Septic Systems in Travis County, Texas

The baseline: Travis County as its own TCEQ authorized agent

For most unincorporated Travis County land, septic permitting runs through the county itself. Travis County holds TCEQ authorized-agent status, meaning its own staff -- not a TCEQ regional office -- reviews site evaluations, issues on-site sewage facility (OSSF) permits, and performs inspections under 30 TAC Chapter 285. Applications go through the county's online permitting platform, and posted fee ranges as of this research run roughly $285 to $475 for a conventional septic system and $475 to $700 for an aerobic treatment unit, with aerobic systems generally required wherever soil conditions or lot size rule out a conventional drainfield. That baseline process is what applies to the large majority of Travis County parcels outside the two exceptions below.

Near Lake Travis: LCRA, not the county, issues the septic permit

Property within roughly 2,000 feet of Lake Travis falls under a separate, older regulatory regime: the Lower Colorado River Authority has independently permitted on-site sewage facilities in this zone since September 1971, predating Travis County's own authorized-agent status by decades. That means a septic application for a lakeside or near-lakeside parcel goes to LCRA's OSSF program, not the county's -- and a Travis County development permit is still required in addition, so a lakefront buyer should plan on two applications, two fee schedules, and two review timelines rather than one. LCRA's own application requirements include proof of ownership, a property survey or drawing, a soil analysis, floor plans, a floodplain compliance letter, a site plan showing the proposed septic system and any wells or structures, and system design plans -- broadly similar in substance to a standard OSSF application, but submitted to LCRA's office rather than the county's.

Because the 2,000-foot line is measured from the lake itself rather than from a road or a subdivision boundary, a parcel's status isn't always obvious from a plat alone -- LCRA's own site lets a buyer enter an address or use its jurisdiction lookup to check before assuming which agency applies. Confirm this before budgeting a septic system or a closing timeline on anything near the lake.

On the Edwards Aquifer recharge zone: an added TCEQ review

Separately from who issues the OSSF permit itself, land on the TCEQ-mapped Edwards Aquifer Recharge Zone, Transition Zone, or Contributing Zone -- present in western and southwestern Travis County -- triggers an additional layer: TCEQ's own Edwards Aquifer Protection Program (EAPP), under 30 TAC Chapter 213, requires its own plan review and approval before construction (including a septic system) can proceed on mapped recharge-zone land. This is a genuinely separate TCEQ program from the septic rules in Chapter 285, and it should not be confused with the Edwards Aquifer Authority, a different agency that regulates groundwater pumping in a set of counties well south of Travis (Bexar, Medina, Uvalde, and others) and has no jurisdiction here. For a Travis County parcel on the recharge or contributing zone, expect the county's or LCRA's OSSF review to run alongside this separate TCEQ EAPP review, not instead of it.

Practically, a buyer should ask three questions before relying on any septic-cost or timeline estimate for a specific Travis County parcel: which OSSF authority applies (county or LCRA, based on distance from Lake Travis); whether the parcel falls on TCEQ's mapped Edwards Aquifer recharge, transition, or contributing zone, triggering the added EAPP review; and, if so, what specific setback, casing, or treatment requirements TCEQ's regional Austin office is currently applying to new construction in that zone. Treating this as a single, county-only process is the most common way a Hill Country land buyer underestimates the actual permitting timeline here.