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HomeMy WebLinkAboutTechnical Information Report for Safeway Fuel Facility Addition - COM Engineering / Geo-Tech Reports - 3/16/2001 TECHNICAL INFORMATION REPORT FOR Safeway Store No. 1571 Fuel Facility Addition S.R.3 and Clifton Lane Belfair, WA for Safeway Stores, Inc. by Bush, Roed & Hitchings, Inc. 2009 Minor Avenue East Seattle, WA 98102 BRH Job No. 2000289.01 March 16, 2001 G. oF waste rj w 20703 0TEB�'9 s`sI�NAL��Cs 3. Ito• 1 r—EXPIRES 12/1/d1 TABLE OF CONTENTS I. Project Narrative II. Core Requirements III. Special Requirements IV. Holding Tank and Oil/Water Separator Required Operations I. PROJECT NARRATIVE This proposal is for the construction of a fuel facility (gas station) on an existing pad within the existing Belfair Valley Plaza/Safeway development. Sewage disposal and site storm drainage detention and water quality was provided for the overall development in off-site facilities and have been sized and constructed to accommodate development of this pad. (See plans and specifications prepared by West Sound Engineering for Belfair Valley Plaza, prepared November, 1998). The proposed development will involve the construction of a kiosk structure, canopy covered pump islands, underground fuel storage tanks, new asphalt paving and landscape plantings. The pad is plumbed with all necessary utilities and will involve the following utility connections; SANITARY SEWER: A sewer stub and grease interceptor connection is plumbed for the anticipated construction of this facility. The kiosk sewage effluent disposal will be connected to the existing sewer stub but the facility will not utilize the existing grease interceptor connection as no food preparation is being proposed. DOMESTIC WATER: A water meter is present for the proposed building but will be relocated to facilitate the proposed layout. A water service will extend to the kiosk and from the kiosk to an air/water unit for customer use. An approved backflow preventor will be installed inside of the kiosk. STORM DRAINAGE: This proposal will involve the construction of approximately 19,964 square feet of impervious surfacing (paving and structures). Site storm runoff will be conveyed to a series of existing catch basins, which ultimately connect to the above mentioned storm detention and water quality facility. Those areas subject to potential fuel spills will be segregated and disposed of in accordance with Washington State Department of Ecology(DOE) Best Management Practices and are further explained in the following Core Requirements section. H. CORE REQUIREMENTS Core Requirement #1: Discharge at natural location. Surface runoff from this development will be contained within the existing drainage basin. No drainage pattern modification will result from this activity. Core Requirement#2: Offsite analysis. No off-site storm runoff will migrate through the facility. The proposed canopy covered pump island area will be raised in grade so that no adjacent storm runoff will pass over the facility. Core Requirement#3: Flow Control The existing flow control facilities will not be affected by this development. Core Requirement#4: Conveyance System A new storm conveyance system will be constructed in the area of the new fueling facility Core Requirement#5: Erosion and Sediment Control Erosion and sediment control (ESC) shall be provided for the duration of construction. For this development, ESC measures will include, but not be limited to, the installation of a temporary rock construction entrance, silt protection at all adjacent existing catch basins(with potential of receiving storm runoff from the construction area)and perimeter filter-fabric fencing. It shall be the contractors responsibility to maintain all ESC facilities during all phases of construction. Maintenance shall include replacement of the ESC measure upon first signs of failure, periodic top dressing of rock and any additional measures deemed necessary by City of Belfair inspection staff Core Requirement #6: Maintenance and Operations Drainage facility maintenance will continue as specified under agreements of the previous design development documents. The oil/water separator which serves the under canopy area will be maintained by the owner on a semi-annual basis. The holding tank will be maintained on an as-needed basis. Core Requirement #7: Financial Guarantees and Liability Bonding will be provided as required by the City of Belfair. Core Requirement#8: Water Quality Water quality for that area disturbed by these improvements will be provided for in a coalescing plate oil/water separator. III. SPECIAL REQUIREMENTS Special Requirement#1 - Other Adopted Area-Specific Requirements Not applicable. There are no known Area-Specific Requirements. Special Requirement#2 - Floodplain/Floodwav Delineation Not applicable. The site is not located within a floodplain or floodway. Special RequirementO - Flood Protection Facilities Not applicable. The site is not located within a floodplain or floodway. Special Requirement #4 - Source Control The proposed commercial use is considered a significant source pollution generator. The proposed fueling facility is covered and that area lying beneath the canopy drains to the storm sewer system via an oil/water separator. The tank slab runoff will be isolated and discharged to a 5000-gallon capacity holding tank. No other source controls are applicable. Special Requirement#5 - Oil Control The site is classified as a high-use site, therefore oil control is required. An oil/water separator has been provided for oil control. M HOLDING TANK and OHJWATER SEPARATOR REQUIRED OPERATIONS HOLDING TANK, REQUIRED OPERATIONS To address any potential fuel spill,this facility is equipped with a 5000-gallon capacity holding tank, which receives surface runoff from the tank slab area. An internal alarm will be activated upon this tank being filled to 80%capacity. At that time, the operator shall contact the appropriate pump-out firm (see contacts list) for disposal. To minimize surface runoff from the tank slab, discharge is controlled by a gate valve on the outlet pipe adjacent to the receiving catch basin. This gate valve shall remain CLOSED at all times except during times of product delivery. During product delivery, the operator shall: l. Open the gate valve. The gate valve shall remain OPEN for the duration of product delivery activities. 2. Close gate valve immediately upon conclusion of product delivery activities. 3. In the event of a fuel spill during delivery, product will be directed to the holding tank. The operator shall immediately notify the pump-out firm for disposal. As this valve is in a CLOSED position, periodic ponding will be evident around the tank slab catch basin. It is recommended that this standing water be periodically swept away, particularly during the winter months. OIL/WATER SEPARATOR, REQUIRED OPERATIONS Runoff from the canopy slab discharges to the storm sewer via an oil/water separator and will be limited primarily, to that water runoff generated from periodic washdown of the fueling area. (Dry sweeping is recommended to minimize surface runoff). The oil/water separator is fitted with a gate valve on the outlet pipe. This gate valve is to remain in the OPEN position. In the event of a fuel spill in the dispensing area, the operator shall; 1. CLOSE the gate valve to contain the spill within the oil/water separator. 2. The operator shall immediately notify the pump-out firm for disposal. The gate valve shall remain in the CLOSED position during all phases of cleanup. 3. Upon completion of cleanup, return gate valve to the OPEN position.