First, I want to thank all the Daphnia who gave their lives to prove my hypothesis! Daphnia are a small shrimp-like creature, about the size of a grain of salt. Scientists use them to do experiments because they reproduce quickly, so you always have alot on hand. And they are very sensitive to environmental pollutants, so they tell us if other water creatures might be affected by the same substances.
For my animal experiment I took the Daphnia and put 10 of them each  in four bowls.  In one bowl I put grass water; in another I put synthetic turf runoff water; in another I put spring water and in another I put tap water. All of the Daphnia in the tap water died within 24 hours. (I checked them about every four hours.) All of the Daphnia in the spring water and the grass water were alive after 24 hours. But in the turf runoff, the first time I ran this experiment 6 of the 10 Daphnia died within 24 hours. I ran the experiment again with just 10 Daphnia in grass water and 10 in turf runoff water, and again, all the grass water Daphnia survived. But 8 of the 10 Daphnia in the turf water died. This tells me that there is something in the turf that kills most of the Daphnia.
Our nutrient analysis from Dr. Adina Paytan’s lab show that there is a lot of zinc and some other heavy metals that the Daphnia may not appreciate, but we don’t know for sure what killed them.