Interim Measures Several interim measures have been conducted at the SSFL Site. For detailed information on each Interim Measure, see below. Former Sodium Disposal Facility In 1999, DTSC directed Boeing to remove soils contaminated with dioxin, PCBs, solvents and other waste at the Former Sodium Disposal Facility (FSDF) also known as the Former Sodium Burn Pit. The contamination in soil remained a source for potential movement to surrounding areas and to groundwater in the bedrock below. In 2000, over 14,000 cubic yards of contaminated soils were excavated from this area. The soils were removed down to the bedrock below. Following removal of the soils, the exposed bedrock surfaces were swept and vacuumed clean and mapped for fractures and chemical residues. A DTSC-registered geologist collected samples to confirm that soil and bedrock were remediated to the required health-based cleanup levels prior to installation of a clay backfill cap. DTSC will continue to monitor the cap’s effectiveness and will share any results from the monitoring as they are available. Happy Valley Perchlorate Excavation and Biodegredation at Building 359 This Interim Measure included two major activities: 1) removal and restoration of soils, sediment and bedrock containing perchlorate, and in some cases, metals; and 2) biotreatment of the excavated soils containing perchlorate at the Building 359 Area. Happy Valley and Building 359 are located in the east-central portion of Area I. Excavation of soils that contained metals and perchlorate were completed in October 2003, re-contouring of soils, implementation of erosion control measures and restoration of vegetation in the Happy Valley Drainage were completed in January 2004. The biotreatment of perchlorate in soils began in Fall 2004. The Happy Valley site was used for solid propellant research and testing and gun propellant testing between the 1950s and 1993. The primary use of perchlorate at the Happy Valley site occurred in the 1960s in support of flare research, development and production for the military, as well as for rocket propellant research and testing activities during the 1970s through 1993. Additional perchlorate use occurred in the northern portion of Happy Valley, where turbine spinners were tested in the 1950s. 1999 Interim Measures at Happy Valley and Building 359 The primary purpose of the 1999 interim measures at Happy Valley was to identify and remove suspect energetic and/or ordnance items simplify from soil and sediment in the Building 359 and Happy Valley Areas. The Interim Measures were conducted at the Happy Valley and Building 359 sites, located in Area I, as part of the RCRA corrective action program at the SSFL, in accordance with DTSC-approved work plans. The scope included screening the subsurface for metallic anomalies lay terms, and then removing and sifting soil where metallic debris was present. The primary soil/debris removal area was south of Building 372, within the upper reach of the Happy Valley Drainage. Approximately 1,800 cubic yards of soil/debris were removed during the 1999 Interim Measures. To learn more, please visit the Interim Measures Documents or Photos page under the Document Library on this website. | 
