Trash Compactors and Waste Disposal
1. WASTE PROCESSING - GENERAL WEIGHTS & MEASURES
- 1 cubic yard (i.e., of dumpster space) is composed of 46,656 cubic inches.
- 1 gallon equals 231 cubic inches of capacity
- 1 cubic yd (of dumpster space) equals 202 gallons of capacity. (46,656 / by 231)
- Therefore, an 8-yd dumpster will hold 1,616 gallons of capacity when totally full.
2. HOW MUCH LOOSE AND COMPACTED WASTE FITS INTO A DUMPSTER
The typical volume capacity, density and other characteristics of wastes vary from industry to industry and location to location within an industry. It is fairly logical that waste streams or trash profiles with the highest air content achieve the highest benefits from compaction. Since trash profiles can vary considerably within the same industry (and even within the same exact market segment) the compaction benefits derived from trash compactors will also vary accordingly. Some basics are as follows:
A) LOOSE, NON-COMPACTED WASTE
An average of approximately 200 gallons of trash (i.e. the equivalent of 4 of the 50-gallon bags of loose, non-compacted waste) will fit into each cubic yard of dumpster space. Since an 8-yard dumpster is the equivalent of approximately 1,616 gallons of capacity (i.e. 202 x 8) this means that, if full, an 8-yard dumpster would hold roughly 30 of the 50 gallon bags (or 50 of the 30 gallon bags etc) of loose, non-compacted waste. (i.e. 1,616 divided by 50 gal).
B) TYPICAL VOLUME REDUCTION CAPABILITIES OF TRASH COMPACTORS
There are numerous types of Commercial Trash Compactors (or waste compactors) including Indoor Trash Compactors, Outdoor Trash Compactors, Automatic Compacting Receptacles (such as the Smart-Pack), High Rise Compactors, Bin Compactors, Compacting Dumpsters, Stationary Compactors, Self-Contained Compactors, Pre-Crushers, Specialty Compactors and others. The compaction benefits or volume reduction benefits of various types of waste equipment can vary widely, from a range of approximately 25 to 1 down to a range of about 2 to 1. Generally speaking, the Indoor Trash Compactors average a range of up to 25 to 1 compaction ratio down to around 10 to 1. Compactors such as the Automatic Compacting Receptacles (i.e. Smart-Pack) can be used indoor or outdoor and can average anywhere from 15 to 1 compaction ratio down to around 8 to 1. The Outdoor Trash Compactors average a range of 5 to 1 compaction ratio down to around 2 to 1. Thus, a Commercial Trash Compactor can help to reduce waste disposal costs and waste hauling requirements as a direct result of the volume reduction benefits.
C) TYPICAL SIZE 'HOLDING CAPACITY' OF TRASH COMPACTORS
Automatic Compacting Receptacles (Smart-Pack) usually have a holding capacity of about 20 – 25 gallons of loose trash (or roughly .10 - .12 cubic yards). Regular Indoor Trash Compactors usually range from about 25 gallon capacity (.12 cubic yards) up to around 55 gallons (.27 cubic yards). The larger indoor compactors have inside containers with approximate dimensions that is roughly 34” W x 22” D x 17” H. By multiplying the three dimensions, this equals approximately 12,716 cubic inches, divided by 231 (since there are 231 cubic inches in each gallon) for a result of approximately 55 gallons. Hi-Rise Compactors can vary but usually start in the range of roughly 40 gallon capacity and go up from there. Of course the 40 gallon capacity is compacted trash so that actual volume of loose trash is roughly 600 - 1000 gallons or roughly 3 - 5 cubic yards of loose trash. Outdoor compactors usually have a holding capacity of anywhere from 2 – 5 cubic yards, which includes vertical outdoor compactors, stationary compactors outdoor compacting dumpsters and others. However, additional holding capacity can be added to some types of compactors such as the stationary compactors, which are made to work in conjunction with larger containers. The containers (usually ranging from 30 – 40 cubic yards) are attached to the compactor in order to accumulate the compacted trash. Basically the stationary compactors have a chamber capacity that is usually in the 2 – 5 cubic yard range that serves as the area for compacting the trash, and then as it is compacted it is pushed into the larger container area for accumulation and subsequent pick-up by the hauler.
