Texas Wastewater Class B Practice Exam

What circumstance will increase the chances that sewage will turn septic?

1. Increased rainfall

2. Stoppages in the main line

3. Frequent maintenance

4. Higher flow rates

The correct answer is: Stoppages in the main line

The circumstance that increases the chances of sewage turning septic is stoppages in the main line. When there is a blockage, sewage can’t flow properly and begins to accumulate. This stagnant sewage environment creates conditions that promote the growth of anaerobic bacteria, which thrive in low-oxygen situations. As a result, the sewage can decompose without sufficient oxygen, leading to a septic condition where foul odors and harmful gases are produced. Higher flow rates typically help dilute and transport sewage more efficiently, mitigating the risk of stagnation. Increased rainfall can cause dilution but may not directly lead to septic conditions, depending on how the system is designed. Frequent maintenance helps prevent accumulation and blockages, further reducing the likelihood of the sewage turning septic.