Ben Hillyer/The Natchez Democrat — Natchez waste water treatment plant lab technician Terrance Logan takes biosolids samples from the sludge drying greenhouse.

What a waste? Sludge nearly ready for sale

Published 12:01am Tuesday, December 20, 2011

NATCHEZ — The City of Natchez is stockpiling a load of sewer sludge in hopes of turning it into a load of cash.

Natchez City Engineer David Gardner said the city is currently collecting a large pile of the biosolid made from decontaminated and dried out sewage sludge at the Natchez Wastewater Treatment plant’s solar-powered greenhouse.

Once a large amount has been accumulated, it will be sent to the state Department of Environmental Quality for quality testing.

Gardner said a smaller sample of the biosolid made at the plant has already been tested by DEQ, and the plant received a Class-A certification, which means the biosolid can be used as organic fertilizer. He said the stockpile’s quality will be tested again to make sure it is up to standards.

Gardner said the city will then apply for a license from the Department of Agriculture to sell the fertilizer. He said the city could use the fertilizer itself or give it away without a license, but selling it requires the license.

The sludge from the plant’s sewage lagoon is dredged and then pumped to a belt press that presses out some moisture before being dried in the greenhouse. The robot aerates the sludge to help evenly dry out the material.

The biosolid stockpile, Gardner said, should be large enough by sometime this spring to be tested and then possibly sold as fertilizer.

The city could not only profit from the sale of the fertilizer, Gardner said, but it is also saving money by not spending an average of $200,000 each year to remove the sludge from the plant.

Instead, Gardner said, Natchez Water Works took out a $200,000 20-year loan from the state’s revolving loan program to fund the remaining costs of upgrades to the plant for the fertilizer program. The loan covered costs not funded by the $4.3 million in American Recovery and Reinvestment Act funds for the project.

Gardner said the city will pay $31,000 a year on the loan until its paid off in 2031.

“We’re only paying $31,000 versus paying the $200,000 we have been paying,” he said. “It’s a huge savings.”

The upgrades to the plant for the sludge-recycling program started in early 2010 and were completed earlier this year. The upgrades included the construction of the greenhouse and the installation of a mechanical filter system the sludge passes through.

The greenhouse also has a computer system that can manipulate weather conditions to speed up the biosolid’s drying process.

Water Works also bought a $15,000 used 18-wheeler truck approximately a month ago for the project. He said the truck transports the biosolid on a trailer approximately 100 yards from the filter press conveyor belt to be dried and stored in one of the two greenhouses.

Gardner said the city was renting a truck to use at the plant, and its purchase is saving money in the long run.

Water Works also received an award from the Mississippi Development Authority’s Energy Division in October for the fertilizer project. Gardner said the award was in recognition of energy reduction and technology used for the program.

“We’re just really excited about this project,” he said. “We’re saving a lot of money and turning a liability — the toxic sludge — into a beneficial use.”




  • Anonymous

    A Short History LessonGenotoxic Contaminated Compost from EPA to Your Lawn and Garden
    Sewage sludge compost is a biologically active solid waste composed of biofilms that include active and inactive bacteria, viruses, worms parasites as well as chemicals and the residue of treated sewage which includes nutrients and moisture (biosolids). The heat of composting removes moisture which dries (desiccates) bacteria causing them to go inactive (dormant). Studies have shown that bacteria may be reactivated up to one year after composting with the addition of moisture. Composted Class A sludge may also contain elevated levels of heavy toxic metals that would prevent it from being disposed of in a Part 503 surface disposal site. You may be exposed to unknown levels of chemicals, metals, and disease causing organisms which also may be taken up in vegetables.

  • Ham Bone

    Why not pay off the whole 200K this year? If we were already spending that much every year, then just take that money and pay the thing off.

  • Anonymous

    Darn!! You had a good thing going until you put this article in the paper. Now some thug is going to get someone to read it to him and then he will get his peeps from the hood and they will steal all your shi——–er, sludge. He won’t know where to sell it but you can bet if someone thinks they can make money on it and it is just laying around the thugs will steal it.

