FLAT ROCK, Mich. - About six million gallons of water are processed each month at AAI's on-site Waste Water Treatment Plant. The treatment plant removes oils, solids and metals from the water before it is recycled back into Lake Erie. Water treatment can be an expensive part of the business, but improved paint processes have helped to reduce the use of water, paint and other chemicals.
According to Terry Filipiak, Environmental Manager, the paint processes have come a long way over the years when it comes to adhesion, emissions and waste. With better application processes, there is less paint that needs to be removed from the waste water and similarly less paint is used overall. More paint hitting the target (car) means less usage and less waste. These improvements are not only environmentally significant, but they also create costs savings for the plant.
Much of the waste water comes from the cleaning necessary when producing a vehicle. When sheet metal is pressed into parts in Stamping, the presses leave behind an oil residue to protect the metal while in transit to be painted. After the Body team puts the pieces together, the vehicle shell makes its way through the Paint Department where various chemicals and solvents are applied during the paint process.
First, the oils are removed from the metal with a phosphate cleaner that is then rinsed off with water. Then a phosphate etch is applied which eats into the metal, crystallizes the surface and creates an adhesion surface that will allow the paint to stick properly. The body etching process also binds metals like nickel and zinc to the sheet metal, but also requires rinsing. This prepares the metal for painting and provides added corrosion protection.
The water that is left after the paint process is filled with pollutants that must be removed before the water can reenter Lake Erie due to federal and state regulations. At the water treatment plant, the floating oil is simply skimmed of the top because it is less dense than water. The metals are removed by adding a sodium hydroxide compound which binds to the metals and creates large metal crystals that sink to the bottom and are settled out.
According to Filipiak, it is important to limit the overall amount of water use by only using as much as necessary. When it comes to AAI's environmental impact, the strategy is to reduce, reuse and recycle. Whether that is reusing a rag that isn't completely dirty or making sure cardboards, scrap metal and certain plastics are recycled properly; everyone has the ability to support in AAI's environmental efforts.