What is the best septic system if your land fails a perc test?

You’ve bought a lot to build your new home away from the city, and it’s perfect. The plans are going smoothly — until you fail the soil percolation test for your new septic system. Suddenly your dream home feels like a dead end.

The good news is that you have options. With the right septic system, you can keep your project on track, even if your land fails a perc test.

In this article, we’ll explain what a percolation test is, why it matters, and what to do if your land is not suitable for a conventional septic tank system. We’ll also explain why the Ecoflo compact biofilter is the ideal septic system for properties with challenging soil conditions.

Table of contents

1.	What is a soil percolation test?
2.	Acceptable percolation rates for septic systems
3.	Reasons why land fails a percolation test
4.	Why Ecoflo is best for land that won't perc
5.	Ecoflo vs. other alternative systems for poor soils
	5.1.	Flatbed biofilters
	5.2.	Aerobic treatment units
	5.3.	ATUs with stream discharge

What is a soil percolation test and why does it matter?

A percolation test measures how quickly water drains through your soil. It’s usually done by a soil scientist, engineer, or another accredited professional.

For properties not connected to a municipal sewer, on-site septic systems handle wastewater treatment in stages. Many systems discharge effluent into soil for final purification. Natural microorganisms in the soil break down contaminants before water reaches groundwater or nearby water sources.

The catch is that soil needs to drain at a certain rate to treat wastewater. If it drains too quickly, wastewater passes through before pollutants are effectively removed. If it drains too slowly, wastewater can pool at the surface, creating health risks for you and your family.

Percolation tests confirm if your soil can absorb and filter wastewater properly, which helps protect nearby groundwater and surface water.

What is a good percolation rate for a septic system?

Premier Tech technician performing a soil percolation test.

Percolation rates measure how long it takes for 1” of water to pass through your soil. Results are usually expressed in minutes per inch (MPI).

Acceptable percolation rates for septic systems vary by state. But in general, your land will pass a perc test in most states if the result is between 1 and 60 MPI.

Soil that percolates faster than 1 MPI may not provide enough contact time to properly treat wastewater. Soil that percolates slower than 60 MPI may drain too slowly for wastewater to pass through.

Reasons why land fails a percolation test

Certain soil and site conditions can prevent water from draining at a rate suitable for a septic system. The main factors include:

Sandy soil
Sand comes in various grain sizes that affect drainage. Coarse sand can allow water to flow too quickly, while finer sand may slow drainage to the point that water can’t pass through.
Clay soil
Clay expands as it absorbs water. This can prevent additional water from passing through, making it difficult for the soil to achieve a safe percolation rate.
Impermeable soil layers
Some soil layers don’t allow water to pass through. Water may percolate initially, but once it hits the impermeable layer, it can’t continue downward, causing it to rise back to the surface.
Shallow bedrock
Dense bedrock acts like a barrier. Water cannot pass through it, leading to pooling or surface backup.
High water table
When groundwater is close to the surface, it can saturate your land and limit the amount of adequate soil available to properly filter and treat your wastewater.
Seasonal saturation
Snowmelt or heavy rainfall can temporarily saturate soil and raise the water table, preventing proper drainage and safe wastewater treatment.

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Why is the Ecoflo compact biofilter the best septic system for land that won’t perc?

Installing the Ecoflo compact biofilter Pack model on a site with poor soil.

Installing the Ecoflo compact biofilter on a property with poor soil.

Failing a percolation test doesn’t mean you’ve reached a dead end in your building plans — it just rules out a conventional septic system.

If you find yourself in this situation, an advanced septic system designed for challenging soil conditions may be the answer.

The Ecoflo compact biofilter, manufactured by Premier Tech Water and Environment, offers two key advantages that make it an ideal solution for properties with failed perc tests: high treatment performance and resilience in poor soils.

High treatment performance

Properties fail perc tests because the soil or site conditions don’t allow wastewater to be absorbed and treated.

The Ecoflo compact biofilter solves this with its coco filter. The coco filter provides advanced treatment directly within the biofilter unit. This allows the system to safely treat wastewater on any property — even those that fail a perc test.

In certain cases, the Ecoflo compact biofilter can bypass soil entirely by discharging effluent to a stream or ditch. This is typically done by adding the Rewatec UV disinfection unit, which can be integrated directly inside the Ecoflo tank.

Resilience to clay and high water tables

Properties with failed perc tests often have clay soil or high water tables. These conditions not only limit the land’s ability to drain wastewater but can also create challenges for septic installations. Clay can compress over time, putting pressure on system components. High water tables can shift systems and stress pipe connections.

The Ecoflo compact biofilter has concrete models that are designed to handle these challenges. Their structural strength withstands the pressure of clay soil, and their weight keeps the system firmly in place when water tables rise.

Natural, renewable, and compostable coco filtering medium used to treat wastewater in Ecoflo biofilter septic systems.

The heart of the Ecoflo compact biofilter: a filter made of 100% natural, renewable, and compostable coco fragments.

How does the Ecoflo compact biofilter compare with other septic systems for poor soils?

Choosing the right septic system starts with having the right information. To help you choose the best installation for land that won’t perc, let’s compare the Ecoflo compact biofilter with other alternative systems in three states: Iowa, New Jersey, and Pennsylvania.

Scenario 1: Ecoflo compact biofilter vs. flatbed biofilters in Iowa

In Iowa, flatbed biofilters are a popular septic system for land that doesn’t perc.

