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Posts Tagged ‘construction waste management’

Reuse reflection

Wednesday, October 27th, 2010
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Right or wrong, I feel that I own bragging rights to the amount of reclaimed lumber we’ve used on our sustainable rehab.

In all, I estimate that I purchased about 5% at a regular home improvement store or lumber yard. Those were specialty items, such as cedar trim or treated lumber. The remaining 95% is all reclaimed, whether from our deconstruction process or purchased.

So – how did it work out – the handling of reused framing material? Well, I learned a few things along the way.

  • Always purchase the lumber at least 6 inches longer that what you really need. It is pretty common to have split or perforated ends that you need to cut off. Even if the ends are sound, they may need to be squared off.
  • Working with reclaimed lumber involves a lot of cutting, as the note above implies. It is safe to assume that most pieces require a cut at both ends. Contrast that with new lumber that may not require any cutting at all, such as a pallet of 8 foot studs for an 8 foot wall.
  • Reclaimed lumber is usually carefully de-nailed. Still, it is advisable to watch out for remaining nails, screws and staples. You hit one of those with the circular saw, and you will need to run to get a new saw blade.
  • Pay attention to the lumber dimensions. Take studs for instance. Today they measure 1 ½ by 3 ½ inches. Reclaimed studs from older buildings are typically bigger. I have found true 2 by 4 inch old growth, as well as 1 ¾ by 3 ¾ and 1 5/8 by 3 5/8 inch studs. It’s a good idea to match material dimensions.

stud-dims

  • I always check to see if the material is bent or warped. That is for salvaged materials as well as for new studs.

Some of the older studs are good quality, hard wood with dense growth rings. The disadvantage, if you will, is that they are also heavier to haul around. Some of the material is so hard that it is difficult to sink a framing nail or even a screw without pre-drilling. I think sturdy is the word that I am looking for…

I think it is fair to say that it takes more time to handle and prepare reclaimed lumber. But it doesn’t outweigh the fact that this is material that otherwise would have been destined for the landfill, and you can purchase it for cheap!

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Where did all the concrete go?

Wednesday, December 30th, 2009
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I hope you enjoyed the last post about the basement floor removal. We had fun swinging the sledge hammer busting that concrete floor. It ended up to be a lot of concrete!

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What did we do with it – other than throwing it in the back of my truck?

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While researching Construction Waste Management (CWM) options, I compiled a list of various recyclers. I found my go-to places for deconstruction debris (WasteBox, Inc.), scrap metals and clean wood debris (which is turned into wood chips).

A few weeks back, when I was getting masonry supplies for the parapet repair at the Illinois Brick Company on California, just north of I-55, I noticed their neighbor across the street, Lindahl Brothers, Inc. They have a huge pile of old concrete in their yard, which was the give-away that they run a concrete recycling facility.

Mine and any other concrete received is crushed, sorted and sieved, turning it into aggregate that can be re-used in construction. Eventually I will need some aggregate for the new basement slab. If I get my materials here, I may end up re-using the very concrete that we removed.

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As prices for scrap metal fluctuate, so does the cost for recycling concrete. If nobody is buying the aggregate, the concrete pile gets bigger and the cost for dropping off concrete for recycling goes up. If the aggregate ‘flies of the shelves’, you may even be offered a buck to deliver your concrete for recycling.

I was very happy to get charged as little as $15 per truckload. It made the whole operation rather affordable.

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From jungle to scrap yard

Sunday, November 22nd, 2009
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The radical clear cut through our utility jungle made me feel really good – maybe because of the radical and liberating nature of the work. The clear cut left us with a big and very heavy pile of truncated pipes and fittings, now merely reminiscent of the formerly impressive utility jungle.

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As part of the overall construction waste management (CWM), all cast iron, ferrous and nonferrous piping, as well as wiring was separated and is destined for the scrap yard.

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We repurposed our pickup truck for the day to haul the ferrous (and not so ferrous) harvest to the scrap yard for its final milling?

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A nice side benefit of this ferrous management work: It generated enough income to pay for two tanks of gas for the truck.

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Insulation – which material cuts it?

Monday, October 26th, 2009
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If you have followed the previous posts about the insulation conflicts and moisture management issues, you may ask why not go simple – skip insulation altogether and just have brick wall exposed on the inside. A very tempting thought, isn’t it? It would look pretty good and we could avoid all these problems.

