Stacy:
Is it possible that this structure might be a septic tank system? Is 
it also possible that there may be a similar structure behind each 
house in your row house area. The stand pipe could be used to vent 
the pit. (?) Just a guess! The city engineers' office should have a 
set of specifications for this especially if they have lot house plans.
DP

At 02:23 PM 5/14/2008, you wrote:
>Dear Histarch List,
>
>
>This query on Metafilter seems perfect for the histarch list:
>
>         "While digging out the backyard of our Philly rowhome to lay a
>patio, I came across a brick-lined pit with a pipe in it (pictures
>here and here). What is it?"
>
>         http://ask.metafilter.com/91380/What-is-this-hole-in-my-backyard
>
>Picture links:
>
>         http://www.flickr.com/photos/zempf/2492493640/in/photostream/
>
>         http://www.flickr.com/photos/zempf/2491674973/in/photostream/
>
>Apart from the obvious admonitions about conducting exploratory
>excavations in the backyard, I'm sure this fellow would love some
>expert opinions on the feature!
>
>
>
>Stacy Kozakavich
>Berkeley, CA