1.1 General
1.2 Transfer Station Systems

2.1 General Location
2.2 Area Requirement
2.3 Zoning
2.4 Buffer
2.5 Site Servicing

3.1 Quantity Estimation
3.2 Storage Volume
3.3 Access Roads
3.4 Surface and Ground Water Quality
3.5 Weigh Scales
3.6 Wildlife Control
3.7 Site Security
3.8 Signs
3.9 Water Supply
3.10 Materials Recovery
3.11 Safety Features

4.1 Prohibited and Difficult Wastes
4.2 Waste Storage
4.3 Supervision
4.4 Wildlife Control
4.5 Emergency Procedures
4.6 Site Tidiness
4.7 Nuisance Control
4.8 Scavenging

5.1 Landfill Costs
5.2 Transfer Costs
5.3 Decision Model
5.4 Financing Transfer Stations

Table 1 — EXAMPLE LANDFILL COSTS
Table 2 — EXAMPLE TRANSFER STATION COSTS
Table 3 — TYPICAL VALUES OF TRANSFER COST PARAMETERS a & b
Table 4 — UNIT DIRECT HAUL COST PER KILOMETRE
Table 5 — EXAMPLE LANDFILL UNIT COSTS

Figure 1 — TYPICAL GREEN BOX SITE
Figure 2 — TYPICAL ROLLOFF BIN SITE
Figure 3 — TRANSFER STATION WITH HYDRAULICALLY TIPPABLE BIN
Figure 4 — TYPICAL COMPACTION TYPE ROLLOFF FACILITY
Figure 5 — TRANSFER STATION PUSH PIT SYSTEM
Figure 6 — UNIT TRANSFER HAUL COST ($/t) AND WASTE TONNAGE (t/yr)
Figure 7 — UNIT DIRECT HAUL COST ($/t) AND HAUL DISTANCE (km)
Figure 8 — UNIT LANDFILL COST ($/t) AND WASTE TONNAGE (t/yr)

• Economics — If the destination of the wastes is far away from the area in which they are collected, then it may be more economical to transfer the wastes to large vehicles for haulage than to haul them directly in the original collection vehicles. This situation is becoming increasingly common, as landfills become more difficult to site and, therefore, more remote from populated areas.
• Service — For a rural area without a garbage collection service, a transfer station is often provided as a service to local residents, so that they do not have far to drive to drop off their wastes. A transfer station is often established at a landfill after it has been closed because people are accustomed to taking their waste to that location. Such a transfer station may or may not be economical.

Ideally, a transfer station should be sited as close as possible to the centroid of the population served, in order to minimize collection costs, or some distance along the haul route to the landfill. The transfer station should be sited and operated so as to create no environmental or health hazard, and no nuisance.

1.2 Transfer Station Systems

1. Green Box — This rural system is shown in Figure 1, at the end of this section. It is similar to that used for commercial establishments in urban areas. Metal containers with hinged lids, varying in size from 2.3 to 6.1 cubic metres (three to eight cubic yards) are placed at strategic locations such as cross-roads, city works yards and rural stores. The containers are picked up and emptied by front, rear, or side loading compaction trucks. One cubic metre of packer truck capacity would equal about three cubic metres of bin capacity. Therefore, as an example, a 22 m³ truck could service eleven 6 m³ bins on one trip.

Although economical in terms of capital cost, the relatively small bins are unable to accommodate large items such as furniture and demolition/land clearing/construction (DLC) waste. They are awkward to use because waste must be lifted up to be dumped. A problem with multiple bins (i.e. more than three) is that people become frustrated on finding successive bins full, and may dump their waste indiscriminately. A transfer station employing small bins is normally considered suitable only for small annual tonnages, say less than 100 tonnes/year, and for serving areas that have some other convenient alternative for disposing of bulky waste.

2. Dedicated Truck — Some rural areas have found it convenient to arrange for a compaction waste collection truck to be available at a specified location, on a regular schedule, for an advertised time period, usually once per week. Local residents bring their waste to the truck, and are charged a prearranged rate per bag or can by the truck driver. Although this system is not a "transfer station" it can be a substitute for one, and has the advantages of requiring no capital cost, assuming a collection contractor is available, only minimal operating cost for a subsidy and advertising, and users pay much of the cost directly for the service. The major disadvantages are that it is relatively expensive, and that service can usually only be afforded for limited periods, say one day per week or less.

3. Rolloff Container — This rural system, illustrated in Figure 2, uses large steel containers, typically varying from eleven to thirty-eight cubic metres (fifteen to fifty cubic yards). Full containers are picked up by a rollon/rolloff tilt frame truck, and transported singly or in pairs by a truck/pup arrangement, to the landfill. An empty container is deposited by the same truck that picks up the full one. Rolloff bins often achieve their legal load limit without compaction. For example, the legal payload for a 38 m³ (50 cu yd) bin is about 8 tonnes, which is equivalent to a density of about 210 kg/m³.

