No, you don't have to do it, but why would you not if you intend to build? You want to know if the land allows you to actually live on it before building a home. Testing is the way you find this out!

Contact me at Barbara@Novitsky.com if you'd like to discuss this further and I'll be glad to help.

To build a house? Yes, unless the property is or can be served by the public sewer system. I've worked with quite a few large tracts of land going into development as well as residential lots, and it's totally possible that the area available for an installed septic system, with the appropriate soils, etc., is limited to one relatively small section. It just depends on the specific piece of land. There are some very good civil engineers who specialize in land development -- please contact me at Nellie@MarylandHouse.com for a list.