But we also would create a big problem. A three wythe (or 12”) thick brick wall may have a R-4 value. The air film on the wall would give me another R-1, totaling R-5. That is if the brick is dry. If it is wet, these values will drop. A decent window may have a better R-value than the brick wall! We need good insulation, if we want to have a decent shot at our zero-energy goals.

There is quite a variety of materials to pick from, starting with the very common fiberglass batts, the more expensive rigid foam boards, or materials with high recycled content such as blown-in cellulose or recycled cotton batts.

Understanding the limitations and opportunities that come with our masonry shell, and having distilled two key principles, the choice actually narrows to just one material: blown-in foam insulation.

“A low[…] risk approach to interior masonry retrofits that has been used for several years involves spraying an airtight insulating foam directly to the back of the existing masonry [shell].”

Reference: Building Science Digest 114 (Interior Insulation Retrofits of Load-Bearing Masonry Walls in Cold Climates)

Also known as spray polyurethane foam (or in short: spray foam), it would eliminate air gaps and air leakage if applied across the entire interior shell, including the roof. Basically, it would give us an airtight building envelope and act as a moisture barrier (or vapor retarder) helping with the control of incidental rain penetration.

A Building Science publication (Building Science Digest 114) explains spray foam rationales and choice in detail and is worth while reading.

Because spray foam is semi-permeable (a vapor retarder but not a vapor barrier), it will allow moisture in the masonry shell to diffuse to the outside and in. I have to make sure that the perm rate of the entire interior wall assembly is greater than 1 – and we are all set!

There are two kinds of spray polyurethane foams out there:

Closed Cell

As the name suggests, each little cell (or bubble) encloses an air pocket, forming a monolithic airtight layer at an R-value of around 6.5 per inch. Most closed cell spray foams have a density of about 2 pounds per cubic foot (pcf) and have a low diffusion or perm rate (around 1 to 2 at 1 inch thickness).

Open Cell

This foam is much lighter at a density of 0.5 pcf and forms more of a web structure. It is still considered airtight if applied at a depth of several inches. The R-value for open cell products hovers around 3.5 per inch. Water vapor can diffuse freely through the material.

The one disadvantage of spray polyurethane foam that is often mentioned is cost. And yes, it is much more expensive than your typical fiberglass batts – closed cell more so than open cell, because it requires more material. Plus, it needs to be installed by a trained professional.

  • 6” of fiberglass batts (around R-19): $0.30 to $0.60 per square foot (material only)
  • 6”of open cell spray foam (around R-21): around $2.50 per square foot (material and labor)
  • 6”of closed cell spray foam (around R-39): $5.00 to $6.00 per square foot (material and labor)

We would pay more – and that is fine – because we will get more. With spray foam, we don’t have to worry about air leakage, condensation and potential mold problems, or diminished R-values. Instead, we get the airtight building envelope we need, and lasting R-values. If we would try to accomplish the same results with cheaper insulation materials, we probably would, in the end, pay as much.

A drawback that I still debate is that spray polyurethane foam is a petroleum based product. The good news is that most spray foams are now VOC (volatile organic compounds) free, using water as their blowing agent. Some products are marketed as green because of some soy based oil content. That overall content is, however, relatively small, plus I am not sure if I would accept soybean farming as a sustainable practice.

Another unanswered question that keeps me pondering has to do with the end-of-life use. There is no known recycling option or second use for this material. If the spray foam ever gets torn out, it is likely to end up in a landfill. The only conciliation I have is that it should serve and maintain its performance for several generations.

More info on spray foam:

What is:

Air barrier

Moisture barrier: See references below to vapor barrier and retarder.

Vapor barrier and vapor retarder

Additional resource: Consumer’s Guide to Vapor Barriers at the U.S. Department of Energy

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What to do with the carpet?

Saturday, August 15th, 2009
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We got around removing all the old carpet from the building (see also 08/11/2009 post). Some of it was pretty icky – and I am diplomatic here. Take the second floor for instance. Some kind of pet must have lived there. Whenever we walked upstairs, even on moderate warm days, we were greeted by a stinging and unpleasant smell. The carpet had to go!

