comprehensive site investigation and remediation objectives report

GROUNDWATER MONITORING WELL INSTALLATION
AND DEVELOPMENT PROTOCOLS
Monitoring Well Construction
Hollow stem augers (HSAs) will be used to advance borings for well construction. The
monitoring well will be constructed with 2-inch diameter Schedule 40 polyvinyl chloride
(PVC) riser pipe and 10-feet long, 10 slot, Schedule 40 PVC screen. The final design of
the well will be determined in the field. The screen length will allow for fluctuation in the
local water table and enable collection of groundwater samples representative of the
shallow saturated zone.
The filter pack sand will extend approximately 2 feet above the top of screen. The
thickness of the filter pack sand will be determined by the relationship between the water
table and the top of screen to the ground surface. If the water table is near the surface in
the well, the filter pack thickness may have to be reduced to ensure that a minimum 2-
foot thick annular seal can be installed above the filter pack. Filter pack material will be
selected that will impede fine-grained soils from entering the well.
The annular space seal will consist of bentonite slurry and (or) bentonite pellets and will
be a minimum of 2-feet thick. The well will have either a flush-mounted or 3-foot stick up
well protector, and a 3-foot by 3-foot concrete pad installed at ground surface.
Monitoring Well Development
The well will be developed no sooner than 24 hours after installation to allow for grout
curing. Development will consist of mechanical surging and bailing until little or no
sediment enters the well. This will continue for a maximum of 2 hours. Sediment that
enters the well during the process will be removed. After surging and bailing, the well will
be pumped using a submersible pump. Temperature, pH, specific conductance,
oxidation-reduction potential (ORP) and turbidity will be measured after each well volume
is removed. Development will continue until these parameters have stabilized within the
following ranges for three consecutive readings: + 0.1 unit for pH, and + 3% for specific
conductance, + 20 mV for ORP, and + 10% for turbidity and temperature. If these criteria
have not been attained after 2 hours, development activities will be suspended, the well
will be considered “developed” and water samples will be collected.
\\ilch-itfs01\V3il_Chi\ADMIN\STD OPERATING PROCEDURES\SOPs Source Docs\5.0 Data Gen and Acq\5.1 Field
SOPs\Protocols\Groundwater Well Installation & Sampling\GW monitoring well installation and development.doc