The best rolloff station designs incorporate elevated ramps, with the bins sitting at a lower level, so that waste can be dropped down into the bin, and hinged counterweighted lids that are easy to move. A sheet metal or screened cover is often used over the bin to reduce blowing litter and exclude birds and animals. Site development can include fencing, a lockable gate, and paved roads.

This system is fairly economical in terms of capital cost, is capable of accepting all household solid waste, is uncomplicated, is flexible because more containers can be added when volumes increase, and is generally well accepted by the public. However, the bins cannot successfully receive waste from standard collection trucks. These trucks must direct haul to the landfill. Scheduling is the major concern with this system. Haul costs can be high because containers may not be completely filled. In summary, rolloff stations are the most common and accepted system in BC.

4. Hydraulically Tippable Containers — These come in a wide range of sizes. The smallest are up to three cubic metre roadside units that use a quick-connect hydraulic system on a side loading collection truck to tip the bins into the truck. Larger units, as shown in Figure 3, with a capacity of about thirty cubic metres, use their own hydraulic system to tip their contents into a large transfer trailer, typically holding 90 m, and hauled by a tractor. The large units are set up similar to rolloff stations, with a ramp leading to an upper level, so that waste can be thrown down into the container. The transfer trailer parks at the lower level to receive waste. The advantages of this type of system, compared to a rolloff system, are that it can receive waste from standard collection trucks, and that only the waste is hauled. The expense of hauling containers is avoided. Disadvantages of this system, compared to rolloff bins, are problems caused by cold weather on the hydraulic cylinders, potential damage to the hydraulic systems resulting from vandalism and fire, and problems that arise from overloading with heavy material, which becomes jammed in the hopper.

5. Direct Dump — Sometimes called a "push pit" system, these urban transfer stations, as shown in Figure 5 at the end of this chapter, allow waste collection trucks to dump their loads either directly to a large transfer trailer parked at a lower level, or to a tipping floor, from which it is usually pushed by a loader or Bobcat into a 90 m³ trailer. A variation on this theme is for the waste to be lifted from the tipping floor or bunker by a crane, thus eliminating the need for a lower level for the transfer trailer. The tipping floor and trailer are usually housed in a building. Other amenities generally provided at a larger station include weigh scales, bins for receiving recyclables, a storage area for white goods, and an office, washroom, and lunchroom for staff.

6. Compaction — The use of compaction at a transfer station may be economically advantageous, since it allows a greater weight to be hauled in a given container. The economic viability of compaction depends on the nature of the wastes, the type of vehicle used to collect wastes, and the distance from the transfer station to the landfill. Wastes containing a significant amount of dense material, and/or waste collected in packer trucks (even though it rebounds upon dumping) may already achieve legal truck weight limits without compaction. The fundamental question in deciding whether to use compaction or not is this: Can the legal gross vehicle weight of the transport units be reached without compaction?

Compactors may be used even at small facilities. Rolloff compactors are available and are sometimes used at rural transfer stations, as shown in Figure 4. These compactors typically achieve a compaction ratio of about 6:1. They are limited as to the size and type of waste they can accept, so often a standard rolloff container is provided to receive bulky objects and demolition debris. There is a variety of compactors available for urban direct dump transfer stations; waste may be compacted directly in the trailer that receives it, or in a separate receiving compactor that then discharges to the transfer trailer.

FIGURE 1. TYPICAL GREEN BOX SITE

FIGURE 2. TYPICAL ROLLOFF BIN SITE

Adapted from Alberta Environment Transfer Station Manual

FIGURE 3. TRANSFER STATION WITH HYDRAULICALLY TIPPABLE (TRANSTOR) BIN

Adapted from Alberta Environment Transfer Station Manual

FIGURE 4. TYPICAL COMPACTION TYPE ROLLOFF FACILITY

Adapted from Alberta Environment Transfer Station Manual

FIGURE 5. TRANSFER STATION PUSH PIT SYSTEM

2. SITING GUIDELINES

2.1 General Location

It is desirable that a transfer station be located near the centroid of the population to be served, and near a major haul route to the destination landfill. The specific location of a transfer station shall be described in the Regional Solid Waste Management Plan, and should be acceptable to the majority of the public and the regional district board. As required in the Guide to the Preparation of Regional Solid Waste Management Plans by Regional Districts (BC Environment, 1994), if a new station is proposed, and is not included under an approved Plan, then an amendment to the Plan shall be prepared, documenting the public discussion and acceptance of the site.

The location of solid waste management facilities, including transfer stations, in relation to the presence of indigenous and migratory wildlife, is an issue of increasing importance as the activities of human beings intrude more heavily into the traditional habitat of bears and other wildlife. It is important that attention be paid to avoiding areas of high concentration of wildlife, such as migratory paths and other high use/high presence locales, in the siting of transfer stations and other solid waste management facilities. Local staff in the ministry's regional wildlife sections should be consulted for information related to a specific site under consideration as well as for advice as to general areas to be avoided.

