Superbugs? Toilet to tap is safer than surfing*

Hyperion-Treatment-Plant.jpgHyperion treatment plant looking north toward LAX.

Monday's LAT reports that Deadly superbugs from hospitals get stronger in the sewers and could end up in the Pacific Ocean.

I'm happy whenever infrastructure gets front page real estate. But, I want to point out that, while this problem is a serious concern for workers at the sewage treatment plants, wildlife, surfers, and people who eat near-shore fish, lesser-known dangers also pose grave risks.

The LAT said:

Scientists at the Environmental Protection Agency recently announced they had discovered a lethal superbug -- the same one that caused outbreaks at UCLA and two other Los Angeles-area hospitals -- in sewage at one of those plants. They declined to name the facility.

The EPA did not name the superbug, though the LAT story speculates.
* UPDATE: The EPA did name the class of CRE superbugs. Read their abstract Wastewater as a Source of Carbapenem Resistant Escherichia coli.

First of all, the story says that superbugs have been found at a treatment plant, but not whether they also leave the plant after enduring treatment processes at LA-area sewage treatment plants. (This is a link to general information because their specific link to a description of their treatment processes is broken.)

Some of the water that leaves Hyperion goes into Santa Monica Bay via tubes on the bottom of the sea where they could potentially make there way back to shore. But much of the water leaving Hyperion is sent across the street to the Edward C. Little Water Recycling Facility (ECLWRF) for further cleansing.

The biggest near-shore risk is water runoff through storm drains that flow untreated into rivers and the ocean. The EPA has an informative video about stormwater runoff and a handy calculator, too.

In 2010, I toured the ECLWRF and wrote up a report. Since then, the facility has expanded. A friend who does research in water reclamation says that the state-of-the-art has leap-frogged in the last 5 years so it is time for me to revisit the plant.

ECLWRF is giving free public tours this Saturday, March 12. Email to reserve a spot. I hope to see you there. (Send a message to @gspeng if you want to meet up on the tour.)

Of course, I'll write up a new report on the updated treatment plant.

If you read either my 2010 report or West Basin's ECLWRF virtual tour, you can see that the process includes several steps designed to filter out bacteria-sized particles. Even if the bacteria were to evade the filters, they still need to survive UV irradiation. The enterococcal bacteria mentioned in the LAT story has been shown to be highly susceptible to UV radiation.

March 6-12, 2016 is National Groundwater Awareness Week. The European Geophysical Union is also celebrating #GroundwaterAwarenessWeek and tweeted a link to Christopher Barry's series about The Impacts of Climate Change on Global Groundwater Resources. Part 2, about saline intrusion, is particularly relevant to Angelenos and why we spend so much money to build and operate ECLWRF.

Consider this West Basin graphic.


Treated waste water from ECLWRF feeds a network of 105 injection wells along our coastline.

West Basin pumps ultra-pure treated waste water into the ground under high pressure as protection from sea-water intrusion to our heavily-pumped aquifer. Then we pump it back up again, after the water percolates through the ground to pick up contaminants. Then we treat the water to imperfectly remove the contaminants.

We can save ourselves a lot of money and energy (and enjoy cleaner water to boot) if we just adopt toilet to tap.

I alluded in the beginning to lesser-known risks. Want to know what really keeps a scientist up at night?

Triclosan, that ubiquitous chemical additive in 'antibacterial' soaps and even toothpaste, is a leading cause of superbugs in the first place.

When you put triclosan down the drain, and it ends up in biosolids spread on farmland or in a secondary treatment plant such as ECLWRF, it gets exposed to UV light. Triclosan, when exposed to UV light, degrades into several chemicals, including different flavors of dioxin. Triclosan in the presence of detergent is even more likely to degrade into dioxin when exposed to UV light.

Not purchasing or using triclosan is something I can control. But my efforts will be for naught unless you do likewise.

More by Grace Peng:
Recently on Native Intelligence
New at LA Observed