Skip to content

What Is a Perc Test (and Why Does It Matter)?

Short answer

A percolation (perc) test measures how fast water drains through your soil. It's the single biggest factor in sizing your drainfield and choosing your system type — no septic system can be designed or permitted without it.

What it measures

The test gauges your soil's texture, class, and how quickly it absorbs water across the proposed drainfield area — the soil's loading rate.

Why it sets your system

Better-draining soil needs a smaller drainfield and may allow a conventional system; tighter, clay-heavy soil needs a larger field or an aerobic system. The result drives the whole design and cost.

What to expect

We perform the test, document the results, and design a permitted system around your actual site conditions — so it passes county inspection and performs for decades.

Ready for a real number?

Get your instant estimate, or call and we'll schedule a free on-site evaluation.