  • Anonymous

    Another way to move the pawns on the chessboard.  Also, could repair the roof on the depot, but this money has already been reallocated elsewhere in the recently passed budget, I’m sure. The term used by Obama/Congress is “kicking the can down the road”.

  • Anonymous

    This is probably a perfect article for this comment:

    SOMEONE in Natchez has been using my name to make phony comments on HER blog. Apparently no sane person visits HER blog … so SHE just cops innocent (in the generic sense of the term) other bloggers’ names and uses them to make it appear that someone is reading and commenting on HER blog. 

    No names, please … gotta protect the GUILTY.

  • Anonymous

    too much s— for me.

  • Anonymous

    A further aside, no mention of the potential revenues from selling stink.

    This stuff grows shrubs, I put some foot high hibiscus in “treated” soil some years back, less than 3 months later they were fascia high with beautiful flowers, just don’t eat them per other posts.

  • Suzie D


  • Anonymous

    Sounds like a load of crap to me!

  • Anonymous

    Yep and now the meth heads have a new ingredient for their meth soup, pre-decontaminated fertilizer.  Maybe the anti-government mountain dwellers can use this instead of A-N in their homemade fireworks.  They”ll really have some explosive sh— uh, sludge…

  • Anonymous

    There is NO mechanism for simply “paying off” a debt with municipalities….it’s all about how much money they have on hand and how they can spend it…no matter what their debt amounts to. Any savings are immediately “spent” in other ways faster than the taxpayers can be taxed. Its “spend it or lose it” mentality.

  • Anonymous

    Great idea…but if not fully treated to kill the bacteria…there is always an issue of liability.

  • Anonymous

    Another example of how Green House can help save the economy by making money from our waste. GOD’s plan in protecting his Earth:) while Man’s only ambition is Money?Power?.

  • Ham Bone

    So you’re telling me that we won’t see a tax decrease from the savings and any profit made from selling this stuff??????

  • Caroline Snyder

    Sewage treatment plants are not designed to create fertilizers. They REMOVE pollutants from the waste water which then CONCENTRATE in the resulting sludge or biosolids. Drying this waste in greenhouses or running it through digesters or filter presses inactivates most of the pathogens, but more robust pathogens can re-grow when the material is stockpiled.  Thousands of other industrial sludge  chemicals, some very toxic and persistent, REMAIN in Class A biosolids, which can not legally  be used to grow food that is certified organic.  Most consumers prefer clean soil amendments made from green feedstock and avoid buying material made from sewage sludge. However Natchez could still profit from this waste if it used it as an renewable source of non-fossil fuel energy. The conversion technology exists and is increasingly being used in Europe and even  some areas in our country. For more information, visit

  • Anonymous

    I’m not only telling you that the taxpayers will not see a tax decrease from any “perceived” savings and any “profit” made from selling this stuff…I’m telling you that any small incremental blip in the overall budget will be far exceeded by out of control spending. That’s what municipalities do…spend money…fast and furious. I’m sure that the supposedly $200,000 per year savings has already been spent (and more) elsewhere. There is NO true budget…only a false ceiling “goal” of sorts that each department purposely over ”budgets” to get more of the pie. It will never change until public officials are forced to practice sound financial principles.

  • Anonymous

    This is NOT saving the economy…far from it. It took several millions in grants to even build this project. What this article and municipa officials won’t tell you is that their are many, many other costs associated with this process….utilities, manpower, maintenance, replacement parts, equipment, etc. While this may actually be a good idea environmentally…it may cost more in the end for good intentions.

  • Anonymous

    Excellent post. I have extensive experience with contract work in wastewater treatment plants across the Southeast. The biosolide sludge cake that comes off of belt presses or from grit from vortex chambers is a soup of biological waste and bacteria. Some older plants had sludge drying beds that the sludge was pumped to dry in the sun. These drying beds had GYNORMOUS tomato plants…and even some strawberry plants…(seeds do not digest). But every one of the municipal workers KNEW not to even attempt to harvest the sometimes 2lb tomatoes or strawberries because of the bacteria.