Engineering: Re-designing the Waste System in the Cafeteria

Criteria

• Make it easy and quick for kids to go through and throw stuff away

  • • Logical and sequential order

    • One-way flow

    • Labeling

• Dumping station for on both sides of cafeteria

• Separate spaces for each of the following: 

  • Bins for trash, compost, recycling,

  • A place to stack trays

  • Spaces for bus bins for reusable plates and silverware

• If possible a place to set your tray down and unload stuff off of it, but not too big so the waste doesn’t go in the bins

• An open back or place to take out the trash, recycling, and compost to dump them

Constraints

• Budget/ Materials to make it 

• Shouldn’t make more work for school maintenance/cafeteria staff

Design 1: Compost, Recycling, Trash, Food Share Bin, Bus Bins, Trays

Pros: Compost and recycling are before trash, so people don’t just dump everything in the trash, trays are last so that people can empty everything off their tray first, before you have to put it down.

Cons: Food share bin is after compost so people might just open their unopened milk and dump it in the compost, or compost an uneaten apple instead of putting it in the food share bin. Also, silverware has to be put back on tray after scaping compost, because compost is not near silverware bin (or trash, if silverware is not reusable).

Meets criteria: Order is mostly logical, with a one-way flow, bins for trash, compost, recycling, trays, and bus bins

Meets constraints: Should not be more work for school maintenance/cafeteria staff

Design 2: Food Share Bin, Compost, Bus Bins, Recycling, Trash, Trays

Pros: Food share bin is before compost, so that reusable uneaten food (like apples and milk) is put there rather than in the compost, trash is near the end of the order so that everything isn’t just dumped in the trash, reusable plates and silverware are before the recycling and trash so that they are not accidentally put in the wrong place. You can use reusable silverware to scrape into the compost, then put it in the next spot without having to put it back on the tray.

Cons: If there is non-reusable silverware that you use to scrape compost into the bin, then you have to put it back on the tray because the trash is several things later, also the food share bin might be better at the end of the line if it is less used?

Meets criteria: Order is mostly logical, with a one-way flow, bins for trash, compost, recycling, trays, and bus bins

Meets constraints: Should not be more work for school maintenance/cafeteria staff

Design 3: Food Share Bin, Compost, Recycling, Trash, Bus Bins, Trays

Pros: Food share bin before compost so that uneaten food that someone else could eat would be put there instead of tossed into the compost, trash being the last waste to dispose of in the line so that people are encouraged to put what they can in the other categories, and only trash what’s really necessary.

Cons: Silverware bin is not near compost, so if you use silverware to scrape compost, you then have to put it back on your tray.

Meets criteria: Order is mostly logical, with a one-way flow, bins for trash, compost, recycling, trays, and bus bins

Meets constraints: Should not be more work for school maintenance/cafeteria staff

Design 4: Food Share Bin, Recycling, Compost, Trash, Bus Bins, Trays

Pros: Same as in design 3, but additionally recycling and trash are on either side of the compost so once you empty the food out of a container you can put the container straight where it goes (in trash, or in recycling if it is clean and recyclable).

Cons: Same as design 3, but also that the compost isn’t directly next to the food share bin, so disposing of food waste would be a bit more spread out, rather than dealing with the food waste all at once during the process of disposing of waste.

Meets criteria: Order is mostly logical, with a one-way flow, bins for trash, compost, recycling, trays, and bus bins

Meets constraints: Should not be more work for school maintenance/cafeteria staff

Research:

We met with someone from Central Vermont Solid Waste Management District about waste system designs that would work best for our cafeteria.

We asked Steven (principal) about the budget.

We talked with the cafeteria and maintenance staff that would actually be working with the waste system.

We measured the trash, recycling, and compost in the cafeteria to figure out the sizes we would need to incorporate in our design.

To see the full details of my research mentioned above, go to my final product document for this project.

Comparing Designs:

Una and I discussed possible variations of designs many times. Below are some images of some of our process - some of our work on figuring out which design ideas would work best.

We tested whether it would work better for the waste system to be around the poles, or against the walls in the cafeteria.

We moved one of the current waste systems in the cafeteria against the wall for a day, leaving the other one by the pole like they usually are. We took pictures of what was in the waste systems in the morning before lunches started, and then during C lunch. There was more food in the waste system that was near the pole, and so we used this data to figure out that we should build the new waste system to be around the poles like the current waste system that we have is (because that works better for the flow in the cafeteria).

Here is the link to the document with the pictures from the test: Pictures from Test of Waste Stream Placement (Poles/Wall).

Here are the links to my final products for this project:

Defining the Problem

Designing and Selecting Solutions