Transfer Station Planning and Design Reported by SWANA Transfer Station Planning and Design Committee James Ballowe, City of New Braunfels, Texas Jon Carlson, City of Brentwood, California James Frey, Resource Recycling Systems, Inc., Ann Arbor, Michigan Wayne Gill, Allied Waste, Nashville, Tennessee Bruce Henning, City of Phoenix, Arizona
Karl R. Hufnagel, Chairman, R.W. Beck, Inc., Seattle, Washington Stephen Lippy, Baltimore County, Maryland Michael Reed, Ramsey County, Minnesota Jerry Ross, American Landfill, Inc., Waynesburg, Ohio
Peer Reviewers Eric Grotke, CDM, Vero Beach, Florida Kevin McKeon, Earth Tech, Trevose, Pennsylvania
Leo Kypuros, Snohomish County, Washington Jeff Stamm, Gannett Fleming, Baltimore, Maryland
FINAL DRAFT: July 2005 This report provides a useful guideline for planning and design of solid waste transfer stations. The report looks at elements and attributes that typically are incorporated into the primary components of transfer stations. For the purposes of this report, the committee limited the components comprising transfer stations to site work (including off-site), scale facilities, transfer buildings, solid waste handling equipment and support facilities. The report does not consider other types of station components, such as separate self-haul customer drop off facilities, moderate risk waste facilities, recyclable material drop off facilities, or material recover facilities, all of which could be, and often are, co-located with or integrated into transfer station sites. The report does not differentiate between publicly and privately developed facilities. Readers who are interested or involved in developing a new transfer station should utilize this report as a general checklist to ensure that their planning and design process considers all relevant issues and aspects of the new station.
SWANA Transfer Station Planning & Design Report
SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist FOREWORD Municipal solid waste transfer stations in various forms have been part of solid waste management systems around the United States for the past forty to fifty years. The purpose of these facilities is to provide a safe, convenient location where smaller loads, usually delivered by collection trucks and selfhaul vehicles, can be consolidated into larger loads for more efficient transport to a final disposal facility usually a landfill or a municipal waste combustion (e.g., waste-to-energy) facility. As the trend continues for local landfills to be closed and replaced with larger, more remote, regional, and even out-of-region landfills, the economic necessity for transfer stations has become much more widespread. Determining when a transfer station is needed in lieu of direct hauling waste in collection vehicles to the final disposal site is an economic, and sometimes political, decision that must be made as a first step. This report provides a guideline for the planning and design of solid waste transfer stations. The report looks at elements and attributes that typically are incorporated into the primary components of transfer stations. For the purposes of this report, SWANA’s Transfer Station Planning and Design Committee limited the components comprising transfer stations to site work (including off-site), scale facilities, transfer buildings, solid waste handling equipment and support facilities. The report does not consider other types of station components, such as separate self-haul customer drop off facilities, moderate risk waste facilities, recyclable material drop off facilities, or material recover facilities, all of which could be, and often are, co-located with or integrated into transfer station sites. The report does not differentiate between publicly and privately developed facilities. Readers who are interested or involved in developing a new transfer station should utilize this report as a general checklist to ensure that their planning and design process considers all relevant issues and aspects of the new station. This report is the combined product of SWANA’s Transfer Station Planning and Design Committee, whose members include: James Ballowe, City of New Braunfels, Texas Jon Carlson, Solid Waste Manager, City of Brentwood, California James Frey, CEO, Resource Recycling Systems, Inc. Ann Arbor, Michigan Wayne Gill, Allied Waste, Site Manager, AAA Transfer Station, Nashville, Tennessee Bruce Henning, Director of Solid Waste, City of Phoenix, Arizona Karl Hufnagel, R. W. Beck, Inc. Seattle, Washington Stephen Lippy, Refuse Disposal Division Chief, Bureau of Solid Waste Management, Baltimore County, Maryland Michael Reed, Ramsey County Environmental Health, Ramsey County, Minnesota Jerry Ross, American Landfill, Inc. Waynesburg, Ohio The Committee hopes that this report will prove useful to those responsible for planning and design of new transfer stations. Karl R. Hufnagel, P.E.