Location has a strong influence on the cost of operating a transfer station, on its convenience to the public and on operational problems associated with wildlife such as bears. Notwithstanding these issues, suitable land may not always be available in the best general location or may not be acceptable to the public.

2.2 Area Requirement

Sufficient area should be provided for existing needs and buffers, but also for potential future expansion. The planning horizon for the provision of transfer services at a particular site, or at an alternative site, should be a minimum of twenty years, or consistent with the applicable Regional Solid Waste Management Plan.

2.3 Zoning

The selected site should conform to local zoning bylaws relative to land use, and building heights and setbacks. Appropriate land use designations include industrial, commercial, institutional, and agricultural. Residential zoning may be appropriate in areas where the lots are large, and where the station is accepted by the local residents.

2.4 Buffer

A vegetated or landscaped buffer zone of at least 15 metres should be left around the perimeter of the active transfer area, in order to minimize any potential nuisance associated with noise, dust, or odours, or any objections based on visual aesthetics. For small, unmanned, rural stations adjacent to forested areas, and where there is a threat of fires being set in the waste containers, an additional buffer zone may be desirable. In this situation, it would be appropriate to provide a cleared firebreak of 35 metres between the waste bins and the vegetated buffer.

Some flexibility should be allowed, based on local conditions and adjacent land use.

2.5 Site Servicing

Consideration should be given to the availability of utilities, including water, sewer, and electricity, particularly for stations accepting more than 1,000 tonnes per year.

Mid-size to large transfer stations need to provide water for firefighting and washdown of floors, need electrical power for machinery and lighting, and need to provide for staff amenities such as showers and toilets. The proximity of services can have a strong impact on capital and operating costs.

3. DESIGN GUIDELINES

3.1 Quantity Estimation

Solid waste quantities anticipated at a transfer station should be based on estimates for the area to be served. These estimates are normally contained in the Regional Solid Waste Management Plan. These estimates are usually given in tonnes per year. Since a transfer station is concerned with the volume of waste that must be received, held, and transported, the estimated annual tonnage should be converted to cubic metres. Where local density information is not available, a conversion factor of 150 kg/m³ may be used for standard, uncompacted municipal refuse. Compacted refuse may have a density of 2 to 4 times greater, but waste discharged from a packer truck does tend to "spring back" and reduce its density again. For a station receiving about half of its waste from packer trucks, a density of about 200 kg/m³ may be assumed.

The annual tonnage or volume should be used as a basis to calculate the average daily quantity, based on the number of days that waste is received at the station. A peaking factor should then be applied, to convert the average daily quantity to a peak daily quantity. It is often useful to calculate an estimated peak weekly quantity as well, particularly for small stations, that may only haul waste weekly. Failure to provide for peak volumes may result in premature filling of the containers to the point of over-flowing, an unplanned for increase in haulage (and the associated costs) and unsightly conditions at the site.

Local conditions are very important in determining densities and peaking factors. For example, local building demolition activity can contribute high density wastes. The appropriate peaking factor can vary widely, depending on local waste stream components and population characteristics. Areas with large seasonal tourist populations or seasonal agricultural activities can have high peaking factors. For these reasons, average and peak quantities must be estimated in the context of local conditions, with reference to the Regional Solid Waste Management Plan.

3.2 Storage Volume

A transfer station must provide sufficient volume, between one waste pickup and the next, to ensure that the bins or transfer trailer provided do not fill to overflowing. A direct dump station must provide sufficient tipping area to accommodate the numbers and types of vehicles arriving, their unloading times, and any waste sorting or processing that is to be done. Sufficient volume must be provided to accommodate peak waste periods, statutory holidays, and long weekends. Storage volume provided and pick-up frequency are essentially a trade-off. For a given population served (or waste generation rate), the larger the storage volume provided, the less frequent the waste pickups.

Bulky Goods

In some cases, acceptance of bulky goods such as appliances, auto hulks, furniture and wood wastes at transfer stations may provide the most convenient and practical method to the public for handling these types of wastes. Volume (space) provisions should be made for storing these wastes, if they are accepted at the site. Failure to provide bulky goods services may result in these items being placed in transfer station bins, resulting in inefficient use of bin space, premature filling of the bins to the point of over-flowing, more frequent hauling and an associated increase in operating and haulage costs. For transfer station sites in remote locations, the option of requiring the public to haul bulky items to a regional landfill site may be too onerous.

If bulky items are accepted at a transfer station site, they should be segregated to dedicated storage piles/containers. The piles, if kept properly clean of contaminants, could be allowed to build-up until economical loads are available for transport. The time period before economical loads are available for transport could be several months to several years.

