Public thresholds for chlorinous flavors in U.S. tap water

Abstract

Considering this rapid growth in the purchasing of bottled water and home filtration devices, utilities are increasingly concerned about consumer dissatisfaction with tap water quality. This project aimed to characterize public perceptions of chlorinous flavors in drinking water, and how these impact customers' choices with respect to consumption of tap water alternatives. On-site taste tests at seven water utilities with 30 to 40 panelists at each site, were conducted using a forced-choice triangle test method (ASTM method E679-91) to measure public sensitivity to chlorine and chloramine in drinking water. The chlor(am)ine concentration increased from set to set. The best-estimate sensitivity limit for each panelist was the geometric mean of that concentration at which the last miss occurred and the next (adjacent) higher concentration. The measured sensitivity limit of average American populations to free chlorine (159 persons tested) and chloramine (93 persons tested) in tap water were 0.8 and 3.7 mg/L Cl2, respectively. These thresholds are much higher than those previously reported in the literature using trained FPA panels. No significant differences were observed between tap water users and users of tap water alternatives or between the various markets tested with respect to average sensitivity, though individual sensitivity varied widely.

Simultaneous determination of eight common odors in natural water body using automatic purge and trap coupled to gas chromatography with mass spectrometry

“…Taste and odor (T&O) compounds are troublesome in natural waters because they have a terrible malodor influence on the quality of drinking water and aquatic products, causing great economic losses [1][2][3][4]. Recently, it is frequent that consumers strongly complain about the malodor of recreational waters, tap water and aquatic products, especially during the outbreak period of algae blooms [5,6].…”

Quantitative method to determine the regional drinking water odorant regulation goals based on odor sensitivity distribution: Illustrated using 2-MIB

“…In general, each person has a specific odor threshold (Doty et al, 1985;Schweitzer and Suffet, 1999;Devesa and Fabrellas, 2003;Mackey et al, 2004). In an odor episode, people may try to report a complaint when the odor level exceeds their odor threshold.…”

Microwave-assisted purge-and-trap extraction device coupled with gas chromatography and mass spectrometry for the determination of five predominant odors in sediment, fish tissues, and algal cells

“…Dimethyltrisulfide (DMTS), 2-methylisoborneol (MIB), geosmin (GSM), ␤-cyclocitral, and ␤-ionone are the frequently encountered odors during cyanobacteria bloom episodes [7][8][9][10]. These notorious compounds are a serious nuisance in municipal water supplies [11][12][13][14] and aquaculture [15,16] worldwide. The evaluation of off-flavors in water is essential in water science [17], environmental science [10,18], ecology [19,20], toxicology [21], and epidemiology [22].…”