Several years ago when I was a young engineer, I was leading a "pollution prevention" survey for a major pharmaceutical manufacturer. This was a large plant and had many processing and support departments including manufacturing operations for solid dosage form (pills and capsules) as well as soft gel capsules and liquid formulations.
As part of our survey, we were escorted through every area in the facility (except for the management offices where we understood there was no waste) including several maintenance and support shops where various routine activities were based. This was a substantial plant and one of the many shop functions included a fully-staffed paint shop. This paint shop did everything from applying corrosion inhibitors to exterior surfaces to painting offices to painting exposed metal beams and those bright yellow caution lines on the floor.
I have owned my own house for many years and have worked my way through many painting projects. I was familiar with how this worked. You get the paint, brush, drop-cloth from the paint shop and go to the assigned area. You paint. You return to the paint shop, put away the paint, clean the brush and you are done. Not much to it.
Then I asked a really simple question. What was involved in cleaning that paintbrush? Turns out, quite a bit.
- The painter had to stop painting 5 -10 minutes early so he had time to clean the brush.
- Approximately 5-15 gallons of clean water was used to clean the brush
- That same 5-15 gallons of waste water was discharged to the waste treatment facility
- The wet brush had to drip dry for several hours before it could be reused
- The expensive high-quality brushes occasionally disappeared from inventory
It didn't take a lot of analysis to conclude that through the simple act of washing a brush we were effectively turning one pound of concentrated waste into 40 - 125 pounds of dilute waste. In a study that considered a 10% reduction in waste to be huge, imagine a 98% - 99% reduction. The recommendation - buy the least-expensive, acceptable-quality brushes in bulk, use them once and throw them away.
Counter-intuitive? Yes. and we did get some push-back.
Lesson learned - our assumptions sometimes mislead us.