3.3 Access Roads

Roads to a transfer station site and within the site should be designed to provide all season, all weather access. The minimum road width should be 8 metres. Designs must be in accordance with standard practice for the anticipated traffic volume and speeds. Sufficient space should be provided for queuing, such that vehicles need not stop on a public road or highway when entering the site. Traffic flow through the site should be considered. Gravelled surfaces may be acceptable, depending on the local context, but if dust or mud is a problem, asphalt paving should be provided.

3.4 Surface and Ground Water Quality

Provision should be made to prevent stormwater and runoff from contacting waste. All waste containers should be leak-proof, or should provide for the collection of contaminated water and illegally dumped liquids. Tipping floors should provide drains and sumps to collect washdown water and illegally dumped liquids. Proper disposal of contaminated water should be ensured.

3.5 Weigh Scales

Transfer stations serving populations of 5,000 or more, or receiving 5,000 tonnes/year or more should install weigh scales. Smaller stations should consider installing weigh scales or using an alternative (ministry approved) method of measuring waste quantities received, or instituting charges per vehicle or waste container, as a means of allowing the collection of tipping fees and thus of paying the costs of staffing and operating the station. The accuracy of specific scales or types of scales, for the purpose of charging fees, should be confirmed with the federal department of Consumer and Corporate Affairs — Weights and Measures.

3.6 Wildlife Control

Perimeter fencing, such as the chain link variety, is the first defence against wildlife intrusion. Bear-proof electric fencing has been used with success for both black bears and grizzly bears at several landfills in the province and should not represent a prohibitively expensive alternative for the small perimeters associated with most transfer stations. Electrifying the normal perimeter security fence may be feasible, with appropriate attention to warning humans of its presence, such as by using signs and other measures, and otherwise ensuring it is safe and user friendly. Careful attention must be paid to gate design, on the one hand to promote responsible use by humans (including both easy access and after use closure) while at the same time to prevent wildlife from entering the site.

Containers intended to receive organic waste should have lids, screens, or covers that will prevent access by bears and other predators, rodents, and birds. Alternatively, containers may be placed inside predator-proof enclosures that provide both easy access to users and promote closure after use (e.g., garage door type designs). Consideration should also be given to washing out containers between uses, either at the transfer station or at the landfill. Only sturdy, easily cleanable, animal-proof containers should be used. Buildings at direct dump facilities should be designed to minimize areas/spaces that afford a harbour for rats and other small mammals, and to be predator-proof. The importance of predator-proof containers cannot be over-emphasized as this design feature will prevent rewarding wildlife with a food source in the event that the exterior fencing is breached (e.g., by a gate left open, etc.).

3.7 Site Security

Fencing should be provided around the perimeter of the site, with a lockable gate at any entrance point. The type of fencing may vary with the natural site features.

3.8 Signs

Transfer stations should be provided with a sign (or signs) posted prominently at the entrance, that contains the following information:

• facility name
• owner / operator with phone number and address
• emergency phone numbers for fire, police and medical assistance
• hours of operation (if applicable)
• prohibited materials
• materials accepted for recycling
• tipping fee schedule (if applicable)
• the presence of an electric fence (if applicable)

If recyclables are not accepted at the station, a sign should indicate the location of the nearest facility that does accept them. In addition, the sign should indicate locations, if known/available, where prohibited materials such as paint, used oil, lead-acid batteries and other items can be safely taken.

3.9 Water Supply

For facilities with buildings, employing staff during operating hours, water for fire protection should be provided in accordance with the Water Supply for Public Fire Protection — A Guide to Recommended Practice, as available through the Insurers Advisory Organization. For these larger stations, washdown water should also be provided.

3.10 Materials Recovery

A transfer station is an ideal location to provide bins for the dropoff of reusable and recyclable materials. Similar design considerations apply as for waste; the station should provide sufficient storage space, weigh scales and fire protection for larger stations, and signs giving users appropriate instructions. The dropoff of organic materials for composting requires that the bins be emptied frequently, depending on the type of material. Yard waste containing a significant amount of grass should be picked up daily, unless it can be shown that odours are not a problem at either the transfer station or the composting site. Yard waste consisting mainly of brush and leaves may be picked up weekly. Food wastes should be picked up daily.

At some rural transfer stations, waste oil receptors and lead-acid battery bins (with alkali material placed in the bottom to neutralize spilled acids) have been provided. This allows the public a convenient method of disposing of these materials which might otherwise be put into the transfer station bins.

In cases where recycling facilities are not located at the transfer station, a sign should be provided directing patrons to the nearest available facility.

3.11 Safety Features

Most transfer stations involve the dropping or pushing of waste down into a bin or trailer. It is important that safety features such as guard rails be incorporated to prevent people from falling into a bin, and stop logs or bars to prevent vehicle accidents. Transfer buildings should be designed with sufficient ceiling clearance to accommodate the vehicles that may enter and dump. It is desirable that transfer buildings have clear spans, without central columns to impede traffic.

