From
http://www.world-nuclear.org/sym/1997/stout.htm:
The Smith Ranch in situ leach (ISL) uranium production facility is located in Converse County, Wyoming, USA. It is slated to become the largest alkaline ISL operation in the world.
Injection and recovery wells will be cased and cemented to isolate the open hole or screened ore bearing interval from all other aquifers. Production zone monitor wells will be located in a pattern around the mining unit or units with the completion interval open to the production zone. Production zone monitor wells are located approximately 150 m between wells. One overlying and one underlying monitor well will also be completed in the aquifers immediately above and below the production zone for each 1.6 hectares (4 acres) of well-field area.
Figure 5 shows a typical well-field development pattern.