HomeMy WebLinkAboutSDP202100017 Other 2021-07-27 (2)7/06/21 Page 1 of 2
Capacity Assessment/SAP Analysis
Onsite Wastewater System
VA Asphalt Z
Physical Address: 1536 Avon Street Extended Charlottesville, VA
Mailing Address: 493 Burchs Creek Rd, Crozet VA 22932
ATTN: Virginia Department of Health
Assessment conducted by Old Dominion Engineering (ODE)
The Facility
Virginia Asphalt Services has a shop at 1536 Avon Street Extended (TM 77-8, 1.69
acres). An AOSS was permitted through VDH and installed in 2016 (HDID101-16-0162,
Permit Dated 5/2/16). Old Dominion Engineering (ODE) inspected the drainfield
installation on 5/26/16 and the balance of the treatment system components on 12/5/16
and 12/8/16. ODE was onsite during the entire drainfield installation due to potential
issues in the dispersal area. The Engineers completion statement is attached to this
report.
Virginia Asphalt Services wants to expand their equipment storage by paving over areas
behind the building in the vicinity of the septic treatment and dispersal system. This
capacity assessment/SAP analysis is to determine if the additional paving behind the
building will impact the treatment and/or the dispersal system.
Dispersal Area Drainfield Inspection 5/26/16
Due to potential issues in the underlying soils, ODE was present during the entire
drainfield installation by Christians and Associates. The drainfield was installed at 42" to
take advantage of a seam of naturally occurring soils beneath fill material so that both
drainfield trenches would be in a more permeable soils horizon. Two trenches were
installed with a total of 300 square feet of dispersal area (2 trenches, 42" deep, 3 foot
wide, 50 foot long, 9 foot on center).
Note - Virginia Asphalt Services has added approximately 18" of additional fill material
over the drainfield area since it was installed yielding a 60" depth from surface to trench
bottom.
Proximity of Existing Drainfield Area to the New Parking Area
Based upon the proposed site plan prepared by Alan Franklin PE, the proposed additional
parking area is directly over the existing drainfield. The new parking area will be paved.
The depth from the new surface to the trench bottom exceeds 60".
Page 1 of 2 Old Dominion Engineering - 366 S. Linden Avenue - Waynesboro, VA 22980 - olddomeng@ntelos.net
7/06/21
Page 1 of 2
Proximity of Treatment System to the New Parking Area
The treatment system at Virginia Asphalt Services includes:
• 1000 gallon plastic septic tank with effluent filter
• TL3 Treatment with Aqua Safe AS500
• UV Disinfection with ETI AS UV Disinfector
• Sampling Port
The treatment system is installed parallel to the back of the building approximately 10'
off the building to the edge of the tanks (see as -built on completion statement). All tanks
and treatment devices are visible from the surface. The Lincoln survey has identified the
visible components of the septic treatment system. Labeling is generic terminology
(cleanout and septic lid) (see attached blow up survey in treatment area.
The existing treatment components are outside the proposed pavement areas.
ODE Conclusions
1. The existing drainfield will be under the proposed parking area. Since the depth
to the surface will exceed 42" and the surface is paved this meets VDH
regulations.
2. The treatment system will NOT be under the proposed pavement. The location of
the septic treatment system is NOT in conflict with the new parking area.
3. It is recommended to install some type of simple barricade (i.e. bollard, asphalt
curbing, etc.) to keep trucks from inadvertently backing off the pavement and
over the treatment system.
4. The proposed site plan is not in conflict with the existing AOSS.
Page 2 of 2 Old Dominion Engineering - 366 S. Linden Avenue - Waynesboro, VA 22980 - olddomeng@ntelos.net