During World War I, the U.S. Army conducted chemical warfare research at the site of the present Spring Valley neighborhood in Washington, DC. Chemical weapons were detonated in several areas during research and training operations. Chemical agents, including hazardous substances, ordnance, and explosive waste, were buried in parts of the area, which has since been developed. It is now occupied by residential homes and the American University campus.
In December 2000, contaminated soil was identified at the child Developmental Center at American University. Surface soil samples collected from the center's playground were found to be contaminated with arsenic at an average concentration of 57 parts per million (ppm) and at a maximum concentration of 498 ppm (ATSDR, March 14, 2001). ATSDR conducted an exposure investigation (hair analyses for arsenic) at the center on February 1-2, 2001. Hair samples from 28 children and 4 adults indicated no elevated arsenic exposure in children or workers at the center. The property subsequently has received remedial actions to reduce arsenic levels in the soil (ATSDR, March 8, 2001). Detectable levels of arsenic were measured in hair samples from 8 of the participants at concentrations, ranging from 0.10 to 0.14 ppm, which is within the range reported for unexposed populations.
On February 10 and 15, 2001, Washington Occupational Health Associates, Inc. (WOHA), collected hair and urine samples at American University. The target population for this exposure investigation consisted of Child Developmental Center staff and children (who attended the center for the prior 12 months), maintenance and grounds workers, and university athletes who play on the intramural fields near the daycare center. Sixty-six people (39 adults and 27 children) provided hair samples. Urine samples were provided by 4 adults. WOHA concluded that results of its exposure investigation indicated no elevated levels of arsenic in the population tested (WOHA, March 26, 2001).
Testing of residential soils in the Spring Valley neighborhood has shown composite soil levels of arsenic ranging from background (an amount normally found in soils in the region) to approximately 202 ppm. Eleven properties with one or more grid (discrete) sampling results exceeding 150 ppm have been identified (go to the Army Corps of Engineers Web site for more information on their sampling results). The maximum background level of arsenic in Spring Valley soil is approximately 17 ppm, which is well within the background levels for arsenic in soils of the United States. Residents of Spring Valley have expressed concern about possible arsenic exposure they might have received from soils at their residences.
The Army Corps of Engineers began removal of arsenic-contaminated soil from residential yards in July 2002. As of February 2011, one hundred fifteen (115) properties in Spring Valley, with elevated arsenic levels, have been remediated. This update and other information can be found on the USACE website.