Calibrated Test -- Geothermal Well

Bowman Consulting and Northern Virginia Drilling completed a calibrated test of the well's capacity. Today's test, with the geologist's report, will confirm the well's potential as a source of water for the geothermal system. We have requested Northern Virginia Drilling complete one additional test to determine the well's potential as an ejection well. The drillers will pump water into the well to measure the speed at which the water is absorbed into the aquifer. The School is considering an "open loop" geothermal system with one well serving as the water source and the second well serving as the ejection well.

The picture shows the drilling team reading the pump dial and a sonic water level meter. The latter instrument measures the temperature of the water (55 degrees) and the level of the water table at various pump speeds (generally around 74' below the surface of the parking lot).

FINAL REPORT Geothermal Test Well

Northern Virginia Drilling successfully installed a 4" PVC pipe in the existing well on Thursday, August 21st. The drillers estimate the flow at 120 gallons per minute, an excellent result that meets the requirements specified by our Mechanical, Electrical, and Plumbing (MEP) Engineer. The drilling equipment has been removed; some cleanup remains. Thanks to everyone for your patience.

Pervious Concrete Site Visit

Chuck Schwartz, Chair, Board of Trustees, and Jim Woolwine, Business Manager, met with Haejin Kim, Materials Research Engineer, National Ready Mixed Concrete Association, to explore the option of paving the School's parking lot with pervious concrete. Haejin explained the technical considerations for the surface material and the environmental advantages that this installation would convey. We also learned that the surface texture can vary depending on the aggregate mix, an important consideration for the School as the parking lot is also used for a play area. Double click on the picture to see the water seep through the concrete. Pretty cool stuff.

Progress Report, Well Drilling, Wednesday, August 13th

Northern Virginia Drilling will return to School Friday, August 15th to repair the broken well lining. They will inject a mixture of concrete and bentonite to fill the hole. This material will cure for approximately three days. The full drill rig will be back on site Tuesday, August 19th to drill down through the sediment and fill material to bedrock, insert an inner liner, and again attempt to measure/test the aquifer to see if it produces an adequate water flow. The "well" is the cylindrical capped PVC pipe in the picture.

Thanks to Harrison Crecraft, Bowman Geothermal, Jack Miller, Northern Virginia Drilling, Farooq Ahmadzai, Potomac Energy Group, and School Trustees Chuck Schwartz and Winfield Sealander for their contributions.

Progress Report, Well Drilling, Thursday, August 7

Northern Virginia Drilling reached bedrock 293 feet below the School's parking lot. The drillers installed porous screens, a PVC well wall, and a large quantity of sand to filter and purify the water in the aquifer. As the initial test of water volume was underway the PVC well liner exploded at approximately 86 feet below the parking lot filling the bottom of the well with silt. At the time the wall collapsed the well was producing approximately 100 gallons per minute and the water temperature was a chilly 57 degrees.

Several options are currently under consideration.

Progress Report, Well Drilling Friday, August 1st

Northern Virginia Drilling reached bedrock at 290 feet late Thursday evening. There appears to be approximately 55 feet of sand strata. The well should generate adequate water flow for the School's intended purposes. The firm will now pipe the well and perform several pump tests to generate data for the engineers at Bowman Consulting. Based on the test data Bowman will determine the size/capacity/functionality of the pumping equipment for the building addition. Thanks to Jack Miller, John Brown, and Kent Wilkes, our drilling team.