Water quality in Los Angeles rivers became slightly better in 2019 compared to the prior year, according to a report card released Tuesday by a nonprofit organization that grades bacteria levels in water throughout California.
Heal the Bay released its River Report Card, which assigns water quality grades from worst to best — or from red to yellow to green — for 28 freshwater sites in Los Angeles County based on observed bacteria levels in 2019 compared to 2018.
The nonprofit tests multiple sites in the rivers and watersheds. Green means there is a low risk of illness to humans when they make contact with the water. Yellow indicates a moderate risk, and red signals a high risk.
Heal the Bay reported that across all 28 River Report Card sites in 2019 in Los Angeles, 66% of grades assigned were green — a 9% increase in green grades compared to 2018.
All four watershed study areas included in the report had a decrease in overall red grades in 2019.
Seven sites in the San Gabriel River Watershed and three from the Upper Los Angeles River Watershed made Heal the Bay’s “Top 10 Honor Roll” of freshwater sites with lowest public health risk detected, including seven that earned perfect scores of 100% green grades.
The River Report Card also includes a “Freshwater Fails” list, which found six sites in 2019 in the Los Angeles River Watershed. This is a reduction from 10 entries in the 2018 report.
Hansen Dam at Tujunga Wash was once again the area’s number one failing site, but it improved to 44% red grade tests, down from 80% in 2018, the nonprofit stated.
Lake Balboa Boat Ramp and Rattlesnake Park were a close second and third worst, with 43% and 41% red grades, respectively.
Nine Los Angeles sites graded had poorer water quality in 2019 compared to 2018, including both test sites in the Malibu Creek Watershed.
Heal the Bay said its tests do not detect the presence of the COVID-19 virus in the water, but they do detect fecal indicator bacteria. The COVID-19 virus has been detected in sewage, indicating that fecal matter from infected individuals can contain the virus, Heal the Bay stated.
Heal the Bay’s weekly updated River Report Card interactive map is at healthebay.org/riverreportcard.