At-Grades & Mound Systems

At-Grade Systems

An at-grade system is a type of septic system used when the soil is not deep enough for a normal system. Instead of placing the pipes down in the ground, the pipes are set on top of the natural soil surface. Clean sand or soil is then placed over the pipes to help the system work properly. At-grade systems are used when the soil is too shallow, when the water table is high, or when water does not drain well enough for a standard system.

In an at-grade system, wastewater flows from the home into a septic tank. From the tank, the water moves into the pipes that sit on top of the ground. A layer of sand or soil helps clean the water as it moves through, and the soil filters the water before it reaches the natural ground.

Below are the documents you can download for at-grade system information and forms.

Mound Systems

A mound system is used when the soil cannot soak up water well enough on its own. To fix this, a mound of clean sand is built on top of the ground to help treat the water before it reaches the natural soil. Mound systems are needed when the soil is too wet, drains too slowly, is too shallow, or when the water table is too high for a regular system.

In a mound system, wastewater flows from the house into a septic tank. The water is then pumped into pipes inside the sand mound. The sand filters and cleans the water first. After the water moves through the sand, it slowly enters the natural soil underneath the mound.

Below are the resources you can download for mound systems.