HomeMy WebLinkAboutSUB200700364 Review Comments Groundwater Assessment 2007-11-08Tier II Groundwater Assessment
TMP 14 - 19
Application Number: SUB200700364
Groundwater Reviewer: J. Rubinstein
Date: 8 November 2007
Description: 1 division — 2 lots
Water Quantity
The Albemarle County Database shows five wells within half a mile of the
lot. The wells range from 65 to 305 feet in depth with a mean depth of 240
feet. The well yields range from two to sixteen gallons per minute with a
mean yield of seven gallons per minute.
Water Quality
As shown on the Virginia Department of Environmental Quality (DEQ) GIS
website, there are no leaking underground storage tank sites (LUST) within
a mile of the parcel.'
Buffers
The site is in the Moormans River watershed. According to the county GIS
site, the Doyles River, the eastern boundary of the lot, has a required buffer.2
The parcel is within the watershed for the South Fork of the Rivanna public
water supply reservoir. It is not within the reservoir's buffer.
Site Description
According to the Virginia Department of Mineral Resources 1993 Map, the
bedrock beneath most of the parcel is in the charnockite gneiss of the Blue
Ridge Basement Complex (Yc).
In a groundwater assessment done for the Albemarle County, ENSAT
Corporation divided the county into `hydrologic units'. Below is ENSAT's
description of the unit containing the parcel:
' http: / /gisweb.deq.virginia.gov /deqims /viewer.htm ?SERVICE= VA_DEQ
2 http: / /gisweb.albemarle.org/
The Colluvial Fan unit lies at the base of the eastern slopes of the Blue
Ridge Mountain and is characterized by relative steep drainage swales
that extend to more gradual sloping conditions. The area includes a
series of intermittent drainages that include ephemeral drainage ways.
Many of the intermittent drainages become perennial streams as this
area includes stream bottom valleys. A significant portion of the unit
area consists of transported soils including the Braddock and
Thurmont. These soils are formed in colluvial and alluvial materials
found on colluvial fans and terraces and are the product of weathered
granite, granodiorite, granite gneiss, and greenstone. Both of these
soil series are deep and well drained with slopes ranging from 2 -25 %.
Residual soils including the Hayesville and the Chester are also
abundant. These soils are also deep and well drained and are formed
on upland slopes from weathered products of granite and granite
gneiss. Slopes of these soils typically range from 2 -45 %. The
accumulation of transported soils (colluvial and alluvial) can form
"cappings" over residual soils and parent material, which can add to
the overall thickness of the overburden.