System comparison hub

Which Septic System Types Does Tennessee Use?

What each design does, which site problem it solves, what it costs to build, and what it asks of you for the next 20 years.

What are the types of septic systems in Tennessee?

Tennessee permits five main septic system types: conventional gravity, low-pressure pipe (LPP), mound, oxidation lagoon, and aerobic treatment with subsurface drip (ATS/SDD). Conventional costs least, roughly $8,000 to $15,000. The other four are alternative systems for harder sites. Your soil map, reviewed by TDEC, decides which one your lot gets.

At a glance

Cheapest to build
Conventional gravity, about $8,000 to $15,000

Pressure distribution
Low-pressure pipe (LPP)

Elevated absorption
Mound system

Treatment plus shallow dispersal
ATS with subsurface drip disposal

Alternative-system soil detail
Extra-high-intensity map before TDEC evaluation

Who picks the system
TDEC, based on the soil map and your plan

How do Tennessee septic systems compare?

Costs are our planning ranges, not quotes. TDEC doesn't publish how many of each type are in Maury County, so the last column is a qualitative read.

System: Conventional gravity
Function: A tank settles solids, then gravity carries effluent to an approved absorption field.
Potential soil and site fit: Suitable depth, drainage, slope, and space for the initial and duplicate fields
Installed allowance: $8,000 to $15,000
Footprint: Design-specific baseline field
Ownership: Inspection, pumping, water management, and soil protection
Maury use signal: Common planning baseline where approved; no public Maury type count

System: Low-pressure pipe (LPP)
Function: A pump doses septic-tank effluent through small pipe for controlled distribution.
Potential soil and site fit: A site where pressure dosing addresses distribution and the mapped soil qualifies
Installed allowance: $12,000 to $22,000
Footprint: Different layout, but not soil-free or reserve-free
Ownership: Pump, float, alarm, controls, power, pumping, and field protection
Maury use signal: Relevant to constrained sites; no public county share

System: Mound
Function: A pumped design doses a specified absorption profile above a qualifying natural site.
Potential soil and site fit: Certain shallow limiting conditions, slopes, and natural soils meeting mound criteria
Installed allowance: $15,000 to $30,000+
Footprint: Visible elevated area and protected side slopes
Ownership: Pump, controls, erosion control, and strict traffic and water protection
Maury use signal: Only fits sites meeting mound criteria; never a generic shallow-rock fix

System: Oxidation lagoon
Function: A designed lagoon provides treatment within the state-approved system path.
Potential soil and site fit: Sites with enough area, separation, soil, topography, safety, and approved design
Installed allowance: Design-specific; carry $15,000 to $30,000+ until priced
Footprint: Large and open compared with buried fields
Ownership: Banks, vegetation, water level, safety, access, and permit duties
Maury use signal: TDEC lists it; no public Maury residential count

System: ATS with subsurface drip disposal
Function: Advanced equipment treats wastewater before shallow, controlled drip dispersal.
Potential soil and site fit: A constrained site where the approved treatment and dispersal address documented limits
Installed allowance: $15,000 to $30,000+
Footprint: Flexible tubing layout with qualifying initial and duplicate space
Ownership: Lifetime provider contract, power, treatment checks, filters, pumps, controls, and alarms
Maury use signal: Important for some difficult sites; no public county mix

System: Approved substitute or engineered combination
Function: An accepted product or package performs a defined tank, treatment, dosing, or dispersal role.
Potential soil and site fit: The issued design names the product and how it works with the mapped site
Installed allowance: Price the exact permit and product schedule
Footprint: Controlled by the approved package and sketch
Ownership: Manufacturer, permit, pumping, electrical, and service duties vary
Maury use signal: Case-specific; a product name is not site approval

