Ecological Research Series WATER SOFTENING AND CONDITIONING EQUIPMENT: A Potential Source of Water Contamination Environmental Research Laboratory Office of Research and Development U.S. Environmental Protection Agency Gulf Breeze, Florida 32561 ------- RESEARCH REPORTING SERIES Research reports of the Office of Research and Development, U.S. Environmental Protection Agency, have been grouped into nine series. These nine broad cate- gories were established to facilitate further development and application of en- vironmental technology. Elimination of traditional grouping was consciously planned to foster technology transfer and a maximum interface in related fields. The nine series are: 1. Environmental Health Effects Research 2. Environmental Protection Technology 3. Ecological Research 4. Environmental Monitoring 5. Socioeconomic Environmental Studies 6. Scientific and Technical Assessment Reports (STAR) 7. Interagency Energy-Environment Research and Development 8. "Special" Reports 9. Miscellaneous Reports This report has been assigned to the ECOLOGICAL RESEARCH series. This series describes research on the effects of pollution on humans, plant and animal spe- cies, and materials. Problems are assessed for their long- and short-term influ- ences. Investigations include formation, transport, and pathway studies to deter- mine the fate of pollutants and their effects. This work provides the technical basis for setting standards to minimize undesirable changes in living organisms in the aquatic, terrestrial, and atmospheric environments. This document is available to the public through the National Technical Informa- tion Service, Springfield, Virginia 22161. ------- WATER-SOFTENING AND CONDITIONING EQUIPMENT: A Potential Source of Water Contamination by Allan M. Crane and Anne E. Freeman Bears Bluff Field Station Environmental Research Laboratory - Gulf Breeze Wadmalaw Island, S. C. 29487 EPA-600/3-77-107 Environmental Research Laboratory Office of Research and Development U.S. Environmental Protection Agency Gulf Breeze, Florida 32561 ------- DISCLAIMER This report has been reviewed by the Environmental Research Laboratory, Gulf Breeze, U.S. Environmental Protection Agency, and approved for publica- tion. Mention of trade names or commercial products does not constitute en- dorsement or recommendation for use. ii ------- FOREWORD The protection of our estuarine and coastal areas from damage caused by toxic organic pollutants requires that regulations restricting the introduc- tion of these compounds into the environment be formulated on a sound scientific basis. Accurate information describing dose-response relationships for organisms and ecosystems under varying conditions is required. The Environmental Research Laboratory, Gulf Breeze, contributes to this informa- tion through research programs aimed at determining: 0 the effects of toxic organic pollutants on individual species and communities of organisms; the effects of toxic organics on ecosystem processes and components; 0 the significance of chemical carcinogens in the estuarine and marine environments. An integral part of these endeavors is the chemical analysis of the pollutants being studied. Assurance that these analyses are quantitatively and qualitatively valid depends in part on the elimination of interferences from extraneous chemicals. One such source of contamination is addressed by this paper. Thomas W. Duke Director Environmental Research Laboratory 111 ------- ABSTRACT Chloroform, trichloroethene,and tetrachloroethene as well as two uniden- tified compounds were adsorbed from contaminated ground water onto anion-cation exchange resins during their regeneration and cleaning at the distributing plant. Contaminants leached into water passed through the resins after dis- tribution resulted in contamination of deionized water supplies of users. Concentrations of chloroform and trichloroethene, greater in filtered water than concentrations observed in contaminated ground water, indicate the ability of resins to concentrate these compounds. Regeneration and cleaning of contaminated resins by commercial procedures with clean water is ineffec- tive. Contaminated resins, which leached 60 yg/1 of chloroform into water, leached 47 yg/1 after being returned to the distributor and regenerated with clean water. Increased awareness by users of the limits of ion exchange resins together with stricter water quality control of distributors is indi- cated. This report covers a period from September 28, 1976, to January 27, 1977, and work was completed as of March 1977. IV ------- CONTENTS Foreword iii Abstract iv Figures vi Tables vi Acknowledgements vii 1. Introduction 1 2. Conclusions 2 3. Experimental 3 4. Results and Discussion 6 References 8 ------- FIGURES Number Page 1 Typical Gas Chromatogram of Pentane Extract from Water Passed through Contaminated Ion