What are primary sources of contamination?

• A. Drums, underground storage tanks, pipelines
• B. Wind
• C. Rainwater runoff
• D. Soil, rock, field equipment

Answer: (A)

Primary sources of contamination are the items that release pollutants directly into the environment. Leaking drums, underground storage tanks, and pipelines fit this role because they contain hazardous substances and can spill or leak, introducing contaminants into soil, groundwater, or air. Wind and rainwater runoff are transport pathways that move contaminants once they’re released, but they don’t originate the release themselves. Soil and rock can act as media that harbor contaminants, and field equipment can spread residues after becoming contaminated, but they are not the initial sources. So the drums, underground storage tanks, and pipelines best represent the primary sources of contamination.