HomeMy WebLinkAboutSUB200800189 Review Comments Groundwater Assessment 2008-07-31Tier II Groundwater Assessment
TMP 28 -26
Application Number: SUB200800189 Hersey Division (2 Lot) -Final
Groundwater Reviewer: J. Rubinstein
Date: 31 July 2008
Description: 1 division — 2 lots
Water Quantity
The Albemarle County Database shows seven wells within half a mile of the
lot. The wells range from 32 to 285 feet in depth with a median depth of
145 feet. The well yields range from 0 to 25 gallons per minute with a
median yield of 15 gallons per minute.
Water Quality
As shown on the Virginia Department of Environmental Quality (DEQ) GIS
website, there are two leaking underground storage tank sites (LUST) within
two thousand feet of the parcel.' Section 500 through 503 of Albemarle
County Code requires that new wells within two thousand feet of a LUST
site be tested for the volatile organic compounds Benzene, Toluene,
Ethylbenzene and Xylenes before a building permit can be issued. 2
Buffers
According to the Albemarle County GIS site, the buffer shown on the plat is
not required by the Water Protection Ordinance.3 Most of the parcel is in the
Buck Creek Watershed. The south west corner of the parcel is in the
Moormans River Watershed. Both watersheds are within the public water
supply watershed for the South Fork Rivanna Reservoir. It is not within the
reservoir's buffer.
1 http: // gisweb. deq .virginia.gov /deqims /viewer.htm ?SERVICE= VA_DEQ
2 http: / /www.albemarle.org /department. asp ?department= ctyatty &relpage =2784
3 http: / /gisweb.albemarle.org/
Site Description
According to the Virginia Department of Mineral Resources 1993 Map, the
parcel is in the charnokite and charnokite gneiss of the Blue Ridge Basement
complex (Ycm).
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:
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.
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