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HomeMy WebLinkAboutSDP201600012 Assessment - Groundwater 2016-10-31TRU EE RTH EnvironmentahLc 118 Buckingham Circle, Charlottesville, VA 22903 October 17, 2016 Mr. Justin Shimp Shimp Engineering 201 East Main Street Charlottesville, Virginia 22902 Re: Tier III Assessment; 2300 Hunters Way Dear Mr. Shimp, True North has completed the following Tier III Groundwater Assessment of the Hunters Way development. Key Findings Based upon the results of the Tier III the following key findings can be reported: • Hydrogeologic Units: IE (The Blue Ridge East Unit) • Groundwater availability zone: Class 2 (medium relative groundwater availability) • Hydrogeologic conditions favorable to proposed use? Yes • Site within groundwater sensitivity zone? No. • Contamination threats on record: No significant threats • Additional contaminant threats observed in field reconnaissance? No 1.0 Background The 1.46 -acre parcel currently includes two commercial building. One of the existing buildings is unoccupied and the other is currently in use as storage space. The parcel is currently served by a private well and drainfield located in the northern portion of the parcel. The owners plan to build an auto repair shop/garage with six bays with some limited office space. Groundwater usage has been estimated to be approximately 270 gallons per day (gpd), or about 0.20 gallons per minute (gpm). The existing well is to be properly abandoned and will be replaced by a new well (OSE Design - Old Dominion Engineering —February 24, 2016-). The general site plan is included in Attachment A. Tier III Assessment True North Environmental 2300 Hunters Way Charlottesville, Virginia October 17, 2016 2.0 Setting The property is located on the northwest corner of the intersection of State Route 250 (Richmond Road) and Rt. 1146 (Hunters Way) in Albemarle County (Figure 1). The setting of the parcel is commercial, existing land uses surrounding the property are commercial, industrial and some small farms. The parcels in the immediate vicinity of the site are served by individual wells and drainfields. The property is bounded on the west and north by Hunters Way (Rt. 1146), on the south by Richmond Road (Rt. 250). The adjoining property to the north is in use as a commercial day- care business. The property across Richmond Road to the south is rural. Properties across Hunters Way to the east and north are in commercial, light industrial uses. The property possesses moderately steep terrain, sloping generally to the south, and to the southeast in the eastern portions of the parcel. Elevation ranges from approximately 408 feet in the northern corner of the site to approximately 360 feet at the southeastern boundary (Figure 1). Runoff from the property drains into an engineered roadside ditch along Richmond Road. The drainage crosses Richmond Road in a culvert which drains into an unnamed tributary of Barn Branch, approximately 2,100 feet to the east. Barn Branch empties into the Rivanna Rover approximately 1,500 feet to the south. The Rivanna River is a part of the James River drainage basin. 3.0 Geology & Soils According to the Geologic Map of Virginia produced by the USGS and the Virginia Department of Mines and Minerals, the property lies within the Catoctin Formation rock unit as graphically shown in Figure 2. The Catoctin geology is described by the USGS as grayish -green to dark - yellowish -green, fine-grained, mafic metabasalt of Proterozoic Z -Cambrian age. The soils of the site have been mapped by the National Resource Conservation Service as principally Rabun clay (Figure 2). In general, Rabun clay is well drained, accommodating moderate to rapid runoff, and moderately permeable. 