Agmt21 Environmental Science Associates

Browse Search

Proposed Work Program June 2021 City of Redwood City / Gatekeeper Projects Subsequent EIR 14 environmental science associates An increase in construction under the Gatekeeper Projects may also result in an increase in construction-related sedimentation and pollutants in stormwater runoff and/or groundwater. The increase in new development as a result of the project may also change the amount impervious surfaces and resultant surface runoff within the DTPP area, and thus increase pollutants in surface water, and/or interfere with groundwater recharge; ESA will work with the City to develop appropriate assumptions with respect to changes in impervious surface. These effects will be addressed in conjunction with a discussion of governing federal, State and local regulations and requirements (e.g., NPDES/SWPPP requirements, and local stormwater management programs and ordinances) that are in place to ensure potential short- and long-term hydrology and water quality impacts would be minimized. Noise and Vibration The DTPP Final EIR determined significant but mitigable impacts under the DTPP associated with construction related noise and vibration effects; new residential exposure to noise levels in excess of General Plan guidelines; and residential exposure to groundborne vibration within the vicinity of the Caltrain railroad tracks. Noise and vibration impacts of the Gatekeeper Projects will be evaluated in the SEIR. Generally, this analysis will address construction noise and vibration, operational traffic noise increases on local roadways, and stationary source noise from mechanical equipment and loading areas. Additionally, if requested by the City, the analysis will consider non-CEQA related impacts of the environment on the projects inclusive of noise and vibration from operation of the Caltrain rail line on proposed sensitive land use sites in the SEIR. ESA will collect short-term noise measurements in the DTPP area to re-establish existing conditions. ESA will describe the existing noise environment at the project site by collecting up to 10 short-term (20-minute) noise measurements in the DTPP area and at receptor locations in the vicinity. Federal, State and City noise policies, regulations, as they would pertain to development under the projects will be summarized. ESA will estimate the noise levels likely to be generated by construction equipment associated with development under the SEIR project. Predicted noise levels will be assessed relative to existing standards contained in the City noise ordinance that limit construction noise. Construction impacts will also be assessed in terms of the increase over existing ambient noise levels using the Roadway Noise Construction Model and provided for a series of assumed distances and presented in a tabular format. ESA will also provide a discussion of construction-related vibration impacts that will address the potential for building damage to adjacent structures as well as for annoyance to adjacent receptors. Operational noise analysis will also generally describe potential noise that may result from stationary sources of (e.g., mechanical equipment operation, deliveries). ESA will calculate the change in noise levels due to existing plus project and cumulative traffic along up to 10 street segments most affected by traffic for the SEIR. Algorithms of the noise prediction model of the Federal Highway Administration (FHWA) will be used to determine whether there would be significant project or cumulative effects on noise levels along these roadway segments. Noise and vibration abatement measures from the DTPP Final EIR will be reviewed as appropriate, and any additional practical and feasible mitigation, as needed, will be identified for noise and vibration impacts associated with the project. REV: 06-23-21 MI ATTY/AGR.2021.150/Environmental Sciences Associates (Gatekeeper Projects) (Page 24 of 58)