D. APPLYING SOME BASIC COMPACTION RATIOS
Using a compaction ratio (or volume reduction) of approximately 20 to 1 as an example, certain basics can be derived. Applying this compaction ratio and using the larger indoor compactors (as an example) this would mean that (theoretically) the equivalent of approximately 30,000 gallons of compacted trash could be placed into the same space that 1,616 gallons of loose trash would normally occupy. (i.e. 8 yd dumpster normally holds 1,616 gallons (202 gallons per cubic yards x 8) multiplied by 20 (20 to 1 compaction ratio) which actually equals 32,000 gallons or roughly 600+ of the 50-gallon bags of compacted waste. (This would be assuming that the full space of the dumpster is utilized perfectly of course). In this example, each cubic yard of dumpster space, would hold the equivalent of roughly 75 of the 50 gallon bags of compacted waste (versus roughly 4 of the 50 gallon bags of loose trash per cubic yard).
As mentioned previously, since densities and air content of various types of waste streams vary, the compaction benefits and volume reduction capabilities will also vary. The more ‘air volume’ or air space in the trash profile, the greater the compaction benefits. Waste that contains a lot of air, such as cups and cartons achieves a much higher reduction ratio from compaction. With a consistent waste stream it is easy to extrapolate more reliable data and expectations. To be conservative (in figuring expectations of compaction benefits) it may be appropriate to assume a lesser compaction ratio. For example, figure the compaction ratio at 15 to 1 and adjust the numbers accordingly.
Since the larger Indoor Trash Compactors have inside containers that are equal to approximately 55 gallons, when the waste is compacted, these inside containers could conceivably hold the equivalent capacity of roughly 1,100 gallons of compacted waste. (i.e. approximately 20 of the 50 gallon bags of trash versus just 1 of the 50 gallon bags of loose, non-compacted trash). Since one cubic yard of dumpster space equals 202 gallons, roughly 3.5 of these compacted cubes of waste will fit into one cubic yard (i.e. 202 gallons divided by 55 gallon capacity of the inside cube = 3.67 compacted cubes per cubic yard). This is assuming these trash cubes are packed perfectly within the dumpster space area, which is not practical of course. But, if each of the compacted cubes was packed perfectly in a dumpster, then an 8 yard dumpster would, on average, hold roughly 30 cubes of compacted waste from these compactors (i.e. 3.67 X 8 YD). And each cube would hold roughly 1,000 gallons of trash (at a 20: reduction ratio ‘trash profile’).
3. COMPACTION BENEFITS (Using the above example with 20:1 compaction ratio)
Using the example of a location that has an 8 yard dumpster and is getting ‘tipped’ by the waste hauler 3 times per week, and also assuming that the dumpster is completely full at each pick-up, this would be roughly 4,848 gallons of ‘dumpster capacity’ generated each week. (Note: The term ‘dumpster capacity’ is used since the dumpster could be half-empty with each pick-up). Again, the 4,848 gallons is derived by taking the 1,616 gallons of waste per pickup (202 gallons per cubic yard times the 8 yard dumpster) and then multiplying that times 3 pickups per week, (based on non-compacted waste). Therefore, the 4,848 gallons (in dumpster capacity) of non-compacted waste is equal to roughly 100 of the 50 gallon bags of( loose, non-compacted) trash being discarded each week (i.e. 4,848 divided by 50). Note: If only a portion of the trash going into a particular dumpster is compacted, then the appropriate adjustments have to be made as well. For example, if only 50% of the trash going into a dumpster is compacted and the other 50% is loose trash, then adjust accordingly.
