121-18 Attachment.pdf

mN September 29, 2017 Ras Fire House No. 4, 280 Pleasant Valley Way “wis TWOROH-17002 Page 3 In order to comply with NJDEP regulations, T&M will retain a NJDEP licensed well driller to properly abandon monitoring wells MW-1, MW-4 and MW-11, as these wells are located in the vicinity of the excavation area. The wells will be sealed in accordance with the requirements of N.J.A.C. 7:9D with cement-bentonite grout. After completing the excavation work, T&M will retain a New Jersey licensed driller to install replacement for monitoring wells MW-1R and MW-AR. The monitoring wells will be constructed in accordance with the NJDEP Monitoring Well Requirements for Unconsolidated Aquifers. The monitoring wells will be developed by pumping groundwater into 55-gallon drums until clear and sediment-free water is obtained from the well. The wells cuttings will be containerized in 55-gallon drums on Site for future off-Site disposal at an approved disposal facility. A total of 10 drums will be disposed of and the cost is included in this proposal. A New Jersey licensed land surveyor will survey the newly installed monitoring wells and the NJDEP required certifications (Form A and B) will be prepared and submitted to the NJDEP in accordance with the NJDEP requirements. Task 4: Scope of Work and Supervision for Impacted Soil Excavation & Post-Excavation Soil Sampling T&M proposes excavating and removal of impacted soil that acts as a source of groundwater contamination at a limited area located between MW-11 and MW-4 in front of the garage doors. The suspected impacted soil area is mainly located closer to MW-4. The Attached Figure presents the approximate extent of suspected impacted soil and proposed excavation. T&M will prepare the scope of work and informal excavation specifications for the Township of West Orange to provide it to the selected contractor. The Township of West Orange will hire the contractor to excavate, remove, dispose and backfill with certified clean fill material. Approximately, 150 tons of potential contaminated soil located under the existing asphalt surface. The proposed excavation area is approximately 300 square feet and up to a maximum depth of 15 feet below ground surface. Field screening techniques will be performed in accordance with the NJDEP Technical Requirements for Site Remediation (N.J.A.C. 7:26E) to determine the potential

epth of 15 feet below ground surface. Field screening techniques will be performed in accordance with the NJDEP Technical Requirements for Site Remediation (N.J.A.C. 7:26E) to determine the potential presence of impacted materials. The field screening will include evaluating the extracted materials for the potential presence of volatile organic compounds using a photoionization detector (PID). If visual observations and/or field screening measurements indicate the presence of contamination, the observed contamination will be removed from the excavation as part of the 150-ton total. The LSRP representative will collect post-excavation soil samples upon removal of the observed contamination in accordance with the NJDEP Technical Requirements for Site Remediation (N.J.A.C. 7:26E). Post-excavation sample locations will be selected in accordance with the Technical Requirements for Site Remediation (N.J.A.C. 7:26E). Sample locations and frequency will be at a minimum, sufficient to satisfy the requirements of the applicable Technical Requirements for Site Remediation (N.J.A.C. 7:26E). The soil samples will be analyzed for EPA Target Compound List volatile organic compounds (TCL VO+15) with a library search of the 15 highest Tentatively Identified Compounds (TICs) and tertiary butyl alcohol (TBA). The contractor will have appropriate equipment (e.g., vacuum truck) to remove, store and dispose of any free-phase product and contaminated groundwater encountered in the excavation. The excavated soil will be temporarily stockpiled at the Site, and will be sampled for waste classification, loaded and transported to an approved off-Site facility for disposal.