System	Function	Potential soil and site fit	Installed allowance	Footprint	Ownership	Maury use signal
Conventional gravity	A tank settles solids, then gravity carries effluent to an approved absorption field.	Suitable depth, drainage, slope, and space for the initial and duplicate fields	$8,000 to $15,000	Design-specific baseline field	Inspection, pumping, water management, and soil protection	Common planning baseline where approved; no public Maury type count
Low-pressure pipe (LPP)	A pump doses septic-tank effluent through small pipe for controlled distribution.	A site where pressure dosing addresses distribution and the mapped soil qualifies	$12,000 to $22,000	Different layout, but not soil-free or reserve-free	Pump, float, alarm, controls, power, pumping, and field protection	Relevant to constrained sites; no public county share
Mound	A pumped design doses a specified absorption profile above a qualifying natural site.	Certain shallow limiting conditions, slopes, and natural soils meeting mound criteria	$15,000 to $30,000+	Visible elevated area and protected side slopes	Pump, controls, erosion control, and strict traffic and water protection	Only fits sites meeting mound criteria; never a generic shallow-rock fix
Oxidation lagoon	A designed lagoon provides treatment within the state-approved system path.	Sites with enough area, separation, soil, topography, safety, and approved design	Design-specific; carry $15,000 to $30,000+ until priced	Large and open compared with buried fields	Banks, vegetation, water level, safety, access, and permit duties	TDEC lists it; no public Maury residential count
ATS with subsurface drip disposal	Advanced equipment treats wastewater before shallow, controlled drip dispersal.	A constrained site where the approved treatment and dispersal address documented limits	$15,000 to $30,000+	Flexible tubing layout with qualifying initial and duplicate space	Lifetime provider contract, power, treatment checks, filters, pumps, controls, and alarms	Important for some difficult sites; no public county mix
Approved substitute or engineered combination	An accepted product or package performs a defined tank, treatment, dosing, or dispersal role.	The issued design names the product and how it works with the mapped site	Price the exact permit and product schedule	Controlled by the approved package and sketch	Manufacturer, permit, pumping, electrical, and service duties vary	Case-specific; a product name is not site approval

How do treatment and disposal differ?

Every system has two jobs: clean the wastewater, then get rid of it. The septic tank does the first cleaning by letting solids settle. An aerobic unit adds a second round of treatment with air. Gravity trenches, LPP, mounds, and drip lines handle the second job, spreading the water into soil.

So when someone says “we have an aerobic system,” ask where the water goes next. In Tennessee the answer is usually drip lines, and Rule .23 requires a maintenance contract for both parts. That's why TDEC treats ATS/SDD as one package.

Which system fits which Maury County soil condition?

Mapped condition: Adequate suitable soil, practical slope, gravity route, and full reserve area
Possible path: Conventional gravity may be the simplest candidate
What it does not prove: A neighbor's permit or acreage does not establish your layout

Mapped condition: Suitable mapped soil but gravity distribution is not accepted for the proposed configuration
Possible path: LPP may provide controlled pressure dosing
What it does not prove: Shallow rock, wet soil, and setbacks still control the layout

Mapped condition: A qualifying shallow limitation with suitable natural site and mound criteria
Possible path: A mound may add the specified treatment profile
What it does not prove: Imported material cannot make every rock, slope, or drainage problem eligible

Mapped condition: Site can support advanced treatment and a qualifying shallow dispersal layout
Possible path: ATS/SDD may combine treatment with drip dosing
What it does not prove: Approved soil and dispersal area are still required underneath it

Mapped condition: No compliant soil, area, setbacks, or disposal path for the design flow
Possible path: The proposed home may have no onsite option
What it does not prove: A higher budget does not guarantee approval

Mapped condition	Possible path	What it does not prove
Adequate suitable soil, practical slope, gravity route, and full reserve area	Conventional gravity may be the simplest candidate	A neighbor's permit or acreage does not establish your layout
Suitable mapped soil but gravity distribution is not accepted for the proposed configuration	LPP may provide controlled pressure dosing	Shallow rock, wet soil, and setbacks still control the layout
A qualifying shallow limitation with suitable natural site and mound criteria	A mound may add the specified treatment profile	Imported material cannot make every rock, slope, or drainage problem eligible
Site can support advanced treatment and a qualifying shallow dispersal layout	ATS/SDD may combine treatment with drip dosing	Approved soil and dispersal area are still required underneath it
No compliant soil, area, setbacks, or disposal path for the design flow	The proposed home may have no onsite option	A higher budget does not guarantee approval

Maury County's state geology atlas maps limestone, sinkholes, unstable ground, and flood-prone areas. It explains why two lots on the same road can end up with different systems. The system itself comes from the soil map of your parcel.

Which septic types in national guides does Tennessee not list?

National guides, including the EPA's list of septic system types, cover designs you won't see on a Tennessee residential application. TDEC's online septic application names four alternative systems: LPP, mound, oxidation lagoon, and ATS/SDD. Everything else is either a form of conventional system or needs a special route.

Type in national guides	Where it stands in Tennessee
Chamber or gravelless systems	Handled as a conventional system or approved substitute product. TDEC's $400 conventional fee explicitly covers large-diameter gravelless pipe.
Drip distribution	Permitted as ATS/SDD, paired with advanced treatment
Aerobic treatment unit	Permitted as ATS/SDD, with a required maintenance contract
Mound	On TDEC's alternative list
Sand filter, evapotranspiration, constructed wetland	Not on TDEC's standard residential list; would need an approved product or experimental permit ($500)
Cluster or community system	Shared systems serving several homes go through separate state and county approvals for decentralized wastewater systems, not a single-home permit

Why can't you choose a system before the soil evaluation?

Because the soil picks it. The map shows what the ground can absorb and where the limits are. Your bedroom count sets the flow, and the survey adds property lines, the well, and setbacks. Put those together and usually only one or two designs fit.

