#1 in Septic Services – Responsive, Professional & Courteous

NAWT Certified Inspectors and Installers

Realtors Preferred Septic Services Company

Call or text us now @ 719-687-6435

Why Septic Systems Fail – Repairing a Leach Field

The purpose of a standard septic system (without a the Pirana^® ) is to recycle and purify the water component of sewage on your property where the sewage originates. This is done by the three components of a septic system essentially by filtration. Learn about the three parts and function of your septic system and what causes failure below.

A filter is defined as an appliance, apparatus, device or process that removes a portion of any stream of material passing through it. That defines how the three parts of a septic system work. The first filter is the anaerobic septic tank (no oxygen in the water); the second filter is the construction of the disposal field; the third filter is the native soil surrounding the disposal field that provides the final treatment.

First Filter

Sewage enters an anaerobic septic tank as solids carried in water. Human intestinal bacteria and microbes in the feces survive in an anaerobic (no oxygen) septic tank. They become suspended in the water. The bacteria breaks down the solids in the water into two layers: settled sludge on the bottom and floating solids on the surface. Eighty to ninety percent of solids are retained in the septic tank within these two layers. The water between these two layers is the waste water that will flow into your disposal field. It contains reduced numbers of problematic intestinal bacteria, organic material and fine suspended particulates. This contaminated anaerobic (no oxygen) water leaves the septic tank and flows to your disposal field. This separation and retention of solids in your septic tank the first filter.

Second Filter

The contaminated anaerobic (no oxygen) water from the septic tank enters the disposal field. The anaerobic (no oxygen) contaminated water slowly moves through the disposal field allowing some of the soluble organic material to settle to the bottom of the disposal field along with suspended particulate matter, including bacteria and microbes This forms a kind of sludge referred to as biomat. Some of the waste water with reduced contamination is then absorbed by the surrounding native soil. This process is filtration.

Third Filter

The twice filtered contaminated anaerobic (no oxygen) water is then absorbed by the aerobic native soil surrounding the disposal field.

After passing through three to five feet of undisturbed aerobic native soil the water will be purified by the soil pores capturing and holding the remaining soluble organic matter, particulates, bacteria, and microbes in the contaminated water. The surfaces of the undisturbed native soil in the disposal field capture the highest concentration of the soluble organic matter, particulates and bacteria, and microbes. Anaerobic intestinal bacteria colonize these infiltrative surfaces. They secrete a black slime layer called ‘biomat.’ The biomat slime also filters and holds organic matter, particulates, and microbes.

Leach field failure is caused by biomat slime. Biomat slime clogs the soil pores in the infiltrative surfaces of the leach field inhibiting the movement of water into the native soil. The bottom of the leach field clogs first. Eventually a small portion of the contaminated water can’t be absorbed each day. Contaminated water collects in the bottom of the leach field. Where the contaminated water contacts the side walls of the leach field, intestinal bacteria colonize these surfaces secreting more clogging biomat. The liquid depth of the contaminated water in the leach field rises. Over years and decades, the biomat clogs all of the infiltrative surfaces of the leach field and the leach field fills with contaminated water. Failure of the disposal field occurs. Per the Federal EPA, Biomat is the cause of 95% of septic system failures.

Common Septic System Problems

Septic System failure has a number of common symptoms:

1) Soft, damp soil over the disposal field or septic tank.

2) Wet spots or standing water over the leach field or septic tank.

3) Slow draining toilets or not draining at all when they are flushed.

4) Sewage coming out of the shower or tub drain when the toilet is flushed.

Foul, nasty odors occur with most failure symptoms.

Before the Pirana^®, the only solution to a failed septic system was to replace the leach field. Increasingly, complicated engineered treatment systems are required that cost tens of thousands of dollars more. These engineered systems are so inefficient they still require the three filters after adding an aerobic process between the first and second filter. Since 2000, the Pirana^® has provided the only certified cost-effective alternative to this expensive and damaging solution.