Sign: Water Quality Improvement Project

Lake Temescal is tested for bacterial levels weekly from April to October. Water quality samples are taken from four different locations around the Lake, including the swim beach. Nearby communities located above the lake can play a significant role in introducing nutrients. Runoff from the streets storm drains flows into Temescal Creek. Impervious surfaces in cities, including pavement, buildings, and large areas of compacted earth diminishes the amount of rain soaking (percolating) into the soil. Sanitary and storm sewer lines run parallel to each other here, resulting in stormwater overflowing into the sanitary sewer collection system. Urban stormwater runoff is a major source of nonpoint water pollution. Pollutants such as suspended solids, heavy metals and nutrients have been found in samples of urban stormwater runoff. The nutrients carried in runoff catalyze cyanobacteria growth, resulting in blue-green algae blooms that can kill aquatic animals.