When I evaluate vacant land in Upstate South Carolina, one of the first questions I ask is not how pretty the property is, how many acres it has, or even whether the location is desirable.
The first real question is much more practical:
Can you actually build on it?
For property that does not have access to public sewer, that question often comes down to whether the land can support an onsite wastewater system, commonly referred to as a septic system.
This is an area where I believe very strongly in one principle: no surprises.
If I am representing a seller of vacant residential land, I would much rather know the septic situation before the property goes on the market than discover a serious problem after we already have a buyer under contract. In fact, I would take that philosophy even further. Ideally, septic suitability should have been investigated before the current owner ever purchased the land.
South Carolina’s own environmental agency advises prospective land buyers to determine water and sewer availability before purchasing and to investigate the soil, drainage, rock, slopes, flooding, wetlands, and other conditions that can affect whether a septic system will work.
That advice is important because a beautiful piece of land does not automatically make it a buildable homesite.
What People Mean When They Say “Perc Test”
Most buyers, sellers, builders, and even many real estate professionals still use the term “perc test,” which is short for percolation test.
Traditionally, a percolation test involved digging holes, adding water, and measuring how quickly that water moved through the soil. The idea was to determine whether the ground could absorb and properly treat wastewater from a home.
If water moved too slowly, the soil might not adequately absorb wastewater. If it moved too quickly, the soil might not provide sufficient treatment before that water traveled deeper into the ground.
South Carolina, however, no longer relies on the old-fashioned percolation test as the primary method of determining septic suitability.
Today, the South Carolina Department of Environmental Services, commonly abbreviated SCDES, uses a much broader site and soil evaluation. Many South Carolinians still refer to the agency as DHEC because septic permitting was historically handled by the Department of Health and Environmental Control. After South Carolina reorganized DHEC in 2024, environmental programs, including onsite wastewater permitting, moved under SCDES.
So when someone says, “I need DHEC to perc my property,” what they are really talking about today is having the property evaluated through the current SCDES onsite wastewater permitting process.
The modern evaluation looks at much more than whether water disappears into a hole. Inspectors evaluate the soil itself, the terrain, the seasonal water table, available space, setbacks, drainage conditions, the proposed number of bedrooms, and the amount of usable land available for both the initial drainfield and a future repair area.
That distinction is important because a property does not simply “pass” or “fail” in a vacuum.
It may be suitable for one type of septic system, in one specific location, for a certain number of bedrooms.
That means a parcel that can support a three-bedroom home may not necessarily support a five-bedroom home. A homesite that works in one corner of a tract may not work in another. The location of a proposed house, driveway, well, pool, accessory building, or future addition can all affect the septic layout.
From a real estate perspective, that is a major issue.
Why Septic Suitability Matters So Much
Septic suitability is important because it is really a question of utility.
When someone buys vacant land to build a home, they are not simply buying acreage. They are buying the right combination of location, access, utilities, topography, and buildability.
If a property has no sewer access and cannot support a septic system appropriate for the buyer’s intended home, that can dramatically limit what the buyer can do with the land.
I have seen beautiful acreage with hardwoods, creeks, privacy, and excellent road frontage become far less attractive to a typical residential buyer once significant septic limitations are discovered.
This is why I believe septic due diligence should come early in the process, not late.
A buyer should know before closing whether the property is likely to support the home they intend to build. A seller should ideally know before listing whether the property can truly be marketed as a residential building site.
How Do You Obtain Septic Approval in South Carolina?
The process begins by determining whether public or community sewer is available. That should always be the first question. If qualifying sewer is available to the property, an onsite septic permit may not be appropriate or permitted.
If sewer is not available, the property owner can begin the onsite wastewater application process through SCDES.
For a typical residential parcel, the owner should have a deed or plat available and should have a reasonably good idea of what they intend to build. The number of bedrooms matters because septic systems are sized according to anticipated wastewater use.
For residential systems, South Carolina uses bedroom count as an important design factor. That means it is not wise to simply tell the state that you want the smallest system possible just to get some kind of approval. If the eventual buyer is likely to build a four-bedroom home, then it is much more useful from a real estate standpoint to understand whether the property can actually support a four-bedroom residence.
