@carl, As per your statement:
- "..but in Iowa and other states it is a very big issue and wells contaminated with nitrates are unsafe for human drinking water..."
I am not advocating Septic Systems and Wells.
Personally, I will not consider purchasing a MHP with Septic Systems/Well Combination.
However, what I am stating is that in South Carolina not every parcel of land has the ability to be connected to public sewer.
Thus, South Carolina has provided the ability to develop properties with the use of Septic Systems. In South Carolina there are specific laws (DHEC) concerning Septic Systems that should be followed.
As per SC DHEC Rules - (75 Feet To Private Well & 100 Feet To Public Well):
The area of the lot or plot of ground where the onsite wastewater system is to be installed shall be of sufficient size so that no part of the system will be:
(1) Within five (5) linear feet of a building, or under a driveway or parking area;
(2) Within seventy-five (75) linear feet of a private well (less than 1500 gpd sewage flow), one hundred (100) linear feet of a receptor (greater than 1500 gpd sewage flow), and within the Department's established minimum distance from a public well;
(3) With in one hundred (100) linear feet of a public well;
I am by no means an expert in Septic Systems.
However, for Septic Systems we have received SC permits; have installed; have repaired and have removed Septic Systems in South Carolina by State Licensed Companies by following DHEC's Rules.
It is my understanding that the expert in Septic Systems is:
Perhaps @Coach62 could further explain the "nitrates" issue?