Florida Drinking Water Operator "B" Practice Test

What two contaminants pose an immediate health threat when MCL's are exceeded?

1. Lead and Copper

2. Nitrate and E. coli

3. Fluoride and Nitrate

4. Bacteria and Viruses

The correct answer is: Nitrate and E. coli

The correct answer is based on the immediate health threats posed by nitrate and E. coli when their Maximum Contaminant Levels (MCLs) are exceeded. High levels of nitrate in drinking water can lead to a condition called methemoglobinemia, commonly known as "blue baby syndrome," which affects an infant's ability to transport oxygen in the blood. This condition can be life-threatening and requires prompt attention. E. coli, specifically certain strains, can cause serious gastrointestinal illness and can lead to severe complications, particularly in vulnerable populations such as children and the elderly. The presence of E. coli in water suggests fecal contamination, indicating that pathogenic organisms may also be present, further heightening health risks. In contrast, while lead and copper can also pose significant health risks, especially when consumed over long periods, their effects are generally more chronic and do not represent an immediate health threat in the same way as high levels of nitrate and the presence of harmful bacteria do. Fluoride, while important for dental health, does not present an immediate acute threat when MCLs are exceeded. Bacteria and viruses encompass a wide range of pathogens, but E. coli is a specific indicator of immediate health concerns related to fecal contamination, making it distinct in