The application is submitted through the SCDES ePermitting system. For a typical residential onsite wastewater application, the current state application fee is approximately $150.
Property identification and the proposed septic area must also be clear enough for the evaluator to understand where the intended homesite and system are likely to be located.
In Upstate South Carolina, another important factor often comes into play. Properties above the Fall Line may require test pits to be dug with a backhoe so that soil conditions can be examined at sufficient depth. That means the owner may need to arrange and pay separately for excavation or equipment work in addition to the state application fee.
Once the property is ready, an SCDES evaluator or other qualified professional examines the soil and site conditions. The evaluation considers things such as soil texture, soil color, drainage characteristics, seasonal groundwater evidence, slope, rock, setbacks, available drainfield area, and the required replacement area.
If the property meets the applicable standards, SCDES may issue a Permit to Construct for an onsite wastewater system.
That permit is valuable documentation. It should be kept with the property records and made available to Realtors, buyers, builders, and other professionals involved in the transaction.
A current permit can significantly improve buyer confidence because it replaces assumptions with actual information.
How Much Does a Perc Test or Septic Evaluation Cost?
The cost is often misunderstood because people hear the state application fee and assume that is the entire cost.
The SCDES residential application fee is currently about $150, but the total amount spent can be higher.
If test pits need to be excavated, the property owner may need to pay a private backhoe operator. If the site requires a Professional Soil Classifier, that creates an additional professional fee. If the property requires the involvement of a Professional Engineer or a specialized septic design, costs can rise considerably.
SCDES also has processes that allow a Professional Soil Classifier to perform certain evaluations. In some state referral arrangements, participating soil professionals may charge up to approximately $450 for a qualifying site evaluation, although private professional fees can vary depending on the complexity of the property.
This is why I never tell a client, “A perc test costs $150.”
The state application may be $150, but the true cost of determining septic suitability depends on the property.
Even so, I consider this one of the most reasonable due-diligence expenses a landowner can make.
Spending several hundred dollars to understand whether a property can support septic is insignificant compared with purchasing a piece of land for tens or hundreds of thousands of dollars and discovering later that your intended house cannot be built there.
Should the Seller Do the Septic Evaluation, or Should the Buyer?
This is where my real estate philosophy is very clear.
If I am representing a seller of vacant residential land, I generally prefer that the seller investigate septic suitability before the property goes on the market.
Why?
Because I believe in no surprises.
Imagine listing a beautiful tract of land. The photography looks great. The acreage is appealing. The buyer visits the property, falls in love with it, and makes an offer. We negotiate the contract. The buyer contacts a lender and a builder. Everyone begins moving forward.
Then, several weeks into due diligence, we discover that the proposed homesite will not support a conventional septic system.
Now the buyer is disappointed, the seller is surprised, the transaction is in jeopardy, and we suddenly have a major piece of information that changes how the property should have been priced and marketed from the beginning.
I would much rather know that information before the sign ever goes in the ground.
If the property does support a septic system, that becomes an advantage.
There is a major difference between marketing a property with language such as “seller believes it should perc” and being able to say that the property has a current SCDES septic approval for a certain number of bedrooms.
“Should perc” is speculation.
A permit is evidence.
That does not mean the buyer should waive their own due diligence. A buyer may want a larger home, an accessory dwelling unit, a pool, a detached garage, or a different house location. Their plans may not match the layout used when the seller obtained the permit.
The best approach is for the seller to reduce uncertainty before the property goes on the market while still allowing the buyer to confirm that the property works for their specific plans.
Ideally, the Buyer Should Investigate This Before Ever Purchasing the Land
From the buyer’s side, I feel even more strongly about this.
If you are buying rural or suburban land with the intention of building a home and public sewer is not available, septic suitability should be investigated before closing whenever possible.
I would not recommend buying land based solely on the assumption that it “ought to perc.”
The fact that the neighboring house has septic does not guarantee your property will work.
The fact that the parcel is large does not guarantee it will work.
The fact that the land looks dry does not guarantee it will work.
The fact that a seller says they have “never had a problem with water” does not guarantee it will work.
Soil changes. Topography changes. Seasonal groundwater conditions change. Rock formations change. Septic suitability is site specific.
