Testing Water Quality Along "Bluegill Bayou"

I just wrote Indiana University:

We live along a bayou that feeds a creek which runs to Galveston Bay in the Gulf Of Mexico.

My daughter is applying for a special "science magnet school".

We are thinking about doing a water analysis of our bayou and maybe several feeders into the creeks which feed the bay.

I taught chemistry a loooong time ago.  I'm embarrassingly rusty. 

Anyhow, would the experiments you've outlined, say for phosphates be doable for us? 

Can we purchase the necessary chemicals and tools to do our own analysis?