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Sewage shows spread of coronavirus across Santa Clara County

Wastewater sampling helps track COVID-19 spikes, declines

City of San Jose Environmental Services Department inspectors Isaac Tamand and Laila Mufty insert an autosampler into a manhole at the San Jose-Santa Clara Regional Wastewater facility to obtain specimens of genetic material for testing the presence of SARS-CoV-2 virus. Courtesy city of San Jose Environmental Services Department.

A study of wastewater is showing that the SARS-CoV-2 virus, which causes COVID-19, is skyrocketing in Santa Clara County, according to online data from the county Public Health Department.

The virus is found in human waste that's made its way to wastewater treatment plants. Researchers from Stanford University have been sampling the wastewater at four plants in Palo Alto, San Jose, Sunnyvale and Gilroy. The sampling measures the quantity of two pieces of the virus known as its N and S genes, which are taken from the virus' ribonucleic acid, or RNA, which is a nucleic acid present in all living cells.

Recent testing shows a significant rise in these genetic components as the county and state are seeing a dramatic increase in COVID-19 cases attributed to the virus' more contagious delta strain. The amount of virus in the wastewater has tripled, and in some cases quadrupled, since June 16, indicating a much higher rate of infection throughout the county.

Significantly, the virus volume has spiked in recent weeks, according to online data from the county Public Health Department. The genetic material collected from the Palo Alto Regional Water Quality Control Plant has doubled in the past two weeks, according to county data, with the steepest climb starting on July 21.

The plant serves the municipalities of Los Altos, Los Altos Hills, Mountain View and Palo Alto, Stanford University and the East Palo Alto Sanitary District (in San Mateo County) and processes the waste of 213,968 residents, according to the county data dashboard.

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The San Jose-Santa Clara Regional Wastewater Facility, which serves 1,458,017 residents in San Jose, Santa Clara, Cupertino, Saratoga, Milpitas, Campbell, Los Gatos and Monte Sereno, showed a similar rise over the last two weeks. It peaked on July 23, showed a decline on July 24 and has been climbing again through July 26, the last date of available data.

The volume of the virus in Sunnyvale has taken a wild ride, steeply rising and dipping throughout the past six weeks. It rose sharply around the July 4 holiday, based on samples collected from the Donald M. Somers Water Pollution Control Plant, which serves 169,000 residents. The virus tripled to its highest level in the period from July 14 to July 23 before leveling off. It began to drop on July 27, according to the data.

At the Gilroy-South County Regional Wastewater Authority, which serves 110,338 people in Morgan Hill and Gilroy, the virus amounts rose more slowly until it hit a steeper rise on July 11. The amount of virus leveled off and stayed relatively stable until July 21 when it also began to nearly triple, according to the county data. Like Sunnyvale, the amount of virus began to decline on July 26, but it is too soon to tell if the numbers represent a meaningful trend.

The samples are collected daily and are taken to a commercial lab for analysis. The results are usually ready within 24 hours after the samples are dropped off. The quick turnaround and posting is one of the major advantages of utilizing this data, according to the public health department.

Michael Balliet, deputy director of public health, said the data is tracking well with other sources of data.

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"It really does a good job and gives us a broader perspective of what's going on in the community. It's particularly helpful if testing rates decline," he said, referring to the testing of individuals for the virus.

A Palo Alto Regional Water Quality Control Plant wastewater treatment operator takes sample of primary sludge for COVID-19 surveillance testing by Stanford University and Santa Clara County. The "settled solids" are being tested to determine the amount of genetic material from SARS-CoV-2 virus, which indicates the spread of COVID-19 in communities served by the plant. Courtesy A. Guizar/Palo Alto Regional Water Quality Control.

The county can compare the wastewater data with other metrics it gathers to understand trends. The staff looks for commonalities, but divergent data can also be helpful.

"We haven't seen major increases in emergency room visits as we have in the wastewater data," which could indicate that fewer people are making their way to the ER, he said. He stopped short of attributing the discrepancy to the effectiveness of the vaccine, however.

The county is continuing to examine trends related to holiday gatherings that attract many people, he said. The wastewater studies can prove to be valuable indicators of those trends.

All of the steepest rises in the past six weeks began about a week to 10 days after the July 4 holiday weekend, with the exception of Gilroy, according to the data.

Balliet noted that although the current spike is concerning, data going back as far as Oct. 1, 2020, shows it is, so far, much smaller than at the peak of winter's deadly acceleration. The virus' genes were at the highest concentration in December 2020 through early January 2021, which correlated with high rates of hospitalizations.

