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worldwide generally consider individual risk levels below 1x10(one-in-a-million)as acceptable,and individual risk levels greater than 1x10"5 (one-in-one hundred thousand)as unacceptable.Although the state and San Joaquin County do not have standards for non-school risk,the following is in the spirit of MHMP Section 6.13: "No Habitable Strictures Zone"—habitable structures not allowed(where risk greater than 2x10-�. "Hazard Notification Zone"—habitable structures allowed with disclosure of potential risk to property owner(where riskbetween 2x10 and 1x10"1). ` "No Constraint Zone"—habitable structures permitted with no conditions or constraints(where risk lower than Ix10-). As indicated by the above, SJCCDD has taken a conservative position with respect to acceptable and unacceptable risk by defining unacceptable risk as 2x10(two-in-one million)instead of the more traditional 1x10-5 (one-in-one hundred thousand)identified by CDE for schools. Table 4.9-3 outlines the potential risk posed by the pipelines to the different types of land uses proposed under the College Park project at given distances from the pipelines. As indicated, the annual individual risk is lower than 1 x10-6 for all of the planned land uses except residential.Therefore,all proposed uses except residential would be located in the"No Constraint Zone"and would not be subject to hazards from the existing pipelines.For residential uses,Table 4.9-3 indicates that the annual individual risk is 1.6x 10-6 at 100 feet from the pipeline and would be located in the"Hazard Notification Zone"and would not be ` subject to hazards from the existing pipelines.In addition,Table 4.9-3 indicates that residential uses proposed at 200 feet of the combined PG&E/Chevron pipeline corridor(pipelines L401, L002, and CSDF 0499)would be subject to annual individual risks of 1.1x10 and thus would fall in the"Hazard Notification Zone;"and that residential uses proposed at distances greater than 249 feet from the pipelines would be subject to an annual individual risk of below 1x10 and thus would fall in the"No Constraint Zone." ` According to the Pipeline Risk assessment,based on a conservative threshold value of 2 x 10-6' a no build zone for residential uses would be designated for areas within 68 feet of the combined PG&E/Chevron pipelines and a"Hazard Notification Zone"would be established for residential uses between 68 feet and 249 feet of the nearest pipeline within the corridor. The setback distances would be measures perpendicular from the nearest pipeline within the corridor to the closest structure intended for residential occupancy, including attached porches and balconies. In addition,the"No Habitable Structure Zone" extends out 68 feet from the edge of the PG&E/Chevron pipeline corridor.This is identified graphically in Figure 4.94. As indicated in Figure 4.94 the"No Habitable Structures Zone"would extend into the first row of residential lots proposed along either side of the PG&E/Chevron easement;and the"Hazard Notification Zone"would extend into several rows of residential lots thereafter. The estimated level of individual risk for open space/recreational use at the pipeline alignment is 42x10-7. The recommended threshold acceptance criteria is 2.0x10-6.Therefore,the estimated risk for open spacelrecreational use is almost an order-of-magnitude lower than the threshold and no setbacks or restrictions are required.Therefore,because the risk is low and that occupancy at these areas is not 100%, impacts to users at the open space corridor or at the parks would be less-than-significant. College Park at Mountain House Specific Plan III Draft EIR EDAW San Joaquin County 4.9-35 Public Health and Safety