Washtenaw County, Michigan septic permits and requirements

Permitting authority

Washtenaw County Health Department — Environmental Health Division / Septic Systems Program

Washtenaw County Health Department Environmental Health Division administers county septic permitting, soil evaluations, installer certification, inspections, operating permits, and septic records through the county Environmental Health program.

Michigan onsite-wastewater framework

Michigan EGLE states that onsite wastewater management is a required local-health-department service under the Michigan Public Health Code. EGLE provides oversight and technical support, while local health departments review and approve ordinary residential onsite systems. Larger or specialized systems can involve additional state review.

Confirm sewer availability and project scope first

These county programs apply to onsite sewage disposal. Municipal sewer availability, wastewater flow, commercial use, additions or bedroom increases, alternative treatment, and large-capacity systems can change the required approval path. Confirm current local and state requirements before excavation or construction.

Environmental Health administers septic permits and records

Washtenaw County Health Department Environmental Health provides sewage permits, soil evaluation, permit inspections, operating-permit information, and searchable well/septic records for county-regulated onsite systems.

A sewage permit is required before installation

Washtenaw County states that a sewage permit must be obtained before a sewage system may be installed. The county provides project-application requirements and inspection information as part of that permit process.

Soil evaluation is required for unsewered new-home sites

Washtenaw County states that a soil evaluation is required before building a home that is not served by a municipal or centralized sewage treatment facility. The evaluation informs whether an onsite sewage system can be approved and how it must be designed.

Installation and repair contractors must be county-certified

Washtenaw County states that sewage-system installations and repairs must be performed by individuals certified by the Washtenaw County Environmental Health Division. The county maintains information and a list of certified contractors.

System design must account for county isolation distances and sizing

The county installation guidance separately identifies minimum isolation distances, sewage-system sizing, site plans, soil evaluation, and permit inspection as required design/review considerations. Applicants should use the county project requirements for the specific parcel and system type.

Official sources

SepticScope summarizes public-agency information for planning purposes. The permitting agency's current instructions control if they differ from this guide.