About that Contaminated Soil at Camelot Landfill

A couple of notes regarding the comment "State regulations require that MSW operators cover the working face each day with a 6" layer of clean soil. This works to reduce odor, and cut down on rainfall entering the waste pile." State regulations require MSW operators to use a daily cover, but their options are not limited to 6" of soil, nor does it have to be clean soil when they use soil.

It all depends on what is approved in their operating permit, including temporary aprovals. Other options range from spray-on "Biocover" to filter cake (a byproduct of raw water treatment) to foundry sand to coal combustion bottom ash to slag and so on. Even reusable and non-reusable geosynthetics tarps are an option (my personal favorite is the Tarpomatic -- seriously, that is the actual name). It is up to the state to approve a given material at a given site. But as I pointed out before, use of contaminated soils is fairly common at landfills.

Also, as I pointed out previously, the use of daily cover addresses multiple concerns – not just odor and rainfall. It also is used to control runoff direction, airborne trash, and scavenging and disease vector pests (birds, rats, flies, etc.). But the most important concerns addressed are (1) to minimize moisture entering into the landfill, and (2) fire control.

While most people think of a landfill as a "dump", it is far more complex in design. Perhaps the biggest surprise to most people is that there is no desire to set up an environment where garbage can break down chemically or biologically. By design, it is not a compost heap in any sense of the word. Any moisture entering the landfill will ultimate percolate to the bottom, picking up chemicals along the way.

This product is known as leachate. An ideal landfill would have none, but that is an impossible goal. For one thing, some moisture is inherently present in the trash itself. But keeping additional water out of the landfill as much as possible is critically important to minimizing leachate, because leachate is the mix that potentially contaminates groundwater beneath the landfill. For that reason, daily cover serves a key role in controlling rainfall runoff by helping it stay at or near the surface as much as possible. Runoff is then collected in a channel around the base of the landfill. Because the runoff should be very low in contaminants, it can be treated by a sewage treatment plant.

Fire control is also critical. I wrote about it previously, but it is worth mentioning again. A landfill that catches fire is similar to a coal mine that has an underground fire. The fire can go on for decades. Needless to say, this would be a disaster for a landfill. By keeping the exposure area during the working day small, and covering that patch, the risk of fire from equipment spark, waste compaction, human error or even lightning is greatly limited.

So if using contaminated soils as daily cover is not unusual, why should Camelot be viewed any differently? Again, if you look back at my previous posts, you will see that there are several reasons to be concerned. For starters, the EPA has designated Denton County as a "serious nonattainment" zone, and we are under significant pressure to clean up our air.

As a side note, for the last three years, the American Lung Association has given our area a score of "F" and ranks the DFW area as "12th worst air quality in the country for ozone". Do we really want someone not just accepting and containing petroleum contaminated soils, but then spreading them out in a thin layer where the contaminants can and will exit the soil and either enter the leachate or escape into the atmosphere? This is the total opposite of what we should be doing to clean up our air.

But it is the other concern that I wrote about that should be equally troubling: the impact of using contaminated soils in a landfill that is separately requesting a massive expansion and has a history of groundwater contamination when it should all be considered as one single request. It should not be piecemealed, attempting to get approval for contaminated daily cover under one shell while attempting to expand the landfill hides under another. TCEQ should force Farmers Branch to submit this as one request, so that the whole of the impact can be considered in one comprehensive evaluation.

Don't forget: this landfill sits literally on the banks of the Trinity River. Any failure to control contamination to the enviroment could be incredibly catostrophic. That failure could potentially go undetected right up until it is too late to undo.

-RNeil

P.S. If anyone is itching to learn more about ADCs and regulations, the starting point is Subtitle D (yes, THAT Subtitle D you have been hearing about) of the Resource Conservation and Recovery Act, Title 40 of the Code of Federal regulations: “Protection of Environment,” Chapter I—Environmental Protection Agency, Subchapter I (Solid Wastes), parts 239 - 282. ADC in particular is Part 258, Subpart 21. However, I won't claim it makes for entertaining reading.

Short, paraphrased version of everything above

Original Post
Talked to a guy from the TCEQ. The guy said contaminated soil may not be as bad as it sounds, and it has to go somewhere. The contaminated soil is already at the Camelot landfill in its own section, and Farmers Branch wants to use it as daily cover. So it may not be all that terrible, but we should be careful.

Councilman Ferguson's Comments
The law isn't very clear on the issue of daily cover, but there are a lot of ways to do it. The process also serves a lot more purposes than the ones Steve listed. Landfills are complex structures, and they leak. There are other concerns, like fire safety and air quality. Denton County air sucks. The two permits, one for the expansion, the other for contaminated soil, should be combined. If anything goes wrong, everybody will be up a creek in more ways than one.

-BC