Septic Systems in Tennessee

95 counties · ~30% of homes on septic · ~614,608 septic systems

State Regulation Overview

Regulatory Body
Tennessee Department of Health/Environment
Inspection Required for Sale
No / Varies by county
Nitrogen Reduction Areas
No
Advanced Treatment Areas
No

Contact county health department for specific requirements.

Top Counties by Septic Systems

Shelby County
~33,471 septic homes
Knox County
~28,738 septic homes
Davidson County
~25,772 septic homes
Williamson County
~22,295 septic homes
Hamilton County
~21,972 septic homes

All Counties in Tennessee

Anderson County
77K pop · ~30% septic
Bedford County
50K pop · ~30% septic
Benton County
16K pop · ~36% septic
Bledsoe County
15K pop · ~42% septic
Blount County
135K pop · ~22.5% septic
Bradley County
109K pop · ~22.5% septic
Campbell County
39K pop · ~36% septic
Cannon County
15K pop · ~42% septic
Carroll County
28K pop · ~36% septic
Carter County
56K pop · ~30% septic
Cheatham County
41K pop · ~36% septic
Chester County
17K pop · ~36% septic
Claiborne County
32K pop · ~36% septic
Clay County
8K pop · ~42% septic
Cocke County
36K pop · ~36% septic
Coffee County
58K pop · ~30% septic
Crockett County
14K pop · ~42% septic
Cumberland County
61K pop · ~30% septic
Davidson County
716K pop · ~9% septic
Decatur County
11K pop · ~42% septic
DeKalb County
20K pop · ~36% septic
Dickson County
54K pop · ~30% septic
Dyer County
37K pop · ~36% septic
Fayette County
42K pop · ~36% septic
Fentress County
18K pop · ~36% septic
Franklin County
43K pop · ~36% septic
Gibson County
50K pop · ~30% septic
Giles County
30K pop · ~36% septic
Grainger County
24K pop · ~36% septic
Greene County
70K pop · ~30% septic
Grundy County
14K pop · ~42% septic
Hamblen County
64K pop · ~30% septic
Hamilton County
366K pop · ~15% septic
Hancock County
7K pop · ~42% septic
Hardeman County
25K pop · ~36% septic
Hardin County
27K pop · ~36% septic
Hawkins County
57K pop · ~30% septic
Haywood County
18K pop · ~36% septic
Henderson County
28K pop · ~36% septic
Henry County
32K pop · ~36% septic
Hickman County
25K pop · ~36% septic
Houston County
8K pop · ~42% septic
Humphreys County
19K pop · ~36% septic
Jackson County
12K pop · ~42% septic
Jefferson County
55K pop · ~30% septic
Johnson County
18K pop · ~36% septic
Knox County
479K pop · ~15% septic
Lake County
7K pop · ~42% septic
Lauderdale County
25K pop · ~36% septic
Lawrence County
44K pop · ~36% septic
Lewis County
13K pop · ~42% septic
Lincoln County
35K pop · ~36% septic
Loudon County
55K pop · ~30% septic
Macon County
25K pop · ~36% septic
Madison County
99K pop · ~30% septic
Marion County
29K pop · ~36% septic
Marshall County
34K pop · ~36% septic
Maury County
101K pop · ~22.5% septic
McMinn County
53K pop · ~30% septic
McNairy County
26K pop · ~36% septic
Meigs County
13K pop · ~42% septic
Monroe County
46K pop · ~36% septic
Montgomery County
220K pop · ~22.5% septic
Moore County
6K pop · ~42% septic
Morgan County
21K pop · ~36% septic
Obion County
31K pop · ~36% septic
Overton County
23K pop · ~36% septic
Perry County
8K pop · ~42% septic
Pickett County
5K pop · ~42% septic
Polk County
18K pop · ~36% septic
Putnam County
80K pop · ~30% septic
Rhea County
33K pop · ~36% septic
Roane County
53K pop · ~30% septic
Robertson County
73K pop · ~30% septic
Rutherford County
341K pop · ~15% septic
Scott County
22K pop · ~36% septic
Sequatchie County
16K pop · ~36% septic
Sevier County
98K pop · ~30% septic
Shelby County
930K pop · ~9% septic
Smith County
20K pop · ~36% septic
Stewart County
14K pop · ~42% septic
Sullivan County
158K pop · ~22.5% septic
Sumner County
196K pop · ~22.5% septic
Tipton County
61K pop · ~30% septic
Trousdale County
12K pop · ~42% septic
Unicoi County
18K pop · ~36% septic
Union County
20K pop · ~36% septic
Van Buren County
6K pop · ~42% septic
Warren County
41K pop · ~36% septic
Washington County
133K pop · ~22.5% septic
Wayne County
16K pop · ~36% septic
Weakley County
33K pop · ~36% septic
White County
27K pop · ~36% septic
Williamson County
248K pop · ~22.5% septic
Wilson County
148K pop · ~22.5% septic

Septic Systems in Tennessee

Approximately 30% of homes in Tennessee rely on septic systems for wastewater treatment, totaling an estimated 614,608 septic systems across the state's 95 counties. This places Tennessee among the states with significant decentralized wastewater infrastructure.

Septic Regulations in Tennessee

Septic regulations in Tennessee are administered by Tennessee Department of Health/Environment, with permits typically issued at the county level through local health departments. Requirements for tank sizes, setback distances, approved system types, and inspections can vary significantly between counties.

While Tennessee does not have a statewide mandate for septic inspections at the time of property sale, individual counties may impose their own requirements. It is common practice for buyers to request a septic inspection as part of their due diligence, even when not legally required.

Common Septic System Types

Homeowners in Tennessee typically use one of several septic system types depending on local soil conditions: conventional gravity-fed systems where soil percolation is adequate, pressure distribution systems in areas with moderate limitations, mound systems where shallow bedrock or high water tables prevent conventional installation, and aerobic treatment units (ATUs) in environmentally sensitive areas.

Septic Maintenance Requirements

The EPA recommends pumping septic tanks every 3 to 5 years, though the exact frequency depends on tank size, household size, and water usage. In Tennessee, some counties have adopted mandatory pumping schedules or maintenance tracking programs. Proper maintenance prevents costly repairs, protects groundwater quality, and extends the lifespan of the drainfield — the most expensive component to replace.

Select a county above to view detailed septic regulations, estimated costs, soil suitability data sourced from the USDA NRCS Soil Survey, and groundwater depth measurements from the USGS.

Data last updated: 2026-04-13