In response to a draft scientific review released in September 2010, the EPA has issued guidance to all public water systems (PWS) recommending enhanced monitoring and sampling programs specifically for hexavalent chromium [also known as chromium-6 or Cr(VI)] in drinking water.

Read more about monitoring for hexavalent chromium in drinking water…

In August 2010 the EPA issued a notice proposing new and revised analytical methods to be used under the Clean Water Act (CWA).

The proposed rule, entitled “Guidelines Establishing Test Procedures for the Analysis of Pollutants Under the Clean Water Act; Analysis and Sampling Procedures”, will affect numerous EPA Methods, ASTM Methods, Standard Methods, and alternative test methods.

EPA methods:

Read more about the proposed CWA Methods…

In a Federal Register notice published June 23, the EPA proposed changes to its permitting program under the Clean Water Act (CWA) to ensure the use of sufficiently sensitive analytical methods for monitoring chemical pollutants in discharge water.

Specifically, the new rule affects the CWA’s National Pollutant Discharge Elimination System (NPDES). Its purpose is to specify that applicants and permittees must use analytical methods that are capable of detecting and measuring pollutants at, or below, current water quality criteria.

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The term “vapor intrusion” refers to the migration of volatile chemicals from subsurface contaminated sources into overlying residential or commercial structures. “Historically, it was thought that vapor intrusion was only an issue where the source of the contaminants was very shallow and the magnitude of the contamination was very great. It is now known that the previous assumptions about the mechanisms that could lead to exposure to vapor intrusion were not complete (NYS DEC DER Vapor Intrusion Guidance).” For a growing number of federal, state and local agencies, as well as environmental consultants and laboratories, vapor intrusion could emerge as the next major environmental challenge.

Vapor intrusion is not a new phenomenon— for some environmental experts, it has been recognized as a potential pathway of contamination for almost 20 years. In the late 1980s, the first vapor intrusion studies were carried out to evaluate potential health effects from chronic exposure to volatile organic compounds. Presently, vapor intrusion is of growing concern to the environmental community due to a number of factors, such as increased recognition of it as a potential pathway for exposure and the risks associated with that exposure, as well as the location and the number of potential sites for investigation and remediation. With this increased focus comes ongoing debate regarding the mechanism of the exposure pathway, compliance concentrations of contaminants, identification of sites, sampling approaches, analytical methodology, use and validity of current models, screening approaches, and risk assessment, among other topics.

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The toxicity and environmental impact of organochlorine pesticides and polychlorinated biphenyls (PCBs) is well documented. Routine environmental analysis of these compounds has remained largely unchanged since the advent of EPA method 8081 and EPA method 8082. However, recent instrumental advances and implementation of ultra-trace extraction techniques have allowed for significant improvements in detection limits.

The CAS Kelso laboratory has developed procedures that produce detection limits low enough to meet the requirements of the majority of studies. The extraction and analysis procedures include modifications to increase sensitivity, but still meet the requirements of the traditional EPA SW846 methods. Samples are prepared according to EPA Method 3520C with modifications, including a 2L continuous liquid-liquid extractor. Special glassware handling techniques are incorporated to minimize potential background contamination.

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Mercury is responsible for over three-quarters of all contaminant-related advisories for threats to human health. During the 1990’s, the number of mercury related fish consumption advisories more than doubled, despite significant decreases in the total mercury emissions over the last 20 years. The increase in advisories is probably the result of more testing rather than more contamination.

While the contamination is showing up in lakes and fish, most mercury does not come from effluent, rather is derived from atmospheric deposition. Atmospheric transport and subsequent bioaccumulation of mercury can affect aquatic ecosystems far from mercury sources. According to EPA estimates, emissions from coal-fired utilities account for 13 to 26 percent of the total (natural plus anthropogenic) airborne emissions of mercury in the United States. Thus, the EPA has begun to regulate emissions from power plant boilers and process heaters.

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