But what are we going to do with it? Just throwing it into the Dumpster did not seem right. Reusing it was out of the question – or was it?

I recalled a discussion with my friend Bill Wilson from Midwest Permaculture. It was about alternative methods of weed treatment, and how you can use old cardboard to smoother and suffocate weeds. We have a lot of weeds in the yard. I don’t have cardboard, but I have the old carpet!

covering the weeds with the old carpet

The rest is history. I cut the carpet into fitting pieces and rolled it out in the yard, covering the weeds up.

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Now remember, I am a landscape architect, and this is what my front yard currently looks like. I see a lot of raised eyebrows, head scratching and the expression “what on earth…” amongst my friends. Our neighbors are more relaxed and eager to ask what the carpet is all about.

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It doesn’t take many words. I just need to roll back a corner and they immediately understand what I am up to. Resource efficiency is part of their daily lives. I am just happy that I got one more use out of the old carpet, before it goes to waste at the end of this season.

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A trashy decision

Wednesday, July 29th, 2009
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I have this major battle going between diligently separating my construction and demolition (C&D) waste (see also 07/12/2009 post), or to give in and start comingling it like everybody else does and have it recycled later (see also 07/17/2009 and 07/25/2009 post).

When asking around to why we (in Chicagoland) don’t separate our C&D waste, the predominant opinion is that the contractors don’t want to deal with it. Hello! Any contractor out there who disagrees? I’d like to hear from you!

I do know that contractors on out-of-state projects do separate their materials on site and that it does work well (see also 07/17/2009 post). And think about it. These are smart people who have to schedule, organize and coordinate complex construction operations. This takes a lot of skill and assuming that they can’t handle a simple task such as C&D waste separation seems – let’s say, unreasonable.

So, what do I do with my C&D waste and where do I go from here with all I recently learned? I will stick to my guns and continue with the separation process I started (see also 07/12/2009 post), because the effort is not in vain. I went over the logistics with my waste hauler (Kevin from WasteBox, Inc.) and determined that we create some efficiency after all.

I understand from my conversations with him that I am somewhat an exception. Not all customers are as diligent (or nerdy) with their separating of materials, and so Kevin must sort through the Dumpster loads and recycle in his yard.  He has visited and seen my operation (and obsession) and has the confidence that I don’t mix or hide materials in the bottom of a container.

When I have a clean, single material load, such as drywall and plaster only, Kevin can transport the material directly to a transfer station without going sieving through the materials searching for recyclables. A load of “clean” wood that I collected, such as all the wood lath, can go directly to a wood recycling facility, eliminating the double handling of materials and reducing the cost for that Dumpster load.

Why should I throw metals or old electrical cables into the bin, if I can put them into the back of my truck, bring them to a metal scrap yard and even get a few bucks for it? And why on earth should I give up the feel-good factor, all the fun and sense of accomplishment I get from my construction waste management adventures?  I’ll keep separating.

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A visit to the recycling facility

Saturday, July 25th, 2009
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In Chicago, we do things our way – we commingle our construction and demolition waste only to have it in some cases sorted, separated and recycled later (see also 07/17/2009 post). I still can’t get over this thinking that separating materials at the source (the construction site) would be so much more effective.

My friend Ted Krasnesky at Pepper Construction had the following advice for me:

“…I’d recommend you visit their [the waste hauler’s] transfer station and watch it [the recycling process] in action.”

Why not? Maybe this will put my mind to rest. I pitched the idea to Kevin Loeffler at WasteBox, Inc. (the waste hauler I use). He offered to come out to my project site to look at the construction waste management set up and advise me about the various materials and their processing, and also to arrange for a visit to the transfer station (or recycling facility) he uses.

Fast forward a week: Kevin introduced me to Joseph Volini at the Heartland Recycling facility where we got to tour the recycling operation. Joseph was generous enough to let me take some photographs for this blog.

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It all starts with a big pile of commingled construction and demolition waste. Yes, I was tempted to start looking for one of my Dumpster loads, but did not want to waste Kevin’s or Joseph’s time.

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Once we walked around the 1000 cubic yards of debris we got to the (mostly) automated recycling facility. Let’s follow the process step by step from the beginning.

