This contaminated soil cleanup site was a small (3/4-1 acre) parcel located on a residential lot north of the 101 freeway in Santa Barbara, CA. Review of the site history indicated that the property had been utilized for many years as a scrap metal yard, junk yard and salvage yard. To facilitate a property transfer, the property owner was required to remediate the polluted soil onsite that contained elevated concentrations of heavy metals and hydrocarbons.
Clean Up Technology (CUT) was contracted by the property owner to conduct an assessment of the onsite contaminated soil. Clean Up Technology determined that soil remediation by solidification/stabilization technology would be the most cost effective remedial alternative for this polluted soil site. Bench scale tests conducted by Clean Up Technology, determined that Cement Kiln Dust (CKD) from California Portland Company would be the best solidification/stabilization add mixture material to treat the contaminated and polluted soil.
George L. Throop Co. was contracted to perform the solidification/stabilization treatment and mobilized a volumetric mobile concrete batch plant to the site. Addition of Cement Kiln Dust and the contaminated soil material into the mixing unit one ingredient at a time was calibrated using a portable digital platform scale and super sacks (3000 lb bulk samples). Treatment water was also calibrated using a 275 gallon tote. Bench tests indicated that 20% add mixture of Cement Kiln Dust was ideal for solidification/stabilization treatment at this site.
Prior to treating the contaminated soil, all excavated and stockpiled soil was processed to a 1-1/2″ minus using a Read Screen All. The polluted soil was processed and treated onsite in approximately 50 cubic yard batches. Each batch was treated and set aside for sampling. Treatment confirmation samples were collected and tested by a state certified analytical laboratory. Leachability tests resulted in confirming that the treatment process met all performance parameters for the site. Onsite contaminated soils were excavated and stockpiled onsite until excavation base and sidewall confirmation samples contained below action level concentrations for all soil contaminants.
When each batch test result came back as meeting all performance parameters the material was replaced back in the excavated area and re-compacted for rebuilding purposes. All excavated material passed leachability testing and the project was completed under budget and within schedule.