Water Quality in the Arroyo

Water DropMajor progress is being made toward cleaning up the water quality in the Arroyo Seco Watershed. Below are some of the projects that have and continue to protect the Arroyo Seco and improve it for future generations.

Citizen Water Quality Monitoring

The Arroyo Seco Foundation maintains a citizen water quality monitoring program in partnership with Pasadena Water & Power. Sampling is carried out by ASF's volunteer corps, the Arroyo Seco Stream Team. Each month, volunteers collect samples from 11 points along the Arroyo, from the confluece with the Los Angeles River, to El Prieto in the San Gabriel Mountains. In addition, ASF provides water quality monitoring in Rubio Canyon and Eaton Canyon. Training is provided by ASF and Pasadena Water & Power and everyone is welcome to participate. See our Water Quality Monitoring page for more information on the program and results.

NASA JPL Cleanup

The City of Pasadena and NASA JPL have signed an agreement to build a treatment plant to clean up the water in the Hahamongna region of the Arroyo that has been tainted by perchlorate. The agreement has taken six years to achieve but reflects substantial progress achieved in the last year to moving forward to clean up the source of the pollution and to treat the contaminated water.

JPL Cleanup Progress | Association of Ground Water Agencies Article

North East Trees Water Quality Study

Jason Pelletier of North East Trees has compiled a major water quality study of the Arroyo Seco Watershed. This project was funded by a water quality grant (Proposition 13) from the State of California. The Plan proposes projects and programs to improve water quality and restore habitat in the urbanized portions of the Arroyo Seco watershed, and builds on the joint work completed by North East Trees and the Arroyo Seco Foundation in the Arroyo Seco Watershed Restoration Feasibility Study, completed in 2002. The appendices provides analysis and background on water quality concerns and best management practices.

To download the plan, please click here: Water Quality Plan  |  Appendix

News Coverage

Water quality fouling the Arroyo, Pasadena Star-News, 10/19/2007

Arroyo Seco channel slammed for pollution, Long Beach Press Telegram, 10/20/2007