Exchange/Carbon Filters 5 TABLES Number Page Distribution and Concentration of Chloroform, Trichloro- ethene, and Tetrachloroethene Contamination Variation in Contaminant Concentration Over Sampling Period 9-29-76 to 1-2-77 VI ------- ACKNOWLEDGEMENTS We thank Dr. Dan Knapp of the Pharmacology Department, Medical University of South Carolina for initial GC-mass spectrometry and Mr. E. William Loy, EPA, Region IV, Surveillance and Analysis Division for mass spectral confir- mations . vn ------- SECTION 1 INTRODUCTION Medical, biological, and analytical laboratories routinely use water for the preparation of reagents, dilutions, bioassays, and analytical procedures as well as for rinsing of glassware. Water free from undesirable contaminants is therefore an absolute necessity; thus, much effort is expended assuring that an abundant supply of pure water is available. In many cases, however, this effort begins and ends with the installation of ion exchange resin filters. Where resins have undergone strict quality control, such as imposed by the manufacturer, the use of demineralizers is sufficient to meet many general laboratory needs. Large units of ion exchange resins that require maintenance or regeneration by distributors, however, are no longer subject to this control and have the potential of becoming a source of contamination. Further, the problems associated with the mistaken but common assumption that deionized water is a substitute for distilled or ex- tracted water become compounded where water free of organics is needed. Ion exchange resins as a source of contamination is exemplified by the following case study. Ion exchange resin and carbon filters distributed to industry, research laboratories, and private homes for water softening and conditioning purposes were contaminating the water they serviced with volatile chlorinated organics. Ground water contaminated by an unknown source with chloroform, trichloro- ethene, tetrachloroethene, and two yet unidentified compounds was used by the water conditioning company for the processes involved in cleaning and regen- erating the filters, resulting in their contamination prior to distribution to customers. Efforts to determine the extent as well as the source of the ground^water contamination were undertaken by the Department of Health and Environmental Control of South Carolina. ------- SECTION 2 CONCLUSIONS Adsorption of contaminants from polluted waters by ion exchange resins dictates that their quality or freedom from contamination is only as good as the water used to regenerate and clean them. Many reports recognize our increasing dependence on ground-water re- sources. They also note the growing evidence which indicates that the nation's ground waters are becoming excessively polluted by various surface and sub- surface disposal techniques (Robertson et al, 1974; Van der Leeden et al, 1975; Crouch et al, 1976; Dunlap et al, 1976; Miller et al, 1977; Tinlin, 1976; Todd et al, 1976). The affinity of ion exchange resins for neutral halogenated organics indicates that once contaminated, standard commercial procedures employed for the regeneration of exhausted resins are inadequate to insure an uncontami- nated product. The need for an increased awareness among laboratories of the limits of ion exchange resins as well as their potential for contamination is apparent. Finally, the sources of potential ground-water contamination are addressed by existing federal and state pollution control programs, but these controls do not provide comprehensive ground-water protection due to the absence of effective monitoring and reporting programs (Easton, 1977). Although such programs would not eliminate the need for improved water quality control among distributors and users of demineralizers, they would help prevent repetition of occurrences similar to the one reported here. ------- SECTION 3 EXPERIMENTAL Water samples were collected from the various systems into 100-ml vol- umetric flasks equipped with teflon-lined screw caps (Table 1). The flasks were brought to volume and immediately extracted by employing a method similar to one reported by Henderson et al (1976). A 5-ml aliquot of pesticide grade pentane (Fisher) was pipetted directly into the flask. The water/pentane mixture was vigorously shaken for approximately five minutes; a 3.0-pi aliquot of the organic layer was then removed with a microliter syringe for chroma- tographic analysis. Gas chromatograms were obtained with a Hewlett Packard model 5710A equipped with a 63Ni electron capture detector. A 1.8-meter by 2-mm i.d. glass column, packed with 12% OV-101 on Anakrom Q 100/120 mesh (Analabs), was utilized. Analyses were run at an injection port and detector temperature of 100°C. The column was maintained at 55°C with 95:5 argon/methane mixture as the carrier gas (40 ml/min.). Chromatographic results of Bears Bluff ground