4.0 Existing Hydrogeologic Information and Well Yields The subject site is located within the Blue Ridge East (IE) Hydrogeologic Unit according to the Albemarle County Hydrogeologic Assessment Summary Report of 2003. According to that report, the average yield of the wells drilled within this Unit for the entire county was 13.72 gallons per minute (gpm). Bedrock wells in this region of the state derive water from a fractured bedrock aquifer in which groundwater occurrence and movement are controlled primarily by fractures and joints within the rock. Groundwater flow patterns in the bedrock can be very complex, depending upon the geologic and topographic setting and upon fracture frequency, size, and geometry. Where present, any overlying weathered rock and soil is typically relatively granular and porous; it may house a shallow water -table aquifer separate from, but connected to and 2 Tier III Assessment True North Environmental 2300 Hunters Way Charlottesville, Virginia October 17, 2016 interacting with, the underlying fractured bedrock aquifer. The water table in shallow aquifers is often a 'subdued replica of topography', in which groundwater flow is generally from areas of higher elevation ('recharge zones') toward areas of lower elevation ('discharge zones'). Figure 3 depicts the estimated direction of shallow groundwater flow. The source of groundwater in both aquifers is ultimately from precipitation (recharge) that infiltrates through the soil and weathered rock. 5.0 Potential and Known Contamination Sources In an effort to identify potential sources of contamination, True North performed a site reconnaissance, reviewed available Risks/Hazards Mapping from the Albemarle County GIS Website, and queried the Virginia Environmental Geographic Information Systems (VEGIS) operated by the Virginia Department of Environmental Quality (DEQ). VEGIS displays reports regarding petroleum release sites, Voluntary Remediation Program sites, Solid Waste Facilities and tank facilities. Two registered tank facilities were listed within 2,000 feet of the subject site. One facility is located at 2320 Hunters Way, which is the parcel directly north of the subject site. The second facility is located at 2440 Hunters Way, which is in commercial use by a parcel transport business. One leaking underground storage tank was listed in the DEQ database at the VDOT facility at 701 VDOT Way, which is located approximately 1,900 feet northeast of the site. A release of gasoline from an underground storage tank at this facility was reported in 1998. The pollution complaint number for this release has been closed by DEQ. True North does not believe that these facilities represent an environmental risk for the subject site. Additionally, True North contracted with EDR Incorporated to independently review all government databases related to any environmental documentation in the vicinity of the site (Attachment B). The results appeared to corroborate the information reported in the previous paragraph and identified a RCRA-CEQG site located at 2440 Hunters Way Road (UPS Facility). These are facilities that generate (and dispose of) less than 100 Kg of hazardous waste, or less than 1 Kg of acutely hazardous waste, per a month. 5.1 Field Summary Review & Sensitivity Mapping Field reconnaissance was conducted on the property on October 6, 2016. Access was good to much of the site. Site reconnaissance did not reveal any visible sources of environmental concern on the site. The neighboring parcels are served by individual wells and drainfields. Based upon a visual inspection and the Albemarle County GIS Website, there are approximately 9 parcels within 1000 feet of the site that may possess well and septic systems (Figure 4). These parcels are either up -gradient or cross gradient to the site. One parcel, located downgradient and across Route 250 is open land. Any existing up -gradient drainfields have been presumably permitted 3 Tier III Assessment True North Environmental 2300 Hunters Way Charlottesville, Virginia October 17, 2016 by the Albemarle County Health Department and thus not thought to pose a threat to the groundwater of the site. 6.0 Groundwater Management Planning The development plan calls for the closure of the existing water supply well, and installation of a new well and the inclusion of an engineered septic waste disposal system. The proposed site plan includes storm water management devices to minimize uncontrolled offsite discharge of storm water. The vast majority of the site, though sloping, is considered to be a groundwater recharge zone where precipitation can infiltrate into the subsurface. The impervious surfaces (parking lot and roofs) drain to grassy areas where storm water can infiltrate. The southern boundary of the site (along Richmond Road) is the foot of the hillslope, such that shallow groundwater discharge there will be routed into the engineered channels that drain into Barn Branch. Land disturbance should be minimized during construction and landscapes stabilized afterwards. This, in conjunction with the storm water management plan, open spaces and recharge of treated effluent should work to maximize groundwater potential of the site. 7.0 Recommendations; Contingency Plans • Implement a runoff -neutral grading designs and water management practices that promote infiltration of rainwater rather than surface runoff, as much as practicable. • The proposed well should be constructed in such a way as to intercept deep bedrock fractures. Such a well should be considered reliable as long as over -pumping does not occur. 