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.

No abstract

Informant: Nah. What can we do? Our houses are there so we cannot just leave everything and go to another place as we do not own land in other place! So even if we have to die, we will live and die in our own house; that is what we think.

Compared with other drinking water regulatory determinations, the cost implications of a perchlorate maximum contaminant level are relatively low because of the chemical's limited occurrence in source waters in the United States. However, a small number of systems are carrying this cost burden and the cost implications to an individual system having to install perchlorate treatment would likely be significant. Several studies have evaluated the nationwide occurrence of perchlorate in drinking water sources, but to the authors’ knowledge, no study has been conducted evaluating the cost implications for treatment of all perchlorate‐contaminated drinking water sources. This study was undertaken to bridge this information gap in anticipation of discussions about whether to regulate perchlorate at a national level. If the perchlorate regulation is revisited by the U.S. Environmental Protection Agency, this study is expected to be a key building block for subsequent evaluation of the cost implications of a national perchlorate standard. This article provides an initial estimate of costs associated with such a standard. Details can be used as guidelines for water suppliers as they assess the cost implications of installing perchlorate treatment at their utility.

Ingestion of trace amounts of 19-norandrostenedione can result in transient elevations of urinary 19-NA and 19-NE concentrations. The addition of as little as 2.5 microg of 19-norandrostenedione to a supplement (0.00005% contamination) appears sufficient to result in a doping violation in some individuals.