A comparison of disinfection by-products found in chlorinated and chloraminated drinking waters in Scotland

Seven water treatment works were selected to compare disinfection by-products (DBPs) formed when using chlorination and chloramination. DBPs measured included trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs), trihalonitromethane, iodinated THMs and nitrosamines. Generally treatment works that used chloramination were able to meet the European THM regulatory limit of 100 μg L⁻¹ whereas the chlorinated works found it significantly more difficult. There were no significant differences in the levels of nitrogenous DBPs between the treatment works using chlorination or chloramination with the exception of the nitrosamine N-nitrosodimethylamine (NDMA) which was present at one treatment works in one season.     

Identification of potential nitrogenous organic precursors for C-, N-DBPs and characterization of their DBPs formation

Nitrosamines are a class of emerging disinfection by-products (DBPs), which are mainly formed when water is treated by chloramination. Nitrosamines are highly carcinogenic and are hence a major concern for drinking water supplies. Although dissolved organic nitrogen (DON) compounds such as dimethylamine (DMA) have been recognized as important precursors of nitrosamines, many of them have not been identified, especially those used in consumer products. In this study, nine representative nitrogenous organic compounds with different DON characteristics and structures were selected to react with free chlorine, chlorine dioxide and monochloramine, respectively, for their DBP formation characteristics (nitrosamines, trihalomethanes (THMs) and haloacetic acids (HAAs)). It was found that in addition to DMA, benzyldimethyltetradecylamine (benzalkonium chloride, BKC) and 3-(N,N-dimethyloctyl-ammonio)propanesulfonate (3-N,N-DAPSIS) inner salt were potent precursors for carbonated DBPs (C-DBPs) and nitrogenated DBPs (N-DBPs). The DBP formation potential (DBPFP) tests showed that 1 mM of BKC formed more than 2 × 10⁵ ng/L of N-nitrosodimethylamine (NDMA) when treated with monochloramine and high levels of C-DBPs (2713 ± 145 μg/L of THMs and 356 ± 5 μg/L of HAAs) when treated with chlorine. 3-N,N-DAPSIS was a less potent DBP precursor: 1 mM of 3-N,N-DAPSIS generated 1155 ± 7 ng/L of NDMA, 1351 ± 66 μg/L of THMs and 188 ± 1 μg/L of HAAs. DMA, 3-N,N-DAPSIS and BKC were examined for their DBPFPs at various pH and temperatures to determine the impact of pH and reaction temperature on DBP yields and their formation mechanisms. The results showed that DBP yields apparently increased with rising temperature. However, no consistent correlations were observed between DBPs yields and pH. Bromide shifted the DBP species into brominated DBPs, and this phenomenon was more apparent when BKC was treated with chloramine.     

Comparison of the disinfection by-product formation potential of treated waters exposed to chlorine and monochloramine

The formation of disinfection by-products (DBPs) from chlorination and monochloramination of treated drinking waters was determined. Samples were collected after treatment at 11 water treatment works but before exposure to chlorine or monochloramine. Formation potential tests were carried out to determine the DBPs formed by chlorination and monochloramination. DBPs measured were trihalomethanes (THMs), haloacetic acids (HAAs), halonitromethanes (HNMs), haloacetonitriles (HANs), haloaldehydes (HAs), haloketones (HKs) and iodo-THMs (i-THMs). All waters had the potential to form significant levels of all the DBPs measured. Compared to chlorine, monochloramination generally resulted in lower concentrations of DBPs with the exception of 1,1-dichloropropanone. The concentrations of THMs correlated well with the HAAs formed. The impact of bromine on the speciation of the DBPs was determined. The literature findings that higher bromide levels lead to higher concentrations of brominated DBPS were confirmed.     

Haloacetic acids in drinking water in the United Kingdom

We measured concentrations of haloacetic acids (HAAs) in the water supply in regions covered by three water companies in the UK Approximately 30 samples in each region were obtained for analysis of both THMs and HAAs to assess the levels of HAAs and the relationship between HAAs and THMs, temperature, pH, free and total chlorine. We have found that there is a range of HAA levels in drinking water with the means ranging from 35-95mug/l and a maximum concentration of 244mug/l. In two out of the three regions there was a high correlation between total THMs and total HAAs, but whereas the HAA and THM levels in one of these companies were approximately equal, in another company the HAA levels were 3-4 times higher than the THM levels. In the third region there was no correlation between total THMs and total HAAs even though the average levels were approximately equal. The ratio of total THM and total HAAs levels was significantly correlated with temperature, pH, free and total chlorine. Overall total THM levels are therefore not considered to be a good indicator of HAA levels. Epidemiological studies using total THM levels should be taking this into account in the interpretation of their results, and regulatory authorities when setting water guidelines.     

