Nationwide assessment of nitrosamine occurrence and trends

Abstract

Nitrosamine data reported from the first rounds of samples collected under the second Unregulated Contaminants Monitoring Rule (UCMR2) and the Ontario Drinking Water Surveillance Program were reviewed to assess the frequency and magnitude of occurrence and the effect of disinfectant type and other treatment factors on reported nitrosamine concentrations. Initial monitoring data reveal that N‐nitrosodimethylamine (NDMA) was detected in drinking water at concentrations higher than the UCMR2 minimum reporting level (MRL) of 2 ng/L in 1 of every 10 samples. Other nitrosamines (e.g., N‐nitrosodiethylamine, N‐nitroso‐di‐n‐butylamine, N‐nitrosopyrrolidine, and N‐nitroso‐methylethylamine) were rarely detected at levels above their MRLs. NDMA was primarily detected in systems using chloramines, with more than two thirds of all chloraminated water systems detecting NDMA in at least one sample. Follow‐up survey results from 45 water systems participating in UCMR2 and 6 water systems from Ontario, Canada, generally followed expected trends based on the literature. NDMA occurrence was more frequent and concentrations were higher in water systems having long contact times with chloramines. A comparison of maximum‐residence‐time distribution system samples with entry point samples indicates that NDMA concentrations may increase in a chloraminated distribution system if precursors have not fully reacted at the entry point.

Occurrence and profiling of multiple nitrosamines in source water and drinking water of China

“…Different types of nitrosamines in finished waters have been detected and characterized in several other locations in North America, the United Kingdom, Australia, and Asia. In these studies, NDMA was the most commonly detected, and the concentrations were up to 18.3 ng/L in North America, up to 65 ng/L in Canada (Russell et al, 2012;Krasner et al, 2013;Uzun et al, 2015;Charrois et al, 2007;Zhao et al, 2008), up to 10 ng/L in Japan (Asami et al, 2009), and up to 35.7 ng/L in China (Wang et al, 2010(Wang et al, , 2012. Compared to those surveys, NDEA and NDBA were also two dominant nitrosamines in finished waters in this study and previous reports of China (Wang et al, 2010(Wang et al, , 2012.…”

Formation of NDMA from ranitidine and sumatriptan: The role of pH

“…With more utilities switching from free chlorine to chloramine as the secondary disinfectant, NDMA has been detected in many chloraminated drinking water systems across North America (Blute et al, 2010;Russell et al, 2012). Most of the time the reported NDMA concentrations have been below 10 ng/L; only a small portion of the samples have shown higher concentrations (Russell et al, 2012). At the time of writing, NDMA has been mainly regulated at regional levels.…”

Modeling NDMA Formation Kinetics During Chloramination of Model Compounds and Surface Waters Impacted by Wastewater Discharges

“…Most studies have found that NDMA is rather associated with chloramination than with chlorination (4)(5)(6). Systems with high plant effluent NDMA (i.e., >50 ng/L) typically use chloramines as the primary rather than secondary disinfectant (6), reflecting the potential for precursor deactivation by strong pre-oxidants such as chlorine.…”