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The debris is moved from the pile onto a large conveyor belt that transports it into the processing facility. Joseph indicated that a lot of recycling is happening right at this point. The key is to have a good equipment operator who has the skill to use the claws on the equipment like tweezers. Rather than dumping stuff indiscriminately on the belt, the operator carefully picks through the piles and pulls out any larger and heavier recyclables such as concrete, wood pieces, cardboard, metal, etc.

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What remains is transferred onto a giant sieve (to the right in the image above), where coarse and fine materials are separated.

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Anything smaller than two and a half or three inches will fall through the sieve and is transferred onto another conveyor belt (to the left in the image above).

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In that process, a large magnet pulls and collects the ferrous metals such as nails, screws, pieces of metal piping, etc. and dumps them into a collection container.

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The remaining fines are now largely free of ferrous metal and are deposited in a stall. Joseph explained that this material is mixed with the slush from catch basin cleanouts to solidify the material. It than is transferred to landfills where it is used as a cover material at the end of each day.

So much for the fine material. But what happened to the coarse stuff that did not fall through the sieve?

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A conveyor belt transports it to what Joseph called the mezzanine, where the manual separation takes place. The belt is loaded with materials when entering the processing area (see image above), but not much is left towards the end of the mezzanine (see image below).

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Along the belt are several workstations that are placed between chutes – the rectangular openings along the conveyor belt. At each station the handler scans the belt for recyclables that belong into his/her respective chute.

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The first material that is pulled out is non-painted, non-contaminated wood (also referred to as “clean” wood) that is thrown onto another conveyor and transported to a wood chipper. The chips sometimes enter into the landscape trade, but are more often used as bedding for animal feed stock.

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Next, cardboard and paper based waste is collected in a Dumpster under the chute…

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…followed by non-ferrous metals one chute over. The more valuable scrap metal such as copper and brass is not thrown down the chute but is actually collected in bins at the mezzanine level.

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Last but not least, chunks of concrete and other masonry pieces are collected. This is basically anything that can be recycled into road base or other aggregates.

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If we look below the mezzanine, we find the stalls that line up with the chute openings. The red equipment to the far right is the wood chipper, followed by the containers for the cardboard and non-ferrous metals and the stall for the coarse aggregate and masonry collection.

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The really sad part is at the very end of the mezzanine, where anything left that cannot be recycled or had been missed is dumped into a large trailer, destined for the landfill.

How much material is actually getting recycled in an operation like this? According to Joseph, between 65 and 70%. This number includes the fines that, after solidifying the catch basin slush, are used as a landfill cover. Joseph indicated that there is some controversy to whether this qualifies as recycling. It apparently does in the eyes of the U.S. Green Building Council, who prefers to see this material with its high waste content being used as a cover, rather than virgin soil.

Kevin (WasteBox, Inc.) explained that some Dumpster loads he hauls are directly transferred to the Heartland Recycling facility. This applies typically to single material loads, such as my plaster from the deconstruction.

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Commingled loads, Kevin continued, go to his yard first, where his crews empties the Dumpster to pull all major recyclables. It is a much simpler operation because WasteBox has not the amount of real estate that Heartland Recycling has.

Kevin indicated that he diverts up to 75% of the construction and demolition debris he receives. He can sell off the salvaged cardboard, clean wood and metal scraps, which helps him to keep cost down and pass the savings on to the customer (yes, that is me!) by keeping his Dumpster rates low. Most remaining items he cannot recycle are transferred to the Heartland Recycling facility.

I am somewhat impressed by the recycling operations and the amount of content that gets diverted from the waste stream. That said, I still cannot shake the impression that separating materials at the construction site is the more efficient way and could probably result in even more waste diversion. That is, however, an item that Kevin or Joseph cannot control. They do the best they can on their end. It would be up to the construction trade and contractors to separate materials before they get to the waste hauler.

I feel privileged to have had the opportunity to visit and learn about the recycling process for my construction and demolition waste. I would like to extend a heartfelt thank you Kevin Loeffler (WasteBox, Inc.) and Joseph Volini (Heartland Recycling LLC) for their time and patience.

WasteBox, Inc. (http://www.wasteboxinc.com)

Heartland Recycling LLC (http://disposall-waste.com)

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Construction Waste Management

Friday, July 17th, 2009
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Call me weird, but I have way too much fun organizing my deconstruction materials into re-use, salvage and recycle piles.  The waste avoidance and reduction process (see also 07/09/2009 and 07/12/2009 posts) is also known as Construction Waste Management (CWM) in the green building industry.

