Life of Poo

I’ve been blogging about my Water Works project all summer and after the Creative Code Gray Area presentation on September 10th, the project is done. Phew. Except for some of the residual documentation.

In the hours just before I finished my presentation, I also managed to get Life of Poo working. What is it? Well, an interactive map of where your poo goes based on the sewer data that I used for this project.

Huh? Try it.

This is the final piece of my web-mapping portion of Water Works and uses Leaflet with animated markers, all in Javascript, which is a new coding tool in my arsenal (I know, late to the party). I learned the basics in the Gray Area Creative Code Immersive class, which was provided as part of the fellowship.

The folks at Stamen Design also helped out and their designer-technicians turned me onto Leaflet as I bumbled my way through Javascript.

How does it work?

On the Life of Poo section of the Water Works website, you enter an address (in San Francisco) such as “Twin Peaks, SF” or “47th & Judah, SF” and the Life of Poo and then press Flush Toilet.

This will begin an animated poo journey down the sewer map and to the wastewater treatment plant.

Not all of the flushes works as you’d expect. There’s still glitches and bugs in the code. If you type in “16th & Mission”, the poo just sits there. Hmmm.

Why do I have the bugs? I have some ideas (see below) but I really like the chaotic results so will keep it for now.

I think the erratic behavior is happening because of a utility I wrote, which does some complex node-trimming and doesn’t take into account gravity in its flow diagrams. The sewer data has about 30,000 valid data points and Leaflet can only handle about 1500 or so without it taking forever to load and refresh.

The utility I wrote parses the node data tree and recursively prunes it to a more reasonable number, combining upstream and downstream nodes. In an overflow situation, technically speaking, there are nodes where waste might be directed away from the waste-water treatment plant.

However, my code isn’t smart enough to determine which are overflow pipes and which are pipes to the treatment plants, so the node-flow doesn’t work properly.

In case you’re still reading, here’s an illustration of a typical combined system, that shows how the pipes might look. The sewer outfall doesn’t happen very often, but when your model ignores gravity, it sure will.

The 3D print of the sewer, the one that uses the exact same data set as Life of Poo looks like this.