Item 16 - Construction Contract with Los Angeles Engineering, Inc. for the Bristol Street

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ENVIRONMENTAL. IMPACT REPORT ADDENDUM Bristol Street Widening Phase IIIA — Civic Center Drive to Washington Avenue No. 2009-2009-DWQ, amended as Order No. 2012-0006-DWQ). Under this General Construction Permit, discharges of stormwater from construction sites with a disturbed area of one or more acres are required to either obtain individual NPDES permits for stormwater discharges or to be covered by the General Construction Permit. In addition, BMPs specified in the Caltrans Storm Water Management Plan are also applicable. The construction contractor is required to conform to the requirements of the General NPDES Permit for Construction Activities and any subsequent General Permit in effect at the time of Project construction. As part of the statewide NPDES permit, the construction contractor would be required to implement BMPs into their construction operations to reduce potential water quality impacts to the maximum extent practicable through preparation of a SWPPP. The General Construction Permit contains requirements that BMPs must meet, including: Erosion Control Erosion control, also called stabilization, is the protection of the soil surface so that soil particles do not become detached by water or wind; and trapping soil particles that do become detached and are moved by water or wind. Non-Stormwater Management Non-stormwater management is the reduction or avoidance of discharges other than stormwater, such as from cleaning of vehicles and equipment, and spills of hazardous materials and hazardous wastes. Non- stormwater management includes requirements for the use and storage of hazardous substances so as to avoid spills and minimizes pollution by cleaning spills that do occur. The SWPPP contains BMPs chosen for a project based on the specific activities that would be conducted as part of that project, and the amounts of stormwater and non-stormwater runoff that are anticipated, and the projected Risk Level, The 1990 FEIS/EIR included a mitigation measure to control stormwater runoff associated with construction activities. Impacts would be less than significant and would be similar to those identified in the 1990 FEIS/EIR. Moreover, the Project would comply with the updated NPDES requirements, as described above. Operational Phase Vehicular travel along the improved Project corridor has the potential to degrade water quality, including increases in such pollutants as oil, gasoline, grease, lead, and dust. Discharge from the Project site to stormwater facilities would consist of non -point sources. Stormwater quality is generally affected by the length of time since the last rainfall, rainfall intensity, urban uses of the area, and the quantity of transported sediments. Typical urban water quality pollutants usually result from motor vehicle operations, oil and grease residue. The majority of pollutant loads are usually washed away during the first flush of the storm occurring after the dry season period. Due to the nature of the proposed Project, occurring within an existing developed area, Project impacts are not considered adverse. Therefore, impacts to water quality would be similar to those identified in the 1990 FEIS/EIR. Mitigation Measures No new additional mitigation measures are required. b.) Substantially deplete groundwater supplies or interfere substantially with groundwater recharge such that there would be a net deficit in aquifer volume or a lowering of'the local groundwater table level (e.g., the production rate of pre-existing nearby wells would drop to a level that would not support axisting land uses orplanned uses for which permits have been granted)? ANA 305-011 (PER 02) CfTY OF SANTA ANA (01/19/2015) YU PAGE 44