Methodology
Visible assumptions, replaceable evidence.
The model starts with separately sourced 2026 bands for installation, diagnosed repair, tank-only, drain-field, full-system, pumping, tank locating and perc-test or soil-evaluation work. System type is built into the applicable project band; smaller visible adjustments then show how capacity, soil and access can move a project. It rounds the output to planning figures and never diagnoses a fault or selects a legally suitable system.
How the model works
- Project types keep diagnosed repair, tank-only, drain-field, full-system, pumping, locating and site-evaluation work separate.
- Conventional, chamber, aerobic, mound and sand-filter work do not share one artificial starting price.
- Bedrooms act only as a planning proxy for likely installation capacity.
- Soil and access adjustments are visible rather than hidden in a ZIP-code claim.
- Local diagnosis, design, testing and permits override the national model.
What the result means
The low and high values are planning bounds. The midpoint is simple arithmetic, not a prediction of the most likely contractor or carrier price. The calculator cannot inspect a property, verify a shipment, choose a legally suitable system, reserve capacity or issue a quotation.
Review date: 14 September 2026. We change a model only when the source, calculation and reason for the change can be recorded.
Current evidence snapshot
These are source observations used to bound a national planning model. They are not additive line items, a local price list or a prediction for a particular property.
- Typical system installation: $3,593–$12,463
Angi's current national range across tank sizes and system types.
- Conventional vs aerobic: $3,000–$8,000 / $10,000–$20,000
Angi's separate 2026 installation observations for these materially different system types.
- Chamber vs mound: $5,000–$12,000 / $10,000–$20,000
Angi's current alternative-system installation observations.
- Tank-only replacement: $3,000–$9,500
Angi's current replacement range when the tank itself fails.
- Drain-field replacement: $3,000–$15,000
HomeGuide's national range; mound fields are listed separately at $10,000–$20,000.
- Tank and drain field: $4,500–$20,000
HomeGuide's combined replacement/installation range.
- Professional perc test: $750–$1,900
Angi's current range, with an average around $1,300.
- Routine pumping: $300–$700
HomeGuide's current pump-out range used as the maintenance baseline.
- Professional tank locating: $100–$900
Angi's August 2026 range for professional locating, with camera or detailed inspection potentially priced separately.
- Local fee example: $1,344–$2,492
Sacramento County's 2026–27 tank-replacement through alternative-system installation fees; soil study is $1,549 separately. This is an example, not a national range.
- Typical diagnosed repair: $627–$3,040
Angi's current common repair range before component-specific or full replacement scope.
Source register
- US EPA septic-system questions
Local permitting, soil assessment, system selection and professional-finding context; reviewed 14 September 2026.
- Angi septic installation cost data
2026 national installation, system-type, testing, permit and component ranges; reviewed 14 September 2026.
- Angi septic repair cost data
2026 tank-replacement and repair-component ranges; reviewed 14 September 2026.
- HomeGuide drain-field replacement data
2026 drain-field, tank-and-field and pumping ranges; reviewed 14 September 2026.
- Angi perc-test cost data
2026 professional soil-testing range and scope; reviewed 14 September 2026.
- Angi septic-tank locating cost data
August 2026 professional locating, inspection and camera-service ranges; reviewed 19 September 2026.
- Sacramento County liquid-waste fees
A current local example showing why permit, soil-study and review fees cannot be represented by one national allowance; reviewed 14 September 2026.
Error corrections
If a source is outdated or a calculation does not behave as described, email [email protected] and identify the URL, input and expected result. Do not include private customer or property information.