Landfill & Waste-to-Energy Facts
In the words of Joe Friday, Jack Webb's on Dragnet: “Just the facts ma'am." That's what you are about to get – facts and more facts.
My offering is not hindered by election results, room size, or even global warming (in this scenario quality of facts is more important than room size). This column was to appear in conjunction with Frederick County Commissioner Kai Hagen’s presentation, which has been delayed once again, this time to November 18. I realize he may have nothing to do with this one particular delay; but how about the half dozen or so prior to this one?
1. Frederick County has only one active landfill, which is known as Site B (at Reich's Ford Road) which, as you may recall, was once a part of the William Schrodel farm. The Site A landfill and old rubble fill have been closed and cannot receive any additional waste.
2. Landfill capacity is determined by its disposal volume, not by weight (tons). The county uses tonnage to account for incoming waste because it is easier to weigh trucks than it is to calculate their delivered waste volume.
3. Since December 2005 most of the solid waste delivered to the Reich's Ford Road disposal facility has been transferred to out-of-state landfills; a small amount (approximately 50 tons per day) has been landfilled in Cell 3 of the Site B landfill.
4. Incoming solid waste tonnages vary from year to year based on the economy and the tipping fee charged by the county. The better the economy, the more waste received. The higher the tipping fees, the less waste received. This is typical of most solid waste disposal facilities.
5. Incoming solid waste tonnage values also vary significantly on a day-to-day basis. Landfills, transfer stations, and Waste-to-Energy (WTE) facilities must be sized to accommodate these normal variations in the amount of incoming waste.
6. Using the current Site-B permitted landfill airspace, including the recently approved (May 2008) vertical expansion permit, the Site B landfill has remaining capacity of approximately 3,229,615 cubic yards of total volume to receive waste, including the dirt which is used daily for intermediate and final cover. This result is an approximate solid waste (trash) capacity of 2,648,284 cubic yards, or approximately 1,536,000 tons of disposal capacity.
7. Using calendar year 2007, incoming waste tonnage (221,552 tons), assuming no increase in population and no change in the waste generation/disposal tonnages received at the Reich's Ford facility, the remaining Site B landfill would provide approximately 6.8 years of capacity if all incoming waste was sent to the Site B landfill (no transfer).
Without the recently approved vertical expansion, the Site B capacity would have provided approximately 2.5 years of capacity if all incoming waste was sent to it instead of most of it being transfer to other jurisdictions. (Note: In this example escalating the annual waste tonnages based on population growth as done in # 11 below would result in a shorter total life for Site-B if all waste was disposed of in Site B.)
8. WTE facilities reduce the volume of the combustible waste by 90%. Therefore, for every 10 cubic yards of waste processed in a WTE facility, only one cubic yard of ash is produced. The ash has a higher density than the trash. However, landfill capacity is based on volume, not weight; so, solid waste processed at a WTE facility and turned into ash requires only 1/10 tenth as much landfill capacity as the same waste directly landfilled. Note that the ferrous and nonferrous metals in the WTE ash is recovered for recycling before the ash is sent to the landfill.
9. So, if the existing landfill with the vertical expansion will last 6.8 years with the direct disposal of trash, one might conclude that it would last 68 years if the waste was first processed at the WTE and reduced by 90%.
Obviously the planning period of the waste disposal project is several decades; so, population growth and the resultant increase in waste generation must be included in the evaluation. Also some of the waste that the landfill receives is not combustible, such old brick, broken concrete, and even contaminated dirt. These materials, which make up a small portion of the total solid waste stream, still need to be disposed of in the landfill or recycled. We believe that by 2012 most, if not all, of this noncombustible waste will be handled using recycling services. In fact a contract to recycle a portion of these materials will soon be brought to the Board of County Commissioners for its approval.
10. Another factor that must be included in the discussion of ash disposal air space in a landfill is the fact that the dirt used in normal landfill operations is not needed if you are landfilling ash. Ash is approved as daily cover; so, even if you have noncombustible materials that have to be landfilled, the ash can be used as daily cover instead of dirt. Thus, almost 100% of the landfill volume is available for ash disposal unlike trash which requires daily and intermediate soil cover, thereby decreasing the amount of volume for actual waste disposal. This yields more volume available for ash disposal than for trash in the landfill since the ash takes the place of the cover dirt.
11. Assuming that all but 50 tons per day is transferred to other landfills until a WTE facility is available to receive the waste (estimated 2014-2015), population growth (and corresponding waste generation) trends follow MDP projections, and we achieve our 60% recycling goal by 2024, we have estimated that the existing landfill will last until 2056.
12. Contrary to what some have suggested, the WTE does not need to operate at full capacity from the day it is placed into service. The 1,500-ton-per-day regional WTE currently being considered – which would serve Frederick and Carroll counties – would provide Frederick County 900 tons-per-day of firm capacity and Carroll County 600 tons per day. Each county would dispose of their proportionate amount of ash.
13. Using the same projections cited above, we need to achieve a 60% recycling diversion rate to continue to have enough WTE capacity to meet the needs of the growing Frederick County population. The excess capacity that will be available in the early years of the WTE operation could be used to generate additional electricity and tipping fee revenues if the commissioners wanted to keep solid waste disposal costs at their lowest possible level. This would require allowing waste from other counties – such as Washington or Howard County – to be processed at the facility.
14. As an alternative, the county could also consider processing its old waste (stored in the Site B landfill) which would increase WTE electrical revenues, but would also have the effect of extending the Site B landfill capacity even further. Removing the old waste (fuel) and combusting it at the WTE facility, and only returning the ash from that waste back to the landfill, could result in the recovery of significant landfill capacity extending the 2056 projection by decades.
15. Has this been done before? Yes. Lancaster (PA) County Solid Waste Management Authority did this in the early 1990s. What was learned from their experience? It’s important to minimize excess dirt in the original landfilling operation if you are planning to recover old landfill capacity.
The county is already looking at how we can do that at the Site B landfill so that this option will be available in the future. Frankly mining your local landfill for fuel may be commonplace in the future as energy costs and waste disposal costs increase.
Please keep in mind that projections can change if actual conditions change. For example, less increase in population over the next few decades would result in longer landfill life for ash disposal. Failure to achieve a 60% recycling rate may shorten the landfill life if excess material needs to be landfilled if the WTE is at its capacity.
I hope this information is helpful. I've discussed many of these items with individuals over the past years but this might encapsulate it better for back and forth reference when comparing concepts offered by others with no facts or backup material. So many times an abundance of words doesn’t help but rather camouflages half-truths and wishful thinking.
Here are some links that you may also find helpful.
’til next time . . .