Community drinking water data on the National Environmental Public Health Tracking Network: a surveillance summary of data from 2000 to 2010

Michele M Monti,Ambarish Vaidyanathan,Mikyong Shin,Felicita David

doi:10.1007/s10661-019-7710-y

Abstract

This report describes the available drinking water quality monitoring data on the Centers for Disease Control and Prevention (CDC) National Environmental Public Health Tracking Network (Tracking Network). This surveillance summary serves to identify the degree to which ten drinking water contaminants are present in finished water delivered to populations served by community water systems (CWS) in 24 states from 2000 to 2010. For each state, data were collected from every CWS. CWS are sampled on a monitoring schedule established by the Environmental Protection Agency (EPA) for each contaminant monitored. Annual mean and maximum concentrations by CWS for ten water contaminants were summarized from 2000 to 2010 for 24 states. For each contaminant, we calculated the number and percent of CWS with mean and maximum concentrations above the maximum contaminant level (MCL) and the number and percent of population served by CWS with mean and maximum concentrations above the MCL by year and then calculated the median number of those exceedances for the 11-year period. We also summarized these measures by CWS size and by state and identified the source water used by those CWS with exceedances of the MCL. The contaminants that occur more frequently in CWS with annual mean and annual maximum concentrations greater than the MCL include the disinfection byproducts, total trihalomethanes (TTHM), and haloacetic acids (HAA5); arsenic; nitrate; radium and uranium. A very high proportion of exceedances based on MCLs occurred mostly in very small and small CWS, which serve a year-round population of 3,300 or less. Arsenic in New Mexico and disinfection byproducts HAA5 and TTHM, represent the greatest health risk in terms of exposure to regulated drinking water contaminants. Very small and small CWS are the systems’ greatest difficulty in achieving compliance.

Highlights

A safe water supply is crucial to public health and plays a critical role in our well-being as well as the success of our society and economy (EPA 2016)
public water system (PWS) are regulated by the U.S Environmental Protection Agency (EPA) and state agencies under the Safe Drinking Water Act (SDWA) (EPA 2017c)
Using the data provided by recipients, we identified annual mean and annual maximum concentrations greater than the maximum contaminant level (MCL) for each contaminant

Summary

Introduction

A safe water supply is crucial to public health and plays a critical role in our well-being as well as the success of our society and economy (EPA 2016). The USA has one of the safest drinking water supplies in the world (EPA 2016; CDC 2014). There are approximately 151,000 PWS of which 52,000 are CWS (EPA 2017a, 2017b) Eight percent of these systems serve more than 82% of the total population of the USA. PWS are regulated by the U.S Environmental Protection Agency (EPA) and state agencies under the Safe Drinking Water Act (SDWA) (EPA 2017c). The National Primary Drinking Water Regulations, or primary standards, protect public health by setting limits on levels of contaminants in drinking water. Those limits are referred to as maximum contaminant levels (MCLs) (EPA 2017b). MCLs have been identified for over 90 drinking water contaminants (EPA 2017c)

Methods

Results

Discussion

Conclusion