Short Answer: Unfortunately, there is no one-size-fits-all answer. It depends on the terms negotiated between the buyer and seller and is part of negotiations.
If you're preparing to sell a parcel of land or looking to buy land for future development, one term that may catch you off guard is the "perc test."
Whether you're unfamiliar with the concept or unsure about who should cover the costs, understanding perc tests is essential when it comes to land transactions.
In this guide, we break down what a perc test is, who typically pays for it, what it costs, and how the results can significantly impact a land deal. With practical insights and expert advice, we’ll help you avoid expensive surprises and make informed decisions.
What Is a Perc Test and Why Is It Important?
A perc test, short for percolation test, is used to determine how well water drains through the soil on a particular property. If you're planning to install a septic system, a perc test is usually a requirement.
The test helps confirm whether the land can support a septic system and is often a dealbreaker in areas without access to a municipal sewer system.
How a Perc Test Works
To conduct a perc test, a soil scientist or licensed inspector digs one or more test holes and fills them with water. They then measure how quickly the water drains. The test evaluates the soil's drainage characteristics and helps determine what type of septic system, if any, can be installed.
Why You Might Need a Perc Test Before Selling or Buying Land
- The local health department may require a perc test to approve a new building permit.
- A buyer might need the test to confirm they can install a septic system.
- If the land is suitable for a septic system, it can dramatically improve market value.
- A failed perc test could meaningfully lower the land’s worth or make it difficult to sell.
Perc tests are a key part of the due diligence process in any land transaction.
Who Pays for a Perc Test? Buyer or Seller?
This is one of the most common questions when it comes to selling land: Who pays for the perc test?
Unfortunately, there is no one-size-fits-all answer. It depends on the terms negotiated between the buyer and seller. Let’s explore the most common scenarios.
Scenario 1: Seller Pays for the Perc Test
In some cases, the property owner may proactively perform the perc test to make the land more appealing to potential buyers.
Advantages for Sellers:
- Increases buyer confidence
- Can justify a higher purchase price
- Speeds up the sale process by addressing testing requirements upfront
A successful perc test improves marketability and may result in faster offers.
Scenario 2: Buyer Pays for the cost of a Perc Test
Often, especially in rural land transactions, the buyer pays for the test as part of their due diligence. This allows the buyer to choose their own inspector and confirm that the land meets their building needs.
Why a Buyer Would Pay:
- They plan to build and need to confirm soil conditions
- The land hasn’t been tested recently or test result is no longer valid
- The buyer prefers not to rely on someone else’s perc test report
Scenario 3: Shared Cost or Negotiated Responsibility
Sometimes, the buyer and seller agree to split the cost of the test or work the cost of the perc test into the purchase agreement. This often happens when both parties are motivated to close the deal.
What Does a Perc Test Cost?
The perc test cost varies significantly depending on your location, testing requirements, soil type, and the complexity of the soil test.
Typical Cost Breakdown:
- Basic residential perc test: $300 - $1,200
- More extensive testing (multiple holes, steep terrain, wet land): $1,500 - $3,000+
- Permitting or inspector fees: May apply, depending on local regulations
Factors that impact the cost include:
- Travel and labor time
- Number of test holes
- Drainage or soil conditions
- Local weather at the time of testing
The initial cost may seem steep, but getting a perc test good result can significantly enhance your land’s value.
Perc Test Requirements
A perc (percolation) test is usually required when you’re planning a septic system / drain field and there’s no municipal sewer. The exact rules are set by your local health/plumbing authority, but the requirements almost always include these parts:
1. Permit + approved tester
Many places require the test to be scheduled/observed by the health department (or their delegate) and performed by a qualified professional (engineer, sanitarian, soil scientist, etc.). For example, Missouri notes perc tests for systems needing DOH permits must be conducted by trained/certified professionals.
2. Site/soil evaluation (often required with or before perc)
A site review may include soil profile pits to check soil layers, restrictive horizons (clay, hardpan), and seasonal water table/bedrock concerns. (Many areas prefer soil morphology evaluations in riskier groundwater settings.)