Senior Director and Solid Waste Facility Development Engineer R. W. Beck, Inc. Committee Chairperson SWANA Transfer Station Planning & Design Report
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SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist
Table of Contents Section 1 – Transfer Station Planning Issues……………………………………………………..4 Section 2 – Off-Site Supporting Infrastructure Requirements……………………………………8 Section 3 – Site Work……………………………………………………………………………..10 Section 4 – Scale Facilities………………………………………………………………………..13 Section 5 – Transfer Buildings……………………………………………………………………16 Section 6 – Waste Handling Equipment…………………………………………………………..23 Section 7 – Support Facilities……………………………………………………………………..26
This document is intended for guidance in planning, designing and executing development of solid waste transfer stations. It is intended for the use of individuals who are very familiar with municipal solid waste collection, handling and transfer, and who are competent to evaluate the significance and limitations of the document’s content. The Solid Waste Association of North America disclaims any and all responsibility for the stated planning and design principles and shall not be liable for any loss or damage arising therefrom. Reference to this document shall not be made in contract documents.
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SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist
SECTION 1 - TRANSFER STATION PLANNING ISSUES Over Arching Issue No. 1: Transfer stations are “essential public facilities”, similar to hospitals, police and fire stations, water treatment facilities, etc. and must be designed with a high degree of reliability in order to survive and function during and after natural disasters. Over Arching Issue No. 2: Transfer stations can have significant off-site impacts such as traffic congestion and noise, site noise, odor, litter and dust, and aesthetics. NIMBY-ism response is inevitable. Thorough, fair and honest impact analysis of site alternatives is essential so that decisions made can withstand strong scrutiny and challenges. •
Review local planning and zoning code carefully in the site selection process. Coordination with local planning and zoning officials and possibly elected officials and/or community groups is often wise.
Over Arching Issue No. 3: Flexibility of design is very important as the future of operations cannot be reliably forecast. Site Characteristics: •
Site Size - depends on: a. Station tonnage and traffic volumes. b. Transfer trailer yard requirements (large turning radii, number of full and empty parking stalls, tractor parking requirements). c. Customer mix (commercial and self-haul). d. Traffic flow pattern to accommodate customer mix. e. Pre-scale and pre-transfer building queuing requirements. f. Stormwater detention and treatment (quality) requirements. g. Recycling facilities. h. Public drop off facilities. i. Site buffers and screening. j. Support buildings including offices. k. Scale facility. l. Room for expansion taking into account population growth. m. Other potential site uses such as hauling fleet yard and maintenance facilities, container storage, etc.
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SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist •
Aspect Ratio (site length to width ratio): 1 to 1 up to 1.5 to 1. Be wary of ratios greater than 2 to 1 (i.e. long and skinny site) unless site size is much more than the actual size needed.
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Topography: a. Flat sites will require fill and/or excavation to create grade separation needed for gravity transfer of waste. b. Assume a minimum17 foot floor-to-floor separation needed if gravity transfer of waste employed. c. Fill and/or excavation will increase overall building footprint or necessitate expensive retaining walls to limit footprint growth. d. Alternatively, flat sites can be handled by using conveyors but this increases O&M cost and reduces the reliability of the station. Alternatively, flat sites can be handled by excavators and loaders but this is not as efficient as gravity loading. e. Consider groundwater table elevation for sites requiring excavation. Construction dewatering and permanent dewatering can be problematic and expensive. f. Topographic changes in elevation can be used to advantage to screen operating areas visually and for noise from sensitive neighboring properties and from wind. g. Berms make effective visual buffers and provide an inexpensive way to use excess soil. Usefulness as a noise buffer dependent on berm height and design. h. Flat sites may require lift stations for sanitary and storm sewer flow. i. Consider topography’s effect on surface water run-on and on site collection of runoff
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Site Soils/Geotechnical Conditions: a. Weather-sensitive soils can increase the project cost (due to soil replacement or conditioning and more expensive foundation systems) and impact construction schedule. Also may lead to future settlement problems. b. Don’t scrimp on geotechnical investigation during design. There are endless project examples where scrimping has led to expensive surprises later. c. Recognize issues related to contaminated site soils. d. At landfill sites recognize potential for gas migration and cost to protect confined spaces from methane.
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Other: a. Sensitive areas such as streams, creeks, wetlands and endangered species habitats can significantly impact project schedule and cost. b. Avoid flood plains. c. Close proximity to airports could be an issue.
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SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist d. Site zoning can be a problem. Rezones and conditional use permits can take time and provide an opportunity for project challenges by the opposition. e. Consider prevailing wind direction so that transfer station doors can be oriented to minimize blowing litter and dust. Site Location: •
Relative to the centroid of the wasteshed served.
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Relative to the disposal site or the intermodal facility.
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Relative to adjacent land uses.