A reactive species model for chlorine decay and THM formation under rechlorination conditions

Chlorine is typically used within drinking water distribution systems to maintain a disinfectant residual and minimize biological regrowth. Typical distribution system models describe the loss of disinfectant due to reactions within the water matrix as first order with respect to chlorine concentration, with the reactants in excess. Recent work, however, has investigated relatively simple dynamic models that include a second, hypothetical reactive species. This work extends these latter models to account for discontinuities associated with rechlorination events, such as those caused by booster chlorination and by mixing at distribution system junction nodes. Mathematical arguments show that the reactive species model will always represent chlorine decay better than, or as well as, a first-order model, under single dose or rechlorination conditions; this result is confirmed by experiments on five different natural waters, and is further shown that the reactive species model can be significantly better under some rechlorination conditions. Trihalomethane (THM) formation was also monitored, and results show that a linear relationship between total THM (TTHM) formation and chlorine demand is appropriate under both single dose and rechlorination conditions. This linear relationship was estimated using the modeled chlorine demand from a calibrated reactive species model, and using the measured chlorine demand, both of which adequately represented the TTHM formation.     

The role of nitrobenzene on the yield of trihalomethane formation potential in aqueous solutions with Microcystis aeruginosa

Algae are one of the most important disinfection by-product (DBP) precursors in aquatic environments. The contents of DBP precursors in algae are influenced by not only environmental factors but also some xenobiotics. Trihalomethane formation potential (THMFP) in both the separate and interactive pollution of Microcystis aeruginosa and Nitrobenzene (NB) was investigated in batch experiment to discover the effects of xenobiotics on the yield of DBP precursors in the algal solution. The results show that in the separate NB solution, NB did not react with Cl₂ to form trihalomethane (THM), whereas in the algae solution, THMFP had a significant positive linear correlation with M. aeruginosa density in both solution and extracellular organic matter (EOM). The correlation coefficients were 0.9845 (p = 3.567 × 10⁻⁴) and 0.9854 (p = 1.406 × 10⁻⁴), respectively. According to regression results, about 77.9% of the total THMFP came from the algal cells, while the rest came from EOM. When the interactive pollution of M. aeruginosa and NB occurred, the growth of algae was inhibited by NB. The density of M. aeruginosa in a high concentration NB solution (280 μg/L) was only 71.1% of that in the solution without NB after 5 days of incubation. However, THMFP in the mixture (algae and NB) and the EOM did not change significantly, and the productivity of THMFP by the algae (THMFP/10⁸cells) increased with the increase in NB concentration. There was a significant linear correlation between THMFP/10⁸cell and NB concentration (r = 0.9117, p < 0.01), which shows the contribution of the algae to THM formation was enhanced by NB. This result might be caused by the increased protein productivity and the biodegradation of NB by M. aeruginosa.     

The impact of water consumption, point-of-use filtration and exposure categorization on exposure misclassification of ingested drinking water contaminants

The use of population-level indices to estimate individual exposures is an important limitation of previous epidemiologic studies of disinfection by-products (DBPs). We examined exposure misclassification resulting from the use of system average DBP concentrations to estimate individual-level exposures. Data were simulated (n=1000 iterations) for 100 subjects across 10 water systems based on the following assumptions: DBP concentrations ranged from 0-99 microg/L with limited intra-system variability; water intake ranged from 0.5-2.5 L/day; 20% of subjects used bottled water exclusively; 20% of subjects used filtered tap water exclusively; DBP concentrations were reduced by 50% or 90% following filtration. DBP exposure percentiles were used to classify subjects into different exposure levels (e.g., low, intermediate, high and very high) for four classification approaches. Compared to estimates of DBP ingestion that considered daily consumption, source type (i.e., unfiltered tap, filtered tap, and bottled water), and filter efficiency (with 90% DBP removal), 48-62% of subjects were misclassified across one category based on system average concentrations. Average misclassification across at least two exposure categories (e.g., from high to low) ranged from 4-14%. The median classification strategy resulted in the least misclassification, and volume of water intake was the most influential modifier of ingestion exposures. These data illustrate the importance of individual water use information in minimizing exposure misclassification in epidemiologic studies of drinking water contaminants.     