4.OPERATIONAL GUIDELINES

4.1 Prohibited and Difficult Wastes

The following wastes should not be accepted at a transfer station unless special arrangements have been made and appropriate containers provided.

• Hazardous Wastes other than those specifically authorized in the Hazardous Waste Regulation
• Bulk liquids and semi-solid sludges that contain free liquid
• Liquid or semi-solid wastes including septage, black water, and sewage treatment sludge
• Biomedical waste as defined in Guidelines for the Management of Biomedical Waste in Canada, CCME, February, 1992
• Dead animals and slaughterhouse, fish hatchery, and farming wastes, or cannery wastes and by-products

Recyclables designated in the Regional Solid Waste Management Plan should be prohibited from disposal in bins or on a tipping floor intended for wastes.

A difficult issue to deal with is the enforcement of prohibitions at an unmanned site. All sanitary landfills are now required to have staff on site during operating hours, although landfills serving fewer than 5,000 people may be exempt, and all landfills are allowed to have waste bins outside the gates for after hours use. Only small transfer stations, accepting less than 1,000 tonnes/year, should be allowed to operate without staff during operating hours, a privilege that should be rescinded if problems develop.

4.2 Waste Storage

The allowable maximum storage time depends on the type of waste, facility size, presence and type of wildlife, and season. Inert waste, such as demolition debris, may be stored for up to two months, given sufficient space. Small rural stations should not store municipal garbage for more than a week in the winter, or more than two days in the summer, unless it can be shown that longer storage will not cause problems. Transfer stations accepting more than 5,000 tonnes/year should transport all garbage off the premises at the end of every working day. Storage of municipal garbage outside of waste containers should be prohibited.

It is difficult to set firm rules for storage, because of widely varying circumstances throughout the province. In northern areas, where waste may stay frozen for months, long term storage may not be a problem. In some areas, the presence of bears that are accustomed to eating garbage may indicate a need for daily removal.

4.3 Supervision

Operating staff should inspect every transfer station at least once per week. Stations receiving 1,000 tonnes/year or more of waste should provide an operator on site during operating hours. Facilities receiving 5,000 tonnes/year or more should employ staff at the scale house and on the tipping floor or in the bin area at all times during operating hours.

Even at the smallest stations, staff are required on at least an intermittent basis to ensure that prohibited wastes are not being dumped, that the facility is functioning properly, and that the site is being kept clean.

4.4 Wildlife Control

Allowable measures for the resolution of wildlife problems at transfer stations will depend on the wildlife species and the severity of the problem. In most cases involving large predators and extreme measures such as poisoning rodents and other small mammals, it is necessary to involve ministry staff or specially trained personnel for the protection of human health and the environment. For large predators such as bears, wolves and coyotes that are or become conditioned to the site, alternatives include trapping and translocation of protected species and shooting of dangerous animals. The local ministry Conservation Officer Service should be consulted for problems related to bears and other large predators. The Conservation Officer will assess whether to attempt translocation or shooting in the case of persistent problems with individual animals. For problems related to rodents and other small mammals, physical methods such as trapping or snaring and poisoning are among the most common options. Physical methods (i.e.: traps, snares, etc.) may be used without ministry control. However, poisoned bait should be used only by personnel licensed and certified under the ministry's Pesticide Management protocols. Fish and Wildlife staff in local ministry offices should be consulted to provide guidance on protected species of birds and animals to prevent unauthorized or illegal poisoning or trapping.

The first priority is to prevent problems with wildlife by designing the station so that animal access is difficult, and by operating the station so that it is not attractive to animals and birds. The important elements are fencing, bin covers, site tidiness, and the prompt removal of wastes. Even with all these elements in place, wildlife may be a problem at transfer stations, particularly those stations that replace small landfills, or stations that have been poorly run, and have provided food for wildlife in the past. Bears that have become accustomed to feeding on garbage can be a particularly difficult problem. As indicated in the design features section, internal measures (bin covers, site tidiness, prompt removal of waste) should not be sacrificed or compromised in favour of external measures (fences) as it is important that wildlife breaching the external measures are not rewarded by gaining easy access to the waste.

4.5 Emergency Procedures

Transfer station staff should be familiar with procedures involving fire prevention and control. A "FIRE HAZARD - NO SMOKING" sign should be posted at the entrance or at the weigh scales. Fire extinguishers should be available inside all buildings and vehicles. Stations receiving 5,000 tonnes/year or more, or with permanent staff, should have telephone communications available to enable the fire department, police, or medical services to be contacted. Staff serving small stations should have a cellular telephone in their vehicle.

Staff should be trained in first-aid procedures. At stations where staff are present during operating hours, a standard BC #2 First Aid Kit should be available. Smaller first aid kits should be available in staff vehicles.

4.6 Site Tidiness

Litter at small unstaffed stations should be cleaned up at least once per week. Cleanup at stations with permanent staff should be done every operating day, or as required. Staffed stations with weigh scales should consider charging users an additional fee if they arrive with improperly secured or improperly covered loads.

