COMPLIANCE INFO - Laserfiche WebLink

Home Browse Search

BACKGROUND Aerially Deposited Lead Ongoing testing by Caltrans throughout the State has indicated that ADL exists along transportation corridors due to emissions from vehicles powered by leaded gasoline. The ADL is generally limited to the upper 2 feet of soil material within the unpaved shoulder and median areas. For a solid waste containing lead, the waste is classified as California hazardous when: 1) the total lead content equals or exceeds the respective Total Threshold Limit Concentration (TTLC) of 1,000 milligrams per kilogram(mg/kg); or 2)the soluble lead content equals or exceeds the respective Soluble Threshold Limit Concentration(STLC) of 5 milligrams per liter (mg/1) based on the standard Waste Extraction Test (WET). A waste has the potential for exceeding the lead STLC when the waste's total lead content is greater than or equal to ten times the respective STLC value since the WET uses a 1:10 dilution ratio. Hence, when total lead is detected at a concentration greater than or equal to 50 mg/kg, and assuming that 100 percent of the total lead is soluble, soluble lead analysis is required. Lead-containing waste is classified as"Resource, Conservation, and Recovery Act"(RCRA) hazardous, or Federal hazardous, when the soluble lead content equals or exceeds the Federal regulatory level of 5 mg/1 based on the Toxicity Characteristic Leaching Procedure(TCLP). The regulatory criteria for suspected hazards on the Site are based on toxicity. Wastes may also be classified as hazardous based on other criteria such as flammability, reactivity, corrosivity, and ignitability. However, for the purposes of this investigation, toxicity (i.e., lead concentrations) and corrosivity (i.e., pH analysis) are the primary factors considered for waste classification. Based on current and past site usage, onsite soil is not expected to exhibit other hazardous waste characteristics. The Department of Toxic Substances Control(DTSC)regulates and interprets hazardous waste laws in California. The DTSC generally considers excavated or transported materials that exhibit "hazardous waste" characteristics to be a "waste" requiring proper management, treatment and disposal. Soil that contains lead above hazardous waste thresholds and is left in-place would not be necessarily classified by DTSC as a"waste."The DTSC has provided site-specific determinations that"movement of wastes within an area of contamination does not constitute "land disposal" and, thus, does not trigger hazardous waste disposal requirements." Therefore, lead-impacted soil that is scarified in-place, moisture-conditioned, and recompacted during landscaping improvement activities might not be considered a "waste;" DTSC should be consulted to confirm waste classification. It is noted that in addition to DTSC regulations, health and safety requirements and other local agency requirements may also apply to the handling and disposal of lead-impacted soil. Waste that is classified as either "California hazardous" or "RCRA hazardous," requires management as a hazardous waste and disposal at an appropriately permitted disposal facility. DTSC Variance The DTSC issued a statewide Variance effective July 1, 2009, regarding the reuse of ADL-impacted soils within Caltrans right-of-way. Under the Variance, soil that is classified as a non-RCRA hazardous waste, based primarily on ADL content, may be suitable for reuse within Caltrans right of way. ADL soil that is classified as a RCRA hazardous waste is not eligible for reuse under the Variance and must be disposed as a RCRA hazardous waste(Caltrans Type Z3). Project No.E8504-06-01 -3- July 13,2011