Jack H. Stewart writes:
"After seeing the request for information on privies, I thought I'd write in.  I
 am about to begin an investigation at one of our local Civil War Battlefields.
 This may include the excavation of a cistern/well.  Does anyone have any
 information on the best way to go about this?"
 
The excavation of a well is _extremely_ hazardous.
 
Will the anticipated information be worth risking someone's life to retrieve it?
 
The following discussion is NOT that of an expert. You should seek the advice
 from an expert as well as structural and soils engineers before attempting it.
 I take no responsibility for anyone who uses the following information.  If you
 use any of this information you do so at your own risk. I am simply passing on
 information and ideas which have been presented elsewhere in formal and
 informal discussions.
 
One approach is to put four foot diameter reinforced concrete or metal culvert
 sections over it, excavate a slightly larger hole and have the section slide
 down gradually around the well casing outside, and dismantle the well as you
 go. You keep adding sections as needed. You would need a backhoe or crane to
 lift the sections into place. I have never done this. I frankly doubt if you
 can legally do this under OSHA requirements. Call your state OSHA or federal
 OSHA to find out the best person within their organization with whom to
 correspond. Get their opinion in writing. By doing so, you will have been
 pro-active and if an accident occurs you may have a chance to stay out of jail.
 Be sure and get lots of liability insurance too.
 
An alternative is to excavate a huge area around it and step trench it down.
 Depending upon soil type, you might get by with a 45 degree slope or step
 trench to approximate that slope. Thus, a 20 foot deep well would require at
 least a 40 x 40 foot excavation to maintain the needed slope/stepping, while a
 40 foot well would need an area 80x80 feet. The other alternative is to use
 massive shoring. It is feasible, but you may not want the headache. You will
 need to hire a structural engineer and soil engineer to evaluate the soils and
 design the shoring.
 
You will need sealed outdoor electrical lights which have been installed using a
 ground fault interruptor to lessen electrocution hazards. You will need an
 electrical pump designed for lifting water. If you use gasoline generators or
 pumps have them located a long distance away to keep the carbon monoxide fumes
 away from the pits. Have an emergency plan in writing and it should include
 contacting local emergency services. Have a carbon monoxide monitor with an
 alarm in the well and with a remote alarm. Keep an oxygen tank at the site.
 
This discussion is not meant to be all inclusive of everything you need to know
 or present all alternatives, it is merely a starting point so that you can
 think about it before you contact the experts.
 
My personal opinion is that deep wells, in most circumstances, are best left
 alone.
William H. Adams
P.O. Box 1177
Philomath, OR 97370-1177  USA
503-929-3102       -3264 fax
[log in to unmask]