Essential Standards for the Water Unit: 8.E.1.1 - Explain the structure of the hydrosphere including: water distribution on Earth, local river basin and water availability. 8.E.1.2 - Summarize evidence that Earth's oceans are a reservoir of nutrients, minerals, dissolved gases, and life forms:  estuaries, marine ecosystems, upwelling, behavior of gases in the marine environment, deep ocean technology and understandings gained. 8.E.1.3 - Predict the safety and potability of water supplies in North Carolina based on physical and biological factors, including:  temperature, dissolved oxygen, pH, nitrates and phosphates, turbidity, bio-indicators. 8.E.1.4 - Conclude that the good health of humans requires:  monitoring of the hydrosphere, water quality standards, methods of water treatment, maintaining safe water quality, stewardship.