The short answer
Replacing a septic drain field costs $3,000 to $15,000 with a national average of $7,900, according to HomeGuide; Angi estimates about $7,000, and Forbes Home and Bob Vila put the range at $2,000 to $20,000. A conventional (anaerobic) field is cheapest at roughly $2,000 to $6,000, while a mound field costs $10,000 to $20,000. Drain field repair or rejuvenation costs $1,000 to $5,000 per HomeGuide and Fixr.
Replacing a septic drain field costs $3,000 to $15,000 for most U.S. homeowners in 2026, with a national average of $7,900, according to HomeGuide. Angi puts the typical replacement at about $7,000. The type of system, the size of the field and the soil drive the price; a conventional field can cost under $6,000, while a mound field can reach $20,000.
| Publisher | Average | Range | Data date |
|---|---|---|---|
| HomeGuide | $7,900 | $3,000–$15,000 (min $1,000, max $25,000) | Dec 2025 |
| Angi | about $7,000 | — | Jul 2026 |
| Forbes Home | $6,000 | $2,000–$20,000 | Feb 2025 |
| Bob Vila | $6,000 (tank and field) | $2,000–$20,000 | Dec 2023 |
| Fixr | — | $2,000–$20,000 | Jan 2025 |
How much does drain field replacement cost by system type?
A septic drain field’s system type is the biggest factor in replacement cost. Conventional (anaerobic) fields are cheapest; aerobic, evapotranspiration and mound fields cost more.
| Drain field type | HomeGuide | Forbes Home | Angi / Bob Vila (average) |
|---|---|---|---|
| Anaerobic (conventional) | $2,000–$6,000 | $3,000–$6,000 | $5,000 |
| Aerobic | $7,000–$10,000 | $7,000–$10,000 | $7,000 |
| Evapotranspiration | $8,000–$15,000 | $8,000–$15,000 | $8,000 |
| Mound | $10,000–$20,000 | $11,000–$20,000 | $12,000 |
Bob Vila notes that about $3,500 of a $5,000 anaerobic replacement is the drain field installation itself. For more on raised systems, see the mound septic system guide.
How much does drain field repair or rejuvenation cost?
Septic drain field repair or rejuvenation costs $1,000 to $5,000, according to HomeGuide and Fixr. Angi and Bob Vila list a broader drain field repair range of $2,000 to $15,000. Ask the contractor to identify the specific failure, such as a clogged or broken line, before choosing between repair and replacement.
Common drain field repair and rejuvenation services include:
| Service | Cost | Source |
|---|---|---|
| Leach field rejuvenation | $1,000–$5,000 | HomeGuide |
| Replacing leach lines | $20–$45 per linear foot | HomeGuide, Forbes Home |
| Septic line hydro-jetting | $200–$1,400 | HomeGuide |
| Jetting | $150–$450 | HomeAdvisor |
| Septic aerator, installed | $300–$900 | HomeGuide |
| Field aeration (fracking) | $10,000–$20,000 | HomeAdvisor |
HomeAdvisor’s field aeration figure is far higher than the other rejuvenation methods, so ask a contractor to explain exactly what a rejuvenation quote includes.
When should a drain field be replaced instead of repaired?
A septic drain field should be replaced when the soil itself can no longer absorb effluent. The EPA explains that drain fields older than 25 to 30 years may develop a thicker biomat, a layer that reduces drainage and can cause ponding, surfacing wastewater or backups. HomeGuide says a properly built and maintained drain field lasts 20 to 25 years. A field of that age with these symptoms is a candidate for replacement rather than repair.
NC State Extension lists the main causes of drain field failure as overloading with more water than the soil can absorb, poor tank maintenance that lets solids reach the field, poor design or installation, and physical damage from driving, paving, building or roots. NC State notes that in a complete system failure, a new system may be the only solution.
What are the signs of a failing drain field?
A failing septic drain field usually shows up in the yard and in the house at the same time. The EPA lists these warning signs of septic failure:
- Sewage backing up into household drains
- Slow drains and gurgling pipes
- Standing water or damp spots over the tank or drain field
- Sewage odors around the yard
- Unusually lush, spongy green grass over the field during dry weather
Any of these signs calls for a professional inspection to confirm whether the drain field, the tank or another component is the cause before you price a replacement.
Does drain field size affect replacement cost?
A larger septic drain field costs more to replace. Angi says larger fields cost more because of the added labor, and HomeGuide lists field size as a cost factor. NC State Extension explains that drain field size depends on soil type, the number of bedrooms, topography and system type, with clay soils and larger homes needing bigger fields. Excavation at $1 to $5 per square foot (HomeGuide, Angi) and sod at $1 to $2 per square foot (HomeGuide) scale directly with the field’s footprint.
What other costs come with drain field replacement?
Drain field replacement involves excavation, testing, permits and yard restoration in addition to the new field.
- Permits: HomeGuide lists installation or replacement permits at $250 to $650; Angi lists $450 to $2,000; Forbes Home lists $320 to $1,880.
- Perc test: HomeGuide lists $600 to $2,000; Forbes Home lists $450 to $1,400; Angi lists about $1,300.
- Excavating the old field: $1 to $5 per square foot, per HomeGuide and Angi.
- New line from tank to field: $40 to $180 per linear foot per HomeGuide; Angi lists new septic lines at $100 to $240 per linear foot.
- Labor: Angi estimates labor at about 60% of the project, averaging around $3,600; Forbes Home puts labor at $1,500 to $10,000.
- Tank pumping: HomeGuide lists $300 to $700 and says pumping is required for a new field.
- Tree removal: HomeGuide lists $400 to $1,200; Forbes Home puts it at about $1,200 on average.