4.7 Nuisance Control

The generation of dust can cause unsightly conditions, and may be irritating to transfer station staff and users. Dust may arise from roads, and from some refuse, such as concrete, demolition waste, ashes, and plaster. Consideration should be given to paving, watering, or brine-sealing unsurfaced roads, and sweeping surfaced roads. If dust problems arise from the handling of waste, consideration should be given to wetting the waste, or if within a building, to installing proper ventilation and dust collection.

Operational practices for reducing odours are the prompt removal of waste and the regular washing of floors, equipment and bins.

If noise is a cause for complaint by neighbours, it may be necessary to limit the operating hours of the station, and/or to provide better noise suppression on equipment and vehicles.

4.8 Scavenging

Scavenging at transfer stations should be prohibited. However, if special arrangements have been made to set aside an area for the dropoff and safe storage of goods and materials, then controlled salvaging should be encouraged.

5. COSTING AND COMPARISON MODELS

This chapter provides capital and operating cost estimates for landfills and transfer stations, cost models to assist in making decisions on transfer haul versus direct haul, and transfer stations versus landfills, and on financing transfer stations. Detailed cost estimates are provided in a number of examples contained in Appendices A and B. The capital costs contained in the first two sections of this chapter were estimated for mid-1994, for a projected Engineering News-Record Construction Cost Index of 5350. The cost examples provided must be used with care, because unit cost information varies throughout the province. Readers are encouraged to investigate local prices for similar work in their area.

5.1 Landfill Costs

In order to create a model to assist in the decision of whether to close a landfill and replace it with a transfer station, it is first necessary to define the capital and operating costs associated with different types and sizes of landfills. Detailed example cost estimates are contained in Appendix A, for landfills accepting 100, 1,000, 10,000, and 100,000 tonnes/year of waste. Estimates are provided for sites where leachate is naturally attenuated and for sites requiring engineering management of leachate. All estimates include elements needed to enable the landfills to meet the BC Landfill Criteria for Municipal Solid Waste. Table 1 summarizes the total annual cost of the landfill examples contained in Appendix A.

The fencing component of the capital costs allowance included in the total annual cost data summarized below does not provide for electric predator/bear-proof fencing. An additional cost of $12-$20 per metre of fenced perimeter should be added to allow for this option.

TABLE 1: EXAMPLE LANDFILL COSTS

5.2 Transfer Costs

This section provides a summary of capital and operating cost estimates for idealized transfer stations that would meet the guidelines recommended in Sections 3 and 4. The detailed example estimates are contained in Appendix B. These example cost estimates for stations of different sizes and types are intended to supply enough information for readers to adapt a given example to their own specific circumstances.

Capital cost estimates contain the following elements:

1) Land Purchase - The example sites contain a 15 metre buffer strip, and are assumed to be purchased at a cost of $25,000 per hectare. This cost is intended to be conservative, and may be much lower in many areas. Frequently, Crown Land may be leased or used at little or no cost.

2) Site Preparation - Typical lump sum costs for clearing, grubbing, and site grading were assumed. However, if stumps and other wood debris are chipped and spread on site or removed from the site for chipping, the costs may increase.

3) Access Road and Ramp - Cost estimates were provided only for internal access roads, not roads leading to the site. The ramp referred to is for the bin sites, where access is required for users to drop waste down into the bins. The estimates are for the spreading of 150 mm of crushed gravel on the road and ramp surfaces, at $8.00/m².

4) Retaining Wall - A retaining wall is provided for a rolloff bin site, such that the bins sit along the base of the wall. Five possible types of wall were considered; reinforced concrete, concrete lock blocks, bin wall(e.g. Armco), railway ties or other wooden material, and old vehicle tires. Wood and tires are not recommended because of their susceptibility to fire damage, and because of their probable higher cost in the long term. Cost estimates were prepared for the other three possibilities, in Example A in Appendix B, for a 100 tonne/year rolloff bin station. The concrete lock blocks were the most economical, at an estimated $7,000, compared to $13,000 for reinforced concrete and $16,000 for bin wall.

Lock blocks are provided by United Lock Block, which has 72 sales locations in BC. In addition to being economical, they provide some flexibility in that they can be salvaged and relocated if necessary. The purchase cost per block, including tax, varies from about $70 to $105 around the province. Freight depends on location and number of blocks ordered, but would typically be $15 to $30 per block. Installation was assumed to require a crane and two men, at about $150/hour, for about $30 per block. A total cost per installed block of $160 was assumed in the examples.

5) Concrete Pad - Rolloff bins work best on a hard surface. The estimates for rolloff stations include a reinforced concrete pad along the base of the retaining wall, of about 1.5 times the width of the bin, 150 mm thick, at $100/m².

