ARCHIVED REPORTS XR0001409 - Laserfiche WebLink

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Mr Micheal Infurna 3 additional five feet of screen in the construction of well MW2 was granted by Mr Infurna while in the field) The wells were constructed of 2-inch diameter, Schedule 40 PVC casing and 0 020 inch slotted screen The filter pack consisted of#3 sand The annular seal contained 2 feet of bentonite, which was overlain by neat cement grout Field notes, well completion details and soil boring logs are included in Attachment A Well Development and Groundwater Sampling On July 19, 1999, prior to well development, the depth to groundwater was measured in each well and subtracted from the surveyed wellhead elevation to determine groundwater elevation The potentiometnc surface ranged from 11 79 to 12 13 feet below mean sea level Groundwater flowed in a southeasterly direction with a hydraulic gradient of approximately 0 004 ft!ft Groundwater elevations are summarized in Table 3 A groundwater gradient map generated using the July 19, 1999 monitoring data is shown on Figure 2 On July 19, 1999, the new wells were developed by surging and bailing until turbidity was minimized At least ten casing volumes were removed from each well Temperature, pH, and electrical conductivity were measured during the well development process Purge water was placed into DOT approved 55-gallon drums pending disposal Groundwater samples were collected from each well after groundwater recovery The samples were submitted to Argon Laboratory for analysis of TPHg and BTEX Field notes and well purge logs are included in Attachment B RESULTS Subsurface Conditions Borings MW and MW3 were drilled to depths of approximately 35 feet below ground surface (bgs) MW2 was advanced to a depth of approximately 40 feet The borings were subsequently constructed into groundwater monitoring wells Soils encountered during drilling consisted of gravel, sand, silt and clays A similar sequence of soil types was encountered in upgradient borings/wells MW I and MW3 In well MW 1, clay and silty clay persisted from the surface to a depth between 21 and 24 5 feet at which point a poorly graded sand was encountered The sand was underlain by lean clay at a depth of 36 feet In well MW3, clay and silt was underlain at a depth between 16 and 19 5 feet by a coarse grained interval consisting of sands and gravels Lean clay was again encountered in MW3 at a depth of 35 feet No indications of hydrocarbon contamination were observed in either of these borings In boring MW2 the soil sequence was almost entirely fine-grained Concrete and engineered fill overlies a bed composed primarily of silty clays from 9 S feet bgs to 31134 5 feet bgs Poorly graded 9-99 \xubsue rpt