Professional Perc Testing & Soil Evaluation
When you’re planning a new septic system, a percolation test—often called a perc test—is the first step to determining if your soil can properly absorb and treat wastewater. At McNair Septic Design & Consulting, we provide fast, reliable percolation tests across Clark, Cowlitz, and Lewis County, helping homeowners and property developers move forward with confidence.
Percolation Testing and Soil Evaluation in
Clark, Cowlitz, Lewis, Skamania, and Klickitat County
A perc test measures how quickly soil absorbs water, which is vital to designing a safe and efficient septic system. Our licensed septic designers perform these tests with precision, ensuring compliance with county health requirements. Whether you’re building a new home in Vancouver or Battle Ground, adding a second dwelling in Longview or Castle Rock, or planning rural development in Centralia or surrounding areas, McNair Septic provides the expertise needed to start your project on solid ground.
Perc testing is more than just digging test holes—it’s about evaluating soil type, seasonal water tables, and absorption rates. By working with McNair Septic, you’ll receive a clear report that satisfies county requirements and gives you a roadmap for septic design. Because we also handle site and soil evaluations, septic system design, and consulting, our team ensures every step aligns with your long-term property goals.
One of the biggest frustrations homeowners face is county paperwork and permitting. We eliminate that stress by managing the entire process for you, from applications to approvals, so you don’t lose time to confusion or delays. Our three generations of septic expertise in Washington mean your property is evaluated with decades of proven knowledge.
When you choose McNair Septic, you don’t just get a percolation test—you get a partner who provides property-specific solutions. Every test we perform considers your soil conditions, building plans, and future land use, ensuring your septic system is designed to last.
Three Generations of Septic Design Expertise
Our family has been designing septic systems in Washington since the 1970’s. That legacy means decades of hands-on knowledge are built into every design, ensuring you get a system that lasts.
4.9-Star Reputation Backed by Hundreds of Happy Customers
Homeowners choose us because we combine creative problem-solving with practical solutions. Unlike other companies, our reviews reflect a consistent track record of designs that fit budgets, meet regulations, and work flawlessly.
Transparent Communication from Start to Finish
We keep you informed with clear timelines, updates, and next steps—so you’re never left wondering where your project stands.
Proven Process That Simplifies a Complicated System
We’ve refined our approach over decades to make septic design as simple and stress-free as possible. From your first call to final approval, our process saves you headaches, time, and money.
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Frequently Asked Questions About Percolation Testing
What is a percolation test and why do I need one?
A percolation test measures how quickly soil absorbs water, which determines if your property is suitable for a septic system and what type of system can be installed.
How long does a percolation test take?
Most tests can be completed in a single site visit, with results and reports delivered to the county shortly after.
Who requires a percolation test?
County health departments require a percolation test for all new septic system approvals, property development, and certain remodels or additions.
Can McNair Septic handle the county applications and fees for me?
Yes, we take care of all county paperwork, fees, and submissions so you don’t have to worry about the permitting process.
What happens if my property doesn’t pass a percolation test?
If your soil isn’t suitable for a standard system, we can design an alternative system—such as a mound, sand filter, or aerobic setup—that meets county approval and works for your property.