After compaction, and assuming: 1) an average compaction ratio of approximately 20 to 1, and; 2) the compacted cubes of trash are not going to be placed perfectly in the dumpster, to the extent that maybe only 2 compacted cubes of trash comprise one cubic yard of dumpster space (versus 3.67 compacted cubes), we can then figure that each full dumpster would hold roughly 16 of the compacted cubes (i.e. 2 cubes per cubic yard multiplied times 8 cubic yard dumpster). Since each of these 16 cubes (of compacted trash) is the equivalent of roughly 1,000 gallons of loose trash (20 of the 50 gallon bags) it means that we would end up with the 8-yd dumpster being able to hold the equivalent of roughly 16,000 gal of loose trash (i.e. if all the trash in the dumpster is compacted at 20:1, but does not fit perfectly in the dumpster).
Summary of Compaction Benefits
This means that since the total amount of dumpster capacity required per week is only about 4,848 gallons, then: a) the weekly tips could be reduced from 3 per week down to just one tip per week AND; b) the dumpster size could be reduced to a 4 yard dumpster. This is assuming that 100% of the trash going in that particular dumpster is being compacted. In other words, considering that the 8 yard dumpster would hold roughly 16,000 gallons of compacted trash, then the 4 yard dumpster would hold roughly 8,000 gallons of compacted trash, which also means that only one pickup per week is required, since the location is only utilizing 4,848 gallons of dumpster capacity, or loose trash, per week.
4. BASIC CONSIDERATIONS OF THE VARIOUS TYPES OF TRASH COMPACTORS.
A) Automatic Compacting Receptacles – ACR’s (such as the Smart-Pack): These compactors are best utilized in public areas (either indoors or outdoors) where people normally make their own trash deposits. The automatic compacting receptacles automatically compact based on traffic flow (or predefined criteria) and the waste deposit door opens automatically (via photo eye) for patrons so they don’t have to touch the door to open it. There are other automated features as well, but the main concept is that the unit is totally automated (and in compliance with safety standards) to the extent that it can be utilized in public areas. For example, it will not compact while the waste deposit door is open and the door locks momentarily while going through a quick compaction cycle. Some of the most common uses are as follows: The dining areas of fast food restaurants; mall food courts, amusement parks, airports, schools and colleges, casinos, resorts & hotels, hospitals & medical facilities, In-Store Feeders, government facilities, family entertainment centers, stadiums and other sporting facilities, and numerous other types of locations where people typically discard their own trash into trash receptacles. Usually, the automatic compacting receptacles offer maximum labor savings and compaction benefits, since: a) the trash profile is generally high in air content, and; b) the trash is being compacted right at the source where it is generated. Labor savings per ACR can be as much as 4 labor hours or more per unit per day. In addition, the compaction benefits also provide reductions in waste hauling requirements.
B) Regular Indoor Trash Compactors. – The most common type of Indoor Trash Compactors are the stainless steel (refrigerator sized) units which are utilized in areas where employees have access rather than the general public. The compaction cycle of these units is typically initiated by manually pushing a button. Usually, these type of compactors are placed in utility rooms at hospitals and medical facilities (usually on each floor of the facility); kitchen areas of family restaurants and cafeteria type establishments, and other such areas not available to the public. Because these units have a larger holding capacity and more compaction pressure (than ACR’s) the compacted trash cubes can end up being 2 – 4 times heavier (than ACR’s) so they usually require hydraulic liftcarts as an accessory.
