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contaminated waters, water extracts of soils and other liquid wastes and is defined in Title 26, Section 22-66194 of the California Code of Regulations (CCR) as the concentration of a solubilized and extractable bioacummulative or persistent toxic substance which, if equaled or exceeded in a waste or waste extract ...renders the waste hazardous. The TTLC refers to the total concentration in soils and other solid wastes and is defined in Section 22-66206 of the CCR as the concentration of a solubilized, extractable, and nonextractable bioacummulative or persistent toxic substance which, if equaled or exceeded in a waste ...renders the waste hazardous. If the total concentration of a specific metal in soil is greater than that metal's TTLC, then the soil is regarded as hazardous waste. If the total concentration of the metal is less than the TTLC, a Waste Extraction Test (WET test), described in Section 22-66700 of the CCR, may be necessary to determine the extractability of the metal and thus the hazard that the metal-contaminated soil poses to runoff water and ground water. The WET test utilizes an acidified sodium citrate solution to extract the metals from the soil or other solid waste. The WET test procedure yields a metal concentration in the soil extract which is equal to one tenth the total metal concentration in the soil if all of the metal in the soil is extracted. Thus, if the total concentration of the metal in the soil is less than ten times the STLC, a WET test will always yield a result lower than the STLC and is therefore not required. However, it is the soluble concentrations of contaminants which are the overriding concern with respect to potential degradation of groundwater quality. Although total concentrations of metals may well be below the TTLC, it is much more difficult to meet the soluble criteria. Therefore, the STLC often becomes the sole criteria driving the remediation strategy. 4.0 IDENTIFICATION OF REMOVAL ALTERNATIVES The sumps and maintenance pit addressed in this EE/CA were identified as containing liquids and sludges contaminated with heavy metals and PCBs. Contaminant concentrations in sludges, sediments, and oil (Table 1) are higher than either their TTLC, or ten times the STLC values specified in Article II of Title 22 of the California Code of Regulations. The sump contents are therefore considered a potential threat to the environment and human health, and a removal action as described in this EE/CA is required. The No-Action Alternative was not considered in this EE/CA, for the above reasons. The following three alternatives were identified for the removal action plan at Site 5, based on removal action objectives identified in Section 3.0. • Removal of contents, followed by cleanup of the sump and pit. • Removal of contents, followed by cleanup of the sump and pit, and abandonment. • Removal of contents, followed by demolition. 12