ONE SHARED SEPTIC ON TWO PROPERTIES

[Austin Jay Toniolo]

Hello BP!! Hope you are all staying safe! Looking into 2 Delaware FLIP parcels(one parcel with 2 units and another parcel with 1 unit) that share the same mound septic system. The seller found out (after building the 3rd unit) that the drain field is too small and overused. Seller was suggested that she take down the 3rd unit (apartment) to expand the field. 

What are your thoughts regarding how to properly analyze my repair budget and should I budget in the installation of a second mound system, in addition to the tear down of the apartment?

Would it be wise to tear down the apartment and combine both septics and expand the drain field? 

What am I not seeing in this never-encountered scenario that you may have seen in the past? How did you proceed and structure the offer?

Thank you for your awesome input as always!