Summary for Wednesday February 10th

Today, we started with the basics of water quality with some of the basic parameters of water. With regard to these parameters, you should be able to answer the following:

General- What are solvents and solutes? What is ppm or mg/L- how are these related to %?

pH- What does it mean, how does the scale work what are the appropriate ranges (what do the numbers mean?)

Turbidity- What does it mean and how is it measured?

Hardness- What exactly is dissolved in hard water? What factors control the equilibrium between dissolution and precipitation? How does natural water vary in hardness based on surface vs. ground water, carbonate vs. non-carbonate aquifer, rainy vs. dry season? What are the positives (tastes better, required for brewing) and negatives (damage to infrastructure, health issues, lower effectiveness of lathering soaps) of hard water? At what point (ppm) is water considered "hard?"

Salinity- What is the continuum of salinity for natural water systems (rain - surface water - groundwater - ocean water - evaporitic seas)? At what concentration is water considered "saline?" What is the recommended maximum for for salinity in drinking water? What is the effect of increasing salinity on crop yields? Why is the dead sea so saline? Where would you find the more and less saline places in the Earth's oceans? What are the more abundant ions found in sea water?

TDS- What does TDS stand for? What does TDS measure? What are the two methods for measuring TDS? What is the relationship between TDS and conductivity? What are the advantages of disadvantages of using TDS as a measure of water quality?

Through all of this, we must remember that: 1. All substances are poisonous: there is none which is not a poison. The right does differentiates a poison and a remedy. (Dr. Theophrastus Hohenheim (Paracelsus) 1493-1541 and 2. our specific water quality requirements will be different depending on the use of that water. For instance, water used for transportation or bathing your pet rhinoceros does not necessarily need to as high in quality as the water that you drink.

Slides shown in lecture today have been posted as a .pdf to Sakai.

The my maps page has been updated with the locations mentioned in today's lecture.

The Superfund Homework assignment is now up here.