The study is led by Stanford's Department of Civil and Environmental Engineering and includes researchers from the Joint Initiative for Metrology in Biology at SLAC National Accelerator Laboratory Stanford, the Stanford University School of Medicine Department of Genetics, the Monterey Bay Aquarium Research Institute and the University of San Francisco Department of Engineering.

Unlike other studies that focused on liquid components of the wastewater, the Stanford study, which looked at the solids, found a greater concentration of the genes, the Stanford researchers wrote in an early paper in the Dec. 7, 2020, journal Environmental Science & Technology.

The sewage data is available online at covid19.sccgov.org/dashboard-wastewater.

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Sewage shows spread of coronavirus across Santa Clara County

Wastewater sampling helps track COVID-19 spikes, declines

by / Palo Alto Weekly

Uploaded: Fri, Jul 30, 2021, 6:57 am

A study of wastewater is showing that the SARS-CoV-2 virus, which causes COVID-19, is skyrocketing in Santa Clara County, according to online data from the county Public Health Department.

The virus is found in human waste that's made its way to wastewater treatment plants. Researchers from Stanford University have been sampling the wastewater at four plants in Palo Alto, San Jose, Sunnyvale and Gilroy. The sampling measures the quantity of two pieces of the virus known as its N and S genes, which are taken from the virus' ribonucleic acid, or RNA, which is a nucleic acid present in all living cells.

Recent testing shows a significant rise in these genetic components as the county and state are seeing a dramatic increase in COVID-19 cases attributed to the virus' more contagious delta strain. The amount of virus in the wastewater has tripled, and in some cases quadrupled, since June 16, indicating a much higher rate of infection throughout the county.

Significantly, the virus volume has spiked in recent weeks, according to online data from the county Public Health Department. The genetic material collected from the Palo Alto Regional Water Quality Control Plant has doubled in the past two weeks, according to county data, with the steepest climb starting on July 21.

The plant serves the municipalities of Los Altos, Los Altos Hills, Mountain View and Palo Alto, Stanford University and the East Palo Alto Sanitary District (in San Mateo County) and processes the waste of 213,968 residents, according to the county data dashboard.

The San Jose-Santa Clara Regional Wastewater Facility, which serves 1,458,017 residents in San Jose, Santa Clara, Cupertino, Saratoga, Milpitas, Campbell, Los Gatos and Monte Sereno, showed a similar rise over the last two weeks. It peaked on July 23, showed a decline on July 24 and has been climbing again through July 26, the last date of available data.

The volume of the virus in Sunnyvale has taken a wild ride, steeply rising and dipping throughout the past six weeks. It rose sharply around the July 4 holiday, based on samples collected from the Donald M. Somers Water Pollution Control Plant, which serves 169,000 residents. The virus tripled to its highest level in the period from July 14 to July 23 before leveling off. It began to drop on July 27, according to the data.

At the Gilroy-South County Regional Wastewater Authority, which serves 110,338 people in Morgan Hill and Gilroy, the virus amounts rose more slowly until it hit a steeper rise on July 11. The amount of virus leveled off and stayed relatively stable until July 21 when it also began to nearly triple, according to the county data. Like Sunnyvale, the amount of virus began to decline on July 26, but it is too soon to tell if the numbers represent a meaningful trend.

The samples are collected daily and are taken to a commercial lab for analysis. The results are usually ready within 24 hours after the samples are dropped off. The quick turnaround and posting is one of the major advantages of utilizing this data, according to the public health department.

Michael Balliet, deputy director of public health, said the data is tracking well with other sources of data.

"It really does a good job and gives us a broader perspective of what's going on in the community. It's particularly helpful if testing rates decline," he said, referring to the testing of individuals for the virus.

The county can compare the wastewater data with other metrics it gathers to understand trends. The staff looks for commonalities, but divergent data can also be helpful.

"We haven't seen major increases in emergency room visits as we have in the wastewater data," which could indicate that fewer people are making their way to the ER, he said. He stopped short of attributing the discrepancy to the effectiveness of the vaccine, however.

The county is continuing to examine trends related to holiday gatherings that attract many people, he said. The wastewater studies can prove to be valuable indicators of those trends.

All of the steepest rises in the past six weeks began about a week to 10 days after the July 4 holiday weekend, with the exception of Gilroy, according to the data.

Balliet noted that although the current spike is concerning, data going back as far as Oct. 1, 2020, shows it is, so far, much smaller than at the peak of winter's deadly acceleration. The virus' genes were at the highest concentration in December 2020 through early January 2021, which correlated with high rates of hospitalizations.

