Arsenic is Ubiquitous

Arsenic, with the exception of hazardous waste hot spots, occurs naturally in the environment. The distribution of arsenic in soil, groundwater and surface water has been extensively investigated during the past two decades. The USGS has collected and analyzed arsenic in potable water from over 18,000 wells in nearly 600 counties across the US. While arsenic is ubiquitous and generally detectable at some concentration, the issue of focus is to what extent are detections of arsenic significant with regard to protecting water supplies and public health.

Regulatory Process Stymied

For centuries, arsenic has been recognized as a toxic element. In 1999, the National Research Council (NRC) reported on historical toxicological studies relating to arsenic and its contribution to a variety of cancers. Further, the NRC recommended that the present maximum contaminant level (MCL) for arsenic in drinking water of 50 ug/l be lowered. After decades of scientific study, followed by the USEPA regulatory process of public review and comment, the USEPA in January 2001 recommended that the standard be lowered to 10 ug/l. Shortly thereafter, in March 2001, the process for EPA to reach a final decision on the rule came to an abrupt halt. With the entrance of the new political administration, and a new head of the USEPA, the recommendation to lower the standard was delayed for reasons cited to be a lack of "clear proof" of the health risk and the need to allow for independent reviews of the science behind the studies and estimates of implementation costs.

Arsenic Symposium

While the extensive and prolonged process of reevaluating the arsenic MCL had reached a tentative milestone early in 2001, the delay had caused intense focus on the regulatory process of developing or changing drinking water standards. This Symposium brought the scientific community, regulators, water purveyors, industry, attorneys, and political representatives up-to-date on the current issues surrounding arsenic in groundwater.

The one-day conference included the following sessions:

1. Arsenic Geochemical Characteristics and Distribution
   
2. Risk, Toxicology and Regulations
   
3. Water Supplies and Social, Political, Economic and Legal Issues
   
4. Treatment and Remediation