MFS coordinated with our in-house drilling agency (MFS Construction, LLC) to conduct seven (7) test borings to depths of 12 to 16 feet below grade and seven (7) infiltration tests adjacent to each test boring. The seven (7) infiltration tests were conducted within cased boreholes at depths of 5 to 9 feet below grade. The purpose of the test borings/infiltration tests was to identify the subsurface conditions within the proposed bio-retention basin and to determine the soil hydraulic conductivity to aid in the design of the Storm Water Management (SWM) practices. The infiltration tests were conducted in accordance with the procedures outlined in the New Jersey Best Management Practices (NJBMP).
During the subsurface investigation, bulk soil samples were obtained in the uppermost two (2) feet below grade in five (5) gallon buckets via hand digging for California Bearing Ratio (CBR) testing. The CBR samples were obtained within the footprint of the proposed parking lot. Three (3) CBR samples/tests were completed at the project site.
During the test boring operations, MFS observed the subsurface conditions and generated test boring logs to include soil classifications in accordance with the Unified Soil Classification System (USCS), groundwater observations, action of equipment, and other noteworthy observations. The boring logs showed borehole and sample diameters and depths at which drilling, or sampling methods or equipment change. Logs showed total depth of penetration, blow counts, groundwater level, and types of sampling, the drilling equipment make and model, drilling method, date and time drilled, casing, any heaving conditions, loss of circulation or voids..
During the infiltration tests, MFS recorded the drop in water at specified intervals to determine the infiltration rates of the soils in accordance with the NJBMP.