On rural land, the septic question is usually the whole question. If a lot can take a normal septic system, it is a homesite. If it cannot, it is acreage with fewer buyers, a lower price, and a harder note to sell.
This is the investor's version: the system types, what each one does to value and financing, and who issues septic permits in the states where we lend most.
Why does septic matter so much on raw land?
Because most rural land has no sewer, so a buyer can only build if the soil can take a septic system.
The EPA says more than one in five U.S. households depend on individual septic or small cluster systems. Source: EPA. On vacant land outside town, that share is much higher, because there is no sewer line to connect to. The soil decides what system a lot can use, and the system decides who will buy the lot.
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Get a Free QuoteLand LoansWhat are the main types of septic systems?
Conventional and chamber systems use the soil as the drainfield. Mound, aerobic, drip, and sand filter systems are alternatives for soil that cannot.
| System | How it works | What it means for your lot |
|---|---|---|
| Conventional (gravity) | A septic tank plus a trench or bed drainfield. Soil microbes finish the treatment. | The system most land buyers expect. The easiest lot to sell and to finance. |
| Chamber | A gravel free drainfield made of connected chambers. Easier to deliver and build. | Still a soil based drainfield. Useful where gravel is scarce or groundwater is high. |
| Mound | Effluent is pumped up into a built sand mound, for shallow soil, high groundwater, or shallow bedrock. | An alternative system. Costs more, needs a pump, and some buyers walk away. |
| Aerobic treatment unit | Adds oxygen to speed up treatment, like a small sewage plant. | An alternative system with power and ongoing maintenance. |
| Drip distribution | Drip lines in the top 6 to 12 inches of soil. Needs a large dose tank and electrical parts. | An alternative system. More parts, more upkeep. |
| Sand filter | Effluent is pumped over a sand bed for a high level of treatment. Costs more than a conventional system. | An alternative system, often used near water or with a high water table. |
System descriptions from the EPA guide to septic system types.
What does an alternative septic system do to land value?
It usually means fewer buyers and a lower price, because the buyer pays more to build and maintain it.
Most people buying a rural homesite want a normal septic system. When a lot needs a mound or an aerobic unit, some buyers walk, and the ones who stay want a discount. The lot still sells, but slower and for less. Price the septic answer into your offer before you buy, not after. This is why I tell subdividers to perc test every lot before they close.
What happens if land fails a perc test?
You test elsewhere on the parcel, move to an alternative system, or sell it as land that is not a homesite.
- Test another spot. Soil changes across a parcel. High ground often drains when low ground does not.
- Ask about an alternative system. The county may permit a mound or aerobic unit where a conventional system fails.
- Change the plan. Fewer, larger lots can put every homesite on good soil.
- Sell it for what it is. Recreation, hunting, or timber land, priced that way.
Walk through these in due diligence, not after closing. See how to subdivide land step by step.
How does septic change your land loan and your note sale?
Our best subdivide terms and our note purchases under 10 acres depend on a conventional perc.
Our subdivide loan goes up to 80% of the purchase price when the plat records at closing and every lot has a perc test showing a conventional system. When you sell lots with seller financing and want to sell us the notes, lots under 10 acres need a perc test showing a conventional system, or at least 40% down from the buyer on an alternative system. We do not buy notes on land that failed perc. See subdivision loans and our note buying criteria.
Who issues septic permits in each state?
Usually the county or local health department, working under state rules. A few states permit directly.
| State | Who sets the rules | Who issues the permit | What to know |
|---|---|---|---|
| Texas | TCEQ sets the rules | Mostly local "authorized agents." TCEQ regional offices permit only where there is no local agent. | A single home on 10+ acres can be exempt from the permit (not the standards) if it meets TCEQ's setback and site evaluation conditions. TCEQ |
| Tennessee | TDEC, Division of Water Resources | TDEC field offices, or the county in nine contract counties (including Davidson, Knox, Shelby, and Williamson). | Splitting land into 2 or more building lots on septic needs a TDEC subdivision evaluation with a soils map, unless every parcel is 5+ acres. TDEC |
| Georgia | Department of Public Health | County boards of health | County boards of health can set minimum lot sizes for septic, so check the county before you draw lots. |
| North Carolina | NCDHHS On-Site Water Protection Branch | Local health departments (private options exist) | You need an Improvement Permit and a Construction Authorization before building. The owner can hire a licensed soil scientist for the site evaluation. |
| South Carolina | SC Department of Environmental Services (formerly DHEC, since July 2024) | SCDES (the state) | Without the septic permit, the county will not issue a building permit. A permit to construct is good for five years. SCDES |
| Florida | Department of Environmental Protection (moved from the Health Department in 2021) | Mostly county health departments; DEP directly in the 16 Panhandle counties and Marion County | Who you call depends on the county. DEP program transfer |
| Ohio | Ohio Department of Health | Local boards of health | No system can be installed without a board of health permit, and local boards can adopt stricter rules. OAC 3701-29-06 |
| Michigan | Local health departments, with state (EGLE) support | Local health departments | Homes are approved under the local sanitary code or the state criteria, whichever is stricter, so rules vary by county. |
State names link to each official septic program page. Rules change, and counties add their own, so confirm with the permitting office before you buy.
What should you check about septic before you buy land?
Sewer access, a perc or soil evaluation, who permits in that county, and any lot size rules.
- Is there public sewer? If yes, septic may not matter at all.
- Get a perc test or soil evaluation in the building area of every lot you plan to sell.
- Call the permitting office from the table above and ask what system the soil supports.
- Ask about lot size and split rules. Some counties set minimum lot sizes for septic, and some states review subdivisions.
- Put the results in your contract timeline so you can walk away if the land fails.
Frequently Asked Questions
What is the difference between a conventional and an alternative septic system?
A conventional system uses a septic tank and a soil drainfield. Alternative systems such as mounds, aerobic units, drip, and sand filters are used where the soil cannot treat wastewater on its own. They cost more and need more upkeep.
Can you build on land that fails a perc test?
Sometimes. The county may permit an alternative system such as a mound or aerobic unit, or another spot on the parcel may pass. If nothing works, the land is usually sold as recreational or timber land.
Who issues septic permits?
In most states the county or local health department issues septic permits under state rules. South Carolina permits through its state environmental agency, and Texas uses local authorized agents.
Does Damen Capital require a perc test?
For the 80% subdivide loan, every lot needs a perc test showing a conventional system. For note purchases on lots under 10 acres, we need a conventional perc or at least 40% down from the buyer on an alternative system.