Wastewater (Septic) Treatment

Important Requirements if you are installing a septic system:

A local wastewater treatment system permit is ALWAYS required before a system (non-public or public) is installed.
Site evaluations must be performed by a Gallatin County Registered Site Evaluator or a Professional Engineer registered in the state of Montana.
A Gallatin County Registered Installer must be on-site during the installation of every system.

Local Wastewater Treatment System Application Process

Types of Wastewater Treatment Systems:

Non-public Wastewater Treatment Systems

Non-public wastewater treatment systems (individual/shared, multi-user) are permitted and installed in accordance with state and local regulations. Proper placement, type, and sizing of systems are based on either a Certificate of Subdivision Approval (COSA) or a site evaluation which assesses the site to determine if suitable conditions exist for on-site wastewater treatment and dispersal.

Public Wastewater Treatment Systems

Montana Department of Environmental Quality (MDEQ) has primary responsibility for public wastewater treatment systems, which are defined as serving more than 24 persons for more than 60 days a year or having more than 14 connections.

Septic Pumpers

Septic pumpers are required to obtain a license from MDEQ. Their equipment and disposal sites are regulated to ensure proper treatment of waste.