These systems pump wastewater from the septic tank into the biofilter. A nozzle inside the biofilter distributes wastewater across a synthetic filter. The filter removes wastewater contaminants and effluent is sent to a stream or ditch for final dispersal.

Flatbed biofilters offer many of the same benefits as the Ecoflo compact biofilter. Still, there are a few key reasons why Ecoflo stands out.

Simple, non-mechanical components
Flatbed biofilters depend on pumps to spread wastewater over their filter. If the pump fails or there’s a power outage, the system can’t treat wastewater until the problem is repaired.

The Ecoflo compact biofilter takes a simpler approach. It uses a non-mechanical tipping bucket that automatically distributes wastewater across the coco filter. With no pump required for treatment, Ecoflo gives you 24/7 performance in all conditions.
A warranty with no time limit
In Iowa, the leading flatbed manufacturer’s warranty ends after 20 years — no exceptions.

The Ecoflo compact biofilter, on the other hand, comes with a 10-year performance warranty that resets each time you renew the filter. This means your coverage can be extended indefinitely, protecting your system’s performance for as long as you own it.
Easy access to important records
Flatbed biofilter manufacturers don’t keep track of your system’s installation or service records. Instead, your installer and maintenance provider each keep their own files. With different companies managing information in different ways, there’s no guarantee you’ll be able to access your records when you need them.

Premier Tech, the manufacturer of the Ecoflo compact biofilter, provides easy access to an online platform where all your records are stored in one place.

The non-mechanical tipping bucket in the Ecoflo compact biofilter.

The Ecoflo compact biofilter uses a non-mechanical tipping bucket to spread wastewater over the coco filter.

Scenario 2: Ecoflo compact biofilter vs. aerobic treatment units in New Jersey

Aerobic treatment units are a popular option for properties that fail a percolation test in New Jersey.

These systems treat wastewater in three steps:

Wastewater enters the unit’s first compartment, which clarifies wastewater by separating solids from liquids.
The second compartment uses an air pump to promote the growth of bacteria, which feed on wastewater pollutants.
Remaining solids settle in the third compartment, and treated wastewater is sent downstream for final dispersal.

While aerobic treatment units address some of the challenges of a failed perc test, the Ecoflo compact biofilter offers advantages that make it a better long-term solution.

Lower operating costs
Aerobic treatment units rely on an air pump to treat wastewater. The pump needs to run continuously, leading to higher energy bills over time.

By comparison, the Ecoflo compact biofilter requires no electricity for treatment. If a pump is needed to move effluent downstream, energy use is minimal. When installed without a pump, it operates passively with no running costs. Either way, Ecoflo is a better long-term investment.
Reliability for seasonal use
Aerobic treatment units rely on a constant flow of wastewater to keep bacteria alive. During periods of non-use, the bacteria can die. When wastewater enters the system again, it may not be treated effectively until the bacterial population recovers.

Seasonal properties are sometimes left unused for long periods. If your system relies on an aerobic treatment unit, it may not perform as expected when you return.

That isn’t a problem with the Ecoflo compact biofilter. Its coco filter maintains a humid environment that supports bacteria year-round, even during periods of non-use. Such consistent performance makes the system perfect for cabins and other seasonal properties.

Ecoflo compact biofilter installed near a seasonal cabin.

Unlike aerobic treatment units, the Ecoflo compact biofilter offers exceptional performance even after periods of non-use.

Scenario 3: Ecoflo compact biofilter vs. ATUs with stream discharge in Pennsylvania

Aerobic treatment units (ATUs) that discharge effluent to a stream or ditch are popular choices for poor soils in Pennsylvania.

These types of ATUs use two tanks to treat wastewater:

Wastewater enters the first tank, which has three compartments. The first compartment works like a septic tank. It separates heavy solids, scum, and liquid wastewater.
In the second compartment, an air blower provides oxygen to bacteria that consume contaminants.
Remaining solids settle in the third compartment.
Treated wastewater moves into the second tank. This tank provides additional treatment before discharging effluent into a stream or ditch.

While ATUs with direct discharge can be effective, the Ecoflo compact biofilter provides the same benefits without long-term complications.

Smaller footprint
Direct-discharge septic systems often require extra treatment processes to make effluent safe for the environment. For ATUs, this usually means adding at least one more tank, which takes up significant space in your yard. This creates a problem on properties with poor soil, where usable space is already limited.

The Ecoflo compact biofilter is designed for tight spaces. It integrates advanced treatment within a single unit, and it can also be combined with the Rewatec UV disinfection system if direct discharge is required. This leaves more usable space on your property.
Passive treatment
ATUs depend on an air blower to support bacteria that treat wastewater. If the blower fails or loses power, the system can’t function until it’s repaired.

The Ecoflo compact biofilter works differently. It uses no mechanical parts or electricity for treatment. That means you get around-the-clock performance, even during power outages.
Flexible septic tank options
The first compartment of an ATU acts as a septic tank — only smaller. This compartment fills quickly and requires more frequent pumping than a full-sized septic tank. It can also overload if your household generates more wastewater than expected. This can happen when hosting family or friends.

The Ecoflo compact biofilter offers more flexibility. It can be paired with a range of septic tank sizes, allowing you to choose one that matches your needs and reduces the risk of overloading.