In this investigation, we aim to test the amount of E. coli present before and after precipitation. We hypothesize that the amount of E. coli will increase in the surrounding waters after rainfall has occurred. As a result, the biodiversity of algae will decrease. Besides the variable of bacteria, two other important factors in this investigation will include salinity and pH. The salinity will serve as a constant to prove that the collected water is in fact fresh water. The pH will be tested to determine if the collected water becomes more acidic. Organisms such as bacteria prefer an acidic environment. Our collection sites will include Argyle Park, Belmont State Park, and Lake Ronkonkoma.