Water Quality in Courtland Creek, East Oakland, California

Courtland Creek is a tributary of the larger East Creek system that runs southeast from the Oakland Hills down to the San Leandro Bay in Oakland, California. In an effort to assess the overall health of Courtland Creek our team conducted a water quality research study. Stream water samples were collected from 4 sites between MacArthur Avenue (describe geographically as not all readers are familiar with Oakland geography) and Thompson Avenue (describe geographically as not all readers are familiar with Oakland geography) at accessible sections of this largely culverted stream. Dissolved oxygen, ammonia, nitrite, nitrate, phosphate, and chlorine concentrations in were measured using wet chemistry procedures. Analysis of collected samples indicates that dissolved oxygen levels in the stream are sufficient for invertebrates, ranging from 5 and 9 parts per million (ppm). Nitrate levels were significantly high, with concentrations ranging from 15 and 40 ppm. Other chemical species associated with waste products--ammonia, nitrite, and phosphate--also were present, but at low concentrations. Small amounts of chlorine also were found in waters of the creek system. The presence of high concentrations of nitrate, together with chlorine, suggests that untreated sewage may be leaking into Courtland Creek at an unidentified location.