If you’re buying a home or building on land in the Raleigh or Wake Forest area, one of the first questions you’ll need to answer is simple but important: sewer or septic?

Homes close to the city or near a wastewater treatment plant are typically connected to city sewer. But if you’re farther out—especially in rural parts of Wake County or Franklin County—you’ll likely have a septic system. It’s your own mini waste treatment plant right in the yard. In some areas, if your property is within 300 feet of a city sewer line, the county may require you to hook in.

The Anatomy of a Septic System

A standard septic system includes several key parts that work together to manage household wastewater:

• Sewer Pipe: Carries wastewater from your home to the septic tank.

• Septic Tank: Usually 1,000 gallons or more, this tank holds solids and liquids long enough for natural separation to occur.

• Dosing Tank: Some systems include this extra tank with a pump to move water through the system.

• Delivery Line: Connects the tank to the distribution box.

• Distribution Box: Levels the flow of water before it reaches the drain field.

• Absorption Field: Sometimes called laterals or “fingers,” this is where wastewater moves through sand, stone, or advanced materials for natural treatment.

• Perimeter Drain: A French drain that lowers groundwater around the system, used only when necessary.

How a Septic System Works

Here’s the simple version:

Solids sink to the bottom of the tank and form what’s called the sludge layer. Grease and oils rise to the top, creating a scum layer, and liquid in the middle—known as effluent—moves out to the drain field.

Microorganisms in the tank break down solids, reducing organic matter and filtering out harmful elements. Before leaving the tank, water passes through an effluent filter, which keeps smaller solids from clogging the drain field. The soil in the absorption field finishes the cleaning process before the water reenters the environment.

Maintenance: How Often Should You Pump the Tank?

We recommend having your tank pumped every two years, depending on how much water your household uses. If you have a dosing tank, it should be cleaned about every four years. And don’t forget the effluent filter—it should be cleaned annually. If it clogs, it can cause backups in your home.

What’s the Role of a Soil Test?

Before a septic system can be installed, a soil test (or “evaluation”) is required. This determines how well your soil absorbs and filters water, helping the health department decide what type of system your property needs.

Soil scientists analyze everything from the structure and depth of your soil to its drainage rate and limiting layers. It’s the first step toward getting your septic permit and, in many cases, your building permit too.

And no, a “perc test” isn’t the same thing. While older systems used percolation tests, today’s counties require a full soil analysis by a registered soil scientist.

How to Get a Septic Permit

Every county handles this a little differently, but here’s the usual process:

• Get your soil test.

• Submit an application (and possibly a well permit).

• Provide your house plans so the system can be sized correctly based on bedrooms.

• The county reviews and issues a septic design or requirements letter.

• Once approved, you’ll receive your septic permit—which you’ll need before getting a building permit.

• Your installer and soil scientist will often meet with the county inspector to confirm the final design.

• Choosing the Right Spot for Your House

• While you can technically build anywhere that meets setback and zoning requirements, elevation and drainage matter. Higher ground is generally better.

• Your builder, soil scientist, and local inspector can help decide the best placement for your home, driveway, and septic system. It’s smart to plan these early—before you start construction.

Thinking About a Basement?

This one’s all about your soil.

Some land is well-drained and perfect for basements; other lots hold too much groundwater. Even if you can build a basement, sometimes you shouldn’t. A soil scientist can check for high water tables or limiting layers that could lead to ongoing sump pump issues and extra costs later.

If a basement is a must-have, test the ground before buying the property.

Want a Pond?

A pond can add beauty and value—but it depends on your soil and your county’s rules. Some counties require a pond permit, while others don’t.

In general:

• Low areas or natural drainage spots are ideal.

• Darker soil is usually better.

• Rocky ground isn’t great.

And if your neighbor’s pond holds water well, yours might too.

Still, there are no guarantees. Always consult a soil scientist or pond specialist, and consider installing a pond liner to prevent leaks from sand veins.

What About the Extra Dirt?

One of the biggest mistakes we see? Spreading leftover dirt across your property after digging for a pond, driveway, or basement.

That “fill material” can create big headaches down the road—especially if you ever need a new septic system. Septic systems can’t be installed in disturbed or moved soil, and once you’ve spread fill across your lot, it’s nearly impossible to reverse.

Bottom line: don’t move dirt unless you’ve planned exactly where it’s going. If you’re unsure, ask your soil scientist before making changes.

Final Thoughts from Jim and Lori

Whether you’re buying an existing home or building your dream home from the ground up, understanding how septic systems work helps you protect your investment. Septic care is simple once you know the basics—and when maintained properly, your system can last 30 years or more.

If you’re planning to buy land or a home with a septic system in Wake Forest, Raleigh, or anywhere in the Triangle, we can help guide you through inspections, permits, and what to look for before you buy.

You have friends in the real estate business.

Reach out to Jim and Lori Hill, Realtors with LPT Realty, and let’s make sure your next home is built on solid (and healthy) ground.