6) Bins - The large rolloff bins, with 38 m³ capacity, are estimated at $5,500 each. This price does not include a lid or cover. The small 5 m3 bins used in another example are estimated at $1,000 each, and the small hydraulically tippable bins of 3 m³ (HaulAll Hyd-a-way), at $3,500 each. A price of $33,000 was allowed for a large 31 m³ hydraulically tippable bin (Transtor). Compactor rolloff bins, with 38 m³ capacity, are estimated at $24,000 each.

7) Rolloff Bin Lids or Covers - Hinged lids for rolloff bins were estimated at approximately $4,000 each. These lids (and the associated costs) were not included in any of the example estimates, as they are an option that may not be appropriate at all locations. Although providing a potential means of excluding precipitation and preventing wildlife from accessing the bin, there are some operational concerns with their use. They can be awkward for people to use, snow and ice can make the lids heavy and difficult to open and people often leave the lids open after use, which allows access by animals.

Predator-proofing transfer stations is a key issue for sites in areas of bear activity. This can be accomplished through a variety of design and operating features, including external fencing, predator-proof containers and/or lids, site tidiness and prompt removal of accumulated wastes.

An alternative to predator-proof containers/lids is to enclose the bins with sheet steel structures with rollup or sliding doors and mesh predator barriers, such as manufactured by Northside Steel Fabricators in Kelowna. The cost of one of these structural steel covers, plus two days for a crane and two men to erect it, was estimated at $16,000.

8) Fencing, Gate, and Signs - Fencing was assumed to be installed around the perimeter of the site, at a cost of $35/lineal metre. $200 to $300 was allowed for a sign. The capital cost estimates provided for fencing do not include provision for electric predator/bear-control fences. An additional cost of approximately $12-$20 per metre of fenced perimeter should be added to allow for this option.

A contingency allowance of 10% was allowed for in each example, plus an allowance for engineering of between 5% and 15%, depending on the complexity of the station. In each example, the capital cost estimate was converted into an annual cost by assuming payback over a ten year period at 8% interest.

Operating Cost estimates include the cost of running the transfer station itself, and the cost of hauling waste to a landfill. The following unit costs were used: labour, $20/hr; front end loader, $65/hr; rolloff truck with single bin, $100/hr; rolloff truck with pup (two bins), $110/hr; transfer tractor and trailer, $100/hr; top loading commercial packer truck, $135/hr; Shu-pak or other small compactor truck, $90/hr. An allowance of 10% was added to each total operating cost, for administration.

Table 2 summarizes the total annual cost for each example transfer station. The cost includes capital payback plus the cost of operation and maintenance.

Based on the example estimates, for a 100 tonne/year station, the cost of using multiple small bins is almost the same (Example B), or considerably more expensive (Example C) than using rolloff bins (Example A). The use of multiple small bins is also problematic; people become frustrated on finding a bin, or successive bins, full and throw their garbage anywhere. Furthermore, small bins do not allow for the disposal of bulky items. Multiple small bin systems may be appropriate for very small annual tonnages, but not for 100 tonnes/year or more.

Example D consists of a packer truck, designated to be available at a specific location for one day per week. People bring their waste to the truck. This system is expensive but it avoids any capital costs or siting commitments. It may be a suitable stopgap measure to institute until a more economical alternative can be implemented. It provides a low level of service, but does allow the truck operator to collect fees and to reject inappropriate wastes.

TABLE 2: EXAMPLE TRANSFER STATION COSTS

At 1,000 tonnes/year and at 10,000 tonnes/year, for the example estimates, economics appear to favour the Transtor type system. However, at the higher tonnages, the direct dump stations are probably better value, because they provide a more flexible operation, and allow waste to be pre-sorted and inspected on the tipping floor.

5.3 Decision Models

This section describes two decision making procedures; transfer haul versus direct haul in collection trucks, and transfer stations as replacements for landfills.

a) Transfer Haul Versus Direct Haul

Section 5.2 and Appendix B describe the cost components associated with transfer haul using some typical examples. The total cost of transfer includes a fixed base cost plus a hauling cost that is a function of haul distance. In general, the transfer cost may be expressed as follows:

T = ax + b (1)

where : T = total haul cost per tonne,
a = unit haul cost per tonne per kilometre of haul distance,
b = fixed base cost per tonne, and
x = the round trip haul distance in kilometres.

Both a and b will vary with the solid waste quantity to be hauled. Table 3 shows typical values of a and b using the examples detailed in Appendix B.

TABLE 3: TYPICAL VALUES OF TRANSFER UNIT COST PARAMETERS

Note: Cost estimates are given in Appendix B, Examples A, F, and I.

Direct haul is assumed to be carried out by 5 tonne packer trucks. The direct haul cost includes the recovery of the truck purchase price, wages of the driver and swamper (waste collectors), insurance and licence fees, and other operation and maintenance costs. Table 4 summarizes the unit costs for direct haul, per haul distance ($/km), for three different crew sizes.