Influence of sampling strategies on the monitoring of cyanobacteria in shallow lakes: lessons from a case study in France

Sampling cyanobacteria in freshwater ecosystems is a crucial aspect of monitoring programs in both basic and applied research. Despite this, few papers have dealt with this aspect, and a high proportion of cyanobacteria monitoring programs are still based on monthly or twice-monthly water sampling, usually performed at a single location. In this study, we conducted high frequency spatial and temporal water sampling in a small eutrophic shallow lake that experiences cyanobacterial blooms every year. We demonstrate that the spatial and temporal aspects of the sampling strategy had a considerable impact on the findings of cyanobacteria monitoring in this lake. In particular, two peaks of Aphanizomenon flos-aquae cell abundances were usually not picked up by the various temporal sampling strategies tested. In contrast, sampling once a month was sufficient to provide a good overall estimation of the population dynamics of Microcystis aeruginosa. The spatial frequency of sampling was also important, and the choice in the location of the sampling points around the lake was very important if only two or three sampling points were used. When four or five sampling points were used, this reduced the impact of the choice of the location of the sampling points, and allowed to obtain fairly similar results than when six sampling points were used. These findings demonstrate the importance of the sampling strategy in cyanobacteria monitoring, and the fact that it is impossible to propose a single universal sampling strategy that is appropriate for all freshwater ecosystems and also for all cyanobacteria.     

Characterization of intracellular & extracellular algae organic matters (AOM) of Microcystic aeruginosa and formation of AOM-associated disinfection byproducts and odor & taste compounds

Algae organic matters (AOM), including intracellular organic matters (IOM) and extracellular organic matters (EOM), are causing numerous water quality issues, among which formation of disinfection byproducts (DBPs) and odor & taste (O&T) compounds are of particular concern. In this study, physiochemical properties of IOM and EOM of Microcystic aeruginosa under an exponential growth phase (2.01 × 10¹¹/L) were comprehensively characterized. Moreover, the yields of DBPs during AOM disinfection and O&T-causing compounds were quantified. Hydrophilic organic matters accounted for 86% and 63% of DOC in IOM and EOM, respectively. Molecular weight (MW) fractions of IOM in <1 kDa, 40-800 kDa, and >800 kDa were 27%, 42%, and 31% of DOC, respectively, while EOM primarily contained 1-100 kDa molecules. Besides, a low SUVA (0.84 L/mg m) and the specific fluorescence spectra suggested that AOM (especially IOM) was principally comprised of protein-like substances, instead of humic-like matters. The formation potentials of chloroform, chloroacetic acid, and nitrosodimethylamine were 21.46, 68.29 and 0.0096 μg/mg C for IOM, and 32.44, 54.58 and 0.0189 μg/mg C for EOM, respectively. Furthermore, the dominant O&T compound produced from EOM and IOM were 2-MIB (68.75 ng/mg C) and β-cyclocitral (367.59 ng/mg C), respectively. Of note, dimethyltrisulfide became the prevailing O & T compound following anaerobic cultivation.     

Formation and fate of haloacetic acids (HAAs) within the water treatment plant

Most research on the occurrence of chlorinated disinfection by-products (DBPs) in drinking water has focused on trihalomethane (THM) formation and evolution, in particular within distribution systems. In this research, we investigated the variability of the occurrence of haloacetic acids (HAAs) during the treatment process in two facilities where surface water is pre-chlorinated before being treated by conventional physico-chemical processes. The investigation focused on both seasonal and point-to-point fluctuations of HAAs. In both facilities, samples were collected weekly during 1 complete year at four points in order to generate robust data on HAAs and on complementary parameters. The results showed that the initial formation of HAAs was the highest and the most variable in the plant where levels of DBP precursor indicators and the pre-chlorination dose were both higher and more variable. Subsequent formation of HAAs from the pre-chlorination point until the settled water occurred due to remaining levels of residual chlorine and DBP precursors. However, HAA levels and in particular dichloroacetic acid (DCAA) (the preponderant HAA species in the waters under study) decreased dramatically during filtration, very probably because of biodegradation within the filter. The effect of filtration on DCAA fate was season-dependant, with the highest degradation in warm water periods and practically no variation during winter. Statistical modeling was applied to empirically identify the operational factors responsible for HAA formation and fate. Model performance to identify HAA variability in waters following pre-chlorination was much better than for water following filtration, which is due to the lack of information on mechanisms and conditions favoring DCAA degradation.     

