Bottoms Up! Purified recycled water is safe to drink

The results are in, and they speak for themselves!

After 15 months of intensive water quality testing and systems monitoring, test results show that highly purified water produced from treated wastewater is just as safe to drink as regular tap water. The Silicon Valley Advanced Water Purification Center (SVAWPC), which opened in March of 2014, receives partially treated wastewater and uses microfiltration, reverse osmosis, and ultraviolet light disinfection to produce highly purified water that meets all California primary and secondary drinking water standards.

Currently, purified water produced by the SVAWPC is not used for potable (drinking) purposes, and is instead blended with existing recycled water to enhance its quality for non-potable purposes such as irrigation, cooling towers and industrial applications. However, the water district has plans in the near future to use this highly purified water to augment our drinking water supplies. To protect public health and ensure that safety standards are met, the water district engaged in an extensive demonstration research project over the last year and half which was overseen by an Independent Advisory Panel comprised of international experts in the field.

As part of the water district’s Potable Reuse Demonstration project, a Test Plan was developed to thoroughly investigate the performance of each component of the advanced purification process (microfiltration, reverse osmosis, and ultraviolet disinfection) at the SVAWPC. It also evaluated an additional treatment process —  advanced oxidation, which was added to the ultraviolet disinfection treatment component and used for further testing production of purified water for potable reuse. Advanced oxidation works with the ultraviolet light treatment process and together these two processes provide robust disinfection and removal of contaminants of emerging concern.

The Test Plan demonstrated effective removal of all tested contaminants, such as:

1. Industrial chemicals
2. Pharmaceuticals
3. Personal care products
4. Biological pathogens, which are microorganisms that can cause illness (e.g., viruses, bacteria, and protozoa such as Giardia and Cryptosporidium)

Over a 15-month period, 284 different constituents were tested every three months, and 4,000 total water quality samples were collected and analyzed. What did the results show?

• All purification processes at the SVAWPC exhibited excellent performance.
• Purification processes exhibited excellent removal of pathogens and contaminants of emerging concern, such as pharmaceuticals and endocrine disruptors.
• Purified water produced by the SVAWPC with advanced oxidation meets or exceeds all California drinking water standards, including all potable reuse regulations for groundwater replenishment.
• New ways of monitoring were proven to accurately verify the removal of pathogens and contaminants.
• Critical Control Points, which are parameters that will ensure highest water quality, were identified.

For more information or to read the full report, please visit www.valleywater.org/testplan.

Curious about the advanced cleaning processes that produce purified recycled water? See them for yourself by scheduling a free tour at www.purewatersv.org