Imagine this scenario:
You finished the last of your peanut butter. You've tried to get out the remaining bit of yummy goodness, but your tongue can't reach any further into the jar. The remnants cover the insides of the plastic container. You don't have a dog to clean it out. What do you do with the jar? Recycle it with the peanut butter sticking to the insides? Wash it out with clean, treated drinking water? Or throw it in the trash to go to the landfill? The guilt for an environmentally conscious person almost makes eating peanut butter not worth the joy it brought. What is a person to do when they are trying to conserve water, be a sewer hero, and recycle?
What to do if you don't have a dog?
The answer: When in doubt, throw it out.
What if I recycle it? The ACC Solid Waste Department needs clean recyclable materials. If too much grease or fat residues are on the container, it can contaminate the collected materials and reduce the market value. When in doubt, throw it out.
What if I wash it out first? Washing out containers made from recyclable material uses water, so not necessarily the best when trying to reduce water use. However, the water use can be offset by the water saved through the reuse of recycled materials vs. the water cost of using virgin materials. If you are efficient with your rinsing and it is a fairly clean container, the water savings of recycling should outweigh your water used for rinsing. Go ahead and rinse. If it is very dirty (think hot fudge glass jar), throw it out. And when it doubt, throw it out.
What about the sewers? Rinsing the peanut butter jar puts the leftover fats into the sewer. This leads to clogs in our pipes. If you have a recyclable with fats, oil, or grease (FOG) inside, throw it out. The FOG contaminates the other recyclables and requires more vigorous washing and water use. Not sure? When in doubt, throw it out.