Comments on Water Quality Analyses

Based on your mini-talks with me, I have some general suggestions for all of you before your POL on Thursday night.

Regarding Turbidity:
1) Make sure that you define this and other important terms. Most people will not know what turbidity means.
2) Although we do not have turbidity numbers from Mexico, you can still use the descriptions as part of your conclusions. Do not completely ignore turbidity in Mexico.

Regarding Temperature:
We did not take the temperature on the water while IN Mexico at the site. The reason that you measured temperature in class is because DO is affected by the temperature of the water. So you can not make direct comparisons of temperature measures between US and Mexico. You should only mention temperature in the context of dissolved oxygen.

Regarding Dissolved Oxygen:
Ideal levels of DO are above 6 ppm for healthy fish. Numbers between 3-5 result in slower fish growth. The lower the number, the less the environment can sustain aquatic life. The upper limit is only due to the solubility of oxygen in water at certain temperatures.

Regarding Nitrates:
It is imperative that you mention nitrate differences since these were the most pronounced of all the measures. Nitrate levels should ideally be less than 2 ppm. Increased nitrate levels could be due to fertilizers, waste, fecal matter and decay.
Use the descriptions and your OWN experience of the water source to justify WHY nitrate levels were high in some Mexico locations.