water and Charleston city water extractions were negative. Water standards were prepared from standard solutions of the three compounds of interest in ethanol. The average recov- ery rate of chloroform was 89%, whereas those of tri- and tetrachloroethene were 91% and 97%,respectively. Trichloroethene and tetachloroethene assignments for two of five gas chromatographic peaks observed (Fig. 1) were obtained at the EPA's Region IV, Surveillance and Analysis Division laboratory, Athens, Ga., where samples were analyzed by the Bellar Volatile Organic Analysis Technique (Bellar and Lichtenberg, 1974), and quantified on a Tracor 210 gas chromatograph. Mass spectral confirmation was made with a Finnigan 1015. Chloroform could not be confirmed by mass spectrometry, but g<3fod GC evidence was obtained for its identification by employing the admixture tech- nique to an extracted water sample. The resulting chromatograms indicated no new peaks nor shoulder or irregularities on the chloroform peak. An increase in peak-height without corresponding increase in peak-width, conveniently measured at half-height, indicated excellent retention coincidence between chloroform and the unknown. The presence of chloroform was further confirmed by GC analysis at the Department of Health and Environmental Control labora- tory in Columbia, S. C. Quantification was accomplished by direct comparison of sample peak areas to those of standards of each of the three identified contaminants. ------- TABLE 1. DISTRIBUTION AND CONCENTRATION OF CHLOROFORM, TRICHLOROETHENE, AND TETRACHLOROETHENE CONTAMI- NATION Sample Location Date CHC13 Mt. Pleasant water system Water Conditioning Service tap Mt. Pleasant, S.C. 11-5-76 <0.1 Ground water (9 meter well) Water Conditioning Service plant Mt. Pleasant, S.C. 11-5-76 1.6 Process water Water Conditioning Service plant Mt. Pleasant, S.C. 11-5-76 6.0 Filtered water, Med. Univ. of S.C. *> Infectious Diseases Laboratory Charleston, S.C. 10-6-76 27 Filtered water, Med. Univ. of S.C. Basic Sciences Building, Rm. 527 Charleston, S.C. 10-6-76 60 Filtered water, Environmental Analytics Inc. Goose Creek, S.C. 10-6-76 NDb Filtered water, EPA Bears Bluff Field Laboratory Wadmalaw, Is., S.C. 10-6-76 29 C2HC13 C2C14 yg/i <0.1 0.7 2.8 383 12 554 <0.1 1.9 5.9 5.8 ND 3.2 54 6.1 filters in use 6 months Not detected ------- o M-l O 0) •fl -p 0) o O •H C 0) A +J A O rtf H +J 0) 0123456 MIN. Figure 1. Typical Gas Chromatogram of Pentane Extract from Water Passed through Contaminated Ion Exchange/Carbon Filters. ------- SECTION 4 RESULTS AND DISCUSSION Having determined that our laboratory ground water was free from contam- ination, initial experiments indicated that contaminants appeared after the water was passed through a commercial water treatment system designed to furnish deionized water rated at 18 megohm-cm. The system was comprised of one activated carbon, followed by two ion exchange filters which contained a cation-anion resin mixture. Follow-up tests on water samples from similar water treatment and condi- tioning systems serviced by the same company showed the same contaminants in systems located at diverse and distant points in Charleston County, S. C. (Table 1). Sampling conducted at the servicing plant revealed the process water used for back flushing, regeneration, and rinsing of the ionic resins and activated carbon employed in the filters was obtained from a 9-meter well contaminated with the same volatile halocarbons. Three of the five observed contaminants (Fig. 1) were subsequently identified as chloroform, trichloro- ethene, and tetrachloroethene. Although the types of contaminants remained constant over four months of sampling, there was degree of variability but no apparent trends of their concentrations in the three systems analyzed during this period (Table 2). TABLE 2. VARIATION IN CONTAMINANT CONCENTRATION OVER SAMPLING PERIOD 9-29-76 TO 1-2-77 . Sample CHC13 C2HC13 C2C14 yg/i Ground water service plant < 0.0-2.8 0.6-2.8 88-383 Process water service plant 1.5-6 < 0.1-7.8 389-594 Filtered water, EPA Bears Bluff Field Lab < 0.1-38 < 0.1-83 3.1-61 ------- Noteworthy was an apparent increase in concentration of chloroform and trichloroethene within the filters during servic- ing. While the concentration of these two compounds in the contaminated ground water never exceeded 3 yg/1 their concentra- tion markedly increased in filtered ground water. Maxiitmms of 27 yg/1 and 60 yg/1 chloroform were detected in samples obtained from the Infectious Diseases Laboratory and the Basic Sciences Building filters (Table 1), respectively, and a high of 38 yg/1 was detected in our laboratory filters (Table 2). In general, the length of time various water treatment sys- tems were in use at their respective locations after being serviced had little effect on the concentration of contaminants leached into the water supply. For example, filters which had exhausted their ion exchange capacity after several months of use continued to contaminate our water at approximately 80% of their original rate with 18 yg/1 chloroform, 0.1 yg/1 trichlo- roethene, and 50 yg/1 tetrachloroethene. The persistence of these chemicals was demonstrated when filters containing old, but freshly washed and regenerated resin and carbon, leached 47 yg/1 chloroform into water passed through this system. ------- REFERENCES Bellar, T. A., and J. J. Lichtenberg. The Determination of Volatile Organic Compounds at the yg/1 Level in Water by Gas Chromatography. EPA-670/ 4-74-009, U. S. Environmental Protection Agency, Cincinnati, Ohio, 1974. 