Tracy Press

Tracy spent $5 million to zap its drinking water with high-tech, ultraviolet, microbe-crippling lights. By John Upton

Glenn Moore/Tracy Press - John Jones Water Treatment Plant supervisor Dan Wengrin shows one of the spare tubes used to shine ultraviolet light on Tracy’s drinking water as part of the purification process. The lights are one of the many upgrades at the plant.

The organs of any microscopic critters that slip through carbon filters between the Delta Mendota Canal and Tracy faucets are now smashed apart by ultraviolet lights before they’re poured into bathtubs and drinking glasses, following a $5 million addition to the city’s water treatment plant.

The 196 mercury gas-filled lightbulbs at the southwestern John Jones Water Treatment Plant were switched on May 10.

“The intense light is effective at penetrating the cell of the pathogens,” said Dan Wengrin, as he held up an example of the newest technology used at the plant he has managed for 11 years. “It disrupts the DNA, and the pathogens can no longer reproduce.”

The light is especially useful for penetrating hardy cryptosporidium, according to Wengrin, which are tough to kill with chlorine alone.

Cryptosporidium spores hatch into worm-like swimmers that reproduce quickly and often cause diarrhea.

Wengrin said the city has suffered no outbreaks of waterborne diseases during his time as John Jones’ treatment boss. The water treatment veteran said cryptosporidium has only emerged as a threat during the last 25 years.

The intense ultraviolet light shines daily on 10 million gallons of water as it flows over the glass-protected, tube-shaped bulbs after leaving the plant’s mixing chambers.

Aluminum sulfate in the chambers clumps together clay and algae before the mixture runs through a newly upgraded network of filters.

Tracy’s thirst for water is expected to grow as summer temperatures climb. The plant’s capacity has doubled over the past two years to 30 million gallons a day, paid for with $44 million collected from water bills, developers and a $20 million state loan. That price includes the cost of the ultraviolet technology.

About a third of Tracy’s domestic water came from the Delta Mendota Canal last year and was sterilized at John Jones, according to Tracy water manager Steve Bayley. Half came from a reservoir near Escalon, and the rest was drawn from eight wells scattered across the city.

Coal has been replaced in the plant’s 5-foot deep filtration system with highly absorbent carbon granules, which Wengrin says will help keep water treated at John Jones relatively tasteless when algae overwhelms the canal.

Chlorine is added to the water from a new, room-sized storage tank after its ultraviolet shower. That stops germs and microbes from sneaking back into the treated water as it snakes through water pipes toward Tracy showers, taps and sprinklers.

After it’s flushed away from Tracy homes, the dirty water is sent by a separate network of pipes to the wastewater treatment plant on the other side of the city. The treated water is poured into Old River, where some of it flows back to the canal and into the John Jones plant’s intake valves.

Operators in a newly refurbished control room watch the water treatment plant through glass and on their computers. The plant rises in front of rugged hills crossed by power lines and blurred by smog on the other side of the canal.

“We click on this box,” said KBL Associates engineer Bill Long on Wednesday, as he touched a flat-screen monitor in the control room with his finger, “now we get a close-up view of the pump station itself. It shows that pump No. 2 is running, the speed it’s running and the mode it’s in.”

Long said he was fine-tuning and debugging the software, which controls the plant’s entire operations, including its pumps and automatic cleaners.

Tracy Department of Public Works Director Pat Wiemiller said he was pleased with the plant’s expansion, which he said was undertaken because of the city’s growth.

“Not only will we be able to treat a greater volume of water,” Wiemiller said in an e-mail Wednesday, “the health protection and quality enhancements will be good for our customers. … Everything is operating as expected.”

To reach reporter John Upton, call 830-4274 or e-mail This e-mail address is being protected from spam bots, you need JavaScript enabled to view it  

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written by David Hardesty , May 31, 2007

Good article John. Now if we can only solve our wastewater woes.

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written by Chris Anderson , May 31, 2007

Owning & Maintaining a home tap water filter is cheap insurance! www.waterfilterfacts.com

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written by David Hardesty , May 31, 2007

Chris
Right you are and they are pretty cheap. I use to dabble with salt water aquariums and quickly learned that Tracy water just isn't good enough. So I installed a reverse osmosis system to "make" my own clean water. You can even hook it up to your ice maker so that your ice is clean as well. I even had the water tested at a lab, because I wanted what was best for my fish, and it came back cleaner than most bottled water you buy in the store.

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written by PomboPosse , June 01, 2007

"The organs of any microscopic critters that slip through carbon filters between the Delta Mendota Canal and Tracy faucets are now smashed apart by ultraviolet lights before they’re poured into bathtubs and drinking glasses, following a $5 million addition to the city’s water treatment plant."

John - did you know that ultraviolet light only works on pathogens in waste water that have a DNA> The problem with this type of waste water disenfectant system is it doesn't affect things like human hormones in the waste stream and it doesn't kill prions the precursor to Mad Cow Disease and its human variant form Creutzfeldt-Jakob disease (vCJD).

A prion is a protein with no nucleic acids - meaning they cannot reproduce. It is a protein with an altered shape or abnormality and is said to be able to bind to other proteins and induce an altered shape or abnormality. This sets off a domino effect, increasing the number of abnormal proteins exponentially.


Prions cannot be destroyed by cooking, canning, freezing, digestion, sterilization, radiation (like untraviolet light) or with formaldehyde. They are considered one of the smallest and most lethal self-perpetuating entities in the world, and can remain infectious for many years in soil, water, and organisms.

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written by Tracy Mom , June 01, 2007

That's pretty scary!