Rangaswamy Rajagopal

Fluoride in drinking water: A survey of expert opinions.

In recent years, public debate over the standard setting process related to fluoride in drinking water and the fiuoridation of water supplies has been steeped in much controversy. Discussion of such issues has been con strained by the limited consideration of options relevant to particular problems. To examine the responses to specific issues, we presented an analysis of the problem of excessive fluoride in drinking water to a group of 120 experts. Ninety-seven of the 120 responded to a detailed mail questionnaire distributed as part of a larger exploratory survey. Definite patterns in preferences were noted with certain aspects of the problem, although in some cases significant differences were found due to such factors as the institutional affiliation, residential status, and the length of professional experience of the participants. In general, our experts preferred immediate corrective action over extensive further research into the reduction of scientific uncertainties; were willing to take personal action to obtain fluoride-free water rather than wait for official action; preferred the supplier to fluoridate the supplies, if needed; and favoured a strong local control of such issues with consumers of public water systems and private well owners shouldering much of the financial responsibility. Preliminary results from such exploratory surveys can lead to insightful research hypotheses for further testing. Verification of such hypotheses by consumers, from areas with excessive fluoride in drinking water, is a valuable area for future research.

Economics of screening in the detection of organics in ground water

Abstract Rajagopal, R., 1990. Economics of screening in the detection of organics in ground water. Chemometrics and Intelligent Laboratory Systems , 9: 261–272. Screening may be defined as the use of efficient test procedures to determine and/or to quantify the presence or absence of contaminants in samples. In support of screening, many commercial laboratories offer price-breaks when analysis for only a few compounds are sought instead of a standard scan (such as those required under a governmental regulatory program). Screening is a step-wise or a decision tree approach to sampling and analysis. For a fixed number of compounds in a screen, a model to maximize the total expected number of positive determinations (detections) of organic compounds in ground water samples is developed and evaluated. This model is tested with extensive data on organic measurements obtained from ground-water samples at hazardous waste sites. The economic viability of the model is evaluated within the context of price-breaks in analytical services offered by commercial laboratories. For a set of price-breaks assumptions, screening is shown to be far superior in the detection of pesticide, acid, and base neutral compounds than in the detection of volatile organic compounds in ground water at hazardous waste sites. By incorporating relevant QA/QC costs, it is further shown that screening is a cost-effective alternative for all groups of organic compounds. A few promising avenues for further research are also outlined.

Optimal sampling strategies for source identification in environmental episodes

Optimal sequential sampling strategies to identify a source of contamination in a variety of stream network configurations are developed and described. The strategies are illustrated with applications to selected enforcement problems that occur in the field of stream water contamination. Additional discussion on the design of surveillance systems, limitations of present strategies, and the content of information received from sequential samples is also presented. Finally, a possible application of some of the sampling strategies developed in this paper to the case of a toxic contaminant release in a sewerage system is briefly explored.

Measuring toxic emissions from landfills using sequential screening

Comparisons of alternate spatial sampling strategies for characterizing hazardous waste sites can be performed using GIS-based stochastic simulation techniques. This work compares a traditional sampling design that uses only precise laboratory analytical methods to a sequential screening strategy that uses field screening methods to focus quantitative analysis on areas having pollutant concentrations above the analytical detection limit. Cost savings that result from eliminating uncontaminated areas from detailed analysis are spent on obtaining additional measurements until a fixed sampling budget is depleted. The screening strategy produces less biased and more precise estimates of volatile organic compounds emissions from an example landfill.

Groundwater Policies in the Agricultural Midwestern United States

ABSTRACT Groundwater quality in the agricultural states of Iowa, Kansas, Missouri, and Nebraska (U.S.A.) is found to vary with depth, location and ownership of well, time of sampling, and geological features. Shallow wells are much more susceptible to contamination than deep ones from surface sources. It is observed that depth and non-uniform well construction practices are two major determinants of ground-water quality. Statutes in these states recognize pesticides and herbicides as potential sources of contamination, but at this time do not specifically include any provisions to protect groundwater from contamination by other sources. This paper describes the status of groundwater quality conditions in the states of Iowa, Kansas, Missouri and Nebraska and discusses research priorities and potential policy options for the protection of groundwater in these states. These discussions would be of value to water resource scientists, planners and administrators, especially those in regions of the world where ...

Groundwater contamination and protection problems in a small rural community

Abstract This article addresses the problem of declining water quality in small communities through an examination of the views of a panel of water resource experts. It is based on the premise that sound decision-making may be facilitated when such problems are confronted by experts, rather than individuals or particular interest groups. A detailed report on ground-water contamination by toxic synthetic organic chemicals in Mount Vernon, Iowa was presented to 120 water professionals from the American Mid-West. In spite of incomplete information, the experts strongly supported positive action to limit further pollution of the aquifer. However, the problem was defined as strictly a community issue that warranted minimal financial support from the state or other agencies. There were some differences of opinion between the experts based, in part, on length of ground-water experience, but a general consensus prevailed that policy-making must take local factors into consideration.

Radioactivity in drinking water: Expert opinion and policy choices.

To examine the preferences of experts to selected economic and policy options in ground-water protection, we conducted an exploratory survey. We presented a group of 120 experts with an analysis of the problem of radium in drinking water supplies of Iowa, and requested their response to a variety of formal questions pertaining to specific issues related to the presence of radium in drinking water. Ninety-seven of the 120 responded. We observed definite preferences in responses to certain aspects of the problem, although in some cases their responses differed significantly due to such factors as length of ground-water related professional experience and residential status. When the presence of excessive radium in drinking water is identified, the respondents preferred immediate action in a world of incomplete knowledge over extensive future research; were willing to undertake personal action to seek radium-free water rather than wait for official action; and favoured local and state government involvement over federal intervention. Findings based on such exploratory surveys can be of much value in defining insightful research hypotheses for field testing. Confirmatory testing of such hypotheses to establish actual preferences in communities with excessive radium in drinking water is a valuable area for further research.

Economics of ground-water quality monitoring: A survey of experts.

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.