All good things come to an end, and this is no different when dealing with machine coolant. Eventually, even with the best coolant management plan in place, coolant will go bad and requires removal and replacement. Once the coolant reaches its useful life, it needs to be disposed of appropriately. Industrial type wastes such as coolants and sump cleaners should never be disposed to a septic or storm system or dry well. With stricter environmental regulations, the burden is put on the machine shop to determine if the coolant and other materials are considered hazardous or nonhazardous waste. The machine shop must test the waste materials or have the necessary information about the waste to assess its status.
If using oil-water emulsion coolants, most of the time, they can be chemically split to separate the oil from the water. Once divided, the water and oil portions are disposed of separately. If your coolant contains dissolved metals, chlorinated oils, or biocides, it may be considered hazardous and require special disposal. When getting ready to dispose of your coolant, do not mix other wastes such as solvents into coolant for disposal. The smallest amounts of a federally listed solvent could cause your entire container or tank of machine coolant to get labeled as dangerous waste. While most states and other governments follow the federal laws, they may surpass or have additional conditions on the dispose guidelines. You should always check your local and state disposal mandates.
Nonhazardous Material Disposal
For all nonhazardous materials, have all MSDS sheets ready and available for everything that went into your machine coolant. If the fluid waste from your machine shop is considered nonhazardous, the materials can be hauled to a treatment facility or if you have been granted access by the sewer utility for disposal, discharged into the municipal sewer system. Never discharge spent fluid into a septic tank system or dump on the ground.
To reduce disposal costs and your shop’s environmental liability, you can pretreat nonhazardous fluids on-site before disposable. Types of on-site treatment include ultra-filtration, chemical treatment, and evaporation. Each process involves the removal of metal fines and other solid contaminants, concentrating the oil, and discharging the water to either the sanitary sewer or the atmosphere. The concentrated oil and solids are disposed of separately or reclaimed, if possible.
Hazardous Material Disposal
Spent machine coolant and solids that are determined to be dangerous must be disposed of by an EPA permitted hazardous waste management company per applicable federal and state regulations. Providers like Safety-Kleen have a used machine coolant and industrial oil reclamation program and provide nonhazardous and hazardous disposal. A benefit of Safety-Kleen is that it has 175 collection facilities and 18 processing facilities nationwide.
Selecting a certified hauler and treatment facility registered with the EPA is critical because your machine shop is ultimately responsible for the waste created. If the waste hauler or waste treater you select does something illegal, it can, and almost certainly will come back on you.