Middletown|Norwalk 345-kV Transmission Line

The United Illuminating Company’s (“UI”) portion of the Middletown/Norwalk Project traverses approximately 6.9 miles of underground 345-kV cross-linked polyethylene (“XLPE”) insulated cable, primarily within or adjacent to road rights of way (“ROWs”) extending from and including the first splice vault west of the Housatonic River in the Town of Stratford to the new Singer Substation in the City of Bridgeport.

BL Companies was retained by United Illuminating (UI) to perform Permit Manager services, provide transportation engineering support services, subsurface utility engineering (SUE), survey services as needed and to conduct a supplemental subsurface investigation. Prior to conducting the subsurface investigation, BL Companies field marked the proposed boring locations for utility clearances, obtained street opening permits from the State of Connecticut and the various towns where the investigation was conducted. The subsurface investigation consisted of the advancement of over 75 soil borings and the collection of soil and groundwater samples along the line and at substation locations. The analytical parameters were chosen based on field screening information, current and/or historic site usage in the vicinity of the soil borings and an evaluation of contaminants that could change the classification of soil from a Connecticut “regulated” waste to hazardous waste. The intent of the subsurface investigation was to obtain pre-authorization from selected disposal/recycling facilities that would allow the Contractor to direct load and transport excess soil from construction areas to an Owner-approved disposal facility without using a temporary stockpile area. The intent of the groundwater classification was to prepare and secure all Local and State Regulatory Permits required to treat and discharge groundwater during construction dewatering activities. In addition, BL Companies prepared and implemented a Soil Management Plan (SMP) for the entire transmission line. Specifically, the SMP outlined the handling requirements for soils excavated during construction that are unsuitable for reuse due to failure to meet geotechnical and/or compaction criteria and the handling requirements for soils that are considered “polluted” or “contaminated” as defined by the Connecticut Department of Energy and Environmental Protection (CTDEEP) Remediation Standard Regulations (RSRs).

Throughout the duration of the project, BL Companies provided full-time construction oversight related to the SMP, erosion and sediment control, groundwater treatment and disposal and coordination between the various Contractors and the approved soil disposal facilities. Most of the soils were considered urban fill with low concentrations of regulated compounds. However, PCB-contaminated soil was discovered during excavation of a portion of the 115-kV and 345-kV trenches at concentrations that required notification to the CTDEEP and the United States Environmental Protection Agency (USEPA). BL Companies developed a sampling plan that was submitted and approved by the CTDEEP and USEPA. The subsurface investigation included advancing 178 borings and analyzing a total of 459 soil samples for PCBs. Subsequently, BL Companies developed a Remedial Action Plan (RAP) that was approved by the USEPA. The ultimate goal of the RAP was to present a remedial action that would meet the applicable clean-up requirements/standards of 40 CFR 761.61 of the Toxic Substance Control Act (TSCA), the 1998 PCB Disposal Amendments and the CTDEEP RSRs. Once remediation was completed, a Remedial Action Report (RAR) detailing the successful remediation of PCB-contaminated soil was prepared and submitted to the CTDEP and USEPA

Middletown|Norwalk 345-kV Transmission Line was last modified: October 16th, 2014 by BL Companies