House Hunting? Inspect the Tank.
A bad septic system can cost you $20,000 in surprise repairs. Your general home inspector won't catch it. Here's what a real septic inspection looks for, and why it's the cheapest insurance in a home purchase.
Why the Home Inspector Won't Save You
The standard home inspection in Texas covers about 200 line items. Septic isn't one of them. Inspectors are explicitly required to tell you when something is outside their scope, and septic almost always is. They might note "septic system present" or "tank lid visible" — that's not an inspection.
A real septic inspection is performed by a TCEQ-licensed inspector who opens the tank, measures the contents, tests the components, and writes a report you can hand to the seller, your lender, or a buyer's agent. Cost is usually $325 to $550. The repair you avoid is often five figures.
The 12-Point Inspection Checklist
Here's what a real Texas septic inspection actually covers, in the order it happens on site:
1. Locating the system
If the lids aren't already exposed, the inspector finds them. Permit records from the county usually show original location. We probe, sonde, or dig as needed.
2. Tank exterior condition
Visual inspection of the tank top, lid, and inlet/outlet pipes for cracks, settling, broken concrete, or root intrusion.
3. Sludge depth measurement
Measured with a Sludge Judge or core sampler. Over 1/3 of tank depth means the tank needed pumping yesterday — and may indicate the field is already being damaged.
4. Scum layer measurement
The floating layer on top. Excessive scum means baffle problems or grease overuse.
5. Inlet baffle inspection
The inlet baffle keeps incoming sewage from disturbing the settled solids. Cracked, missing, or detached baffles are a common failure.
6. Outlet baffle inspection
The outlet baffle keeps solids from escaping to the drain field. This is the most important single component in the tank. A failed outlet baffle is what kills drain fields.
7. Effluent quality check
The clarity and odor of the effluent leaving the tank. Cloudy, smelly effluent points to bacterial problems or tank overload.
8. Drain field surface inspection
Walk the field looking for surfacing effluent, soggy patches, suspiciously green grass, depressions, or odors.
9. Distribution box (if present)
Open the D-box, check for level distribution to each trench, check for root intrusion or buildup blocking individual lines.
10. Aerobic-specific checks (if applicable)
Alarm function, chlorine level, pump cycle, spray head pattern and coverage, control panel function, maintenance contract on file.
11. Permit and history check
Pull the county permit record. Verify the installed system matches what was permitted. Note any unpermitted modifications.
12. Written report with photos
Itemized, photographed report you can hand to your agent, the lender, or the seller. Lists deficiencies, estimated repair costs, and overall pass/fail.
Red Flags That Will Show Up
- Tank installed before 1995 — many older tanks lack the outlet filter that modern systems require.
- No permit on file — unpermitted systems are a title and insurance problem the new owner inherits.
- Drain field over 25 years old — life expectancy is 30 to 40, but neglect cuts that in half.
- Aerobic without maintenance contract — TCEQ requires one. A missing contract means the previous owner was out of compliance.
- System undersized for current bedroom count — additions and finished basements can outgrow the original permit.
- Surfacing effluent or soggy yard — field failure. Could be a $15,000-30,000 fix.
How to Use the Report as Leverage
Every inspection finding has a number next to it. Use the numbers:
- Major repair needed (drain field, system replacement): Seller pays at closing, or you walk. This is what the inspection is for.
- Tank needs pumping: Standard seller concession. Pump should be done before closing at seller's cost.
- Baffle or D-box repair: Negotiable — seller credit at closing or completed before close.
- Aerobic missing maintenance contract: Seller sets up a paid contract for the first year and transfers it. Always.
The Buyer Math
A $500 septic inspection that catches a failed drain field saves you $20,000 to $40,000 in surprise repairs after closing. A $500 inspection that returns "system passes, expected life 8+ years" gives you confidence the system you just inherited won't break next winter. Either way, you're ahead.
Frequently Asked Questions
Is a septic inspection required when buying a home in Texas?
Not by state law for most resale transactions, but most lenders require one when the property has on-site sewage. VA and FHA loans always require a TCEQ-compliant inspection. Cash buyers can skip, but shouldn't.
How much does a septic inspection cost in Greater Austin?
A standard inspection runs $325 to $550 depending on tank size, location, and whether digging is needed to expose the lid. Aerobic systems run higher because there's more to test.
How long does a septic inspection take?
About 60 to 90 minutes on site for a conventional system. Aerobic systems take longer because we test the spray heads, alarm, chlorine usage, and pump cycle.
What if the system fails inspection?
You have leverage. Most failed inspections become negotiation points — the seller fixes it, credits you at closing, or you walk. The repair cost on the inspection report is your number.
Do I need a separate inspection from the home inspection?
Yes. General home inspectors are not licensed to inspect septic systems in Texas. The county and most lenders require a TCEQ-certified inspector.
If You're Selling Instead of Buying
Same checklist, run before you list. Knowing what's wrong lets you fix it on your terms instead of negotiating against a buyer's inspector. Cheap inspection now beats expensive surprise later.