AWWA Water Quality Testing 2

Question 1

Which analytical method is the AWWA standard for measuring total organic carbon (TOC) in drinking water?

Accepted Answer

High-temperature combustion with IR detection

Answer

High-temperature combustion with infrared CO2 detection is the EPA-approved and AWWA-referenced standard method for TOC measurement in drinking water.

Question 2

What does a turbidity reading of 0.3 NTU or less at the entry point indicate under the Surface Water Treatment Rule?

Accepted Answer

Compliance with the turbidity performance standard

Answer

Under the SWTR, filtered water turbidity must not exceed 0.3 NTU in 95% of monthly samples, indicating adequate treatment performance.

Question 3

Which ion is primarily responsible for causing blue-baby syndrome (methemoglobinemia) when present in drinking water at elevated levels?

Accepted Answer

Nitrate

Answer

Nitrate is converted to nitrite in infants' digestive systems, which oxidizes hemoglobin to methemoglobin, reducing oxygen-carrying capacity.

Question 4

What is the purpose of conducting a jar test in water quality testing?

Accepted Answer

Optimize coagulant dose and type before full-scale treatment

Answer

Jar tests simulate coagulation and flocculation at lab scale to determine the optimal coagulant type and dosage for a given source water.

Question 5

Which parameter is used to calculate the Langelier Saturation Index (LSI) and assess corrosivity of water?

Accepted Answer

pH, temperature, calcium hardness, alkalinity, and TDS

Answer

The LSI combines pH, temperature, calcium concentration, total alkalinity, and TDS to determine whether water will tend to deposit or dissolve calcium carbonate scale.

(AWWA) American Water Works Association Practice Test

(AWWA) American Water Works Association Practice Test

AWWA Water Quality Testing 2