Residential

We propose drilling two (2), seven-inch diameter geotechnical test borings (SWM-1 and SWM-2) using the hollow stem auger method to evaluate the subsurface conditions. The proposed test boring depths will be 20 feet. If a confining unit is encountered, outer casing will be installed which will extend 10 feet into the top of the confining unit or to the top of bedrock. Upon completion, each geotechnical test borings will be backfilled immediately with grout to the existing ground surface. The borehole will be tremie-grouted in one continuous operation with a positive displacement pump using a bentonite slurry mix (at least 2 pounds bentonite powder to 1 gallon of water) from the bottom of the borehole upward. Drilling spoils including soils and water from the test borings will be containerized in 55-gallon drums to be removed for disposal after chemical laboratory results of the spoils have been received and reviewed. Spoils will be disposed of in accordance with Federal and District laws and regulations.