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Relative to plans for other stations/facilities (yours and theirs).
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Relative to the collection fleet yard.
Identifying the Transfer Technology to be Used: Top-load versus stationary preload compactors and direct dump versus dump and push, or dump and lift. •
Choice influences trailer/container payload.
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Affects customer throughput rate.
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Determines site electrical power requirements.
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Consider need for redundancy in loadout capability (i.e. multiple hoppers and loading bays).
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Consider bypass capability for emergency.
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Consider alternative loadout method to handle other types of wastes such as bulky, hard to handle wastes, white goods, recyclables, yard waste and construction and demolition waste.
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Consider first cost as well as long term operation and maintenance costs.
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Consider susceptibility to breakdown.
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It is advisable to have truck or axle scales in the top-load bay to help regulate payloads and avoid overloads.
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Both top-load scales and compactors can provide immediate waste tonnage data both locally and at remote sites.
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Consider need for station expansion. Can transfer technology be easily multiplied in expanded station?
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Consider effect choice of transfer technology and bypass will have on trailer fleet.
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Top-load bays will require tamping equipment to produce optimum payloads.
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Excavator, front loader and grapple loading are other alternatives which may have throughput rates that are comparable to other loading technologies and which may be viable on flat sites where grade separation is hard to develop.
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SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist Planning for Surge and Emergency Storage Capacity: •
How many hours of surge capacity are needed on busiest days?
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How many days of emergency storage capacity are needed during system upsets?
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Is emergency storage allowed by local and state permitting agencies?
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Storage in transfer vehicles may be considered if the site and receiving landfill/disposal site do not operate 24/7.
Planning for Traffic and Tonnage Growth: •
What is the planning horizon? A planning horizon of at least 20 years is a prudent starting point.
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Consider the option for developing other stations rather than expansion (i.e. take a holistic, system-wide approach).
“Green Building”: •
Evaluate applicability of green building principals to the project and whether there should be a goal incorporated into the project development.
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SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist
SECTION 2 - OFF-SITE SUPPORTING INFRASTRUCTURE REQUIREMENTS Roads and Streets: •
Road capacity must be adequate considering growth in base traffic and station related traffic.
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Turning radii must accommodate large vehicles.
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There must be convenient access to the regional road system.
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The station frontage road should have turn lanes and be able to handle off-site queues if on-site queuing is not sufficient (less than a desirable situation). If turn lanes are not in place, consider providing space for their construction (and possibly accel/decel lanes) in the future as traffic conditions warrant.
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Weight restrictions may impact facility.
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Safe access/egress is essential: Consider site distances and acceleration and deceleration lane requirements.
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Transfer trailer haul routes should be designed to avoid sensitive areas such as residential districts.
Utilities: •
Municipal water system, if available, must have adequate fire flow (volume and pressure).
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Sewer: In assessing available municipal sewer system consider: a. Stormwater contribution to sanitary sewer from uncovered areas that will potentially have contaminated runoff (leachate). b. Local industrial pretreatment ordinance requirements to pretreat leachate portion of sewer flow.
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Electrical Power: a. 3 Phase power is essential for most stations. b. Consider frequency of power outages at site. c. Consider need for standby engine generation. d. Consider need for future expansion and/or additional equipment such as compactors and balers.
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Natural Gas: Optional.
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Phone and Communications: Consider need for high speed data transfer link.
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SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist Rail Access: •
Consider proximity to intermodal rail facilities that would provide an alternative to road or barge for long haul/waste export.
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SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist
SECTION 3 - SITE WORK Roads: •
All-weather surfacing.
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Curb and gutter edges are preferable to plain edge pavement, especially for site cleanup using street sweeper equipment and for control of potentially contaminated runoff.
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Rolled curb and gutters are preferable to conventional barrier curb and gutter where occasional extra long vehicles may have to use roads.
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Consider need for snow removal in snow country.
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Avoid surface water run-on from adjacent surfaces particularly in winter freeze areas (i.e. avoid road icing).
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Maximum 8% uphill grades.
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12 foot minimum lane widths.
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Consider turning radii needed for large vehicles.
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Provide access for emergency vehicles (fire lanes) and scale facility bypass lanes both inbound and outbound. Consider a separate emergency site entrance.
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Use concrete trailer landing gear pads in asphalt paved parking areas especially in hot areas of the country.
Traffic Patterns/Circulation: •
For busy stations with commercial and self-haul customers, provide separate lanes for each customer type wherever possible to avoid delaying commercial customers in selfhaul customer queues.