A side benefit of the two types of compactors mentioned above is that they utilize an inside durable plastic container which forms a packed cube of trash that can be weighed periodically (when full of compacted trash). This periodic weighing can provide the owner / operator with fairly accurate trash weight information. By knowing the average weight of each compacted cube of trash, then it is just a matter of tracking the number of compacted cubes discarded in order to derive the total estimated weight of trash for a given period of time, whether weekly or monthly. For example, if there are approximately 15 cubes of trash that are discarded into the dumpster each week and each cube of trash weighs 150 lbs, then the weight of the trash would be pretty close to 2,250 pounds. (As mentioned these compactors come with liftcarts that are used to transport the trash to the dumpster and then lift and tilt the trash into the dumpster, so that the employees do not ‘feel the weight.) This method of deriving weights is also fairly reliable since the waste is compressed inside a heavy duty plastic bag into a cube of waste (formed by the inside container). The heavy duty plastic bags offer protection from the elements (including rodents) and make it less vulnerable to being water logged by rain, snow or other such conditions (unlike loose trash discarded into dumpsters). The waste hauler trucks are designed with a lifting capacity of at least 8,000 – 8,500 pounds, which helps when they must pick up extremely heavy trash that is water logged from rain and snow. (Oftentimes, if a waste hauler won’t admit or reveal the actual lifting capacity of these trucks it is because they are hoping to discourage customers from implementing or utilizing compactors since compacted waste reduces waste hauler requirements and revenues.) By deducting for the weight of the dumpster itself, this allows the owner / operator an opportunity to determine how to best maximize their payloads for dumpster pick-ups. (Note: For an empty (steel) dumpster, the owner / operator could figure roughly 500 lbs of weight for each 2 cubic yards capacity and then factor this amount in for deriving total dumpster weights, after adding the compacted trash. Thus, if the dumpster is 8 yard capacity, figure 2,000 lbs for the empty dumpster itself.) Therefore, if the empty dumpster weighs 2,000 pounds then the owner / operator would know that there is approximately 6,000 pounds of capacity remaining for their trash weight. And if the total weight of the dumpster (including trash) ever becomes an issue, then by reducing the size of the dumpster to the appropriate level it can easily become a non-issue. For example, by going from an 8 yd down to a 4-yd, it not only cuts the dumpster weight in half, but also cuts the weight of the compacted trash in the dumpster in half. One of the key concepts to understand is that on a month to month basis the total trash weight is not going to change, with or without compactors. However the number of ‘tips’ or ‘pulls’ will change. And, since landfill charges or disposal costs are easy to verify (by either contacting the facility or other means) it is easy to deduct those amounts from the overall charges to determine what the pick-up (transportation) charges are. If a hauler is picking up 6,000 pounds (3 tons) per month from a particular location and the disposal cost at the landfill is (for example) $60 per ton, then it is fairly easy to determine what the hauler is charging for everything else.
C) Outdoor Trash Compactors (such as Stationary, ‘Dumpster’ type, Self-Contained, Vertical Outdoor Compactors and others) – There are a large variety of outdoor compactors. These include the ‘Dumpster’ type (usually 4 – 6 yard capacity) where the hauler ‘tips’ the unit just like he would a regular dumpster; or the Stationary Compactor that is utilized in conjunction with a container (of varying sizes) provided by the hauler (i.e. 35 yard container). Containers that are too large to ‘tip’ on site are hauled directly to the landfill or disposal facility (but of course an empty container is dropped at the site before hauling off the full one). Similar to the Stationary Compactors are the Pre-Crushers / Compactors which provide much greater force and a slightly different design for crushing bulk materials such as pallets, appliances and Waste_Recycling_Articles.htms. The Self-Contained compactors and Vertical Outdoor Compactors are another option and are generally favored when the trash profile is made up of a good portion of ‘wet waste’. As a general rule, the compaction benefits of the outdoor compactors are much less than the indoor compactors or automatic compacting receptacles. Typically, the reduction or compaction ratios achieved by outdoor compactors are not more than 5 to 1, if that much. Since the compaction benefits of these are much less, the waste haulers usually offer the least amount of resistance to customers using these over any other type of compactors (and oftentimes haulers will even provide outdoor compactors, however be prudent about compaction pressures and benefits of these units).
5. CHECKS & BALANCES - WASTE HAULER / WASTE DISPOSAL REQUIREMENTS
To make a better determination of the waste hauling service requirements that are actually necessary even before compaction, first calculate how many cubic yards of dumpster capacity is being charged for during a given period of time (such as each week). For example, if you have an 8 yard dumpster and it is being tipped 3 times per week, this would equal 24 cubic yards of capacity each week. Next, calculate (approximately) how many gallons of trash are being disposed of (in the dumpster) from business operations prior to each pick-up (or for the same relative time period). For example, if you utilize 30 gallon bags of trash and you have 3 employees who each dispose of 5 full bags per day on weekdays (15 bags per day, and 2 full bags for each of 3 employees on both Saturday and Sunday (6 bags per day each), then that would equate to 15 bags x 5 days equals 75 bags, plus 12 (6 bags x 2) for a total of 87 bags multiplied by 30, for a grand total of 2,610 gallons of trash. Then by dividing the 2,610 by 202 gallons (see above) this equals 13 cubic yards or roughly half of the capacity being ‘tipped’ each week. Therefore, this would be indicating that, on average, the dumpsters are half empty with each tip or pick-up.
