September 10, 2021 Page 3
20210910 Bridge St E Hollis St Nashua Sanborn Head Amend 1.docx 4381.00
Sanborn Head will subcontract with a New Hampshire-licensed driller to complete up to 20
boring in existing landscaped areas where new roadways are proposed. We assume that
the work will be completed in one day using a Geoprobe drill rig. Borings will be
completed to approximately 10 feet below ground surface, or less as necessary to avoid
subsurface utilities. Soil samples will be collected from the upper 5 feet for environmental
laboratory analysis, unless field observations indicate the potential for asbestos-containing
soil at deeper intervals.
This amendment includes the cost of the Geoprobe drill rig and crew plus a Sanborn Head
environmental staff person for one day of drilling and soil sampling. We included an
allowance for one day of police detail with a cruiser during this work. Our field person will
be a New Hampshire certified Asbestos Disposal Site Worker so that sampling of asbestos-
containing soil can proceed without interruption if encountered. Soil samples will be
collected for laboratory analysis by Sanborn Head personnel and transported to the
laboratory using chain-of-custody protocols.
We included laboratory analysis of 20 soil samples for asbestos by Polarized Light
Microscopy (PLM) using USEPA Method 600.
Task PD2 - Environmental Data Report
The results of the environmental field exploration will be summarized in an Environmental
Data Report for distribution to the project team. The data report will include a site plan
showing Geoprobe boring locations, boring logs, a summary table of soil analytical results
compared to regulatory thresholds, and analytical laboratory reports.
Task PD3 - Meeting
We included an allowance for one meeting to be attended by the Sanborn Head Principal-
in-Charge at the offices of McFarland Johnson in Concord, NH during the Preliminary
Design phase.
Final Design
Final Design includes an assumed scope of geotechnical services, plus: (i) environmental
services for preparation of a Soil Management Plan and a site-specific Asbestos Disposal
Site (ADS) Work Plan (if needed); and (ii) coordination with the New Hampshire
Department of Environmental Services (NHDES) to obtain approval of the ADS Work Plan.
The scope of services for Final Design services is described in greater detail below.
Task FD1 - Soil Management Plan
Based on the environmental field exploration (Task PD1), Sanborn Head will prepare a Soil
Management Plan (SMP) that can be included as an appendix to the bid documents. The
SMP will describe the construction procedures for handling, stockpiling, reuse of soil
within the limit of work, and off-site disposal of excess soils, if necessary. The SMP will be
based on the NHDOT Generic LRS Soil Management Plan with project specific revisions.
SANBORN HEAD