The study is led by Stanford's Department of Civil and Environmental Engineering and includes researchers from the Joint Initiative for Metrology in Biology at SLAC National Accelerator Laboratory Stanford, the Stanford University School of Medicine Department of Genetics, the Monterey Bay Aquarium Research Institute and the University of San Francisco Department of Engineering.

Unlike other studies that focused on liquid components of the wastewater, the Stanford study, which looked at the solids, found a greater concentration of the genes, the Stanford researchers wrote in an early paper in the Dec. 7, 2020, journal Environmental Science & Technology.

The sewage data is available online at covid19.sccgov.org/dashboard-wastewater.

Comments

Marion Poole
Registered user
Community Center
on Jul 30, 2021 at 7:31 am
Marion Poole, Community Center
Registered user
on Jul 30, 2021 at 7:31 am

Based on this report, it would seem plausible that testing for Covid-19 could be easily accomplished via stool sample laboratory analysis.

If everyone in Santa Clara Valley were to submit a sample of their excrement, public health officials could then establish an accurate infection rate.

Samples could be dropped off at specified county offices or maybe even the PAPD could be enlisted to collect them at various drop-off locations.


Lenora Peters
Registered user
Crescent Park
on Jul 30, 2021 at 9:24 am
Lenora Peters, Crescent Park
Registered user
on Jul 30, 2021 at 9:24 am

A home testing kit would be more practical and discrete but the results would have to be 100% reported for the statistics to be totally accurate.

And the the question might arise...would privacy-rights advocates consider a periodic stool reportage an invasion of privacy?

This is one for Governor Newsom to ponder along with his other gubanatorial duties and responsibilities.


Arik Chopra M.D.
Registered user
another community
on Jul 30, 2021 at 9:59 am
Arik Chopra M.D., another community
Registered user
on Jul 30, 2021 at 9:59 am

The Delta variant emerged due to poor public sanitation measures in India and then it spread via aerosol contact among countless individuals.

The deceased were often tossed into the Ganges River because of cremation backlogs and/or the inability to pay for proper bodily disposals.

Covid-19 traces can be found in stool samples and here is where we can turn feces into an ally towards combatting the further spread of Covid-19.

If American citizens and current residents were required to provide an individual stool sample on a weekly basis, the path of Covid-19 could be easily traced and monitored.


fred
Registered user
University South
on Jul 30, 2021 at 10:28 am
fred, University South
Registered user
on Jul 30, 2021 at 10:28 am

Is anybody going to take action on this information, or will we just admire the technical prowess of the researchers?


Vicky
Registered user
Crescent Park
on Jul 30, 2021 at 10:40 am
Vicky , Crescent Park
Registered user
on Jul 30, 2021 at 10:40 am

Is there a countervailing legal argument of public good against privacy right?


BGordon
Registered user
Midtown
on Jul 30, 2021 at 10:53 am
BGordon, Midtown
Registered user
on Jul 30, 2021 at 10:53 am

The graphs of "online data" are very interesting -- maybe they could be in the main article.


Biff Connors
Registered user
Barron Park
on Jul 30, 2021 at 11:01 am
Biff Connors, Barron Park
Registered user
on Jul 30, 2021 at 11:01 am

Mandatory vaccinations against Covid-19, face mask requirements while at indoor public venues, and periodic stool sample submittals would go a long ways towards containing the pandemic.

As far as privacy issues, it's not like anyone has any practical use for their
discarded feces so why raise a potential ruckus?

I agree with the previous poster who mentioned possible drop-off sites at various county offices along with the PAPD diligently collecting stool samples at predetermined locations.


Jocelyn Dong
Registered user
editor of the Palo Alto Weekly
on Jul 30, 2021 at 12:36 pm
Jocelyn Dong, editor of the Palo Alto Weekly
Registered user
on Jul 30, 2021 at 12:36 pm

Thank you, BGordon, for your helpful comment. We've added the most recent graphs to the story, although our platform does not allow us to embed the interactive versions.


YP
Registered user
Crescent Park
on Jul 30, 2021 at 5:07 pm
YP, Crescent Park
Registered user
on Jul 30, 2021 at 5:07 pm

Oh crap!!, this is not a good trend....


Midlander
Registered user
Midtown
on Jul 30, 2021 at 5:10 pm
Midlander, Midtown
Registered user
on Jul 30, 2021 at 5:10 pm

Very interesting data. Thanks for publishing this!

