Exhibit A
Nashua - Crown Street Park & Ride Project
Scope of Work and Task Descriptions
June 15, 2016
Task 2.2 — Geotechnical Investigations
Project Coordination and Utility Clearance — GZA will review tne proposed site development plans
and make a site reconnaissance to observe existing site features. GZA will coordinate the
subsurface exploration program with MJ and-our test boring subcontractor, New England Boring
Contractors, Inc. (NEBC) of Derry, New Hampshire. Test boring locations will be determined by
GZA using tape ties from prominent site features and/or hand-held GPS which has a precision of
+/- 10 feet. Dig Safe® utility clearance will be completed by NEBC. However, it should be noted
that Dig Safe® will not mark utilities on private or restricted properties. Adjustments in locations
will be made, as necessary, in the field by GZA to address access conditions encountered. GZA
cannot be responsible for damage or repair to underground utilities unknown to us prior to the start
of drilling. MJ will forward available utility information provided by MJ to NEBC for their use in utility
clearance
Subsurface Exploration Program - GZA will subcontract with NEBC to conduct a three-day
subsurface exploration program. We anticipate drilling a total of up to ten to twelve test borings in
that time.
The type and location of stormwater infiltration features has not been determined. Typically, at
least one test boring with a monitoring well is required for each stormwater Best Management
Practice (BMP) location. For the purposes of this budget we have assumed groundwater and
infiltration rates will be required at four locations across the site. Accordingly, four test borings will
be drilled to a depth of 25 feet below ground surface. Standard Penetration Testing will be
performed continuously in the upper ten feet and at approximately five-foot intervals thereafter. A
two-inch-diameter polyvinyl chloride (PVC) groundwater monitoring well will be installed at each of
the four locations to approximately five feet below existing groundwater table elevation. For
budgeting purposes, we have assumed that the wells will be installed up to 25 feet below existing
ground surface.
It is assumed that development water will not be containerized and can be discharged directly onto
the ground. Following development and stabilization, GZA will collect one round of groundwater
level measurements and water quality samples from the four newly installed groundwater
monitoring wells. GZA will also attempt to obtain groundwater depths from the five wells installed at
the site in 2013. If still present, GZA will also collect one water quality sample from groundwater
monitoring well GZ-1 for analysis.
The remaining six to eight test borings will be drilled to depths of 10 feet below ground surface.
The borings will be drilled with a truck-mounted drill rig using either hollow stem augers or drive-
and-wash cased drilling techniques through the overburden soils which are anticipated to consist of
sand and gravel. Standard Penetration Testing will be performed continuously in the upper ten
feet.
GZA will field screen soil samples for volatile organic compounds (VOCs) using a photoionization
detector {PID} using a 10.6 eV lamp.
Based on subsurface conditions documented during the Phase || ESA at the site, we have
assumed that bedrock will not be encountered to the maximum depths proposed in this subsurface
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