Aerobic vs Conventional Septic Systems in Texas
Which system fits your San Antonio area lot, soil, and county code — and what it really costs.
Conventional gravity systems
Two-compartment tank that discharges to a gravity drain field. Cheapest to install and run, but requires good percolation and a lot big enough for the field. Common in parts of Wilson and Atascosa counties.
Aerobic treatment units
ATUs use an air compressor and spray heads to treat effluent before it's distributed across the yard. Required on most newer Bexar, Comal and Kendall county lots due to soil and lot size. More expensive but works almost anywhere.