Measuring the concentrations of drinking water disinfection by-products using capillary membrane sampling-flow injection analysis

A capillary membrane sampling-flow injection analysis method is presented for selectively measuring the concentrations of total trihalomethanes (THMs) and total haloacetic acids (HAAs) in drinking water. The method is based on the reaction between nicotinamide and THM or HAA species to yield a fluorescent product. Two configurations are presented, one selective for total THMs and another selective for total HAAs. The construction of a capillary membrane sampler is described, and the results of method detection limit, accuracy and precision studies are reported for each method. Interference, selectivity and linearity studies are reported as well as the effect of temperature and ionic strength changes. Drinking water samples were analyzed by each proposed method and the results were compared to USEPA methods 502.2 and 552.3.     

Disinfection and formation of disinfection by-products in a photoelectrocatalytic system

In this study, disinfection and formation of disinfection by-products (DBPs) were studied in a photoelectrocatalytic (PEC) treatment system. Disinfection performance of titanium dioxide (TiO₂) in the PEC system was determined through Escherichia coli (E. coli) inactivation. Humic acid (HA) was used as a model organic compound and its removal was monitored by total organic carbon (TOC) measurements using 410 nm (color) and 254 nm (UV₂₅₄) wavelengths. Trihalomethanes (THMs) were measured for the evaluation of DBPs formation during PEC treatment of chloride and HA mixture. It was found that unlike photocatalytic treatment, THMs might form in the PEC system. To investigate the effects of anions on the PEC treatment, chloride (Cl⁻), sulfate (SO₄²⁻), phosphoric acid (H₂PO₄⁻)/hydrogen phosphate (HPO₄²⁻) and bicarbonate (HCO₃⁻) ions were added separately to the HA and bacterial suspensions. Presence of H₂PO₄⁻/HPO₄²⁻ and HCO₃⁻ ions resulted in inhibitory effects on both HA degradation and E. coli inactivation, which were also examined in the photoanode. It was observed that the presence of HA had a strong inhibitory effect on the disinfection of E. coli.     

Disinfection by-product formation following chlorination of drinking water: Artificial neural network models and changes in speciation with treatment

Artificial neural network (ANN) models were developed to predict disinfection by-product (DBP) formation during municipal drinking water treatment using the Information Collection Rule Treatment Studies database complied by the United States Environmental Protection Agency. The formation of trihalomethanes (THMs), haloacetic acids (HAAs), and total organic halide (TOX) upon chlorination of untreated water, and after conventional treatment, granular activated carbon treatment, and nanofiltration were quantified using ANNs. Highly accurate predictions of DBP concentrations were possible using physically meaningful water quality parameters as ANN inputs including dissolved organic carbon (DOC) concentration, ultraviolet absorbance at 254 nm and one cm path length (UV₂₅₄), bromide ion concentration (Br⁻), chlorine dose, chlorination pH, contact time, and reaction temperature. This highlights the ability of ANNs to closely capture the highly complex and non-linear relationships underlying DBP formation. Accurate simulations suggest the potential use of ANNs for process control and optimization, comparison of treatment alternatives for DBP control prior to piloting, and even to reduce the number of experiments to evaluate water quality variations when operating conditions are changed. Changes in THM and HAA speciation and bromine substitution patterns following treatment are also discussed.     

Impact of sonication at 20 kHz on Microcystis aeruginosa, Anabaena circinalis and Chlorella sp

Blooms of toxic cyanobacteria such as Microcystis aeruginosa periodically occur within wastewater treatment lagoons in the warmer months, and may consequently cause contamination of downstream water and outages of the supply of recycled wastewater. Lab-scale sonication (20 kHz) was conducted on suspensions of M. aeruginosa isolated from a wastewater treatment lagoon, and two other algal strains, Anabaena circinalis and Chlorella sp., to investigate cell reduction, growth inhibition, release of microcystin and sonication efficiency in controlling the growth of the M. aeruginosa. For M. aeruginosa, for all sonication intensities and exposure times trialled, sonication led to an immediate reduction in the population, the highest reduction rate occurring within the initial 5 min. Sonication for 5 min at 0.32 W/mL, or for a longer exposure time (>10 min) at a lower power intensity (0.043 W/mL), led to an immediate increase in microcystin level in the treated suspensions. However, prolonged exposure (>10 min) to sonication at higher power intensities reduced the microcystin concentration significantly. Under the same sonication conditions, the order of decreasing growth inhibition of the three algal species was: A. circinalis > M. aeruginosa > Chlorella sp., demonstrating sonication has the potential to selectively remove/deactivate harmful cyanobacteria from the algal communities in wastewater treatment lagoons.     