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Consider using unattended scales (see Scale Facilities below) at Scale Facility for commercial account customers.
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Provide separate site entrance(s) and lanes for transfer trucks to avoid having them delayed in customer queues.
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Consider self-haul residential tipping areas away from commercial vehicle traffic tipping.
Site Lighting: •
Driven by operational and safety requirements.
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Design to avoid off-site impacts.
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Consider shadow areas created by parked trailers when positioning fixtures so that trailer hookup and unhook operations have needed lighting.
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SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist •
Protect poles located in equipment parking and maneuvering areas.
Parking: •
Provide adequate parking for employees. May need to be distributed around site rather than concentrated. Check zoning requirements.
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Include visitor parking.
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Provide over-size vehicle parking (bus) if group visits are expected.
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Provide customer parking for support buildings.
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Provide engine block heater hookups for cold weather climates.
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Provide for untarping and tarping needs (if any) of customers and transfer trailers/containers.
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Provide parking space for tractors and other mobile equipment not parked inside.
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Provide laydown area for roll-off boxes and haul trucks if appropriate.
Landscaping: •
Provide to “soften” the industrial look where appropriate, improve facility image, and raise employee and customer attitudes.
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Avoid plant materials that provide harborage for rats, vectors and litter.
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Review landscape ordinances.
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Provide visual and wind screening where appropriate.
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Budget for annual landscape maintenance.
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Use native, low maintenance, non-mow grasses where appropriate.
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Provide easy access for large mowers/equipment.
Site Utilities: •
A site fire main system with fire hydrants is normal. Number of hydrants and fire flow determined by the “authority having jurisdiction” (i.e. the Fire Marshal).
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If off site water supply is not available consider using stormwater detention or natural water bodies to meet fire protection requirements.
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Storm drain system including detention and treatment is typical and is driven by local codes and ordinances.
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Stormwater infiltration may be a requirement.
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Expensive underground detention vaults may be required on cramped sites that lack room for surface water ponds.
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SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist •
Expensive underground detention vaults may be required on sites located close to an airport to deter bird congregation.
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Consider need for block heater stations for heavy equipment parked outside overnight
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Review local industrial pretreatment ordinances for sewer discharge when station leachate is part of station sewer flow. Consider use of triple basins in the tipping floor drainage system.
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Consider drip collection pads at the rear of parking stalls for loaded trailers drained to sanitary sewer to minimize stormwater contribution to the sanitary system when parking is uncovered.
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Some health districts may require covered parking for loaded trailers.
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A double-detector check valve assembly may be required for site fire main loop to provide backflow protection of public water main.
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A split on-site sewer system may be advisable (sanitary sewer and separate industrial wastewater) to minimize the quantity of sewer flow that requires pretreatment.
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If site does not have municipal sewer service an on-site septic system or wastewater collection tank(s) will be needed.
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Lift station and septic systems, if required, to be designed to accommodate periodic facility washdown flow.
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Consider oversized rain leaders/downspouts connected to piped drainage system to avoid erosion and periodic large surface water flows.
Other: •
Many public stations incorporate artwork and/or educational exhibits/displays. Planning and design coordination for this needs to start very early in the project development schedule to maximize opportunities and minimize impacts.
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SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist
SECTION 4 - SCALE FACILITIES Major considerations for planning and designing these facilities include: •
Efficiency.
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Flexibility.
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Security.
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Employee health, safety and comfort.
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Ease and frequency of cleaning.
Scales: •
Two basic types of scales: shallow pit type and low-profile, above grade type. Hydraulic load cell scales are also available. All scales, regardless of type, use full electronic load cells to provide weight. Shallow pit scales require less overall width for the same width of scale deck but create a confined space, needs a piped drain system and is more difficult to access for cleaning and maintenance than the above grade type. Above grade scales have simpler, less expensive concrete foundation requirements and usually do not require piped drainage. Regardless of the scale type, scales can have steel or concrete decks.
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70 foot to 80 foot scales should be used if large vehicles will be weighed frequently. Even longer scale may be needed if scale is to function as a reversible scale as is common in 3-scale and 4-scale layouts.
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35 to 40 foot scales should be considered the minimum practical length.
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Specify scale load cells that are non-proprietary so that scale maintenance can be performed by a number of qualified firms to maintain competitive bidding environment for maintenance work.
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Scales need to be recertified at least yearly in most states.
Scale Peripheral Equipment: •
Traffic control lights (red/green stop and go lights) usually considered as optional. Many scale facilities operate satisfactorily without these.
