A beautiful piece of land can look perfect on paper.

Five acres. A quiet road. Great views. Maybe enough room for a custom home, a barn, a garden, or a few animals.

Then someone says:

“The land doesn’t perc.”

For a buyer who has never purchased vacant land, that statement can sound like the property is essentially worthless. That isn’t necessarily true. But it can dramatically change what you can build, what the property is worth to you, and how much investigation should happen before you buy it.

In rural parts of Lancaster County and throughout Pennsylvania, understanding water and sewage is one of the most important parts of evaluating vacant land.

First: What Does “Perc” Mean?

A percolation test, commonly called a perc test, is part of determining whether soil may be suitable for an on-lot sewage disposal system.

If a property isn’t served by public sewer, wastewater from a house has to go somewhere. Usually that means some form of septic system.

The Pennsylvania Department of Environmental Protection administers sewage facilities requirements under Act 537, while much of the actual on-lot sewage program is handled at the municipal or local-agency level. Site investigation and percolation testing are part of that process.

A failed perc test generally means the tested location isn’t suitable for the septic system being proposed. It does not automatically mean nothing can ever be built on the property.

That distinction matters.

A Failed Perc Test Is Not the Same as “Unbuildable”

There can be several possibilities after land fails conventional testing.

Another portion of the parcel might have different soil conditions. Depending on the site, additional testing could identify another suitable area. Certain properties may also be candidates for alternative sewage systems, although those systems can be substantially more complicated and expensive.

In other cases, public sewer could potentially become available in the future.

And sometimes, after all the investigation is complete, there simply isn’t a practical sewage solution for the proposed house.

That is why I would be cautious about labeling land “unbuildable” based only on someone saying that it doesn’t perc.

The better question is:

What sewage disposal options have actually been investigated and documented for this property?

What About a Well?

This is a separate issue.

A perc test determines sewage suitability. It does not determine whether you can drill a well.

Many rural Lancaster County properties rely on a private well for their drinking water. Pennsylvania does not currently have statewide construction or siting standards for private residential wells, although municipalities can have their own requirements. Pennsylvania does require water-well drillers to be licensed.

The bigger practical question is whether the property can produce an adequate and acceptable water supply.

Just because there is groundwater underneath a property doesn’t guarantee that a particular well will provide the quantity or quality of water you expect.

Before buying land that will require a private well, buyers should investigate local requirements, nearby well information when available, expected drilling depths and costs, water-quality concerns, and the possibility of drilling a low-producing or unsuccessful well.

A licensed well driller and, when appropriate, a geologist can provide much better site-specific information than assumptions based on neighboring properties.

The More Serious Scenario: No Practical Septic AND No Public Sewer

This is where vacant land requires considerably more caution.

Imagine buying a parcel with the intention of building a home and discovering afterward that:

• there is no public sewer available,
• the property cannot obtain approval for a workable on-lot sewage system,
• extending public sewer isn’t economically realistic, and
• your intended use requires wastewater facilities.

You may own a lovely piece of ground, but not necessarily a residential building lot.

Pennsylvania’s Act 537 program specifically requires municipalities to plan for sewage disposal associated with new land development. Depending upon the project, that can involve an on-lot system, connection to a sewer system, or another approved sewage facility.

This is why the value of vacant land should never be judged simply by acreage.

Five buildable acres and five acres with severe development limitations are two very different assets.

Can You Still Use Land That Can’t Support a House?

Potentially, yes.

Land without an approved residential sewage solution may still have value for agriculture, recreation, hunting, open space, adjoining-property expansion, conservation, timber, or other uses permitted by local zoning.

But zoning and sewage approval are two separate questions.

A use being permitted under the zoning ordinance does not automatically mean the property has the water and sewage infrastructure necessary to actually develop it that way.

Likewise, a property being legally recognized as a parcel does not necessarily mean it is an approved building lot.

That distinction can surprise buyers.

What About Holding the Land Until Public Sewer Arrives?

This can be a legitimate investment strategy, but it is speculative.

A sewer line running somewhere nearby does not necessarily mean a property can connect to it. Capacity, municipal planning, easements, engineering, tapping fees, extension costs, and other issues can affect whether connection is possible.

Pennsylvania municipalities maintain sewage facilities plans under Act 537, and proposed new development may require revisions or other planning procedures.

If the investment thesis is “I’ll buy this inexpensively now because sewer will eventually come through,” I would want considerably more evidence than a neighbor saying sewer is coming.

Ask the municipality.

Before Buying Rural Land, Investigate the Dirt Before Falling in Love With the View

When I evaluate vacant land with a buyer, I want to understand several things before treating it as a residential building site:

Zoning: What can legally be built or operated there?

Sewage: Is public sewer available? If not, has the property been tested for an on-lot system? Are there previous test results or permits?

Water: Is public water available? If not, what is known about wells in the area and local well requirements?

Access: Does the parcel have legal and practical road access?

Utilities: Where are electric, internet, gas and other services?

Physical constraints: Are there wetlands, floodplain, steep slopes, easements, rights-of-way or other restrictions?

Subdivision history: Was the parcel created as an approved building lot, or was it created for another purpose?

And most importantly:

What exactly is the buyer planning to do with the property?

A parcel that makes no sense for someone wanting to build a house next year could still make perfect sense for a neighboring farmer, recreational buyer or long-term investor.

Don’t Assume Cheap Land Is a Bargain

When vacant land is noticeably less expensive than other acreage nearby, there is often a reason.

Sometimes the reason is harmless.

Sometimes it is zoning.

Sometimes it is access.

Sometimes it is wetlands or topography.

And sometimes it is because providing water and sewage to the property is difficult, expensive or impossible under current conditions.

That doesn’t automatically make it a bad property. It means its price should reflect what the land can realistically be used for.

For buyers, the safest approach is to make land purchases contingent upon the investigations that matter for the intended use and to involve the municipality, Sewage Enforcement Officer, well professionals, engineers, surveyors or other specialists as appropriate.

With vacant land, due diligence isn’t something to do after you buy.

Due diligence is how you determine what you’re actually buying.

This article is intended for general real estate education and is not engineering, environmental, legal or sewage-system advice. Requirements and site conditions vary by municipality and property.