Comparison of trihalomethane levels and other water quality parameters for three treatment plants on the Ottawa River

Otson, Rein; Bothwell, Peter D.; Quon, Tony K.

doi:10.1021/es00091a008

Cited by 19 publications

(7 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Differences in the annual mean concentrations of TCP, total haloacetic acids (THAAs), trichloroacetic acid (TCAA), dichloroacetic acid (DCAA), total chlorine, and free chlorine were found among the four sampling sites (Table 3). In addition, the mean concentrations of some of the DBPs differed in warm (April through October) and cold (November through March) weather at zero and greater than three‐day residence time (Table 3), as has been reported previously for THMs 21 , 25 . In the warm season, the temperature was typically >10°C; in the cold season the temperature was typically <10°C (Table 4).…”

Section: Resultssupporting

confidence: 65%

“…Reported changes in DBP concentration in distribution systems. Changes in the concentration of THMs in several drinking water distribution systems have been reported, 22 – 25 but limited data exist for other DBPs 26 . Laboratory studies 24 , 26 that measured changes of THM concentrations in stored water samples implied that THMs will increase in a distribution system.…”

Section: Dbps In Distribution Systemsmentioning

confidence: 99%

See 1 more Smart Citation

Halogenated DBP concentrations in a distribution system

Chen¹,

Weisel²

1998

Journal AWWA

136

View full text Add to dashboard Cite

With increasing residence time, concentrations of THMs increased, but concentrations of HANs, HKs, CP, and HAAs decreased. Increases in the concentration of disinfection by‐products (DBPs) with increasing residence time in distribution systems have been predicted from laboratory studies but not conclusively demonstrated in the field. DBP concentrations were measured in a central New Jersey water distribution system during one year at four locations with nominal water residence times of zero, one, two, and at least three days. The water was disinfected with chloramine so that finished water left the plant with a free chlorine residual of 0.5 mg/L. Concentrations of trihalomethanes (THMs) increased with increasing residence time in the distribution system, but the concentrations of haloacetonitriles, haloketones, chloropicrin, and haloacetic acids decreased with increasing residence time. Concentrations changed more rapidly during warm months than cold months; temperature and chlorine residual were the most important parameters controlling DBP concentrations.

show abstract

Section: Resultssupporting

confidence: 65%

Section: Dbps In Distribution Systemsmentioning

confidence: 99%

Halogenated DBP concentrations in a distribution system

Chen¹,

Weisel²

1998

Journal AWWA

136

View full text Add to dashboard Cite

show abstract

“…Seasonal variation in the concentration of some DBPs has been reported by various researchers in differing locations (Smith et al, 1980;Otson et al, 1981;Krasner et al, 1989;Arora et al, 1997) . Overall, the higher temperature in the warm season and possibly differences in the type and quantity of organic matter present in the source water increased the production of TTHMs, dichloroacetonitrile, bromochloroacetonitrile, 1,1,1 -trichloropropanone and CP in the water compared with the cold season.…”

Section: Determinants Of Dbp Concentrations In Watermentioning

confidence: 91%

Uptake of chlorination disinfection by-products; a review and a discussion of its implications for exposure assessment in epidemiological studies