A buyer may be looking at a gorgeous five-acre tract with a creek, mature hardwoods, excellent schools, privacy, and beautiful views. None of those things answer the wastewater question.
That is why the proper order is simple:
Understand septic first. Buy the land second.
Not the other way around.
What About a House That Already Has a Septic System?
An existing home is somewhat different from vacant land.
If a house already has an operating septic system, I would not normally recommend ordering an entirely new soil suitability evaluation simply because the owner is preparing to sell.
Instead, I would want to understand the existing system.
Where is the tank located? Where is the drainfield? How many bedrooms was the system approved for? Is there documentation on file? Has the system been maintained? Has the tank been pumped? Are there known drainage or repair issues?
In those situations, a septic inspection by a qualified septic professional can be more useful than a new soil evaluation.
This is especially important if the house has been expanded since the original septic permit was issued. A three-bedroom septic system serving a home that is now being marketed as five bedrooms can create questions during a transaction.
That is another version of the same philosophy: know before you list.
What Can Cause Land to Have Septic Problems?
Many property owners are surprised to learn that acreage alone does not determine whether a property can support septic.
A ten-acre parcel can still have septic limitations.
The issue may be heavy clay soils, shallow bedrock, excessive slope, high seasonal groundwater, drainage problems, fill dirt, creeks, wetlands, easements, or simply insufficient usable area once all the required setbacks are taken into account.
South Carolina requires separation between septic systems and various site features, including wells, buildings, property lines, surface water, and drainage areas. These setbacks can significantly reduce the amount of usable land.
This is especially important on narrow lots, lake properties, creek properties, steep terrain, and parcels that have unusual shapes.
Sometimes the most visually attractive building site is exactly where the septic system needs to go.
That can force the owner to redesign the house location around the septic system instead of placing the house where they originally intended.
What Happens If a Property Does Not Pass for a Conventional Septic System?
A failed conventional evaluation does not automatically mean the property is worthless, and it does not always mean the property can never be built on.
It means more investigation is required.
Sometimes another portion of the property may work. On larger tracts, simply relocating the homesite or drainfield area can solve the problem.
In some situations, the proposed bedroom count may be affecting the size of the required drainfield. A smaller residence may require less wastewater capacity. That does not solve every soil problem, but it can matter where usable area is limited.
A Professional Soil Classifier can also be very helpful when a conventional evaluation is unsuccessful. These professionals are licensed in South Carolina and can conduct more detailed soil investigations.
Depending on the site, there may also be alternative or engineered septic systems that can work where a traditional system cannot.
That possibility needs to be evaluated carefully because specialized systems can be substantially more expensive. The cost difference between a simple conventional septic system and a complex engineered system can run into thousands of dollars.
In more difficult cases, a South Carolina-licensed Professional Engineer may become involved in designing the wastewater system.
Sewer extension is another possibility in certain locations. If public sewer is nearby, the owner may be able to investigate connection or extension costs. Whether that is practical depends on distance, utility policies, easements, tap fees, grading, and infrastructure.
If none of those options works, the property may still have value for uses other than a traditional residential homesite. Agricultural use, timber, recreation, hunting, conservation, assemblage with an adjoining property, or other permitted uses can still create value.
But the market value may be very different.
How Does Septic Suitability Affect the Value of Land?
This is one of the most important real estate questions.
There is no universal formula that says land loses a certain percentage of its value if it cannot support a conventional septic system.
The answer depends on the property’s highest and best use.
Consider two nearly identical ten-acre tracts beside one another.
Both have similar road frontage. Both have similar topography. Both have mature trees. Both are in the same school district.
One parcel has confirmed septic approval for a four-bedroom residence.
The other has no septic approval and significant soil concerns.
Those properties may not have the same value.
Why?
Because the buyer is not simply buying ten acres.
The buyer is buying what those ten acres can do.
If the likely buyer is purchasing the property to build a home, septic approval is directly connected to the utility of the land.
Uncertainty also has a real financial impact.
A buyer looking at a property with no septic information immediately begins calculating risk. Can they build? How many bedrooms? Where will the house go? Will they need an engineered system? How much will it cost? Could they spend thousands of dollars on plans and due diligence only to find out the project is not feasible?
The more questions that remain unanswered, the more cautious the buyer tends to become.
