25B - SANTA ANA BLVD GRADE SEPARATION

Home Browse Search

be conducted at up to one location if a secure measurement location can be identified. ICF Jones & Stokes will conduct traffic noise modeling related to the proposed project using the FHWA Traffic Noise Model (TNM) Version 2.5 and traffic data to be provided by the project traffic engineer. TNM will be used to model worst-noise-hour noise conditions at representative modeled receiver locations under existing conditions and design- year conditions with and without the proposed project. Traffic noise impacts of the proposed project under 23CFR772 will be assessed by determining if implementation of the project is projected to result in traffic noise levels under design-year conditions that approach or exceed the FHWA noise abatement criteria or if implementation of the project is predicted to result in a substantial increase in noise at noise-sensitive uses. If traffic noise impacts are projected to occur, information on the preliminary feasibility and reasonableness of noise abatement as defined in the Protocol will be evaluated and presented for use by decision makers in considering noise abatement. ICF Jones & Stokes will also evaluate potential construction noise impacts using methods recommended by the U.S. Department of Transportation. ICF Jones & Stokes will prepare a noise study report addressing the requirements of 23CFR772 in accordance with guidance in the Protocol and following the noise analysis report format outlined in the Caltrans Technical Noise Supplement (TeNS). If warranted the noise study report will include a preliminary noise abatement design to schematically identify the location, height, and extent of noise walls needed to abate noise impacts. It is assumed that any noise abatement design and or Noise Abatement Data Report (NADR) would be prepared and provided by AECOM. In accordance with Protocol guidance, the description of noise walls will be sufficient for environmental review of the proposed project, but not for final design of the walls. Abatement allowances will be provided for each wall evaluated. It is assumed that any final noise wall designs would be prepared by AECOM due to the detailed engineering that is required for the design of any such noise walls. Natural Environment Study (Minimal Impacts) ICF Jones & Stokes will conduct a literature search, perform field surveys, and prepare a Natural Environmental Study Minimal Impacts (NES/MI) report analyzing potential impacts to biological resources. An NES/MI has been identified due to the limited amount of habitat located within the identified project area. The report will be prepared in accordance with Caltrans SER guidance and will conform to the Caltrans NES/MI annotated outline that is available at the time that the NES/MI is initiated. The following tasks will be performed during the preparation of the reports: Review of Project Information and Applicable Literature A literature review will be conducted to identify special-status species known or reported from the project area. The literature review will include: • Special status species lists from the California Department of Fish and Game (CDFG) and U.S. Fish and Wildlife Service (USFWS); • Database searches of current versions of the California Natural Diversity Database (CNDDB) and the Online Inventory of the California Native Plant Society (CNPS); • The most recent applicable Federal Register listing package and critical habitat determination for each federally listed Endangered or Threatened species potentially occurring within the project site; • The most recent CDFG Annual Report on the status of California's listed Threatened and Endangered plants and animals; and • Other available biological studies conducted in the vicinity of the project site. Field Evaluation for Biological Resource Constraints After reviewing relevant information, the project area will be evaluated, with a thorough walkover covering all portions relevant to potential biological resource constraints. Detailed field notes will be compiled including conditions, visible disturbance factors, species, habitats, and more general biological resource issues observed or detected. The site will be evaluated regarding the presence, absence, or likelihood of occurrence for all special status species, habitats, or more general biological resource issues potentially posing a constraint to the project through applicable laws and regulations. Adjacent areas will also be briefly examined to provide context. It is assumed that access shall be provided by the City City o/'Santa Ana 25B-34