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.

Progress Report -- Drilling a Well

Jack Miller, President, Northern Virginia Drilling Company, and Winfield Sealander, Chair of the Capitol Hill Day School Board of Trustees' Facilities Committee review the status of our drilling project. Northern Virginia Drilling was on site Wednesday and Thursday, July 30-31 to find an adequate source of water for a geothermal HVAC system in the proposed addition to the building. John Brown, Driller, and Kent Wilkes, Assistant Driller worked with Jack on the project.

More pictures and videos of the drilling can be found at the following website: http://www.flickr.com/photos/chds/collections/72157603777742737/

Drilling a Test Water Well

On Wednesday, July 30 and Thursday, July 31 Northern Virginia Drilling, Inc., and Bowman Geothermal LC will drill a water well in the School's parking lot. This is a test to determine if we have adequate subterranean water to install an open loop geothermal heat exchanger in the proposed middle building for the School.

Porous Concrete Surface for the Parking Lot

We will drill several test holes in the parking lot in early August to determine if we can specify in the construction documents that the building contractor repave the parking lot with a porous concrete surface.

The District of Columbia's building code requires us to contain water that would otherwise run off a roof or a parking lot into the storm sewers. This goal is also important as we try to meet an environmental standard.

Where will rainwater from the parking lot drain? One idea that our Design Building Team is exploring is a porous concrete surface for the parking lot, but we have to determine if this solution is feasible by testing to see if the soil under the existing parking lot is sufficiently permeable.

Several holes will be drilled in the parking lot at various levels into the subsoil to determine the infiltration rate. If it is not fast enough the District will require the construction of an underground chamber filled with with sand and gravel along with an overflow drain to the storm sewer. We will realize cost savings if surface water will infiltrate the soil.

Steve Goley, P.E., LSA Associates, contributed to this post.

Geothermal Test Well

Capitol Hill Day School has contracted with Bowman Geothermal, LC, to drill a test well to the aquifer determine if there is an adequate source of water. If the "flow" is sufficient, the School could install a geothermal heating and cooling system in the proposed addition. The date for the drilling has not been set. We expect the drilling to occur over a two-day period.

LEED Design Criteria

What is LEED®?

The Leadership in Energy and Environmental Design (LEED) Green Building Rating System™ encourages the adoption of sustainable green building and development practices. LEED criteria are administered through the U.S. Green Building Council (USGBC), a non-profit organization committed to expanding sustainable building practices. More information on LEED is availaible at http://www.usgbc.org/

GreenShape LLC http://www.greenshape.com/ facilitated a fascinating one-day session for members of the School community and representatives of the design team. Our discussions focused on elements of design that impact the environment and how environmental elements in the building can be incorporated in the School's curriculum.

The School's educational program encourages respect for the environment and a concern for the world's finite resources. We participate with other educational institutions and non-profits in the annual Anacostia River clean up. With leadership from middle school students, the School conducts an in-house recycling program. Students in first grade examine fundamentals of ecology through a study of the life cycles of seeds, insects, plants, and frogs. In the seventh grade students complete a yearlong study of environmental science culminating in an off-site study of the Chesapeake Bay watershed at Port Isobel Island. As the design development team evaluates potential impacts of the building addition, we are excited that plans may include waste water containment through a "green" roof, energy saving lighting, and even the possibility of a geothermal heating and cooling system.

Design Development Phase

The building addition is currently in the "design development" phase. The School is working with the architectural firm of cox graae + spack, www.cgsarchitects.com/, to develop the drawings a contractor will use to bid on the project.

The design team includes:

Professional Consulting Corporation www.professionalconsulting.com/
Loiederman Soltesz Associates, Inc. www.lsassociates.net/
Potomac Energy Group, Inc. www.pegroup.net/
Monarc Construction, Inc. www.monarcconstruction.com/
Bowman Consulting Group, Ltd. www.bowmanconsulting.com/
Northern Virginia Drilling, Inc. www.nvdinc.com