For any alternative system, TDEC wants an extra-high-intensity soil map before it will even evaluate the lot. That map costs more than a standard one, and it doesn't guarantee a yes. It gives the Division enough detail to judge whether LPP, a mound, or ATS/SDD will work.

Read the soil and site evaluation guide for how mapping works. If a conventional layout already failed, the failed soil test options guide walks through a new location, fewer bedrooms, or an alternative system.

Compare designs on the same facts

Same house location and bedroom count
Same accepted soil map and permit path
Same initial and duplicate-area protection
All pumps, panels, alarms, and electrical work
State fees, inspection, startup, and corrections
Power, pumping, service, and replacement parts
Restoration, warranty, and exclusions

What ownership trade-offs come with each system?

Mechanical parts

Gravity fields can avoid a distribution pump. LPP, mound, and ATS/SDD add pumps, floats, alarms, controls, power, and eventual component repair.

Service obligations

Every system needs pumping and field protection. Advanced treatment and drip add an approved maintenance-provider contract and permit-specific service.

Property use

Initial and duplicate areas remain protected. Mounds and lagoons affect landscaping. Drip can be shallow. Additions, wells, pools, and lot splits need review.

About our sources. Maury Septic uses the sources listed below, including TDEC's current system categories, Rule 0400-48-01, soil standards, permit documentation, and Maury County geology atlas. Follow the links for the underlying rules, fees, and guidance.

Sources and further reading

TDEC septic services and online application
Tennessee Department of Environment and Conservation
Conventional, repair, and alternative-system applications, plus soil-map requirements.
TDEC SSDS construction permit
Tennessee Department of Environment and Conservation
Who needs a permit, application requirements, review timing, current state fees, and inspection duties.
Tennessee SSDS regulations, Chapter 0400-48-01
Tennessee Department of Environment and Conservation
Official rule index for permits, design, maintenance, soil consultants, installers, and fees.
TDEC Soils Handbook of Tennessee
Tennessee Department of Environment and Conservation
State mapping standards for soil depth, restrictive layers, drainage, absorption rates, slope, site features, and SSDS interpretations.
TDEC SSDS permit documentation standards
Tennessee Department of Environment and Conservation
Current state policy for digital permit sketches, attachments, reproducible field references, setbacks, and FileNet record quality.
Environmental Geology Atlas of Maury County
Tennessee Geological Survey
State-published geologic, unstable-materials, flood-prone-area, mineral-resource, and sinkhole maps for Maury County.
EPA types of septic systems
U.S. Environmental Protection Agency
Current homeowner overview of drip distribution, mounds, aerobic treatment, chambers, sand filters, and other onsite system types.

What else do owners ask about septic system types?

What type of septic system is best in Maury County?

The simplest one your soil map supports. On a good lot that's a conventional gravity system, which is the cheapest to build and has no pump to wear out. Maury's shallow limestone pushes plenty of lots toward LPP, mound, or aerobic with drip instead. TDEC makes the call from the map.

What is the difference between an aerobic unit and drip disposal?

The aerobic unit cleans the wastewater; the drip lines get rid of it. Drip tubing sits shallow and doses treated water in small amounts. TDEC permits the pair as one category, ATS/SDD, because the drip field only works with water that's already been treated.

Is an LPP system the same as an aerobic septic system?

No. An LPP system pumps ordinary septic-tank effluent through small pipes to spread it evenly across the field. An aerobic system adds a treatment step with air before the water goes anywhere. Both run on electricity, but aerobic units need a lifetime service contract in Tennessee. That rule doesn't cover LPP.

Which septic system costs the least?

Conventional gravity, at roughly $8,000 to $15,000 installed, when your lot qualifies for it. LPP typically runs $12,000 to $22,000, and mounds or aerobic with drip start around $15,000 and climb past $30,000. Those are our planning ranges. Your quote depends on rock, distance, and the permit design.

Can an alternative system make any lot buildable?

No. Each alternative system fixes a specific problem, and each still needs usable soil, setbacks, and room for a backup field. Some ground has no workable option for the house you want. Rock at the surface, a wet bottom, or a lot boxed in by sinkholes can end the conversation.

Does Tennessee allow sand filter or constructed wetland septic systems?

They aren't on TDEC's standard list. The residential application names LPP, mound, oxidation lagoon, and ATS/SDD as alternative systems. Other designs from national guides would need another route, such as an approved substitute product or a $500 experimental permit, and TDEC decides case by case.

After TDEC identifies the design

Do you need an estimate for the permitted system?

Submit the system type and permit details when available. This form does not choose a design, order a soil map, or replace TDEC approval.

Keep your permit, system sketch, and service records together. They help the next professional understand your property.