Question about inspections???

[Lauren Ruppert]

A property owner has offered to sell a home to a friend in Colorado.  The home has a septic system and water catchment(?).   I have zero experience with such properties and would like to know what type of inspections need to happen.  I know that the septic was replaced...but not sure about the leach field (I actually don't know what that is...).  

I typically buy/sell in urban areas where there's a sewer system and public water, so I need resources/referrals for this situation. 

Thanks in advance!