Salt water
Oceans – (contain ~97% of all water
on earth; also responsible for weather,
redistribution of energy)
Fresh water
Polar ice caps, glaciers, Lakes, streams,
ground water, soil water
Brackish water
Water whose salinity is intermediate
between that of fresh water and salt
water
Soil Water

 Aeration zone
Intermediate zone
------------------------- water table ------------------------Zone of saturation (or ground water zone)
The Green Revolution -- based on modern, high
yielding plant varieties, requiring high inputs of fertilizer
and water -- has led to increases in world food production
at a pace that outstripped population growth. Food prices
have declined markedly. Increased water use in irrigated
agriculture has benefited farmers and the poor. But
increased water and chemical use that fueled the Green
Revolution has contributed to environmental degradation,
and threatened the resource base upon which we depend
for food and livelihoods.
1 kg of beef requires 15,000 kg of water
Chemical concentrations
Molarity = Moles of solute/Liters of Solution (M)
Molality = Moles of solute/Kg of Solvent (m)
Mole Fraction = Moles solute/total number of moles
Mass % = Mass solute/total mass x 100
Volume % = volume solute/total volume x 100
ppm = parts per million *
ppb = parts per billion *
* mass for solutions, volume for gasses
Chemical concentrations
Molarity = Moles of solute/Liters of Solution (M)
Molality = Moles of solute/Kg of Solvent (m)
Mole Fraction = Moles solute/total number of moles
Mass % = Mass solute/total mass x 100
Volume % = volume solute/total volume x 100
ppm = parts per million *
ppb = parts per billion *
* mass for solutions, volume for gasses
Chemical concentrations
Molarity = Moles of solute/Liters of Solution (M)
Molality = Moles of solute/Kg of Solvent (m)
Mole Fraction = Moles solute/total number of moles
Mass % = Mass solute/total mass x 100
Volume % = volume solute/total volume x 100
ppm = parts per million *
ppb = parts per billion *
* mass for solutions, volume for gasses
Assuming the density of water to be 1 g/mL we approximate the density of a dilute
aqueous solution to be 1 g/mL
1 g
1 ppm =
1g
1 g 1 g 1 g


1 g 1 ml 1 ml
 1 ppm = 1 μg/mL = 1 mg/L
 1 ppb = 1 ng/mL = 1 μg/L
Determine the ppm of a NaCl solution if 58.5 grams of NaCl was dissolved in 50.0
ml of water (assume the density of water to be 1 g/ml)
Convert ml of water to grams
1g
 50 grams water
 50 ml 
1 ml
Determine total mass of solution
Mass of solution = mass of solute + mass of solvent =
58.5 + 50.0 = 108.5 g
Apply the definition of ppm
58.5 (106) / 108.5 = 5.39 x 105 ppm NaCl
http://www.qualitylogoproducts.com/lib/different-types-of-plastic.htm
Contaminants in Ground Water
Organic:
• Chlorinated solvents
• Pesticides
• BTX component of gasoline
• MTBE component of gasoline
Inorganic:
• Nitrates (animal waste, fertilizers, atmospheric deposition, sewage)
• Phosphates (detergents, fertilizers, sewage)
Biological:
• Bacteria (e.g., E. coli)