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

If the daily water usage is 750,000 gallons and a chlorinator dosage is set at 4.0 mg/L, what should the gas chlorinator feed rate be set at in pounds per day?

1. 20 pounds

2. 22 pounds

3. 25 pounds

4. 30 pounds

The correct answer is: 25 pounds

To determine the gas chlorinator feed rate in pounds per day, given the daily water usage and the chlorinator dosage, it's essential to convert the dosage from mg/L to pounds. Start by recognizing that 1 mg/L is equivalent to 1 pound per million gallons. In this scenario, with a daily usage of 750,000 gallons, the conversion process would work as follows: 1. First, calculate how many million gallons are in 750,000 gallons: \[ 750,000 \, \text{gallons} = 0.75 \, \text{million gallons} \] 2. Next, since the dosage is set at 4.0 mg/L, we can find out how many pounds are needed for 0.75 million gallons: \[ \text{Pounds needed} = \text{Dosage (mg/L)} \times \text{Usage (million gallons)} = 4.0 \, \text{mg/L} \times 0.75 \, \text{million gallons} = 3.0 \, \text{pounds} \] 3. To convert this into a daily feed rate, it is necessary to