Evaluation of the mechanisms of the effect of ultrasound on Microcystis aeruginosa at different ultrasonic frequencies

Blooms of cyanobacteria are now considered to be a common environmental issue. They are hazardous to both domestic and wild animals and humans. Current treatments are unable to effectively control such blooms as they become tolerant to biocides and it is difficult to degrade cyanobacterial toxins in water. Alternative methods for control are currently under investigation. One potential effective method is ultrasonic irradiation. Ultrasound inactivates algal and cyanobacteria cells through cavitation by generating extreme conditions, resulting in a number of physical, mechanical and chemical effects. The aim of this study was to investigate the effect of ultrasound at different frequencies on Microcystis aeruginosa. Flow cytometry was used to measure cyanobacterial metabolic cell viability in addition to the more commonly used haemocytometry, optical density and fluorimetry. Results indicate low frequency 20 kHz ultrasound with high intensity (0.0403 W cm⁻³) is effective for the inactivation of cyanobacterial cells. Higher frequencies of 580 kHz (0.0041 W cm⁻³) also resulted in an inactivation effect, but 1146 kHz (0.0018 W cm⁻³) showed a declumping effect as evidenced by flow cytometry. Ultrasonic treatment over time under different sonication conditions demonstrates the following:1. Acoustic cavitation via mechanical effects can induce sufficient shear forces to directly rupture cyanobacteria cells.2. At higher ultrasonic frequencies the mechanical energy of cavitation is less but a larger proportion of free radicals are produced from the ultrasonic degradation of water, which chemically attacks and weakens the cyanobacteria cell walls.3. At higher frequencies free radicals also damage chlorophyll a leading to a loss in photosynthetic cell viability.4. At low powers ultrasonic energy results in declumping of cyanobacteria.     

Impact of water stagnation in residential cold and hot water plumbing on concentrations of trihalomethanes and haloacetic acids

This study demonstrates that levels of trihalomethanes (THMs) increase considerably when cold water stagnates in residential pipes and, more significantly, when water remains in the hot water tank. Levels of haloacetic acids (HAAs) increase as well in both cases, but less significantly in comparison to THMs. The study also demonstrates that in both the plumbing system and residential hot water tank, chlorinated and brominated DBP species do not behave in the same manner. Finally, the study shows that sustained use of water in households helps to maintain THM and HAA levels close to those found in water of the distribution system. The results are useful to identify methods of indoor water use that minimize population exposure to DBPs and improve DBP exposure assessment for epidemiological studies.     

Effects of low- or medium-pressure ultraviolet lamp irradiation on Microcystis aeruginosa and Anabaena variabilis

A pure culture of Microcystis aeruginosa or Anabaena variabilis, the representatives of water blooming algae, was exposed to low-pressure (LP) or medium-pressure (MP) UV lamps. Irradiated pure culture suspension was subsequently incubated for 7d under white light fluorescent lamps. During incubation, profiles of the number of cells, DNA damage and photosynthetic activity were determined. When UV fluence was 600mJ/cm(2), M. aeruginosa cell numbers decreased throughout the 7-d incubation period, to produce 1.5log reduction (LP) or 1.2log reduction (MP) compared with control. The amount of DNA damage was 2.02x10(-4) ESS/base (LP) and 3.42x10(-4) ESS/base (MP) just after UV irradiation, which became 0.05x10(-4) ESS/base and 0.23x10(-4) ESS/base, respectively, after 3d incubation. However, cell number kept decreasing, even after DNA repair. Photosynthetic activity decreased by 1.5log within 1d (LP) or 3d (MP). Thus, reduction in photosynthetic activity could contribute to the reduction in M. aeruginosa cell numbers. A. variabilis cell numbers reduced by 2.3log (LP) or 2.2log (MP) during the 7-d incubation period; however, after DNA damage repair, cell number began to increase. The amount of DNA damage was 6.07x10(-4) ESS/base (LP) and 4.48x10(-4) ESS/base (MP) just after UV irradiation, which became 0.23x10(-4) ESS/base and 0.40x10(-4) ESS/base, respectively, after 3d incubation. No reduction was observed in photosynthetic activity/cell. Therefore, DNA damage is the main contributor of the reduction in cell number of A. variabilis.     

