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Jerry Lile <br /> March 3, 2014 <br /> Page 5 of 13 <br /> 7) The conceptual site model (CSM) in Figure 3 did not include the OVP as the <br /> primary source with the release mechanism as leaks from the pipe. Surland <br /> Homes are not the source of releases to the environment considered in the <br /> risk evaluation. <br /> 8) Internal inconsistencies <br /> • The location of the former OVP is depicted in Figure 2 as south of W. <br /> Byron Road, but text refers to the former OVP location as north of W. <br /> Byron Road. <br /> Page 4 states that naphthalene was detected in two soil samples <br /> during the 2007 investigation, yet Table 2 reports naphthalene <br /> concentrations detected in 11 samples. <br /> 9) Text does not discuss <br /> • Kinder-Morgan pipeline identified in Figure 2. <br /> • Depths of all the pipelines both current and former. <br /> D. Ecological Screening Risk Evaluation: <br /> The Surland Homes area is a residential development, thus poor wildlife habitat. <br /> As such, ecological receptors are not expected to come in contact with the <br /> underlying area impacted by petroleum products. A Scoping Assessment <br /> consistent with DTSC Guidance (1996) is expected; in essence this consists of <br /> documenting whether any complete exposure pathways exist for ecological <br /> receptors (biota including plants and animals) using a habitat approach to identify <br /> the specific species or habitats which occupy, or potentially could occupy, the <br /> site. Include a qualitative statement which summarizes the findings of the <br /> screening-level assessment. If the conclusion is that the site, and areas actually <br /> or potentially impacted by the site, are not utilized by biota and do not contain <br /> wildlife habitats, or that there are no actually or potentially complete exposure <br /> pathways, this conclusion must be clearly stated and justified. <br /> 3. Screening-Level Risk Analysis by HERO <br /> A. HERO Methods <br /> HERO applied conventional risk assessment guidance by EPA and DTSC to <br /> calculate screening-level risks for direct contact with soil by residents and <br /> construction workers as well as groundwater to indoor air risks from residential <br /> exposures. Construction workers were evaluated for both 90 day exposures to <br /> represent typical construction/development activities within the Suriand Homes <br /> area, and a 1 year exposure duration to evaluate larger scale soil invasive <br /> activities, for example potential OVP/Chevron-contracted pipeline workers. <br /> file:20140303JL.doc <br />