CHRIS WILLETT URS CORPORATION

1906 West Virginia Ave Ne, Washington, Dc 20002
Dccr project proposes to drill 3 direct push borings nebbd-68e-1 ? Nebbd-68e-2, nebbd-68e-3 located at 1906 west virginia ave ne. The dp borings will be 2 inches in diameter and extend feet below ground surface. The borings will be completed using direct push methods with a standard hollow soil rod to collect soil samples. Groundwater samples may be collected via a peristaltic pump. Samples will be analyzed for tph-dro, tph-gro, voc, svoc, rcra metals, plus vanadium, pesticides, herbicides and pcbs. All drill cuttings will be containerized in 55 gallon dot rated steel drums. All drill cuttings will be properly tested and characterized for disposal. The dp borings will be backfilled with hydrated bentonite. Monitoring wells will not be installed. Upon completion, boring will be backfilled with bentonite pellets in 2 foot flights. The amount of water to be used to hydrate the bentonite is contingent on field conditions due to presence of shallow groundwater. Prior to completion, the bore

16 2nd St Sw, Washington, Dc 20024
Urs will conduct subsurface soil sampling using direct push methodology to investigate if subsurface petroleum contamination is present that would be encountered by substation construction. The investigation will include conducting up to six direct push borings to a depth of up to feet below ground surface. Up to two soil samples will be collected from each boring location for a total of 12 samples. Each sample will be analyzed for volatile organic compounds voc, svoc, and petroleum hydrocarbons gasoline and diesel range organics. If groundwater is encountered during advancement of the borings a groundwater sample will be collected and submitted instead of a second soil sample from the boring location. Selection of soil samples for laboratory testing will be based on field observations, staining, odor, organic vapor instrument readings. Please see the attached. Hydration method sheet for additional backfilling information.

12 13th St Se, Washington, Dc
Dccr proposes to drill two geotechnical boarings, ms-mw-02d & ms-mw-02s, located at 12 13th st se. Both boarings will be 6 inches in diameter, 02d will be 36 feet deep wioth a foot screened interval starting at 25 feet deep and 02s will be 23 feet deep with a foot screened interval, starting at 13 feet deep. Both will be dirlled with hollow stem auger. No permanent casing will be installed. See idw mangement and attached schematic for additional information. All drill-generated waste will be drummed, solid and liquid. The well shall be covered and protected from surface water drainage and the vertical migration of contaminants and other materials though the well casing and well annulus.

1241 W St Ne, Washington, Dc 20018
Dccr project proposes to drill 3 direct push boring nebbd-74e-1, nebbd-74e-2, nebbd-74e-3 located at the department of public works complex at 1241 w street ne. The dp boring will be 2 inches in diameter and extend feet below ground surface. The borings will be completed using direct push methods with a standard hollow soil rod to collect soil samples. Groundwater samples may be collected via a peristaltic pump. Samples will be analyzed for tph-dro, tph-gro, voc, svoc, rcra metals plus vanadium, pesticides, herbicides and pcbs. All drill cuttings will be containerized in 55 gallon dot rated steel drums. All drill cuttings will be properly tested and characterized for disposal. The dp borings will be backfilled with hydrated bentonite. Monitoring wells will not be installed.

12 13th St Se, Washington, Dc
Dccr proposes to drill one geotechnical boring, ms-mw 01, located in 12 13th st se. The boring will be 6 inches in diameter and 2 feet bgs, with a screened interval from 135 to 195 feet bgs, drilled by mud rotary. Permanent stell casing will installed and be socketed feet into p/a and grouted before drilling into the ptx. Msds for drilling mud additives attached. See idw management plan and attached schematics for additiional information. All drillling-generated waste will be drummed, solids and liquids. The well shall be covered and protected from surface water drainage and the vertical migration of contaminants and other materials though the well casting and well annulus.