Deluxe Sewer Tour, Part 2

Well it took long enough for me to get to Part II. To refresh your knowledge, or if you missed it, here is a link to Part 1. 

We left off touring the headworks. I forgot to mention that 8.34 pounds "stuff," avoiding a more descriptive word, which comes into the headworks, yields 1 gallon of water, containing a myriad of microscopic "goodies!"  there are 41 lift stations throughout town all working to push this stuff along. The main lift station has three pumps, two of which work at any given time. It is pushed along the force main and arrives at the headworks.

And now we turn 180º to the the end of the Oxidation Ditch, viewing the part that is called the "anoxic zone," the next step in the process after the headworks.

(Click on a picture to enlarge it.)

This zone has very little oxygen in it and the contents are mixed slowly. This is where anaerobic bacteria convert nitrate into nitrogen gas. (This is similar but different from intestinal gas which also uses bacteria to create gas - although some bacteria actually consume gas; hydrogen, carbon dioxide and sulphur-containing gasses are the vaporous result.) Standing next to this vat, while not a perfume factory type experience, was far less offensive than standing next to some gas-emitting biological unit, as say, in a crowded elevator.

The two photos below, well, I am not sure what they are showing.

The handy signs ID some of this stuff.

I have NO idea why I didn't publish this ages ago. I know I have more notes from the tour somewhere, but finding them now.......... Well, I do see some leftover fabric from a skirt I made in the 7th grade, but most of this is stuff on the Los Osos CSD and the sewer! There are worse obsessions I believe.