8.0 Conclusions True North Environmental, LLC concludes the following: The project site is located within the Blue Ridge East Group of rocks where the average yields of wells drilled in this unit is approximately 14 gpm (Albemarle County Hydrogeological Study, 2003). Based upon the existing well yield data and experience, True North believes that the site possesses good groundwater potential as long as reliable water bearing zones are intercepted during construction of the well. 2. The projected water use is quite low (approximately 270 gpd) and would not be expected to have a negative impact on other groundwater resources in the immediate vicinity of the site. 3. Environmental inventory of site and surrounding properties did not indicate the presence of potential sources of contamination that presently threaten the environmental integrity of the site. 21 Tier III Assessment True North Environmental 2300 Hunters Way Charlottesville, Virginia October 17, 2016 Limitations The work performed in conjunction with this project, and the data developed, are intended as a description of available information. This report does not warrant against future operations or conditions, nor does it warrant against operations or conditions present of a type or at a specific location not investigated. Generally accepted industry standards were used in the preparation of this report. Stated opinions and conclusions are not intended as a guarantee. The only reliable way to confirm that a sustainable groundwater resource is present is to drill a well and test it for quantity and quality. True North appreciates the opportunity to be of service to you with this project. If you have any questions, please call me at 434-923-0888. Best regards, irI Vincent Day, CPG Principal/Geologist No, 2801002 Figures Id1 11— Attachments l "JQ ��dV ��ESSIDNP 5 y�rwvystor ds.c A kv Lr "QL7- N -4- \X All % Z' 1 z x 4 13 j > 2300 Hunters Way FIGURE TRUE*RTH Site Location Map Source Ma & Google Earth ,,"vironmentabic p: USGS �{•.y« l J. .r 1 it tir •...4 .r Orjl4v mt.. Y r4' {'.,�r�,. yr I ri lar —� .M.r` Ole r L r. 14 2300 Hunters Way FIGURE Geology Map TRURTH 2 Source Map: Geology of Albemarle County, Etzuirownewalfl., Division of Mineral Resources (1962) r I IN \••• ti 4 (-7- Ft Ft r ► / fit w f� I � I TRU*EnvironmentabicRTH 2300 Hunters Way Map of Estimated Groundwater Flow Direction FIGURE 3 Source Map: Albemarle County GIS & GoogleEarth # Jai Si.S G1Ylti 'ti; k f t 1 47�.'7A ► x �k 254 � - f 24 2300 Hunters Way FIGURE TRU *RTH Parcels within 1000 Feet 4 Euvirownejuab,., Source Map: Albemarle County GIS & GoogleEarth ATTACHMENT A SITE MAP (SEE SEPARATE FILE) ATTACHMENT B EDR OVERVIEW MAP I o I / / / / Q�o OVERVIEW MAP - 4738083.2S * Target Property A Sites at elevations higher than Indian Reservations BIA or equal to the target property Sites at elevations lower than the target property A Manufactured Gas Plants National Priority List Sites Dept. Defense Sites id � q00 SITE NAME: Hunters Way CLIENT: True North Environmental, LLC ADDRESS: 2300 HUNTERS WAY CONTACT: VINCENT DAY CHARLOTTESVILLE VA 22911 INQUIRY #: 4738083.2s LAT/LONG: 38.01 6084 / 78.417946 DATE: September 27, 2016 1:59 pm Copyright cg 2016 EDR, Inc. cc, 2015 TomTom Rai. 2015. 0 1/4 1/2 1 Mlles 0 Indian Reservations BIA County Boundary Power transmission lines 100 -year flood zone 500 -year flood zone . National Wetland Inventory This report includes Interactive Map Layers to display and/or hide map information. The legend includes only those icons for the default map view. SITE NAME: Hunters Way CLIENT: True North Environmental, LLC ADDRESS: 2300 HUNTERS WAY CONTACT: VINCENT DAY CHARLOTTESVILLE VA 22911 INQUIRY #: 4738083.2s LAT/LONG: 38.01 6084 / 78.417946 DATE: September 27, 2016 1:59 pm Copyright cg 2016 EDR, Inc. cc, 2015 TomTom Rai. 2015.