TABLE 4: UNIT DIRECT HAUL COST PER KILOMETRE

The unit direct haul cost may be generalized as follows:

D = cx (2)

where D = direct haul cost per tonne,
c = unit direct haul cost (Table 4), and
x = round trip haul distance in kilometres.

A nomograph shown in Figures 6 and 7, at the end of this section, can be used to estimate and compare approximate direct and transfer haul costs. Figure 6 shows estimates of "a" and "b" for given annual waste tonnages. Figure 7 illustrates Equation 2 with the "c" values shown in Table 4. The procedure to be followed is:

1. Estimate average annual waste tonnage over the design period, say 5 to 10 years. (Let us assume it is 10,000 tonnes/year).

2. Find the per tonne transfer haul cost per km of haul distance (for 10,000 tonnes/year) from Graph a of Figure 6. (This is $0.12/tonne-km).

3. Find the fixed base transfer cost per tonne (for 10,000 tonnes/year) from Graph b of Figure 6. (This is $33/tonne).

4. Use the transfer haul cost data ($33/tonne and $0.12/tonne-km) and Equation 1 with the direct haul unit cost data ("c") and Equation 2 to find the break-even points for direct haul as follows:

5. Determine the round trip transfer and direct haul distances. (Assume they are both 130 km for this example). At 130 km, the direct haul distance exceeds the break-even point for a two-person crew, and transfer haul should be considered. Alternately, a one-person crew direct haul by a 5 tonne packer truck would be more economical than transfer haul up to a round trip haul distance of 190 km, if the waste disposal requirement is about 10,000 tonnes/year.

For rural areas where collection service costs become excessive, transfer facilities may have to be provided for the convenience of the public.

b) Transfer Versus Landfill

Table 1 in Section 5.1 presents a summary of typical landfilling costs to meet the provincial Landfill Criteria, and Appendix A details the various assumptions for the example cost estimates. Table 5 summarizes the landfill costs in terms of $/tonne.

TABLE 5. EXAMPLE LANDFILL UNIT COSTS

Using the cost data shown in Tables 3 and 5, a simple and easy-to-use nomograph was prepared for assisting in the decision of whether to replace a landfill with a transfer station. This decision making procedure is described below, with reference to Figures 6 and 8.

1. Estimate the average annual waste tonnage over a design period of say 10 to 20 years, for two landfills. (Let us assume they are a 500 tonne/year natural attenuation site and a 4,000 tonne/year engineered site).

2. Determine the round trip transfer haul distance from the potential transfer station site (the smaller landfill site in this example; assume 160 km), to the waste disposal site (the larger landfill).

3. Find the landfilling costs for using both sites simultaneously, and for using only the larger site to accept transferred waste as well, i.e. 4,500 tonnes/year. (Using Figure 8, the costs are: $300/t x 500t + $150/t x 4,000t = $750,000 for the two sites; and $140/t x 4,500t = $630,000 for a single site).

4. Find the transfer cost from Figure 6. (Using Equation (1), the transfer cost is $100/t x 500t + $0.48/t-km x 500t x 160 km = $88,400. The total annual cost for transferring waste from the small landfill to the larger sub-regional site is $718,400/yr, which is lower than the cost of running two landfills, at $750,000/yr).

These example decision models should be applied with some reference to local conditions; the user should refer to the underlying cost examples contained in Appendix A and B, and relate the costs to local conditions.

5.4 Financing Transfer Stations

There are a number of ways for local government to finance solid waste management functions including waste transfer via transfer stations. They include general revenue and user fees (uniform fees or sub-area/facility specific fees). Implementation of a true user fee system, which would promote the 3 R's by users, will require facility staffing during operating hours. A modified user fee system would be a fixed charge per user, regardless of the extent or frequency of use. This could be done, for example, by issuing keys to the transfer station gate to local area users, or by using a card lock system, and charging an annual fee to the users who receive keys or cards.

Local governments should be aware of the Provincial Rural Waste Management Financial Assistance Program. Under this program, a portion of the initial capital cost of transfer stations can be considered for by the province as follows:

1. Up to one third of the initial capital cost, to a maximum of $30,000, to close an existing inappropriate rural landfill and replace it with a transfer station.

2. Up to one third of the initial capital cost, to a maximum of $20,000, to install a transfer station at a new site.

Another aspect that should be considered by local government includes establishing a partnership with the private sector. The extent of the partnership could vary from an equipment supply contract to a build/own/operate/transfer (BOOT) contract. Under a BOOT contract, a private contractor would be responsible for construction and operation of the transfer station for a fee.

FIGURE 6. UNIT TRANSFER HAUL COST ($/t) and WASTE TONNAGE (t/yr)

FIGURE 7. DIRECT HAUL COST ($/t) and HAUL DISTANCE (km)

FIGURE 8. UNIT LANDFILL COST ($/t) and WASTE TONNAGE (t/yr)