- Filling, regrading and sod: HomeGuide lists filling and regrading at $0.40 to $2.00 per square foot and sod at $1 to $2 per square foot.
- Abandonment permit for the old field: $100 to $250, per HomeGuide and Angi.
How much does it cost to move a drain field?
Moving a septic drain field to a new location costs more than replacing it in place. HomeGuide puts relocation at $5,500 to $21,500, and Forbes Home at $5,000 to $17,000. NC State Extension notes that North Carolina lots must keep a repair area undisturbed for system replacement, and that using it may require a more expensive system than the original.
How much does it cost to replace the tank and drain field together?
Replacing a septic tank and drain field together costs $4,500 to $20,000, according to HomeGuide. Angi puts a combined replacement at $5,000 to $12,000. If the tank is still sound, replacing only the field is cheaper. See the septic tank replacement cost guide for tank prices.
Do you need a permit to replace a drain field?
A septic drain field replacement generally requires a permit, and every publisher reviewed lists a permit fee in its cost breakdown. NC State Extension tells North Carolina owners to contact the local environmental health department, which sends a specialist to assess a failure and recommend repairs, and not to attempt repairs without its approval. Other states set their own rules; see septic licensing for your state.
How can you make a new drain field last longer?
A new septic drain field lasts longer when it is protected from weight, water and roots. The EPA advises not parking or driving on the drain field, not paving over it, keeping roof drains and sump pumps away from it, and planting native grasses or ground covers rather than trees, shrubs or gardens. Regular tank pumping keeps solids out of the field; HomeGuide recommends pumping and line cleaning every 3 to 5 years. For warning signs to watch for, see signs of septic system failure, and for how the field works, see septic drain field.
Who should replace a septic drain field?
A septic drain field should be designed and replaced by a contractor licensed for septic installation in your state, working under a local permit. Get at least two written quotes that separate excavation, the new field, permits, testing and restoration. You can find a licensed septic company through The Septic Guide, which lists 28,546 septic companies and licensed septic professionals in 45 states, and check the installer’s license before signing.
Common questions
How much does it cost to replace a septic drain field?
Replacing a septic drain field costs $3,000 to $15,000 with a $7,900 national average, according to HomeGuide. Angi estimates about $7,000, and Forbes Home and Bob Vila report a range of $2,000 to $20,000 with a $6,000 average. Mound drain fields cost the most.
How much does drain field repair cost compared with replacement?
Septic drain field repair or rejuvenation costs $1,000 to $5,000 according to HomeGuide and Fixr, compared with $3,000 to $20,000 for full replacement. Angi and Bob Vila list a broader drain field repair range of $2,000 to $15,000. The EPA notes that older fields can develop a thick biomat that reduces drainage, which is when replacement becomes more likely.
How long does a septic drain field last?
A septic drain field lasts 20 to 25 years if it is properly built and maintained, according to HomeGuide. The EPA notes that drain fields older than 25 to 30 years may develop a thicker biomat that reduces drainage and can cause ponding or backups.
How much does a mound drain field cost to replace?
Replacing a mound drain field costs $10,000 to $20,000 according to HomeGuide and $11,000 to $20,000 according to Forbes Home. Angi and Bob Vila put the average mound drain field replacement at $12,000. A mound field is the most expensive drain field type in every publisher's table.
Do you need a permit to replace a drain field?
Replacing a septic drain field generally requires a permit from the local health or environmental agency. HomeGuide lists drain field installation or replacement permits at $250 to $650, Angi at $450 to $2,000 and Forbes Home at $320 to $1,880. Requirements vary by state and county.
Sources
- How Much Does a Leach or Drain Field Replacement Cost? (2026), HomeGuide. Accessed October 20, 2026. Replacement $3,000-$15,000, average $7,900; rejuvenation $1,000-$5,000; costs by system type, per foot and permits; lifespan 20-25 years
- Cost to Replace Septic Tank and Drain Field [2026 Data], Angi. Accessed October 20, 2026. Drain field replacement about $7,000; averages by system type; repair $2,000-$15,000; permits $450-$2,000; updated Jul 8, 2026
- How Much Does Leach Field Replacement Cost?, Forbes Home. Accessed October 20, 2026. Replacement $2,000-$20,000, average $6,000; by system type; relocation $5,000-$17,000; leach lines $20-$45 per linear foot
- How Much Does It Cost to Replace a Septic Tank and Drain Field?, Bob Vila. Accessed October 20, 2026. Drain field by system type; drain field repair $2,000-$15,000 (updated Dec 2023)
- Septic Tank Repair Cost, Fixr. Accessed October 20, 2026. Drain field repair $1,000-$5,000; replacement $2,000-$20,000 (updated Jan 31, 2025)
- How Much Does Septic Tank Pumping Cost?, HomeAdvisor. Accessed October 20, 2026. Field aeration (fracking) $10,000-$20,000; jetting $150-$450; updated Jun 17, 2026
- Frequent Questions on Septic Systems, U.S. Environmental Protection Agency. Accessed October 20, 2026. Drain fields older than 25-30 years may develop a thicker biomat; failure signs
- How to Care for Your Septic System, U.S. Environmental Protection Agency. Accessed October 20, 2026. Do not park or drive on the drainfield; keep roof drains and sump pumps away; plant grass
- Why Do Septic Systems Fail?, NC State Extension. Accessed October 20, 2026. Causes of drain field failure; contact local environmental health before repairs
- Septic Systems and Their Maintenance, NC State Extension. Accessed October 20, 2026. Drain field size depends on soil, bedrooms, topography and system type; repair area must be left undisturbed; replacement may require a more expensive system