Looking at the online data, the long term graphs for the four sewage sites have very similar shapes to the reported Santa Clara Covid-19 positive test numbers. So the two data sources seem consistent, which is always a useful check.

Now that so many people are vaccinated, we're likely to see a much higher percentage of asymptomatic cases. which may not fully show up in the daily test numbers. These will however still show up in the sewage numbers, so they may be useful in tracking asymptomatic transmission levels.


RDR
Registered user
another community
on Jul 31, 2021 at 1:48 am
RDR, another community
Registered user
on Jul 31, 2021 at 1:48 am

While waste samples make sense for community sampling, it doesn't make sense to use stool vs nasal swabs for testing individuals.

I am curious though whether the incidence in the different populations served by the 4 plants can be compared by this sampling. It would be interesting to know about that.


Bystander
Registered user
Another Palo Alto neighborhood
on Jul 31, 2021 at 8:40 am
Bystander, Another Palo Alto neighborhood
Registered user
on Jul 31, 2021 at 8:40 am

How's the contact tracing app doing? I have not heard any more about it since we were all told to get it on our phones. I haven't been pinged yet.


Miriam Stein
Registered user
Professorville
on Jul 31, 2021 at 3:22 pm
Miriam Stein, Professorville
Registered user
on Jul 31, 2021 at 3:22 pm

- it doesn't make sense to use stool vs nasal swabs for testing individuals.

A self-administered nasal swab test might prove dangerous.

A home-style poop analysis would be far less hazardous and easy for anyone to conduct.

Maybe something along the lines of a chemical that changes color when poured into the toilet bowl or toilet paper that changes color.


EmmaP
Registered user
Old Palo Alto
on Jul 31, 2021 at 9:59 pm
EmmaP, Old Palo Alto
Registered user
on Jul 31, 2021 at 9:59 pm

Given that Covid-19 apparently starts in the respiratory system, evidence of infection likely shows up first in that system (e.g., nasal swabs) and only later in stools. For individual people we want results early.
Also a search indicates that anal swabs/stool samples were looked at early in the epidemic and found not to be as useful as a swab in the respiratory system for early detection (though apparently viral evidence lasted longer in the gut so for someone who had been ill for a while and not tested for Covid-19 earlier an anal swab might show evidence of infection where a nasal swab did not).


Cassie Verdugo
Registered user
Mountain View
on Aug 1, 2021 at 10:04 am
Cassie Verdugo, Mountain View
Registered user
on Aug 1, 2021 at 10:04 am
Cam Willard
Registered user
Menlo Park
on Aug 1, 2021 at 12:33 pm
Cam Willard, Menlo Park
Registered user
on Aug 1, 2021 at 12:33 pm
chewie
Registered user
University South
on Aug 1, 2021 at 2:35 pm
chewie, University South
Registered user
on Aug 1, 2021 at 2:35 pm

Where are the long-term studies?


Henry Beamon
Registered user
another community
on Aug 2, 2021 at 4:02 pm
Henry Beamon, another community
Registered user
on Aug 2, 2021 at 4:02 pm
Bethany Giftos
Registered user
Los Altos
on Aug 2, 2021 at 4:46 pm
Bethany Giftos, Los Altos
Registered user
on Aug 2, 2021 at 4:46 pm
Marcie Hanson
Registered user
Barron Park
on Aug 2, 2021 at 5:06 pm
Marcie Hanson, Barron Park
Registered user
on Aug 2, 2021 at 5:06 pm

[Post removed due to same poster using multiple names]


Bob Hernandez
Registered user
Charleston Meadows
on Aug 3, 2021 at 9:27 am
Bob Hernandez, Charleston Meadows
Registered user
on Aug 3, 2021 at 9:27 am
Midlander
Registered user
Midtown
on Aug 3, 2021 at 1:41 pm
Midlander, Midtown
Registered user
on Aug 3, 2021 at 1:41 pm

> Where are the long-term studies?
The link is in the article: Web Link
There are both six-week and nine-month graphs for each of the four sewage treatment plants in Santa Clara County. There is also a bunch of information about how the analysis is done and how they try to correct for various sampling issues. It's all good stuff.


Hughie Daniels
Registered user
another community
on Aug 3, 2021 at 1:45 pm
Hughie Daniels, another community
Registered user
on Aug 3, 2021 at 1:45 pm
Resident 1-Adobe Meadows
Registered user
Adobe-Meadow
on Aug 6, 2021 at 8:35 am
Resident 1-Adobe Meadows, Adobe-Meadow
Registered user
on Aug 6, 2021 at 8:35 am

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