Septic soil suitability screening
Septic Soil Suitability Report by Address
Before a perc test, check what the USDA soil survey says: the septic absorption field rating, water table, bedrock depth and drainage for the property.
Recommended
Pro PDF · $49
The Pro report is the tier with the USDA septic tank absorption field rating and the soil profile by horizon.
- Everything in Standard
- Engineering and erosion considerations
- Soil profile (horizons & texture)
- Data-source appendix
- Priority email delivery
- Project / client name on cover
Choose your tier after the free preview. One flat price per address.
What affects soil suitability for septic
Septic absorption field rating
The USDA-NRCS rating for septic tank absorption fields: not limited, somewhat limited or very limited.
Depth to water table
A shallow saturated zone can keep effluent from being treated before it reaches groundwater.
Depth to bedrock
Shallow bedrock or dense layers leave too little soil to treat effluent.
Drainage, flooding and ponding
Wet, flooded or ponded soils limit where a drain field can work.
Soil profile and texture
Texture by horizon hints at how fast water moves through the soil.
The USDA septic absorption field rating
- Not limited
- Soil features are generally favorable for absorption fields.
- Somewhat limited
- One or more features are unfavorable but can usually be overcome by design or installation.
- Very limited
- One or more features are unfavorable and hard to overcome; expect special design, an alternative system or a different site.
How It Works
Enter the property address
We find the USDA soil map unit at the address and show a free preview.
Review drainage for free
The preview shows soil type, drainage class and hydric rating.
Get the Pro report
The Pro PDF ($49) includes the septic absorption field rating and soil profile.
Take it to the site evaluation
Share it with your septic designer or health department evaluator before testing.
Screening first, field testing second
Use the report to
- Screen a lot before you buy it
- Brief your septic designer or evaluator
- Spot likely limits: water table, bedrock, flooding
- Compare drain-field options across nearby soils
You still need
- An on-site soil evaluation or perc test
- A septic permit from your local health department
- A system designed by a licensed professional
Frequently Asked Questions
Soil suitability for septic systems: the rating, the factors and the limits.
How do I check soil suitability for a septic system?
Start with the USDA soil survey: the septic tank absorption field rating, depth to water table, depth to bedrock and drainage class tell you whether the mapped soil is likely to work. Then a licensed evaluator tests the actual site, which your local health department usually requires for a permit.
Which report includes the septic rating?
The Pro PDF ($49) includes the USDA engineering ratings, including septic tank absorption fields, plus the soil profile by horizon. The Standard report includes water table and bedrock depth but not the septic rating.
Is this a perc test?
No. A percolation test or soil evaluation is done on site by a licensed professional. This report is a desktop screening from regional USDA data that helps you decide whether a site is worth testing.
What does “very limited” mean for septic?
It means the mapped soil has at least one feature, such as a shallow water table, shallow bedrock, flooding or very slow or very fast permeability, that is hard to overcome. It doesn't rule a site out, but expect an engineered or alternative system, or a different drain-field location.
How accurate is a septic soil rating by address?
USDA soil maps are drawn at roughly 1:12,000 to 1:24,000, so a map unit can include pockets of different soil. The rating describes the map unit, not your exact drain-field spot. Use it to screen, then test on site.
Which addresses are covered?
We currently cover Washington, DC. Most properties in Washington, DC use public sewer, so septic screening matters most as we add suburban and rural areas. We record searches outside coverage so we know where to expand next.
Check a property’s septic soil suitability
Free soil preview first. The septic rating is in the Pro report.
More soil tools and guides
- Soil Type LookupFree soil type, drainage and hydric rating for any address.
- Soil Report for Permit DrawingsA preliminary soil PDF for site plans and permit sets.
- DC Soil Boring & DOEE Permit GuideWhen DC projects need borings, permits and a geotech.
- DC DOEE Soil & Stormwater ChecklistErosion control and stormwater triggers, step by step.
- Hydric Soil & Drainage ScreeningHydric rating, drainage class, flooding and water table.
- SSURGO Parcel Reports for EngineersComponent, horizon and engineering data by address.
- SSURGO Soil Data APISoil data by address or coordinates, as JSON.
Septic suitability ratings describe mapped soils, not your exact drain-field location. Septic permits require an on-site evaluation under your state and local rules.
This report is based on USDA-NRCS SSURGO regional soil-survey data and is intended for preliminary screening only. It is not a geotechnical investigation, soil boring report, environmental assessment, or permit approval.