How much do you use your food waste disposer (garbage disposal)? Said another way – how much food waste is put down your disposer? The answer to this question is elusive. Think about it. Once the food waste goes down the drain into the plumbing and on to the water resource recovery facility (wastewater treatment plant) it is gone. It cannot be measured.
For our five city food waste evaluation we applied out of the box thinking to quantify how much people use their disposer by comparing the amount of food waste in people’s garbage before and after installing a disposer. It was important for the results to be statistically significant, so the sample size for the number of households included in the study was relatively high.
We set the goal of 90 households, and a minimum of 70, but these homes also needed to be in the same neighborhood where one garbage truck would collect the waste. We had two separate weeks’ worth of garbage evaluated in the neighborhood before disposers were installed, and then two times after the disposers were installed.
In the U.S. 50% of all homes already have a disposer, so an added challenge to our study criteria was finding 90 homes without one. Indeed in some neighborhoods selected (with input from key individuals in each city), many people already owned a disposer and we were unsuccessful in finding enough participants. Interestingly, some residents suspicious of “free stuff” from the government study resulted in reluctance to participate. “There ain’t no such thing as a free lunch.”
While it was frustrating to not be able to recruit sufficient participation in every city, in the end we did get statistically significant results in 4 out 5…and that’s significant relevance!