Paul Carpenter Associates, Inc. (PCA) was tasked with development of noise monitoring and mitigation plans for the New Jersey Department of Transportation (NJDOT). Construction noise analyses of proposed construction scenarios, using the Federal Highway Administration's Roadway Construction Model (RCNM), were conducted in order to predict noise levels at four sensitive locations, which included residential structures, an elementary school, as well as a NJ Transit Park & Ride lot.
A building attenuation study was performed for the McKinley Elementary School due to its close proximity to the work site. As the project is located within Hudson County, the Noise Ordinance of the Hudson County Health Commission (NOHRHC) was reviewed. Under this ordinance, construction noise is exempt during weekday daytime hours and would provide no protection for the McKinley Elementary School. It was realized that providing mitigation for the school was an important step in building community relations and support of the project.
Since the school did not have an alternative means of ventilation or window air conditioners, it was likely that teachers opened windows during warmer months of the school year. Based on the interior noise measurement study performed by PCA staff, existing noise levels with windows open were double to almost quadruple the Federal Highway Administration acceptable interior noise level applicable for schools. PCA developed a list of weekday daytime allowable construction activities, as well as mitigation strategies for the school, so as not to disrupt students and faculty during active school hours. Mitigation suggestions were also made for the NJ Transit Park & Ride lot to ensure pedestrian safety during periods of construction activities.
With this project, special circumstances presented themselves when creating a noise level limit for contractors. Since the existing background in the project area exceeds noise level limits within the NORHRC, construction noise compliance was not realistic and could not be enforced. Therefore, PCA recommended implementing a project-specific noise level limit based on existing noise levels, so that contractors would not be restricted to unrealistic noise level limits. Along with recommended noise level limits, mitigation strategies were recommended for contractors so that noise impacts were limited as much as possible.