal, R.: 1984, GroundwaterQualityAssessmentfor PublicPolicy in Iowa, First Annual Report (1983-84) to the Joyce Foundation, IL. Department of Geography, University of Iowa. Iowa City, IA. 245p. Rajagopal, R.: 1986a, 'Conceptual Design for a Ground-Water Monitoring Strategy', The Environmental Professionalg(3), 244-264. Rajagopal, R.: 1986b, 'The Effect of Sampling Frequency on Ground-Water Quality Characterization', Ground-Water MonitoringReview 6(4), 65-73, U.S. Department of Commerce: 1983, 1980 Census of Population and Housing, Bureau of the Census,
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R. RAJAGOPAL AND GRAHAM TOBIN
Washington, D.C. U.S. Environmental Protection Agency: 1975, NationalInterim Primary Drinking WaterRegulations, CFR 40, Parts 141-149, Revised July 1984. Waters, W.P., Rajagopal, R., and Pitchford, A.M., 1987, 'Ground-Water Quality Protection: A Case of Management by Exception', in Proceedingsof the Symposium on Monitoring, Modeling, and Mediating Water Quality, published by the American Water Resources Association, Bethesda, MD, pp. 693-707.
