Evaluating the need for regulations due to the impact of nitrosamines in public drinking water systems

The purpose of drinking water regulations is to keep our drinking water safe from contaminants. This research reviewed federal regulation including the Contaminant Candidate List (CCL) regulatory process, the public health effects of six nitrosamines in drinking water, analyzes of occurrence data from Unregulated Contaminant Monitoring Rule (UCMR 2) and suggests how nitrosamines can be regulated. Currently only total trihalomethanes (THM) and haloacetic acids (HA) are regulated at the federal level. However, California has notification action levels and Massachusetts has guidelines of 10 ng/L for nitrosamine concentration. Nitrosamine data collected under the UCMR 2 were analyzed to assess the occurrence and the effect of disinfectant type and source water type. The data showed that N-nitrosodimethylamine (NDMA) was detected in drinking water at concentrations higher than the minimum reporting level (MRL) of 2 ng/L. Four nitrosamines including N-nitroso-diethylamine (NDEA), N-nitroso-di-n-butylamine (NDBA), N-nitroso-methylethylamine (NMEA) and N-nitroso-pyrrolidine (NPYR) and very low detections. N-nitroso-di-n-propylamine (NDPA) was not detected in the sample analyses. NDMA was primarily detected in public water systems using chloramines other than chlorine.