It is a good idea to make a practice of spot-checking the amount of empty dumpster space during dumpster pickups. The objective is to maximize payloads whenever feasible, versus having the waste haulers arrive when there is a lot of empty dumpster space. Many ‘pickup’ schedules do not fit the needs of the customer and this process will help determine the waste hauling requirements more reliably on a monthly or seasonal basis. The main objective is to try to end up with maximum payloads, meaning full dumpsters of compacted trash, versus frequent ‘tips’ of loose, non-compacted dumpsters with a lot of space.
To estimate the savings that could possibly be derived by adding a compactor for processing compacted waste versus loose waste, simply estimate the compaction ratio or volume reduction capability of the equipment and then divide the total loose trash being processed by that factor. Usually the equipment vendor can supply the compaction ratio (or volume reduction ratio). For example, if the equipment vendor indicates that the compactor typically achieves a 4 to 1 reduction ratio then in this hypothetical example above it would mean that the 13 cubic yards of actual measured waste (that is being discarded each week) would actually be reduced down to about 3 cubic yards (of compacted waste). So after determining the total amount of loose waste being generated each week it is just a matter of dividing by the compaction ratio for the specific material being processed. It is important to determine the compaction ratio (or reduction ratio) of the specific material being processed because the same equipment will not process all materials at the same reduction ratio. It is fairly obvious that kitchen food waste or dining area trash would be much easier to compact (reduce) than Plastic Bottles.
Basic Components of Waste Hauling Costs
A. Volume / Service Frequency related charges (for the tips / pulls of containers)
There are two basic types of service charges: ‘Pulls’ (in which the container is hauled to the Waste Disposal Facility for emptying) and On-site ‘tips’ in which the hauler tips or empties the container on-site into the hauler truck. Whenever possible (to the extent the waste volume will allow) it can be advantageous to use the smaller dumpsters that are tipped on-site in lieu of the larger dumpsters that are hauled away for emptying.
B. Weight Charges – Generally, the weight charges are applied to the larger containers that are hauled directly to the waste disposal facility. Dumpsters that are tipped on-site usually do not incur a weight charge. Weight charges are applied per ton of waste and are in addition to the Pull charges.
C. Dumpster / Container Rental Charges – Typically there is a monthly fee for use of the haulers dumpsters and containers or other equipment.
D. Miscellaneous Incidentals – Overflowing dumpsters / containers, restricted or difficult access to the containers (or in and around the premises) as well as other variables can increase the haulers time and resource requirements for handling the account, which can result in extra charges.
E. Labor Requirements – Depending upon the waste volume, placement and number of the containers and dumpsters, unnecessary labor can occur as a direct result of mismanaged waste hauling schedules and routines. This in addition to the labor required for transporting the waste generated from the business to the dumpsters and containers.
TRASH COMPACTORS CAN BE THE DRIVING FORCE BEHIND
HUGE SAVINGS AND INCREASED EFFICIENCY IN THE AREA OF WASTE PROCESSING.
By applying some basic principles, the benefits of compaction and the positive overall effects on business operations can be realized. Oftentimes, there are numerous other operational efficiencies that can result from the benefits derived from streamlining the waste processing routines. Aside from the many operational efficiencies when using compactors (especially the automatic compacting receptacles and indoor compactors) there are also benefits related to sanitation (inside and also around the dumpsters, including rodent control); risk management (reducing the chance of back door robberies due to late night trash runs); reduction of fire hazards (by reducing the amount of trash temporarily stored while awaiting dumpster trips by employees); pilferage (i.e. dumpster trips are usually excellent opportunities for pilferage); general appearance (cleanliness), as well as many other considerations.
