REHS Practice Exam 2026 – Comprehensive All-in-One Guide to Ace Your Registered Environmental Health Specialist Certification!

The correct choice reflects that only a small fraction of Earth's fresh water is accessible for drinking purposes, primarily due to the presence of glaciers, ice caps, and groundwater that is not readily available for human consumption. Specifically, about 1% of the total fresh water on Earth is easily accessible in surface water bodies like lakes, rivers, and reservoirs, which are critical sources for drinking water. The vast majority of fresh water is trapped in ice or located deep underground, making it unavailable or impractical for direct use as drinking water. This understanding is essential for recognizing the limitations in fresh water availability and the importance of sustainable management of the accessible supply.