In Central Texas (including areas like Austin, Travis, Hays, Bastrop, Caldwell counties), soil and site conditions often require a variety of septic system types. Here's a breakdown of the most commonly used ones:
1. Conventional Gravity-Based System
- How it works: Wastewater flows from a septic tank into a gravel-and-pipe drain field via gravity.
- Where it's used: Locations with well-draining, sandy soils.
- Pros/Cons: Simple and low-cost; minimal maintenance—but not viable in clayey or high water-table areas.
2. Low-Pressure Dosing (LPD) System
- How it works: Effluent is pumped under low pressure into a network of small pipes, distributing the wastewater evenly across the drain field.
- Best for: Sites with level terrain but poor soil absorption.
- Pros/Cons: More efficient in subpar soil, but pump maintenance is required.
3. Aerobic Treatment Systems (ATS)
Often mandated in soils that can’t handle conventional systems, ATS includes two main types:
- a. Aerobic Spray System
- Treated effluent is sprayed above ground.
- Works in virtually any soil type.
- Requires electricity and periodic maintenance because of pumps and spray nozzles.
- b. Aerobic Drip System
- Distributes treated wastewater underground through drip lines.
- Ideal for smaller lots or near water bodies.
- Requires ongoing inspections and maintenance.
4. Mound System
- How it works: Constructs a raised sand/gravel mound over poor soil; wastewater is dose-pumped into the mound.
- When it's used: Areas with high water tables or shallow bedrock.
- Pros/Cons: Effective in difficult sites, but expensive and needs pump upkeep.