Looking for your permit? Try our ONLINE PERMIT DATABASE  

Sewage is a potential source of contamination. Many homes in the county have on-site wastewater disposal systems that dispose of sewage into the ground. Gradually that sewage, if not properly treated, can contaminate our drinking water. The design, construction and location of on-site wastewater disposal systems are regulated to ensure that drinking water quality is not negatively impacted by the placement and design of these systems.

Certified Installers List

Septic system installers must be certified by the Missoula Health Department in order to legally install a septic system in Missoula County. More info on Septic Installer Certification.....

 Education  Educational materials on how your septic system works and how to perform maintenance on it.
 FAQ  Frequently asked questions: septic systems, wells, and other environmental health questions.
 Fees  Water & wastewater related fees, fees for land related services increased on April 11, 2022.
Groundwater Monitoring
 Groundwater monitoring may be required before applying for a septic permit. Click here for an application.

Percolation Tests

The requirement for percolation tests (aka perc tests) is determined during the site evaluation process.

PERMITS: Septic & Well

The permitting process is in place to protect public health and environmental quality from risks associated with improper disposal of wastewater. Click here for an application.

Request Septic Information Request a permit record of an existing system or a copy of the sanitation approval documents for a piece of land.
 Rules  Environmental Health rules and regulations.
Septic Determination Septic Determinations are required before enlarging or significantly altering a structure. They are also used in a variety of other situations to determine whether a septic permit is required. Click here for an application.

Site Evaluations

A site evaluation may be necessary before applying for a septic permit to ensure that your site is suitable for a system. Click here for an application.


The Health Department is contracted by MT DEQ to review subdivisions in Missoula County. 

Water Testing

Test your drinking water for coliform bacteria at the Missoula County Water Lab.

Well Logs
 The Health Department does not manage or store well logs, but they can be found online with the Groundwater Information Center (GWIC).
 Variances  Current requests for a variance from the Health Code.



Environmental Health rules and regulations.

Environmental Health rules and regulations.

Environmental Health rules and regulations.

Environmental Health rules and regulations.

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