Sampling was completed at 42 of the 61 properties. Eleven property owners would not grant permission, and attempts to reach eight others were unsuccessful. Based on the results of this sampling, nine properties and several lots on the American University campus were recommended for further detailed sampling. This sampling was completed in January 2001.
One of these locations involved the area around the American University Child Development Center. Given the sensitivity of this area, soil sampling around the center was expedited and the results provided to the university. The results identified arsenic levels higher than acceptable for a residential area. University officials relocated the Child Development Center to another area of the campus. Removal of the contaminated soil began in the summer of 2001. New soil was placed on the site, and restoration activities completed.
Following the discovery of elevated arsenic at the Child Development Center, the D.C. Health Department, EPA, and the Agency for Toxic Substances and Disease Registry (ATSDR) conducted an exposure study of the children attending the center. Study results did not indicate a health risk to the children.
At a public meeting in February 2001, the community turned out in large numbers to urge testing of the entire Spring Valley neighborhood. The Corps, in consultation with EPA and the D.C. Health Department, responded with a comprehensive soil sampling plan that proposed the sampling for arsenic on every property in Spring Valley (1,200 residential properties and 400 non-residential lots), with more intensive sampling in select areas. Sampling under this plan began May 31, 2001.
If a particular property was determined to have an elevated level of arsenic, then a more detailed grid sampling procedure was done. Following this sampling to identify areas of contamination, the results were evaluated to determine any elevated health risk. Working with EPA and D.C. Health Department, the Corps agreed upon a cleanup goal of 20 parts per million (ppm), and 140 properties were identified with one or more grids above 20 ppm of arsenic.
Small Disposal Area
In January 2001, the Corps completed the cleanup of a small disposal area located adjacent to American University. During this work, the Corps removed approximately 44 cubic yards of soil, and some glass and metal debris. The soil and debris were tested, and no chemical warfare agent was found. Following confirmation samples of the excavated area, clean soil was placed and restoration of the site was completed.
The Corps completed anomaly investigations at the university's intramural fields and the Child Development Center early in 2003. Most of the anomalies turned out to be buried utilities and general construction debris that date from the mid-1900s. No chemical warfare agent was found. Arsenic-contaminated soil removal was completed and the areas were restored.
The investigation of 31 anomalies at two properties in the 5000 block of Sedgwick Street was completed in 2002. A trench system used by military personnel to test and explode munitions was once situated in this area. Three munitions fragments and several pieces of metal construction debris were removed. No intact munitions or laboratory-related materials were found. Air sampling did not detect chemical agent or agent breakdown products.
The Lot 18 debris field is located on the southwestern edge of the American University campus and behind properties on Rockwood Parkway. In this area, the Corps discovered a debris area that contained domestic trash, lab glassware and inert munitions debris. Excavation in this area started in 2002 and continued into 2003. In mid-2003, work was stopped temporarily at Lot 18 when a bottle was identified as containing a small amount of lewisite (0.3 percent). During that time the Corps focused its efforts on other areas of the project.
The discovery of the lewisite changed the low probability dig to a high probability dig. The Corps re-evaluated its site safety and work plans at Lot 18, and returned to the site in 2004 with extensive safety measures in place. The dig continued under a pressurized and sealed tent with redundant filtration systems and air monitoring. The workers wore Level B protective gear and were monitored by closed circuit TV from an operations center.
At the end of September 2004, 474, 55-gallon drums of soil had been excavated and about 890 items recovered. Seven items required further analysis. All of the other items were "scrap." Fewer than 30 of these were ordnance-related scrap, such as expended fuzes, empty projectile casings and broken pieces of munitions. Other types of items included empty or broken test tubes and bottles, broken glassware and ceramic pieces, construction debris like pipes and bricks, battery components, and horseshoes.
Work began Nov. 15, 2005, with a larger sifting table and more workers to increase production. Workers recovered 18 suspect items amid the usual debris - 15 sealed glass bottles and three ordnance related items. Breakdown products of mustard, a chemical warfare agent, were identified during analysis of the liquid in one of the recovered bottles. Both chemicals, dithiane and thioxane, were found in low quantities and concentrations. Both have a low toxicity and would not cause adverse effects to someone exposed to the chemicals, experts said.
The site specific work plan for the Lot 18 investigation was further refined in fiscal year 2006 and incorporated the use of a much larger engineering control structure, additional chemical agent filtration systems and a larger excavator. In addition, the method of sifting soil was revised from manually sifting to mechanical sifting, with the use of a mechanical sifting table and conveyor system. The sifted soil was transferred on the conveyor system into a covered roll off dumpster, greatly increasing the efficiency of the operation. At the completion of the investigation on Jan. 22, 2006, a total of 5,500 cubic yards of soil had been removed, 117 munitions debris items, six intact munitions items and 31 intact containers. No munitions items were determined to be explosively or chemically configured. One intact container was determined to contain chemical warfare agents and three contained agent breakdown products (ABPs). Intact container SVS-06-035, unearthed on Jan. 9, 2006, contained 0.28 ppm of mustard. This was the only chemical warfare materiel detected during the Lot 18 high probability investigation. The mustard detected was extremely small - .18 ppm above the PQL, which is the concentration that can be reliably measured within specific laboratory limits.
Testing for remaining chemical contamination was conducted at Lot 18. Results from the testing were incorporated into a work plan. The Corps excavated the areas of elevated chemical soil that exceed target levels. The excavation, backfilling and restoration of Lot 18 were completed in summer 2006.
The investigation of six anomalous areas and 74 single point anomalies surrounding Lot 18 was completed in fiscal 2006. These areas were investigated under a low probability work plan. A total of eight munitions debris items and two intact containers were recovered during this investigation. Also, a large amount of debris and broken glassware were recovered from the areas. All were cleared for chemical warfare agent. Since the debris in one of the six areas extended toward the American University’s Public Safety Building, a separate work plan was developed to address this area. This work at the Public Safety Building began in summer 2008 and is now finished.
A low probability investigation was conducted in summer 2006 at one additional area surrounding Lot 18 that was identified as the Kreeger Hall Roadway investigation. Seventeen single point and two test trenches were investigated in this area. Four properties along Rockwood Parkway were also investigated in summer 2006. A total of 84 single point anomalies on these four properties were investigated.
Spaulding/Captain Rankin Area
In 2003, about 240 anomalies were excavated and field cleared in the area known as the Spaulding/Captain Rankin Area, a small strip of land on American University and on properties along Woodway Lane. A few scrap fragments of munitions were found but no intact munitions.