Chicago has an ordinance that requires the diversion of 50% of construction waste from the landfill. This ordinance applies to residential project with four or more units. The Chicago Green Homes program encourages a construction waste recycling plan that diverts 75% of construction waste from the landfill, exceeding the ordinance by 25%.

So – maybe my obsession and enthusiasm with re-use, salvaging and recycling is not so weird after all. But then, strange things happened.

I diligently separated all the drywall and plaster which cannot be reused or recycled and packed it into our 16 cubic yard dumpster. The dumpster was full to the rim.  I called our waste hauler (WasteBox) and they sent a truck out for pickup. Problem was, the truck was unable to pick up the dumpster – it was way too heavy. They had to send for a bigger truck.

I promptly received a phone call from Jodi (at WasteBox) asking me politely to make the next load less heavy.  Kevin, the owner of WasteBox, also followed up with me. He suggested mixing in some lighter materials (such as wood). But I was confused. What happened to the idea of CWM? What about separating to maximize all recycling opportunities?

Kevin explained that all dumpsters are going to a recycling facility for processing anyway. “That is where all recyclables are pulled out.” Is that for real? I have been working on out-of-state green building projects where the general contractor separated construction and demolition waste onsite, by having a dumpster each for cardboard, wood, metal, plastics, etc. Even a quick Google search leads to examples of onsite material separation.

Example 1

Example 2

Not so in Chicagoland, confirmed my friend Ted Krasnesky at Pepper Construction. It is typical to comingle construction and demolition debris and have it sorted at a recycling facility.

Fine, if this is how we do things here in Chicago, so be it. But it still doesn’t make much sense to me. It would be so much more efficient to separate materials at the source (the construction site) rather than at a recycling facility, and would eliminate all the double handling (and hopefully reduce cost).

I still like to keep my materials separated. But what I really like to know is how materials get sorted and recycled by the waste hauler or in the recycling yard.

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Separating materials

Sunday, July 12th, 2009
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If you have followed some of the recent posts, you will be aware that we are knee deep in the deconstruction process.  It is important to us to get this right, not only from a workflow perspective, but to minimize the amount of construction waste (see also 07/09/2009 post). To get there, we organize all deconstruction materials into four major categories and separate them accordingly:

Reuse

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You’ll be surprised how much materials are available for reuse if deconstructed, rather than just ripping things out. Cathy started with saving all the casings and trims (see also 06/02/2009 post), most of which are high quality oak, beautifully crafted and definitely something we’d like to put back. There also were some doors and associated hardware, electrical accessories, lumber such as old growth and nominal studs, and a big old heavy cast iron bath tub. Another treasure that we will reuse, or better said restore, are all the beautiful quarter-sawn wood floors. Reuse is high on the priority list as it keeps the items out of the waste stream and reuses the embodied energy. Reuse is as close to waste elimination as we can get.

Salvage

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I consider salvaging different from reuse—the next best option. These are items that we have but don’t need and which we plan to donate or resell such as some of the doors, light fixtures, cabinets, the original furnaces, radiators, and those windows that are still intact but which we will replace. Although they are slated for reuse by a new owner, I consider these items are a step closer to the waste stream.

Recycling

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This has become a big buzzword, but we don’t feel that good about it. I would argue that recycling is mostly downcycling and takes the material a big step closer to the waste stream.  It is the product of failure to eliminate waste. With reuse and salvaging, as described above, the material should not lose its original intended functionality or embedded energy. With recycling, it often does.

Did I just spoil your recycling enthusiasm? Here is the upside: at the least it allows us to keep materials such as clean wood/lumber, metals and concrete out of the waste stream and the landfill and give it at least one more purpose in its lifetime, such as woodchips, recycled metal contend in a steel product and road base aggregate.

Remaining, non-salvageable or recyclable waste

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This is the last and very sad category. No matter how hard we try, or which direction we turned or twisted it, there is no reuse and recycling for painted drywall, old plaster, and painted wood/lumber that we can’t otherwise reuse. And there is a lot of it, destined for the landfill.

I really like to finish this post on a positive note, but I just got my mind locked into that landfill thing again.

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