Loureiro was retained to perform a phased characterization of 2,200 linear feet of brook, 2 ponds, and a 1 acre inland wetland located in Connecticut for a large industrial manufacturing facility. The investigations included assessments of various drain and discharge connections, review of historic mapping, and soil, sediment and surface water sampling and analysis. Through the performance of the investigations, we were able to identify the probable sources of impact and provide the analytical data to sufficiently define the horizontal and vertical limits of contamination. The investigations confirmed that historic discharges resulted in the deposition of oils containing polychlorinated biphenyls within and immediately surrounding the stream channel and wetlands.
The sediments within and immediately adjoining the stream channel and wetlands required remediation. Loureiro evaluated a number of remedial alternatives and ultimately selected a remedy involving limited excavation, the installation of a first-of-its-kind subaqueous cap, and the restoration of the area as an urban wetlands complex. The restoration activities performed were focused on restoring this area to a marsh with habitat value. Prior to the initiation of construction activities, Loureiro successfully permitted the project in a little over 18 weeks. This effort involved obtaining seven permits and one temporary authorization. The permits were issued by the Army Corps of Engineers, the State of Connecticut Department of Energy and Environmental Protection, and the Town of East Hartford.
- Soil, sediment and surface water sampling
- Over 500 locations assessed
- Topographic and bathymetric surveys
- Wetland/watercourse resource identification
- Hydraulic and hydrogeologic studies
- Evaluation of dredging and disposal alternatives
- Federal, state and local permitting and all public presentations
The remedial approach that was conducted at the site ultimately saved the client money, increased the habitat value and overall aesthetic improvements. Following the completion of excavation and demolition activities, the entire site was restored. The site restoration involved the installation of three types of engineered controls over the remaining soil and sediments. The engineered controls were designed to accommodate the anticipated stream flow velocities and considered the ultimate use of the areas. The Wetland north of brook was remediated to meet the RDEC. As such, there is no need for an engineered control within this area. The restoration activities performed were focused on restoring this area to a marsh with habitat value.