# What Lies Below: A Theory of Planned Behavior Study of Septic System Owners’ Practices in the Attoyac Bayou Watershed

## TL;DR

This study explores how septic system owners in Attoyac Bayou make maintenance decisions and how these affect watershed health.

## Contribution

The study applies the theory of planned behavior to septic system maintenance in a specific watershed context.

## Key findings

- Most septic systems in Attoyac Bayou are older conventional models with inconsistent maintenance.
- Positive attitudes strongly influence maintenance behavior more than social norms or perceived control.
- Recommendations include targeted messaging to improve maintenance behaviors.

## Abstract

As populations increase, water quality is increasingly affected by failing septic systems that introduce harmful fecal bacteria (e.g., E. coli) into watersheds. Septic system owners play a vital role in reducing the impact of such bacteria. Therefore, our study aimed to examine factors that influence septic system owners’ decisions to improve septic system maintenance and protect watershed health in the Attoyac Bayou, located in East Texas. Using the theory of planned behavior, we addressed three research questions: (1) What are the characteristics of septic systems within the Attoyac Bayou watershed?; (2) How have septic system owners in the Attoyac Bayou watershed maintained their systems?; and (3) How do attitudes, subjective norms, and perceived behavioral control predict septic system maintenance behaviors? We sent a questionnaire to septic system owners in the Attoyac Bayou watershed that included questions about septic system characteristics, maintenance histories, and owners’ perceived norms, controls, attitudes, and intentions about septic systems. We found most septic systems in Attoyac Bayou are older conventional models with many owners lacking service contracts and reporting various times since the last pump out or inspection. While septic system owners generally demonstrate positive attitudes and confidence toward maintenance, our results revealed that attitude accounts for the greatest variance in maintenance behavior, with social norms and perceived behavioral control being less influential. Therefore, we recommend targeted messaging and interventions to reinforce positive attitudes, enhance perceived behavioral control, and promote consistent maintenance behaviors.