That usually means either a lower offer, a longer due-diligence period, more contingencies, or no offer at all.
This is one reason a seller-provided septic approval can improve marketability.
I would much rather market a parcel as having documented septic approval for a four-bedroom home than market the same parcel with no information at all.
A permit does not automatically add a specific dollar amount to the value, but it removes risk.
And in real estate, reducing uncertainty can be extremely valuable.
A Failed Conventional Septic Evaluation Does Not Mean Zero Value
This deserves emphasis because people often hear the word “failed” and assume the worst.
Before deciding that a property has little value, I would want to know much more.
Was the entire tract evaluated, or just one proposed homesite?
Was another location considered?
Has a Professional Soil Classifier reviewed the property?
Is an alternative or engineered system possible?
Is sewer reasonably close?
Could an adjoining parcel solve part of the problem?
Could the intended homesite or house size be changed?
Does the land still have agricultural, recreational, timber, or assemblage value?
Those questions need to be answered before anyone can responsibly determine how much septic limitations affect the market value.
Why I Prefer Sellers to Know Before They List
Some sellers ask me why they should spend money on septic testing when the buyer can do it during due diligence.
They certainly can.
But I believe knowledge creates leverage.
If the property works, we know we have a legitimate building site and we can market it with greater confidence.
If the property has limitations, we can price it accordingly before buyers begin negotiating with us.
What I do not want is to discover a major problem in the middle of a transaction when everyone is under pressure.
That is the same reason I prefer to identify title problems, survey issues, easements, encroachments, structural issues, and other foreseeable concerns before they become a crisis.
A seller who discovers an issue before listing has options.
A seller who discovers it three weeks before closing has pressure.
Those are very different situations.
My Recommendation to South Carolina Landowners
If you own vacant land in South Carolina that is being marketed as a residential building site and there is no public sewer, I recommend investigating septic suitability before you put the property on the market.
Start by verifying whether sewer is available. Review your plat and deed. Identify likely building areas. Think realistically about the type of home most buyers would want to build. Then apply through SCDES and obtain the appropriate site and soil evaluation.
If the property does not qualify for a conventional system, do not immediately assume the worst. Consult a Professional Soil Classifier and determine whether another location, another system type, or an engineered solution is possible.
Once you know the answer, you can make better decisions about price, marketing, development potential, and buyer expectations.
That is exactly what good due diligence is supposed to accomplish.
South Carolina Septic Resources
South Carolina property owners can begin with the South Carolina Department of Environmental Services at:
des.sc.gov/permits-regulations/septic-tanks
The SCDES ePermitting portal can be found at:
SCDES also publishes a useful “Before You Buy Land” guide for prospective purchasers, along with information explaining site inspections and soil evaluations.
For Professional Soil Classifiers, visit the South Carolina Department of Labor, Licensing and Regulation at:
llr.sc.gov/soil
SCDES also provides an online tool to locate septic contractors across South Carolina.
These resources are worth reviewing before purchasing, subdividing, marketing, or planning construction on land that will rely on an onsite wastewater system.
The Bottom Line
If there is one point I want land buyers and sellers to take away from this discussion, it is this:
Do not confuse owning land with owning a guaranteed building site.
If public sewer is unavailable, septic suitability may be one of the single most important factors affecting the residential usefulness and value of that property.
Buyers should investigate it before closing.
Sellers should strongly consider investigating it before listing.
And ideally, the current owner should have investigated it before purchasing the land in the first place.
When I represent a seller, I want to know whether the property can support septic, where that system can go, how many bedrooms it can serve, whether a conventional system will work, and whether there are any conditions that may affect construction.
Those answers allow us to price intelligently, market honestly, and negotiate from facts instead of assumptions.
That is what I mean when I say I believe in no surprises.
Because when it comes to land, the most expensive surprises are often the ones that could have been discovered before closing.
David Locke is a Realtor® and Broker/Owner with Locke & Key Associates at Keller Williams Western Upstate, serving Anderson, Oconee, Pickens, Greenville, and surrounding Upstate South Carolina communities. This article is intended for general real estate information and should not replace site-specific guidance from SCDES, a licensed Professional Soil Classifier, Professional Engineer, surveyor, attorney, septic contractor, or other qualified professional.
