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Mr.M. Scott Mansholt—CEMC <br /> ' Soil Sampling Work Plan August 1,2006 <br /> Surland Homes Property Page 4 of 8 <br /> ' To the extent the information can be collected, this information will be provided in the revised <br /> health risk assessment. <br /> ' 3. Railroad Right of Way. The current name of the railroad adjacent to the site needs to be <br /> provided(Union Pacific or Southern Pacific). <br /> This confusion has been caused by the depiction of the ROW as"SPRR"on maps. UPRR is now <br /> ' the owner of the ROW,which was previously owned by SPRR. <br /> 4. Polynuclear Aromatic Hydrocarbons (PAHs). Detection Limits (DLs) were described as <br /> elevated for soil and groundwater analyses and not adequate for risk assessment purposes. <br /> New soil data collected for analysis for PAHs will have lower detection limits that are acceptable <br /> for risk assessment purposes. <br /> ' S.Metals. Analysis for metals in soils and groundwater were not conducted and metals were not <br /> included in the screening risk evaluation. <br /> CEMC has demonstrated that heavy metals related to crude oil transported in the pipeline are not <br /> ' a concern, and risk analysis for heavy metals is not required. Metals will therefore not be tested <br /> in future samples from the site. This approach has been outlined in the Consistent Technical <br /> Approach Document(Geomatrix,February 2005),and is currently accepted by the lead agency <br /> for the CEMC historical pipeline projects. <br /> 6 Soils. Shallow soils were not investigated. Soils used in the HRSE were collected from 6 to 9 <br /> feet bgs. Shallow soil samples and soil samples to depths 10 to 12 feet bgs are recommended. <br /> ' However, the shallow water table begins at S to 7 feet bgs. <br /> Soil samples from 1 foot bgs will be collected and analyzed to support the risk assessment, as <br /> ' well as deeper soil samples near the water table, currently around 5 to 7 feet bgs at this site. <br /> 7. Groundwater. For human health risk assessment purposes, groundwater analytical chemistry <br /> data are needed from unfiltered samples. <br /> ' As contact with groundwater has been eliminated as an exposure pathway, groundwater samples <br /> are not proposed as part of the sampling program. <br /> ' RESPONSE TO HRSE COMMENTS <br /> L Conceptual Site Model. A conceptual site model is needed. <br /> A SCM has been developed,as discussed above. <br /> ' 2. Onsite Construction Worker. Evaluation of Risks and Hazards for an Onsite Construction <br /> Worker is requested. <br /> t The CTA for OVP sites notes that a DTSC PEA Manual HHSE will be developed for OVP sites, <br /> and the PEA Manual specifies that residential exposures and risks will be evaluated. hr addition, <br /> as the residential area has been developed, future significant construction is unlikely. <br /> ' 3.Indoor Air Exposures. The data collected thus far does not suggest the need to quantitatively <br /> evaluate risks from indoor air exposures. <br /> ' As noted, evaluation of exposure to indoor air will not be performed. <br /> 4. Toxicity Criteria. For non-carcinogenic effects CaIEPA and USEPA toxicity values are to be <br /> used(in that order of hierarchy). <br /> 1 <br />