By Chris Leaf, Project Chemist, Kelso, WA

Imagine turning on a faucet to get a glass of water and discovering that perfluorooctane sulfonic acid, methyl tert-butyl ether, or chloromethane has flowed into your glass. These chemical compounds represent real threats to the public and are present in many public water supplies today.

In September of 2009, the EPA finalized its Contaminant Candidate List 3 (CCL3), comprised of 116 drinking water contaminants. These contaminants have already been discovered in public water systems or pose the risk of existing in public water supplies. Under the Safe Drinking Water Act (SDWA), the EPA is required to evaluate and determine whether to regulate at least five contaminants from the CCL every five years. The EPA decides if regulations will be required based on the following criteria¹:

• The contaminant may have an adverse effect on the health of persons.
• The contaminant is known to occur, or there is a great likelihood that the contaminant will occur in public water supplies with a frequency and at levels of public health concern.
• In the sole judgment of the EPA Administrator, regulation of the contaminant presents a meaningful opportunity for health risk reduction for persons served by public water systems.

Read more about emerging contaminants and health risks…

by Brian Lewis, Ph. D

On January 15, 2010, the Food and Drug Administration (FDA) reversed its position that exposure to bisphenol-A (BPA) is not harmful, stating that they now “have some concern about the potential effects of BPA on the brain, behavior, and prostate gland in fetuses, infants, and young children”.¹ In the same report, the FDA voiced their support for the food and beverage container industry to halt production of baby bottles and feeding cups in the U.S. that contain BPA.

The FDA’s current position on BPA follows a 2008 draft report by the agency that claimed the no observable adverse effect level (NOAEL) of 5 mg/kg body weight/day was “an adequate margin of safety … for BPA at current levels of exposure from food contact uses,” and that the 2.42 μg/kg body weight/day and 0.185 μg/kg body weight/day exposure levels found in infants and adults, respectively, was safe.² However, when that draft report was submitted to a seven-member panel of experts for peer review, the panel refuted the FDA’s position, stating that “the available qualitative and quantitative information … provides a sufficient scientific basis to conclude that the Margins of Safety defined by FDA as ‘adequate’ are, in fact, inadequate”.³

Read more about Bisphenol-A…

A recent United States Geological Survey (USGS) study of public drinking water wells in California, Connecticut, Nebraska and Florida found that some were contaminated, but in amounts so minimal, human health was unlikely to be affected. The USGS tracked the movement of contaminants in groundwater and public-supply wells in four different aquifers.

According to the USGS, wells are not equally vulnerable to contamination because of differences in three factors: the general chemistry of the aquifer, groundwater age, and direct paths within aquifer systems that allow water and contaminants to reach a well. The importance of each factor differs among the various aquifer settings, depending upon natural geology and local aquifer conditions, as well as human activities related to land use and well construction and operation. However, the USGS feels that the study of the four different aquifer systems can be applied to similar aquifers and wells throughout the nation.

Read more about drinking water contamination…

This article describes the background, stages and the new deadlines for public water systems to comply with the most current disinfectants and disinfection byproducts rule.

By Dr. Harlan H. Bengtson, PE

Background on Disinfection and Disinfection Byproducts

Jersey City, NJ was the first U.S. city to routinely disinfect its municipal water supply, starting in 1908.¹ Soon after, thousands of cities and towns across the country began to do the same and this dramatically decreased the prevalence of waterborne diseases such as cholera and typhoid. To demonstrate, the incidence rate of typhoid fever in the U.S. dropped from about 100 cases per 100,000 people in 1900 to 33.8 cases per 100,000 people in 1920.² By 2006, this rate had dropped to 0.1 cases per 100,000 people.³

Read more about disinfectants rule…

Chlorine has been used to disinfect water for almost a century due to its ability to kill bacteria and viruses in water. The use of chlorine as a disinfectant has been an effective contribution to public health eliminating plagues such as cholera and typhoid, and reducing the incidence of intestinal illness and other health problems caused by waterborne pathogens such as cryptosporidium. The benefits of disinfection, however, do not come without an effect.

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Every day millions of gallons of treated and untreated wastewater are discharged into the waterways of the world. This wastewater may contain varying concentrations of pharmaceuticals and personal care products (PPCPs) including prescription and over the counter medications, nutraceuticals, illicit drugs, detergents, perfumes, insect repellent, sunscreens, and steroids, some of which have been identified in a recent article by The Associated Press¹.

Recent studies have shown that many of these PPCP compounds at low concentrations can have negative effects on the endocrine systems of aquatic organisms. These compounds are collectively known as Endocrine Disrupting Compounds (EDCs). Other concerns regarding PPCPs include contamination of drinking water, estrogenic effects on humans and wildlife, and development of antibiotic resistant bacteria.

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On Tuesday, January 11, 2005 the Committee to Access the Health Implications of Perchlorate Ingestion, convened by the National Research Council at the request of the EPA, DOD, NASA, and the DOE, released their report on the adverse health effects of perchlorate ingestion from clinical, toxicological and public health perspectives. The report also evaluated relevant scientific literature and key findings of the EPA’s 2002 draft risk assessment document on perchlorate. The full report can be found online here.

The committee noted that a no observed-effect level (NOEL) or lowest observed-adverse-effect level (LOAEL) identified from a critical study, is used as the basis for establishing a reference dose for daily oral exposures. The committee decided to use a NOEL rather than a LOAEL as the basis for perchlorate risk assessment. They based their reference daily dose on the identified critical study done by Greer, et al (2002)1 in which healthy men and women were given doses of perchlorate of 0.007 to 0.5 mg/Kg body weight per day for 14 days. In this study, the NOEL was found to be 0.007 mg/Kg/day. Using this amount and applying an uncertainty factor of 10 to protect the most sensitive population (identifi ed as pregnant women who may have hypothyroidism or iodide deficiency), the committee recommended a reference daily dose of perchlorate of 0.0007 mg/Kg of body weight per day from all sources. The EPA’s draft reference daily dose from the 2002 risk assessment was 0.00003 mg/Kg per day. The committee also noted that additional studies are needed, especially long-term, chronic exposure as well as clinical, mechanistic and epidemiological studies.

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