[Shop-talk] plumping question and sandrock sewers

[Doug Braun]

Thanks for the interesting information about the
geology of St. Paul!  I've heard  there are a lot of
interesting old tunnels in St. Paul.

Doug

--- pethier at comcast.net wrote:

> 
> I have mentioned that Saint Paul is a river-bluff
> town.  Our city datum for 
> elevations is USGS sea level minus 694.10 feet. 
> This is based on some 
> point at some steamboat landing circa 1850.  I'm in
> an office downtown in a 
> building on top of a bluff.  The city datum at the
> front door is about 95 
> feet.  A nearby storm sewer is essentially down to
> river level, so the 
> dropshafts here are about 90 feet deep.  The
> 150-foot-deep tunnels are out 
> in the Midway district, carrying storm water to
> outfalls in the Mississippi 
> on the west edge of town.
> 
> There are also some deep sanitary-interceptor
> tunnels.  The metro-wide 
> treatment plant is located in Saint Paul, so
> sanitary flows are conveyed by 
> a combination of tunnels and conventional pipes from
> other cities such as 
> Minneapolis through Saint Paul to the plant.
> ============