It is mind-boggling that industrial sludge, which comes from the dissolved air flotation process, is allowed to be applied to Maryland farm fields without better oversight. Rick Hutzell detailed this issue in a recent column.

Legislation in the Maryland General Assembly to regulate industrial sludge from protein rendering by dissolved air flotation is long overdue.

During my 36-year career in wastewater treatment, I often sold these systems to industrial consumers. The system is designed to separate contaminants from wastewater by floating the scum to the liquid surface of the tank and then skimming into a collection trough. This scum/liquid sludge is then sent out for further treatment or disposal.

Lord only knows what’s actually in this sludge. Depending on the specific industry, one might have fats, blood, feathers, floatables, etc. If I were a farmer, there is no way I would apply untreated dissolved air flotation sludge to my crops.

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I find it hard to fathom that Maryland regulatory agencies allow this waste product to be dumped on farmers’ fields without additional treatment. Other states require permits for sludge handling. Why don’t we?

I recognize the excess of this material needs to go somewhere. But there are other solutions for disposal.

One solution for treatment of this waste is in operation at the Kilby Farm anaerobic digester in Cecil County. The Kilby digester treats cow manure waste along with dissolved air flotation waste and others. The digester operates in the mesophilic range — 100 degrees Fahrenheit is common. Finished products from the Kilby digester are compost that can be used as fertilizer, liquid effluent that can be field applied, and biogas that generates enough energy to power 190 homes per year. A University of Maryland report provides a detailed discussion of the Kilby Farm anaerobic digester system.

The industrial sludge plaguing Maryland does not go through this additional treatment. Until the technology can be scaled for statewide sludge treatment, Maryland needs to address how dissolved air flotation waste is stored and applied. Legislation proposed by Democratic Del. Sara Love of Montgomery County and Sen. Justin Ready, a Republican who represents Frederick and Carroll counties, would require permits for industrial sludge handling. That’s a step in the right direction.

Everyone in Maryland should care about this issue, not just the people who are dealing with the unbearable smells and threats to water quality. Land application of untreated dissolved air flotation industrial sludge is contaminating land, streams, and the Chesapeake Bay.

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I will be letting my local legislators know that this kind of industrial sludge needs a solution, so we don’t continue to be a dumping ground. I encourage you to do the same.

Ron Hartman, Fair Hill