D1_-_Underdrain_Report_for_Informational_Purposes.pdf

The document is an Underdrain Report prepared by Hillis-Carnes Engineering Associates, Inc. for the Mill Hill Road project in Charles County, Maryland. The report documents a shallow subsurface exploration study conducted for George, Miles & Buhr, LLC, with project number W15067. The investigation consisted of 10 hand-augered borings along the proposed roadway improvement from Devonfield Avenue to Homecoming Drive, with soil samples obtained and tested for groundwater levels, particle size distribution, and Atterberg limits.

The soil exploration revealed varied geological conditions, with most borings showing layered compositions of gray to light brown sandy clay, silty sand, and silt with varying moisture content. Particle size distribution reports indicate the soil samples primarily classify as CL (clay with low plasticity) or SM (silty sand) according to the Unified Soil Classification System (USCS). The moisture content of the samples ranged from approximately 14% to 29.7%, and the boring depths were generally limited to 3.5 to 6 feet below existing grade. The report concludes that no groundwater was detected within 6 feet of existing grades, and no significant underground conditions were encountered that would impede the proposed road improvement project.