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Semaphore gates are also considered as optional traffic control devices. These are often broken due to erratic control/performance or due to customer error.
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Traffic control lights and gates can be computer controlled automatically or manually controlled.
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Customer displays (tariff and weight) are an essential item for facilities handling self-haul residential (non-account) customers.
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SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist •
Automated vehicle identification (AVID) systems and systems with remote card readers and ticket printers are essential components for scale facilities employing unattended scales.
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Attendant computer, ticket printer, report printer and digital display with proprietary solid waste data management software are essential components needed to complete an efficient scale facility system.
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Closed circuit TV monitoring systems are optional equipment to consider to provide attendant with load surveillance monitoring and to record vehicle license numbers.
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Audio/visual recording equipment to record scale transactions are an option.
Scale House/Scale Booth: •
Must be fully ADA compliant.
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Ideal interior width is about 13 feet to allow one attendant to cover both the inbound and outbound transaction windows during non-peak times.
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Consider a break area (kitchenette with microwave, small refrigerator and sink). Lockers in this room are optional.
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Toilet room – essential.
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Attendant room (the toll booth) should face inbound traffic lanes with a recess in the outbound side wall that provides a window looking back at approaching outbound traffic.
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Adjustable height work surfaces at each attendant’s station to accommodate different height people.
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Easy gliding transaction windows (using over-hung ball bearing track system) with or without electric operation are essential items to avoid attendant repetitive motion issues.
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Bullet-resistant and solar tint glazing are essential features.
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Resilient flooring (such as carpet or anti-fatigue pads) in the toll booth room.
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Maximize counter and shelf storage.
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Mechanical Systems: a. Fresh air intake via a stack with inlet located well above roof line to minimize vehicle exhaust gas intake. b. Consider carbon filtration of intake air. c. Maintain positive interior pressure to help prevent exhaust gas infiltration. d. Use 2-stage supply air fan with upper stage to provide additional interior pressure during exhaust gas intrusion to “flush” building. Connect to CO/NO2 gas detection equipment to activate higher fan speed.
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SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist e. Use spot heaters (radiant ceiling panels and wall or base board radiant/convection heaters) locally controlled at each attendant’s station to compensate for heat loss through frequently opened transaction windows. •
CO/NO2 gas detection and alarm system with electronic chart recording capability. Connect to HVAC system as described above.
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Security Measures: a. High power, small arms bullet resistant glazing. b. High security door lock system. c. Intrusion detection and alarm system with off-site monitoring. d. In-floor or floor anchored safe. e. On-site communications system(s) such as radio or phone. f. Closed circuit TV cameras for monitoring incoming trucks and scalehouse operations.
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Storage room – optional
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Guard posts/bollards at all vulnerable exterior points of buildings and exterior equipment.
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SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist
SECTION 5 - TRANSFER BUILDINGS General: Designed around type of waste transfer technology, waste receiving floor type (i.e. pit, true flat floor or modified flat floor), type, size, number and unloading requirements of customer vehicles, surge and emergency storage capacities, bypass requirements, traffic flow patterns, and future expansion needs. Customer service criteria (such as wait times and maximum time on site) and waste delivery rates (average versus peak) are important factors to be considered. Waste Receiving Floor Alternatives: •
Pit type provides good storage capacity for emergencies without need to stack waste, creates a fall hazard, provides positive separation between customers and waste handling operations, and increases overall building grade separation requirements. Pit can be operated as a maceration pit using a bulldozer in which case the floor should slope up slightly to the loadout hopper, or it may be operated as a flat floor with rubber-tired front end loader in which case the floor should be flat (not sloped).
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True flat floor requires a larger area for commercial loads to be deposited compared to a pit thereby increasing the overall size of the building, provides maximum operating flexibility in the station, increases the need for a clear span building which is more expensive than a building with interior columns, lacks a positive separation between customers and waste handling operations/equipment, leads to tracking of waste by customer vehicles, minimizes overall building grade separation requirements, requires stacking to store waste.
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A modified flat floor has the same benefits and drawbacks as the true flat floor except that it provides a positive grade and barrier separation for some or all of the customers depending on the configuration.
Structural/Architectural Systems: •
Concrete foundation and substructure.
