Thoughts on Landfill Mining and Solid Waste

The Denton Record Chronicle published an article on Saturday, September 9 titled “Denton officials investigating garbage dump operations: Landfill mining ends before it starts”.  Read the DRC article for context if you have not already, and then read through the analysis presentation that is being discussed by our Public Utilities Board on Monday.

At this point in the process I do not know what the ultimate fate of our landfill mining operations will be. There are some questions and concerns with the operations – in particular the cost benefit analysis which led to the program’s creation – that need to be looked at closely before we move forward. This is a process, and the process needs to play out. And it needs to play out in public work sessions of the Public Utility Board and City Council, as it will.

The Municipal Solid Waste Management Magazine (MSWM is the official trade publication of the Solid Waste Association of North America) published an article from August of 2016 that appears to reinforce some of the emerging concerns regarding the original cost benefit analysis which spurred our council to green-light our landfill mining operation.  In particular this MSWM analysis points to a best practice of not anticipating any financial value (significant revenues) from the recyclables that are recovered from landfill mining when conducting a cost benefit analysis.  These MSWM findings indicate that those recyclables either won’t be of value at all, or are of a monetary value in the market that will be lower than the cost to extract and process them.  According to this research the real value of landfill mining appears to be in recovering significant amounts of soil from old landfills, which if clean and not toxic, can create more space for future landfill operations and be reused in the landfill more efficiently.

This piece from MSWM is just one analysis, but it reinforces some of the emerging questions about the landfill mining project which should give us pause.  There can be value for sure in creating more “air space” in our existing landfill cells.  But that value is dependent it seems on how much soil we believe we will recover, how we are going to handle the storage and re-disposing of the waste we are mining (we will likely fill up our existing active landfill cells at a much quicker rate throughout the years of this mining process), what hazardous materials we will encounter and how we will handle those with people and technology (asbestos, chemicals, sludge, etc.), and how much remediation we will have to do (gasses, odors, toxic soils, toxic liquids, etc.).

When this project was originally presented to council it was a slam-dunk win/win that I think a lot of people (citizens and city leadership) felt great about.  But now that I am seeing this report which warns against including the resell of recyclables into the cost benefit analysis of a landfill mining project and knowing that we did have that element factored significantly into our original cost benefit analysis…. and not only did we have it in there, but according to the report being discussed by our PUB on Monday which includes some stark revised projections for the mining revenue projections… it appears that those mining revenues from the resell of recyclables were grossly overestimated to the tune of roughly $13.5 million dollars. To say that I am uneasy about this prospect would be an understatement.


We allocated significant money (~$4.5 million) to this project based on the original cost benefit analysis presented to council. I would hate to find out that the information we were provided was incorrect or flawed.  But if it was incorrect or flawed, we have to decide if there is any possible way for this project to be of significant public and/or environmental benefit.  The recycling of materials sounds good on the surface – it truly did, and still does to me – but considering that many of the recyclables won’t be accepted by the market (meaning they will be unacceptable for reuse and returned to the landfill) and those that are accepted for reuse by the market appear to be worth half as much per ton than we were told in the original cost benefit analysis… the real value of the landfill mining project appears to be purely based on how much soil we can reclaim, what condition that soil is in, and how much hazardous waste we come across.

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The Current Analysis shows a Net Loss of $14M and tells a completely different story than the Original Analysis which showed a Net Benefit of $16M.  This is clearly cause for pause on our landfill mining operations. Each of these analyses need to be scrutinized thoroughly before taking any aciton.

Important questions that should be asked as our Public Utilities Board reviews the landfill mining project prior to any eventual council discussion and consideration:

  1. So what hazardous waste is in our landfill, how much of it is there, and where it is buried?
  2. How much soil do we anticipate reclaiming from our old landfill cells… put another way, what percentage of our landfill cells are waste and what percentage are soils that could possibly be reused?
  3. Once we completely mine an old landfill cell, are we going to need to re-line it to meet current landfill standards/regulations and were those costs correctly factored into the original cost benefit analysis?
  4. Is the condition of our old landfill cells such that they need to be excavated and relined and remediated anyway in order to comply with federal and state regulations?

I know that if this project were brought before council today, that it would be met with a much higher level of detailed scrutiny based on recent experiences and revelations with other projects across the city. At this point we have committed (and apparently already spent) significant dollars to this project.  If we are truly in a situation where going forward with landfill mining would just be throwing more and more taxpayer dollars down a hole without appreciable benefit then the right thing to do would be to back out of this landfill mining exercise and minimize our losses.  But that would be an extremely hard loss. Or maybe, there is still a need and public benefit in this project that should be evaluated. For that reason it is important for us to critically review in microscopic detail the assumptions in both the revised cost benefit analysis, as well as the original cost benefit analysis.  Whatever we decide to do, we need to make sure we are extremely transparent in the process and reasoning behind our decision(s), as well as make it clear to all what verification processes and accountability are now in place (and I believe that real improvements have been made in our auditing, purchasing/contracting procedures and policies) to assist this council or future councils in making the best decisions for the long-term benefit of our community.

I consider myself one of the most, if not the most, environmentally sensitive members of our council. I want programs in this city which increase our sustainability and make our community good stewards of our land and and in this world. But we have to make sure we are doing the right things the right way.  To learn that there may (and I stress at this point, may) be significant flaws in the information that was presented to council leading to the allocation of millions of dollars to this landfill mining operation is concerning and should not be taken lightly.

Please let me know what concerns, questions, and ideas that you have.

Your humble representative,

Keely G. Briggs – Denton City Council, District 2