27 pp. Crouch, R. L., R. D. Eckert,and D. D. Rugg. Monitoring Groundwater Quality: Economic Framework and Principles. EPA-600/4-76-045, U. S. Environ- mental Protection Agency, Cincinnati, Ohio, 1976. 97 pp. Dunlap, W. J., D. C. Shew, D. R. Scalf, R. L. Cosby, and J. M. Robertson. Isolation and Identification of Organic Contaminants in Ground Water. In: Identification and Analysis of Organic Pollutants in Water, L. H. Keith, ed. Ann Arbor Science Publishers Inc., Ann Arbor, Michigan, 1976. pp. 453-477. Easton, E. B., ed. Air/Water Pollution Report. _L5_(3) . 1977. pp. 25. Henderson, J. E., G. R. Peyton, and W. H. Glaze. A Convenient Liquid-Liquid Extraction Method for the Determination of Halomethanes in Water at the Parts-Per Billion Level. In: Identification and Analysis of Organic Pollutants in Water, L. H. Keith, ed. Ann Arbor Science Publishers Inc., Ann Arbor, Michigan, 1976. pp. 105-111. Miller, J. C., P. S. Hackenberry, and F. A. DeLuca. Groundwater Pollution Problems in the Southeastern United States. EPA-600/3-77-012, U. S. Environmental Protection Agency. Cincinnati, Ohio, 1977. 361 pp. Robertson, J. M., C. R. Toussaint, and M. A. Jorque. Organic Compounds Enter- ing Ground Water from a Landfill. EPA-660/2-74-077, U. S. Environmental Protection Agency, Cincinnati, Ohio, 1974. Tinlin, R. M., ed. Monitoring Groundwater Quality: Illustrative Examples. EPA-600/4-76-036, U. S. Environmental Protection Agency, Cincinnati, Ohio, 1976. 88 pp. Todd, D. K., R. M. Tinlin, K. D. Schmidt,and L. G. Everett. Monitoring Groundwater Qualtiy: Monitoring Methodology. EPA-600/4-76-026, U. S. Environmental Protection Agency, Cincinnati, Ohio, 1976. 154 pp. Van der Leeden, F., L. A. Cerrillo,and D. W. Miller. Groundwater Pollution Problems in the Northwestern United States. EPA-660/3-75-018, U. S. Environmental Protection Agency, Cincinnati, Ohio, 1975. 361 pp. ------- TECHNICAL REPORT DATA (Please read Instructions on the reverse before completing) 1. REPORT NO. EPA-600/3-77-107 4. TITLE AND SUBTITLE WATER-SOFTENING AND CONDITIONING EQUIPMENT: A Potential Source of Water Contamination 5. REPORT DATE September 1977 issuing date 6. PERFORMING ORGANIZATION CODE 3. RECIPIENT'S ACCESSION-NO. 7. AUTHOR(S) Allan M. Crane and Anne E. Freeman 8. PERFORMING ORGANIZATION REPORT NO. 9. PERFORMING ORGANIZATION NAME AND ADDRESS Gulf Breeze Environmental Research Laboratory Bears Bluff Field Station Wadmalaw Island, S.C. 29487 10. PROGRAM ELEMENT NO. lEAfil 11. CONTRACT/GRANT NO. 12. SPONSORING AGENCY NAME AND ADDRESS Environmental Research Lab. - Gulf Breeze, Office of Research and Development U.S. Environmental Protection Agency Gulf Breeze, Florida 32561 FL 13. TYPE OF RE PORT AND PERIOD COVERED Final 8/28/76-8/27/77 14. SPONSORING AGENCY CODE EPA/600/04 15. SUPPLEMENTARY NOTES chloroform, trichloroethene, and tetrachloroethene as well as two unidentified compounds were adsorbed from contaminated ground water onto anion-cation exchange resins during their regeneration and cleaning at the distributing plant. Contaminant leached into water passed through the resins after distribution resulted in contami- nation of deionized water supplies of users. Concentrations of chloroform and tri- chloroethene , greater in filtered water than concentrations observed in contaminated ground water, indicate the ability of resins to concentrate these compounds. Regenera tion and cleaning of contaminated resins by commercial procedures with clean water is ineffective. Contaminated resins, which leached 60 g/1 of chloroform into water leached 47 g/1 after being returned to the distributor and regenerated with clean water. Increased awareness by users of the limits of ion exchange resins together with stricter water quality control of distributors is indicated. This report covers a period from September 18, 1976, to January 27, 1977 and work was completed as of March 1977. KEY WORDS AND DOCUMENT ANALYSIS DESCRIPTORS b.IDENTIFIERS/OPEN ENDED TERMS COSATI Field/Group Ground water Water conditioning Ion exchange resins Deionized water Chlorinated organics Water softening and conditioning equipment Contamination South Carolina 06/F 3. 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