248 E. Foothill Blvd., Suite 200, Monrovia, CA, 91016

Water Quality

Water Quality 

Water quality is an important public health and water supply issue in the San Gabriel Valley. Not only does water pollution and contamination threaten water supplies, but remediation and clean-up are costly and important matters for Southern California and the San Gabriel Basin.

In the 1970s, industrial pollution impacted many wells making it necessary for Upper District and local water agencies to be proactive in ensuring clean and safe water for the region. The seriousness of the groundwater contamination problem became evident when high concentrations of volatile organic compounds (VOCs) were discovered in Azusa in 1979 near a major industrial complex. Over the next four years, further investigation revealed widespread VOC contamination significantly impacting the San Gabriel Basin.

As a direct result of these findings, WQA was established by the State Legislature under SB 1679 on February 11, 1993 to develop, finance and implement groundwater treatment programs in the San Gabriel Basin. Since its formation, over 30 groundwater treatment facilities have been constructed that operate full-time to remove contaminants from the groundwater supply and to ensure that the highest quality of water is available within the San Gabriel Valley.

The total cost to construct and operate these facilities is estimated to be $1.2 billion, with over 100,000 pounds of contaminants removed thus far. Upper District is a member of the WQA with one representative sitting on its seven member governing board. To learn more about the San Gabriel Basin Water Quality Authority’s role and operations click below.

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Trust Your Tap Video 

In the San Gabriel Valley, your tap water is safe to drink! Your local water supply undergoes extensive treatment and filtration processes, and is tested multiple times per day by your water retailers before it reaches your home.

They ensure that your water supply meets and exceeds federal drinking water standards. Learn more about the process by watching this video!

Per-and Polyflournalky Substances (PFAS) and Contaminants of Emerging Concern

Consistent with our mission to meet the region’s needs for reliable, high quality, and affordable water, Upper District continues to work with other water agencies to ensure that the San Gabriel Valley has a safe water supply. In light of the growing concern over the presence of emerging contaminants known as PFAS, below are fact sheets, briefing materials and visuals that may be helpful when answering questions about these chemicals. Click on the links below.

Quality - PFAS