Characteristics of water-well yields in the Blue Ridge of Loudoun County, Virginia

Mean yields and the numbers of wells drilled are presented for 35 rock types
containing 4,115 wells in the Blue Ridge of Loudoun County, Virginia. Analysis
of variance of the well yields shows that Harper's Formation phyllite and
Catoctin Formation metabasalt have yields significantly different from those of
other rock types. Preliminary variography has identified an anisotropy that
roughly parallels the general compressional trend of the Blue Ridge.