By carefully evaluating various details, waste processing routines can be maximized for efficiency both from a labor productivity standpoint and a waste hauling standpoint. There are substantial labor productivity gains and cost savings that can be derived by using Compactors (and other Waste Handling & Recycling Equipment) to streamline waste processing activities. And by understanding natural tendencies or incentives of waste haulers (much like other trucking companies that are in business to haul products) it is easier for the business manager to understand why and how they must be armed with the right information for reducing costs. There are, of course, many waste haulers who want to help customers save money (just like any other industry) but there are many who resist the use of compactors since it reduces service requirements.
One of the first steps for reducing waste hauling charges is to request (or derive) a detailed breakdown of waste hauling costs (before implementing compactors). This information can be used as a basis to derive the appropriate reductions in charges that should be applicable. Most haulers forward ‘lump sum’ invoices which means customers have no idea how they are being charged. But for example, if you know that you are being charged $50 per ‘tip’ and you reduce the ‘tips’ by 5 per month, then theoretically the appropriate reduction in services would translate into a savings of approximately $250 per month. However, it may be prudent to seek reductions of less than the ‘translated amount’ so that the hauler is more receptive to the reduced services. In addition to the ‘tip’ or ‘pull’ fees and any disposal (or landfill) costs, there is usually a small rental charge each month for any dumpsters or containers provided by the hauler.
In effect, by not taking advantage of the benefits of compactors whenever possible, it is basically the equivalent of the waste hauler picking up many empty dumpsters each month. And, the customer still pays for those empty pickups.
As mentioned above, oftentimes waste haulers will try to discourage the implementation of compactors. This includes the threat of excessive weight charges, heavy surcharges or a different pricing scheme (even low volume customers). Customers are often told that the extra weight at each pick-up will tear up the haulers truck or that it will cause them to go over the highway weight limits. These and other deterrents are a separate subject matter, however the main point is that customers are entitled to know (and should know) exactly how they are being charged (via itemized breakdowns) regardless of whether or not compactors are involved. A very basic premise to keep in mind is that on a ‘month-to-month’ or ‘week-to-week’ basis, the overall weight of the trash flow is not going to get any heavier just because compactors are implemented. (i.e. a location generating 6,000 pounds per month before compaction is still going to generate 6,000 pounds per month after compaction). The thing that will change is that the customer’s waste hauling requirements will be reduced considerably. Approximately 75% - 80% of waste hauling charges / revenues (and profits of course) are rooted in transportation (pickup & hauling) versus weight charges attributable to disposal (landfill) costs. Disposal costs (such as landfill weight charges) can be easily verified as to competitiveness and fairness based on the average rates in the area. Again, by knowing (for example) the cost per ton that is being charged for landfill costs, it allows the owner / operator the opportunity to back those costs out of the equation in order to determine what everything else is costing for trash pick-up. And, the bottom line is that ‘fair trade’ implies that a reduction in service justifies a comparable reduction in charges.
As an awareness develops with respect to the waste stream and waste processing activities in general there will be many areas where savings can be evaluated and derived with greater ease. For example this could include reductions in waste volume and waste hauling resulting from compaction and densification, reductions in waste weights resulting from a greater percentage of the waste stream being recycled or reused, reductions in labor resulting from much less handling of waste, and better utilization of waste and recycling equipment as the efficiencies begin to increase exponentially.
As it relates to the areas of waste management, there are many other types of Waste Equipment & Recycling Equipment that are available. For example, a few of these products and resources include Balers, Shredders, Grinders and Densifiers. Balers are quite useful for baling cardboard, plastics, metals and other materials as a means of removing certain recyclable materials from the waste stream. Shredders and Grinders can be used effectively not only for waste processing benefits, but also for security benefits, such as destroying sensitive documents as well as credit cards, passports, Hard drives, Tapes, CD’s and other such items that involve security concerns.
With the right understanding and approaches, customers can achieve the operational efficiencies and the waste processing reductions that they deserve. In addition to being able to streamline labor productivity and waste processing routines, customers can also maximize the benefits and savings that are available to them in the area of waste disposal and transportation.
EndBy Matt Kennedy - Contributor / Author
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