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Concrete customer maneuvering and waste handling floors. a. Provide minimum 3” (4” preferable) of concrete cover over upper main reinforcement mat for floor surfaces subject to wear from waste handling operations. b. Consider providing #4 wear indicator bars 24” on center perpendicular and halfway between the top reinforcement mat and the floor surface in waste handling floors. c. Minimum 5,000 psi compressive strength concrete with maximum possible coarse aggregate size (1-1/2”) for concrete in waste handling floors. 6,000 psi is ideal. If optional abrasion resistant floor topping not used, consider the availability and cost of hard aggregate (i.e. trap rock) for additional floor durability. d. Consider optional abrasion resistant floor topping such a emery/corundum or metallic aggregate shake-on topping or high-build surfacing for high wear floors.
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SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist •
Steel armor plated concrete walls in waste handling areas to at least 8 feet above floor.
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12 foot high push and stacking walls in waste handling areas.
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Constant slope floors (avoid counter slopes), sloped to drain to waste charging hoppers/chutes in waste handling floors.
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Do not drain waste receiving floors to exterior doors and openings.
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Avoid floor and trench drains in any floors that receive waste.
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Minimum 6-inch diameter pipe size for floor drain systems with well placed cleanouts.
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Fall restraint systems for tipping floors that have grade separation between the customers and the receiving floor: a. Pipe guardrails. b. Post and chain (can be defeated by customers). c. Post and cable (can be defeated by customers). d. Concrete barrier (requires scuppers to allow sweeping off of waste spill at vehicles).
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Unloading stalls: a. Orientation to waste receiving floor. 1) Angled – preferred. 2) Perpendicular – requires wider floor. b. Width (self-haul customers): 12 foot preferred, 10 foot minimum. c. Width (commercial customers): 20 foot preferred, 16 foot minimum.
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Building Superstructure Options: a. General Considerations: 1) System cost. 2) Ease of cleaning. 3) Dirt shedding and lack of ledges and horizontal surfaces for dirt/debris collection. 4) Noise reverberation/sound absorption. 5) Bird and vector exclusion. 6) Light reflecting surfaces. 7) Durability. 8) Fire resistivity. 9) Repair-ability. 10) Seismic resistance.
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SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist 11) Wind resistance. 12) Aesthetics. 13) Future expandability. b. Structural steel framed (pre-engineered or custom designed) with metal siding and roofing panels. 1) Least cost. 2) Damage protection for siding needs more attention. 3) Optional high quality factory coating for panels preferable for long life and continued good appearance. Baked on enamel finish is least first cost choice. 4) Consider need for interior pushwalls and armor protection of vulnerable areas. c. Precast concrete or cast-in-place concrete or masonry or a combination thereof. 1) Most expensive first cost. 2) Creates high seismic loads. 3) Different aesthetic look compared to metal building; may be more appropriate in some settings. 4) Good fire resistivity. 5) Low maintenance. 6) More durable than steel building. d. Hybrid structural steel framed and precast/cast-in-place concrete/masonry walls with metal roof deck (built-up roofing over metal roof deck or metal panels). e. Cement stucco wall panels over steel framing system. • Avoid interior columns where possible to maximize flexibility and usability of interior space. • Minimize elevation changes and distance between operating areas and employee break and office facilities. Consider age and condition of workforce. • Minimum interior vertical clearance to structural and non-structural elements: 30 feet minimum, 35 feet allows for future growth in vehicle size. • Higher clearance and greater interior volume appears to reduce interior noise levels. • Substantial, over-designed guardrails, pipe guards, bollards at all vulnerable areas liable to equipment or vehicle impact damage. • Doors and Openings: a. Vehicle doors – electrically operated coiling overhead doors, minimum 16 feet wide by 16 feet high. Taller doors (up to 27 feet high) preferred for commercial vehicles
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SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist with raised bodies. 24 feet may be a practical limit for overhead door width. Consider aircraft hangar style doors if wider openings are desired. b. Use over-height vehicle warning devices where lower doors are used for large commercial vehicles. c. Consider wind loading issues when sizing wide doors in high wind areas, especially for doors in excess of 20 feet wide. d. Personnel doors – locate where required by life safety code/building code for egress and at all points where quick, convenient operational access is needed. Protect with bollards where pedestrian pathway is in close proximity to vehicle/equipment travel way. e. Protect vehicle door openings with bollards (two at each jamb). f. Consider wind direction when locating door openings to minimize blowing litter. •
Natural Lighting: a. Use skylights and/or translucent wall panels to provide maximum natural daylighting of interior. b. Consider automatic dimming system for artificial lighting when good daylighting is provided to save energy.
