Texas Commission on Environmental Quality (TCEQ). Class C Water License Exam

A boil-water notice can be triggered by which of the following?

1. High chlorine residual

2. Water outages

3. Reduced water pressure

4. Both water outages and reduced pressure

The correct answer is: Both water outages and reduced pressure

A boil-water notice is typically issued to inform consumers that their drinking water may be contaminated and unsafe for consumption without proper treatment, particularly boiling. The primary triggers for a boil-water notice include scenarios where there is a risk of water supply contamination. Water outages can lead to a boil-water notice because, during an outage, air may enter the water distribution system, which can create a pathway for contaminants to enter. When the water supply is interrupted, the protective barrier that normally keeps harmful bacteria and other pathogens out of the drinking water is compromised. Reduced water pressure is another critical factor that can trigger a boil-water notice. Low water pressure in the system can also allow contaminants from the surrounding soil or plumbing fixtures to infiltrate the water supply. This occurs because there may not be enough pressure to keep the water flowing securely through the pipes. When both water outages and reduced pressure are present, the potential risk of contamination is heightened, which is why both scenarios are valid triggers for a boil-water notice. Thus, the correct answer incorporates both of these conditions, as they represent significant risks for public health concerning water quality.