The Waste Water Plant
This place was just plain awesome.  This former waste water treatment plant has apparently been closed since the mid-'50s, so it has been decaying for quite a while as nature reclaims what must surely be a great source of fertilizer.  Still, most of the structures are fairly intact (if not exactly functional), and there's a lot to see... and quite a few surprises along the way.

This is a Google Earth image of the entire plant.  It's a bit shy of two tenths of a mile across in any direction, but that's a lot to explore.  There is a road along the left side of the image, if that helps as to the scale.

I'll try to refer back to this image to help orient you throughout.

Here's a small corner of the place (lower left of map image).  In the center of the frame is a tower that's about two stories tall.

Here's a look down it.  There is a side tunnel at the bottom of it (above the water, thankfully), and I checked that out on a subsequent visit.  Unfortunately, it was a dead end that was sealed off now.

This is where the raw stuff enters from.  It is pumped in, and gravity from the column of material is used to force the matter through into the rest of the system.

A look out from the tower toward the skimmer pits.  (More about those in a bit.)

Also from the tower, here's a look out at some of the other buildings.  You can see the top of another structure we'll get to later off in the distance.

Note that we visited this site in early March, so there was very little foliage on the trees.  I returned less than two months later, and the place was so overgrown that it was difficult to even move through some of the vegetation let alone see structures ahead.

The strainer.  The raw stuff comes from the pipe at the bottom of the tower and enters the plant through the strainer where most of the big insoluble stuff is removed and sent to the landfill.

The skimmer pits.  While solids settle out in here, the conveyors skim oils from the surface of the water.  Obviously the levels on this day were lower than they would be if this were a functioning facility.

Another view from the opposite end of the pits.  I believe these are aeration tanks on this end.  They are separated from the previous section.  

This portion is where microbes do their number on the solids.  I don't know if it was the case here, but in modern systems, air is added to fuel the microbes as well as to mix the material and make it more accessible to be degraded.

So how deep were they?

That deep.  Of course, much of that was muck from half a century of fallen leaves, etc.

Next we went into this L-shaped building...

...which housed many dismantled pipes.  Presumably there were pumps in the missing sections which were reused at another location.  I'm not sure of their purpose in this process, however.

A different view.

Another section of the building had about three feet of water in it.  It was too cold to swim that day, however.

In one of the buildings along the way, we found old paperwork dating from the '50s (this one was from 1955).  I'm not sure when the plant went out of commission, but this was the most recent date we found, and the fact that full-grown trees have since invaded areas that would have once interfered with daily operations, I'm guessing it couldn't have been far from this point that the place was closed.

Continue to Part II