Nieuwenhuijsen

Toledano²,

Elliott³

2000

J Expo Sci Environ Epidemiol

160

View full text Add to dashboard Cite

We have reviewed the relevant issues in the exposure assessment of disinfection by -products ( DBPs ) of chlorination for epidemiological and health risk assessment. Various DBPs can be detected in drinking water and swimming pools, and the reported levels show a considerable range, but were generally below the current health standard for total trihalomethanes ( TTHMs ) ( 100 g / l ) . Relatively little information is available on the correlation between the various DBPs in drinking water and in swimming pools. Chloroform was generally, but not always, the most predominant DBP. In epidemiological studies, TTHM levels have been used as an indicator for total DBP load, even though TTHM levels do not always correlate well with individual DPBs. Factors such as residence time, temperature, pH, organic content, including humic and fulvic acid and bromide levels affect the composition and levels of DBPs. Although there are biomarkers of DBPs, mainly for chloroform and more recently for the other volatile trihalomethanes ( THMs ) and the nonvolatile haloacetic acids ( HAAs ) such as trichloroacetic acid ( TCAA ) and dichloroacetic acid ( DCAA ) , they have not been used in epidemiological studies. The THMs have been measured in exhaled breath and serum, while the HAAs have been measured in urine. These biomarkers have been useful to estimate the actual uptake of the DBPs and the relative contribution of various exposure routes. Physiologically based pharmacokinetic ( PBPK ) models exist for, e.g. chloroform, but their main target organs are the kidney and liver and they have not been used in epidemiological studies. Tap water ingestion, showering, bathing, swimming, boiling water and dishwashing are all activities that have been associated with the uptake of DBPs, and considerable variation in these activities has been observed between people. No studies have reported on the correlation between human uptake of DBPs and water -zone mean estimates, but various studies found a good correlation between THM concentrations in exhaled breath and THM concentrations in water during showering and swimming. In general exposure assessment in epidemiological studies has been limited which complicates the interpretation. These findings have implications for epidemiological studies, particularly with reference to Berkson and classical error type models, study power, attenuation and precision of health -risk estimates and study efficiency. Recommendations are made for further areas of study.

show abstract

“…This could result in reductions in the free chlorine residual in distribution systems as protection against possible recontamination. For Ottawa River plants, Otson et al (1981) noted that increased prechlorination dosage requirements were strongly correlated with increases in turbidity. In the United States, well-operated slow sand filtration plants may be allowed to have higher turbidity in filter effluents if there is no interference with disinfection and the turbidity level never exceeds 5.0 NTU (US-EPA 1989).…”

Section: Turbiditymentioning

confidence: 99%

Monitoring of Coliforms and chlorine residual in water distribution network of Rawalpindi, Pakistan

Farooq

Hashmi

Qazi

et al. 2007

Environ Monit Assess

View full text Add to dashboard Cite

The present study was undertaken to examine the drinking water quality of Rawal Treatment Plant, Rawalpindi and its distribution network by collecting samples from eight different locations. The aim was to determine potential relationship between the presence of microorganisms and chlorine residual in the distribution network. Quantification of chlorine residual, turbidity, standard plate count (SPC), fecal and total coliforms by Most Probable Number (MPN) was performed. Three different forms of chlorine were measured at each sampling station such as free chlorine, residual chlorine, chloramines and total chlorine residual. A critical evaluation of data presented indicated that pH generally ranged from 7.02-7.30; turbidity varied from 0.34-2.79 NTU; conductivity fluctuated from 359-374 microS/cm; and TDS values were found to be ranging between 180-187 mg/l. Station # 7 was found to be most contaminated. The value of total chlorine was found to be 0.86 to1.7 mg/l at Station # 3 and 6, respectively. Highest standard plate count was 62 CFU/ml at Station # 7. Total coliforms were less than 1.1 MPN/100 ml at almost most of the stations except at Station # 3 where it was found to be greater than 23.0 MPN /100 ml. Overall aim of this study is to create awareness about contamination of drinking water in the water distribution networks and to make recommendations to provincial agencies such as EPA, CDA and WASA that regular monitoring should be carried out to ensure that the chlorine residual is available at consumer end.

show abstract

Comparison of trihalomethane levels and other water quality parameters for three treatment plants on the Ottawa River

Cited by 19 publications

References 10 publications

Halogenated DBP concentrations in a distribution system

Halogenated DBP concentrations in a distribution system

Uptake of chlorination disinfection by-products; a review and a discussion of its implications for exposure assessment in epidemiological studies

Monitoring of Coliforms and chlorine residual in water distribution network of Rawalpindi, Pakistan

Contact Info

Product

Resources

About