Catalysis of copper corrosion products on chlorine decay and HAA formation in simulated distribution systems

This study investigated the effect of copper corrosion products, including Cu(II), Cu₂O, CuO and Cu₂(OH)₂CO₃, on chlorine degradation, HAA formation, and HAA speciation under controlled experimental conditions. Chlorine decay and HAA formation were significantly enhanced in the presence of copper with the extent of copper catalysis being affected by the solution pH and the concentration of copper corrosion products. Accelerated chlorine decay and increased HAA formation were observed at pH 8.6 in the presence of 1.0 mg/L Cu(II) compared with that observed at pH 6.6 and pH 7.6. Further investigation of chlorine decay in the presence of both Suwannee River NOM and Cu(II) indicated that an increased reactivity of NOM with dissolved and/or solid surface-associated Cu(II), rather than chlorine auto-decomposition, was a primary reason for the observed rapid chlorine decay. Copper corrosion solids [Cu₂O, CuO, Cu₂(OH)₂CO₃] exhibited catalytic effects on both chlorine decay and HAA formation. Contrary to the results observed when in the absence of copper corrosion products, DCAA formation was consistently predominant over other HAA species in the presence of copper corrosion products, especially at neutral and high pH. This study improves the understanding for water utilities and households regarding chlorine residuals and HAA concentrations in distribution systems, in particular once the water reaches domestic plumbing where copper is widely used.     

Effect of chlorination on the formation of odorous disinfection by-products

In order to explain some of the possible origins of an odor episode, which took place in a drinking water supply in the region of Paris (France), the chlorination reaction of some simple amino acids (valine, leucine and phenylalanine) was investigated. In addition to the commonly admitted intermediates and products of this reaction (monochloramines, aldehydes and nitriles), the formation of far less documented products was observed: N-chloroaldimines which proved to present particular properties. These products appeared to remain relatively stable in water, especially at low temperatures, and can be formed under disinfection conditions relevant to those of drinking water treatment (i.e. at high chlorination rates). N-chloroaldimines also present strong swimming pool odors with a floral background, with odor detection thresholds close to 1microgL(-1) and even less. These values were established with a laboratory-made protocol. These products appeared more odorous than the corresponding aldehydes, known for a long time as potent odor causing chemicals and which have previously been involved in some odor problems in the field of drinking water treatment. N-chloroaldimines are consequently products of interest for water treaters and are now suspected to be a source of off-flavor concerns among consumers. We have therefore developed an analytical method (gas chromatography coupled with mass spectrometry) to demonstrate the presence of some of these compounds in water at concentrations close to their odor detection thresholds. Considering the levels of amino acids that can be reached in water, this level of chloroaldimines concentration could be obtained under certain pollution conditions.     

2. Comparison of the disinfection by-product formation potentials between a wastewater effluent and surface waters

In this study, the chemical reactivity with chlorine as measured by disinfection by-product formation potential (DBPFP) is compared among samples of a wastewater effluent and surface waters. Water samples that had higher anthropogenic impacts were found to have higher overall DBPFP due primarily to higher dissolve organic carbon (DOC) concentrations. Effluent-derived organic matter (EfOM), however, was found to be less reactive with chlorine on a per DOC concentration basis. Yet, EfOM had higher proportions of brominated DBP, which may be associated with greater health risks. In this research, pyrolysis-GC/MS was used to establish relationship between structural features of DOC and DBPFP. We show that there is a critical set of pyrolysis fragments that separates the waters based on the degree of anthropogenic influence. Even though no single chemical marker was found to be indicative of the formation potentials of different classes of DBP, combinations of chemical fragments were found to be associated with the formation potentials of total trihalomethane (THM), brominated THM, total haloacetic acid (HAA), and brominated HAA for this set of samples. In contrast to previous work, the phenolic signature of these samples was negatively correlated to DBPFP, whereas strong relationships were found between DBPFP and the organic nitrogen and halogenated signatures.