Drilling and monitor well installation has been requested by EPA at three (3) locations on BLM managed lands over the next 6-months. Each location will include one or more wells installed as a closely spaced cluster to minimize the total land disturbance. Drill locations are presented on the attached USGS topo maps at a scale of 1:24,000. Brown and Caldwell will access drill sites using existing roads and does not anticipate any of the proposed locations will require any ground disturbance (e.g. road building or drill pad construction) off the existing roads, although there may be a need to set up the drill rigs or support vehicles off the edge of existing access roads causing some minor disturbance to the vegetation. Time to complete each borehole will be approximately 2 to 5 days depending on the location, depth and whether intermediate (zonal) water samples will be collected during the drilling process. Locations that have more than one borehole will likely require the drilling to be completed in two phases: 1) an initial phase of drilling the deeper hole and conducting zonal sampling, and 2) a follow-up phase to install the shallower well with a second sonic drill or the bedrock well using the air rotary drill rig. Atlantic Richfield and Brown and Caldwell will need to continue accessing the completed monitor wells each month for water level measurements and once per quarter for sample collection. A 3 foot tall monument with 2’ x 2’ concrete pad will be the only permanent installation remaining at each monitor well location. The wells will remain locked at all times with keys managed by Brown and Caldwell. Well abandonment will be addressed under a separate action.