WORK PLANS - Laserfiche WebLink

Home Browse Search

organic carbon and texture of the soil. These characteristics will be used to evaluate the attenuation capacity of the soil based on the chemicals of concern that may be identified in the dredged material. The following section describes our approach to evaluate site attenuation. Chemical Analysis of Dredged Material Samples of the dredged material will be analyzed using a deionized water (DI) waste extraction test (WET) for the COCs identified in Task 3 for evaluating the groundwater. The purpose of this analysis is to determine the quantity of COCs that can be removed from the dredged material with DI water. The analyses will include dissolved concentrations of barium, copper, lead, and zinc, as well as analysis of the acid generation potential of the dredged material. Collection and analytical costs for dredged material are not included in this work plan and are assumed to be part of the Port's scope. Chemical Analysis of Placement Area Soil Soil samples will be collected from the DPS for laboratory analysis of cation exchange capacity, pH, and organic carbon content (per Task 2, above). In addition, soils from the DPS will be analyzed using a DI WET for the COCs identified in Task 3 for evaluating the groundwater. Batch Test for Leaching Analysis Batch leaching is a procedure for determining how contaminant mass is distributed between solid (dredged material) and aqueous phase at equilibrium. The batch testing will consist of two steps. The first step is to obtain a leachate from the dredged material. This will be done using the DI WET test as described above for the dredged material. The second step will focus on the disposal site soil to evaluate its attenuation capacity. This will be done using a modified ASTM D 4319 - Standard Test Method for Distribution Ratios by the Short-Term Batch Method. Modifications to this method are as follows: • The contact solution in the test will be extractant produced during the DI WET Test. • Distribution Ratios will not be calculated - rather the amount of each COC that can be removed from the contact solution by the soil will be determined. TASK 5—EVALUATE ACID GENERATION POTENTIAL The RWQCB is concerned that the initial analyses from the dredge material indicated the possibility of acid generation when the material is placed on the existing soils in the DPS. This L\MARKET\PROPOSAL\2000 Props\6988-POS\Amended work plan.doc 5