Environ Monit Assess. 2025 Dec 16;198(1):46. doi: 10.1007/s10661-025-14783-z.
ABSTRACT
Chlorination of drinking water is the most widely utilized disinfection technique; however, its reaction with naturally occurring organic matter causes the production of disinfection byproducts (DBPs), such as haloacetic acids (HAAs), which are the second most common DBP after trihalomethanes. This study investigates the occurrence and spatial variation of five HAA species (monochloroacetic acid (MCAA), dichloroacetic acid (DCAA), trichloroacetic acid (TCAA), monobromoacetic acid (MBAA), and dibromoacetic acid (DBAA)) in drinking water samples collected from eight locations in Jamia Nagar, New Delhi, during March-April 2023. Among these, only two species, i.e., DCAA and TCAA, were quantified, with mean concentrations of 13.97 ± 2.87 µg/L and 13.22 ± 3.47 µg/L, respectively, and total HAAs ranging from 20.81 to 34.95 µg/L. These concentrations were well below the maximum contamination limit of 60 µg/L given by USEPA, whereas no corresponding standards exist in India. Statistical analysis revealed strong positive correlations of HAA formation with residual chlorine, total organic carbon, and pH, while temperature exhibited a weak negative influence. Principal component analysis confirmed that residual chlorine, total organic carbon, and pH were the dominant contributors to HAA variability. Spatial mapping using kriging interpolation demonstrated higher HAA concentrations at sampling locations farther from the water treatment plant, indicating the effect of longer contact time between chlorine and organic precursors. The results highlight the need to consider HAAs in Indian drinking water standards and suggest that spatial monitoring can guide treatment upgrades and evidence-based policy making to ensure safe drinking water.
PMID:41400868 | DOI:10.1007/s10661-025-14783-z