Do Now for 1/29/13 Take out HW HW: Complete chart Complete analysis questions 1 through 5

C31 Willow Grove’s Troubled Waters Today’s Target: I will be able to identify possible sources of water contamination. Check HW C30 – Vocabulary Introduce activity Reading KWL Chart C31 Vocabulary Analysis questions 1 through 5 on page C-10

C30 Vocabulary C30 1. Dissolved solids: Any solid materials dissolved in water, typically while the water is in contact with earth materials. Dissolved solids are most commonly metal ions like calcium, sodium, and magnesium. 2. Distilled water: Water that has been heated and re- condensed so as to drive off mineral impurities. Distilled water may have a slightly acidic pH. 3. Spring water: Water that comes from an underground spring or comes out of the ground on its own and is bottled.

C31 Willow Grove’s Troubled Waters Where does drinking water come from? How might drinking water become polluted or contaminated? Contamination – Any substance picked up by water. Packet Handout - Take out student sheet 31.1

C31 Willow Grove’s Troubled Waters Read background on page C-7. Read first section on page C-8 – Complete first two columns of the KWL chart (student sheet 31.1) K=Know, W=Want to know. Read the remainder of the activity. – Complete the L column. Complete the analysis questions.

C31 Vocabulary 1. Contaminant: Impurities in a substance. 2. Contaminate: To introduce or mix a substance into an otherwise pure substance, to pollute. 3. Contamination: When a pure substance has had impurities introduced into it.

C31 Key Points 1. Drinking water comes from either surface water or ground water – Surface water examples – Ground water examples 2. Water may contain chemical or biological contaminants, which may have come from wastewater. 3. Thinking critically about evidence includes deciding which evidence should be used.