06/09/2026
Reading the Dirt: How We Interpret a Soil Report — and Why It Decides the Deal
Justin Tahilramani, Sandhills Real Estate Holdings
Every piece of land we look at gets the same question asked of it before we get excited about anything else: what does the dirt say?
Most of the ground we develop isn't on city sewer. That means every home is going to treat its own wastewater with a septic system, and whether that's even possible — and what it costs — comes down to the soil under your feet. Not the view, not the road frontage, not the asking price. The soil.
So one of the first things we do on a project is order a comprehensive soil investigation from a licensed soil scientist. We just got one back on our 8-lot subdivision off Ruth Vinson Road in Cumberland County. I want to walk through how we actually read a report like this, because it's one of the most important documents in the whole deal — and most people never see one until something has already gone wrong.
The job of the report is narrow and specific.... To determine the ability of each lot to support a subsurface wastewater dispersal system and repair area.
Break that down and there are two things we're really buying:
The system — can each lot physically support a septic field that will work for a normal house? And the repair area — is there also room for a second, full-sized field if the first one ever fails? In North Carolina you generally need both: the initial system and a 100% repair area. A lot that can fit one but not the other is a problem, and it's exactly the kind of thing a soil report flags before you've sunk money into a lot you can't use.
What the report tells you:
Soil depth. This is the headline number. The deeper the usable soil before you hit rock, clay, or a water table, the more freedom you have. On Lots 1–7, we found suitable soils "for greater than 42 inches." That's deep, and deep is good — it means a normal system can go in the ground the normal way.
Soil texture. Described as ranging "from sandy loams to loamy sands." That's close to ideal for septic. Sandy soils drain and accept water at a healthy rate; heavy clay does the opposite and chokes a system. When I see "sandy loam to loamy sand," I relax a little.
The acceptance rate (LTAR). This is the technical one, but it's worth understanding. The Long-Term Acceptance Rate is how many gallons per day each square foot of soil can absorb — Lots 1–7 at "0.6 to 0.9 gal/day/sqft." A higher rate means the soil drinks water faster, which means you need a smaller drain field to handle the same house. Smaller field, lower cost, more room left over. A low rate means bigger fields and tighter siting. This single number quietly drives a lot of the economics of a lot.
Suitable vs. unsuitable. The soil map that comes with the report color-codes the ground into suitable and unsuitable soils. We're not just asking "does this lot pass" — we're looking at where on the lot it passes, because that tells us where the house and the field can actually go.
Seven of the eight lots came back clean. Deep, sandy, well-draining soil that "appears adequate to support a conventional septic system and repair area for at least one residence." On those lots, a builder can put in a standard, lowest-cost system and move on.
Lot 8 is a different animal. The soils there are "limited in soil depth" — shallow enough that a conventional system won't fit the normal way. Our options include:
An ultra-shallow system, which would need roughly six inches of approved soil brought in and placed over the top to cover it.
A Low Profile Chamber (LPC) system, a shallower-profile design for tight soils.
A mound system, where the drain lines sit at or above grade inside a built-up mound of imported fill. Hal's words: mounds "typically cost more and take up significantly more space than a conventional system."
A subsurface drip dispersal system, which can work in shallow soils but "would likely require additional soil testing" to design.
Same road. Same tract. One lot that needs an engineered solution while its neighbors don't.
The good news is Lot 8 can still support a modified or alternative initial system and 100% repair area — so it's buildable. It just comes with a different cost basis, and now we know that going in instead of finding out later.
That's why we test the ground first. On rural land, the soil is the deal.
Sandhills Real Estate Development acquires, entitles, and develops residential and commercial land across the North Carolina Sandhills. Have a piece of land and not sure what's under it? That's a conversation we're always happy to have.