3. Test hole setup + pre-soak
While procedures vary, a common standard includes:
- Multiple test holes spread across the proposed drain field area (some specs call for six or more).
- Scarify/scratch hole walls/bottom (to remove “smearing” from digging) and often add gravel at the bottom.
- Pre-soak by filling with clear water and keeping water in the hole for at least several hours and preferably overnight (especially in many soils).
4. Measurement + reporting
After pre-soak, refill to a set depth and measure the drop in water level over timed intervals, then convert to a percolation rate (often expressed as minutes per inch or an equivalent metric).
5 “Passing” criteria (varies a lot)
There is no universal pass number - each county/state/city sets limits. For example, Missouri guidance notes results are accepted for design only if rates are between 10 and 60 minutes per inch; outside that range, another evaluation method may be required.
Quick checklist (what inspectors usually want)
- Site plan showing proposed house/septic/drain field + water sources
- Test hole locations + depths + soil notes
- Pre-soak notes (time, water depth)
- Timed drop measurements + calculated perc rate
- Signed report from the qualified tester
What Happens If the Land Fails a Perc Test?
If the land fails, it doesn’t always spell the end of the road. But it does require a closer look at your options.
Why Land Fails a Perc Test
- Poor drainage (e.g., hard clay, high water table)
- Steep slopes or rocky terrain
- Contaminated or compacted soil
A failed perc test means you likely can't install a conventional septic system, which drastically limits the septic system suitability of the property.
Next Steps After a Failed Perc Test
- Conduct a second test in a different part of the parcel
- Investigate whether an alternative septic system is allowed
- Consult with the local health department for options
- Adjust your purchase agreement or ask for a price reduction
It's possible that an alternative septic system could still be approved depending on your area’s rules. However, these systems come with a higher septic system installation price tag.
When Selling Land, Should You Order the Perc Test?
If you’re a landowner or land investor, deciding whether to order the perc test in advance comes down to strategy.
You Might Consider Testing Before Listing If:
- Your land is in a rural area with no sewer system
- You want to attract developers and buyers
- You’re trying to avoid any surprises that might delay or derail negotiations
- Your competition has already conducted perc tests
A known perc test result can reassure buyers and help justify your pricing. It also helps ease negotiations regarding responsibility for the perc test.
If you're listing your land for sale, it’s important to know the common mistakes when selling land, like failing to confirm septic system approval early.
What If You Want to Sell Fast and Skip the Complications?
At Sell Land Cash, we’ve helped hundreds of property owners across the U.S. close quickly without dealing with realtor fees, inspections, or even a perc test.
Because we buy land directly for cash, we often assess parcels “as-is” - meaning you don’t always need to conduct a perc test prior to selling land.
Avoid the red tape, delays, and uncertainty around the cost of the test, and explore how you can sell land efficiently and on your own terms. Want to learn more? See our helpful guide on how to sell land effectively.
Tips to Avoid Unexpected Perc Test Costs
- Speak to your county first: Get clear on testing requirements
- Clarify upfront who pays - buyer or seller
- Include in your agreement whether you’ll need a new test or can rely on an old one
- Use a licensed soil scientist to avoid invalid results
- Budget for contingencies in case the perc test fails
Whether negotiating a deal or trying to make the land more attractive, having a plan around the perc test helps prevent delays and costly surprises.
Final Thoughts: Know Before You Test
Understanding perc testing can significantly impact how smoothly your land transaction goes. It’s more than just checking off one box. The test to confirm if the land can host a septic system could affect everything from permits to price negotiations.
If you’re not sure where to start, or want to explore options to sell land without the stress of extensive testing, reach out to experts like Sell Land Cash. We specialize in buying land directly, fast, and without unnecessary hurdles.
Thinking about dividing your land? Don’t miss our guide on selling part of your land with a mortgage.
Got a parcel and need to move quickly? Let us help you skip the second-guessing and get to closing faster.