The Minnesota River is getting healthier, and the Minnesota Pollution Control Agency says it shows efforts to reduce pollution from wastewater treatment systems are making the difference. MPCA staff monitored a 20-mile stretch of the lower river for three weeks in August to see if the hot, dry summer and low flows would deplete oxygen levels, which had been a problem in previous droughts. Scientists were encouraged to find that oxygen levels remained high enough to support fish, bugs and other aquatic life despite the stressful conditions. Officials credit the success to $250-million in public and private investments to reduce phosphorous discharges all along the river.