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Fully Enclosed/Partially Enclosed/Open: a. Fully enclosed with doors is becoming the standard. b. Considerations for degree of enclosure: 1) Containment of waste. 2) Exclusion of birds and other vectors. 3) Containment of noise. 4) Increased interior noise. 5) Containment of odor. 6) Aesthetics. 7) Customer/employee comfort during adverse weather. 8) Need for artificial lighting. 9) Need for mechanical ventilation. 10) Fully enclosed buildings more susceptible to impact damage (siding) if not properly designed. 11) Wind direction and average speed. 12) Hours of operation.
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SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist •
Building Insulation: a. Heating large transfer buildings is not economically practical. b. Roof insulation may be needed to control condensation depending on climate in fully enclosed buildings.
Mechanical Systems: •
Water supply for washdown hoses should have 120 psi pressure at the hoses.
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Provide booster pump to deliver needed water pressure, use PRV’s on each branch line.
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Water supply for washdown should be isolated (backflow prevention/cross-connection prevention) from potable water system.
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Washdown hoses should be mounted on spring or electric rewind reels with minimum 1” diameter hose and adjustable nozzles.
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Drainage: a. Floors sloped to drain towards the waste tipping and load out areas. b. Avoid floor drains and trench drains in waste processing floors as these will plug frequently and require extensive maintenance. c. Use minimum 6-inch diameter drain pipes when piped systems are used to minimize blockage. d. Use trash baskets/buckets in all floor drains.
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Provide truck washout/wash off hoses for commercial customers. Use special drain sump for this area suitable for accumulation of a large amount of trash without plugging. Standard street catch basin with cast iron grate and custom stainless steel basket insert works well.
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Freeze protection required for all exposed piping in winter freeze areas (would not apply to dry-pipe fire sprinkler system piping).
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Use roof and/or through-wall exhaust fans distributed over primary waste handling areas and in all areas where vehicle exhaust will accumulate.
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Consider wall louvers to increase outside air intake circulation especially in hot climate areas.
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Filtering and scrubbing of general building exhaust is usually not practical.
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Dust suppression misting system (high pressure, low volume) recommended in most transfer stations. Can have odor neutralizer added to supply line which is effective in neutralizing odors.
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Fire sprinklers may be required by code or needed to reduce the station fire flow requirements to manageable level. Consider impact to insurance rates if not sprinkled.
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SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist •
Emergency eyewash and shower units (freeze protected where necessary) should be provided at various locations convenient to staff and customers liable to be splashed with harmful fluids. These units require a potable water supply (health code).
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Dust extraction system may be advisable for high dust areas such as above loadout hoppers. These systems can be designed to run on demand from wireless handheld controls.
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Provide spill isolation such as shutoff valves on drain lines and containment dikes and sumps for areas where hydraulic power equipment and hoses can leak.
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Compressed air system with outlets located where air tools may be needed is optional.
Electrical Systems: •
Lighting: High Intensity Discharge (HID) lighting such as high pressure sodium fixtures with rapid re-strike capability for at least 25% of the fixtures (uniformly distributed). Consider automatic dimming controlled fixtures if substantial amount of natural lighting is provided.
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Consider 30 foot candles at floor level as a desirable lighting level.
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As fixtures age and get dirty resulting in reduced light output. Design for ages/dirty conditions.
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Use emergency lighting fixtures to provide pathway and corridor lighting during power outages as required by code.
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CO and NO2 gas detection and alarm in areas where gasoline and diesel engine emissions are liable to accumulate is advisable.
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A fire detection and alarm system is normally a code requirement and can affect allowable building area. Use heat detectors rather than smoke detectors in areas where dust and diesel exhaust will set off smoke detectors.
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Close circuit TV system (CCTV) for after-hours security monitoring is an option.
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Phone and communications networks including data highway to carry waste tonnage data from compactors and/or top-load scale equipment is recommended.
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Consider use of wireless communications between loader operator, floor spotters, commercial customers and transfer trailer drivers.
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Transfer building should have reliable direct phone or radio communication with scale facility staff.
Other Features to Consider: •
Customer and transfer trailer un-tarping and tarping stations inside or outside transfer building.
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Over-height vehicle warning system to protect low door openings.
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SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist •
A hot-load dump area (concrete slab) outside building where a smoldering load can be dumped spread and quenched. This area should not be in a critical pathway area that would shut down operations due to a hot load incident.
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Portable fire extinguishers.
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Spill containment packs.
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First aid packs/kits.
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Signage.
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Public viewing/education room.
