Posted 11/3/2010                                    Printable Fact Sheet 

Union Creek - Prior to Sediment Remediation

Union Creek - During Sediment Excavation

Site SD001 consists of the main branch of Union Creek and the associated Storm Sewer Systems A & C. The main branch of Union Creek runs parallel to the southern portion of the base runway. Union Creek is not a source of contamination but has received contaminated groundwater or storm sewer contaminants from upstream sources.

To prevent trichloroethylene-contaminated groundwater at Site SS016 from entering the creek, the base installed an extraction system to clean up and contain this contaminant source. Due to the success in cleaning up solvent plumes that were hydraulically connected to the creek, the extraction system was shut down and decommissioned. Additionally, polycyclic aromatic hydrocarbons (PAHs) had been identified in the local soil; and pesticides, PAHs, and metals had been detected in the creek sediment and may have been a source of potential ecological risks.

Based on assessments of the potential risks posed by the contaminants, the North/East/West Industrial Operable Unit Soil, Sediment, and Surface Water Record of Decision selected No Action for both soil and surface water and Excavation for the sediments.

In the summer of 2009, Travis AFB carried out a sediment cleanup action at SD001. The base excavated the contaminated sediment and transported it to an off-base landfill. The excavation was conducted to minimize impacts on the existing habitat. The sediment cleanup action achieved residential cleanup levels for all chemicals of concern, so there are no Land Use Controls in place at the site. The results of the sediment cleanup action are presented in the SD001/SD033 remedial action completion report. Since there are no other media of concern associated with the main branch of Union Creek, site SD001 is closed.