Environment Busy Coralville Lake Algae Levels Safe; Battle Continues At Eastern Iowa Recreation Areas Beach-goers in eastern Iowa's Johnson County looking for a final summer swim before school starts should be aware of two unpleasant dangers — toxic algae and E. coli. [One of two stories in a special IowaWatch-Iowa City Press-Citizen collaboration.] By Stephen Gruber-Miller/Iowa City Press-Citizen / 15 Aug 2015