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Restroom facilities for transfer trailer staff if two level facility.
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Bird deterrent system on roof.
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Support structure or barrier to prevent end-dump vehicles from tipping over.
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SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist
SECTION 6 - WASTE HANDLING EQUIPMENT Stationary: •
Compaction equipment: a. Stationary preload compactors (such as SSI and Harris AMFAB). 1) Produces high density payloads. 2) Expensive ($650,000 to $900,000 depending on model and options). 3) Dependent on electrical power supply. 4) Large motor horsepower makes standby engine generator backup impractical. 5) Significantly increases station electrical power costs. 6) Generally proven high reliability. 7) Requires routine cleaning and regular maintenance. 8) Works well with closed top intermodal containers. 9) Can process fairly bulky materials without size reduction ahead of the compactors. 10) Seven to 10 year service life before major rebuild depending on tonnage through put and quality of maintenance care. 11) Can be operated by employee in tipping floor mobile equipment using wireless handheld control device. Bale ejection sequence must be executed by employee at compactor level. 12) Vertical end gate increases floor-to-floor clearance requirement or necessitates positioning compactor so that gate can project up through non-operational floor area or is located outside building. 13) May limit station flexibility. b. Refuse cranes (also called knuckleboom refuse loaders). 1) Dedicated to one top-load hopper. 2) Requires a trained operator. 3) Can cause significant damage to trailers/containers if not used properly. 4) Requires well-engineered structural support due to loads. 5) Can be easily retrofitted at a later date if initial design takes into account. 6) Can produce densities and overall container payloads similar to preload compactor when properly used and time permits.
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SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist 7) Dependent on electrical power to operate. 8) Small enough power demand that can be operated on a reasonably sized standby engine generator. 9) Fairly reliable. 10) Requires regular maintenance. 11) Expensive ($125,000 to $175,000 depending on model and options). c. Balers: 1) Used in some areas to ensure high landfill densities and decrease landfill operational cost. 2) Expensive ($350,000 to $ 600,000) including conveyor feed. 3) Requires some presorting to eliminate potentially damaging materials. 4) Requires significant electrical power to operate. 5) May require additional conveyors. 6) Consider handling of leachate from baling process. 7) Has special layout considerations. d. Shredders: 1) Rarely used in transfer stations. •
Axle Scales: a. Used in top-load bays to help operator achieve optimum payload and avoid axle overload. b. Front and rear platforms provide better front and read load distribution than single platform. c. Location in top-load bay increases cleaning maintenance with attendant confined space issues. d. Requires electrical power to operate.
Mobile Equipment Requirements: •
Waste Loading Equipment: When used for direct loading of transfer vehicles, offer good operational flexibility, reduced capital cost and can be used at various locations on site. Easily and quickly replaced. May achieve load compaction sufficient for obtaining legal payloads. a. Refuse cranes, tracked or rubber tired. b. Excavator with grapple. c. Dozer.
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SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist •
Yard Tractors.
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Mobile Compaction Equipment.
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SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist SECTION 7 - SUPPORT FACILITIES Mechanical and Electrical: •
Standby Engine Generators: a. Necessary to keep facility running, lights on, and waste moving through facility. b. Diesel, natural gas or propane fired. c. Size to carry critical loads necessary to keep station including scale facility operational.
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Fueling Systems: a. Dedicated system is optional alternative to having fueling truck visit the site. Check codes to ensure that fuel truck fueling is permitted. b. Having a dedicated system is not common.
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Equipment Maintenance Facility. a. This is an option depending on how equipment maintenance is handled in the solid waste system.
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Leachate Pretreatment Facilities: a. Need for is driven by local industrial pretreatment ordinance. b. pH adjustment is primary function. c. Can be primarily an in-ground vault system with some above ground chemical storage and dosing equipment and some monitoring equipment.
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Mechanical room.
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Electrical room.
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Storage rooms.
Personnel Support Facilities: •
Maintaining employee welfare, morale, health and loyalty are essential to a “happy ship”.
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ADA accessible.
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Employee break areas inside and outside.
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Office space.
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Meeting room.
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General reception area for visitors/tour groups with window(s) overlooking operating floor to reduce public interaction with equipment/vehicles.
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Toilet rooms – unisex or male and female.
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SWANA Transfer Station Planning and Design Committee Transfer Station Planning and Design Checklist •
Locker rooms: 1) Dedicated locker for each employee. 2) Showers. 3) Benches. 4) Space and electrical outlets for boot dryers.
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