CWD Water Quality & Environmental Regulations 3 — Questions and Answers
Question 1: What does the term 'wellhead protection area' (WHPA) refer to?
- The physical cover placed over a well casing
- The surface and subsurface area surrounding a well that supplies water to the well (Correct answer)
- The zone within a well casing where the pump is installed
- The concrete pad at the base of a well casing
Correct answer: The surface and subsurface area surrounding a well that supplies water to the well
A WHPA is the surface and subsurface area through which contaminants are reasonably likely to move toward and reach a public water supply well.
Question 2: Which groundwater contaminant is measured in picocuries per liter (pCi/L) and originates from uranium decay in soil and rock?
- Nitrate
- Radon (Correct answer)
- Arsenic
- Fluoride
Correct answer: Radon
Radon is a radioactive gas produced by uranium decay that dissolves into groundwater and is measured in picocuries per liter.
Question 3: What is the EPA's Maximum Contaminant Level (MCL) for nitrate in drinking water?
- 5 mg/L
- 10 mg/L (Correct answer)
- 25 mg/L
- 50 mg/L
Correct answer: 10 mg/L
The EPA MCL for nitrate is 10 mg/L as nitrogen (NO3-N) to protect infants from methemoglobinemia (blue baby syndrome).
Question 4: Which document must a well driller typically submit to the state after completing a well?
- Well completion report (driller's log) (Correct answer)
- Environmental impact statement
- Stormwater pollution prevention plan
- Aquifer yield certificate
Correct answer: Well completion report (driller's log)
Most states require drillers to submit a well completion report or driller's log documenting construction details, geology, and water quality.
Question 5: A water sample shows total coliform present but E. coli absent. What is the correct interpretation?
- The water is safe to drink without treatment
- Fecal contamination is confirmed
- The result is an indicator of possible contamination requiring follow-up testing (Correct answer)
- The well must be permanently abandoned
Correct answer: The result is an indicator of possible contamination requiring follow-up testing
Total coliform presence without E. coli indicates possible contamination; a repeat sample and investigation are required before declaring the water safe.
Question 6: Under the Underground Injection Control (UIC) program, what class of injection well is used for disposal of hazardous wastes?
- Class I (Correct answer)
- Class II
- Class IV
- Class VI
Correct answer: Class I
Class I injection wells are used to inject hazardous and non-hazardous industrial and municipal wastes into deep, isolated rock formations.
Question 7: pH levels in drinking water are regulated as a secondary standard. What is the EPA's secondary MCL range for pH?
- 5.0–7.0
- 6.5–8.5 (Correct answer)
- 7.0–9.0
- 4.0–6.0
Correct answer: 6.5–8.5
The EPA Secondary MCL for pH is 6.5–8.5, a range set for aesthetic and corrosion control purposes rather than direct health effects.
CWD Water Quality & Environmental Regulations 3
What does the term 'wellhead protection area' (WHPA) refer to?