|By Monique Ching, San Angelo Standard-Times, Texas|
|McClatchy-Tribune Information Services|
The future, apparently, is upon
For two weeks in May, the city began bringing in some water through the newly finished 60-mile pipeline connection from the Hickory Aquifer to test blending operations with surface supplies at a dilution of 10 to 1. By fall, officials hope to complete the groundwater treatment facility that will bring the water's radium content to within
The process itself was long and arduous -- as is typical for most water infrastructure endeavors.
Once complete, though, the Hickory's promised 6 to 9 million gallons per day will not be
THE HICKORY JOURNEY
City officials approved the preliminary design of the Hickory Aquifer in 2009 -- two years before 2011, when
Plans to develop a groundwater source had arisen a couple years prior, in 2007, when the city drilled into two different brackish water aquifers nearer
The 30-inch transmission main to deliver water from the well fields to
The process begins 62.4 miles away in the
The Groundwater Treatment Facility will remove iron and radium from the Hickory water by a flow-through process. The water then will be taken to the clearwell where it's distributed to the rest of the city.
The treated material will be removed and handled by contractor Water Remediation Technologies, which has agreed to give the city a 10-year guaranteed treatment cost of
THE RADIUM RUMPUS
Since officials declared they would develop a pipeline to bring Hickory water to
Radium is a radioactive element present virtually in all rocks and soil. It also occurs in plants, animals and water and the general environment.
People expose themselves to radiation all the time when they swallow it in food, inhale it in air and -- at high levels -- when they are screened by X-rays.
According to the
Radiation is measured in picocuries, and the
According to the
For years, residents in
Not the case for
Amid some public consternation at the idea of having to drink "radium-infested" water,
Once the radium is removed from the Hickory water, however, it "is way better than Ivie," said
THE HICKORY TREATMENT
The two main components of treatment for the Hickory water will remove iron and radium.
Once the water arrives at the plant, Combest said, it first will be treated for iron.
"Iron is actually dissolved in the Hickory water just like the radium," Combest said.
The water is oxidized, making the iron insoluble and possible to filter.
"We will oxidize it when it gets to the head of the plant," Combest said, after which it is filtered.
After it's filtered, the water is passed through an ion exchange medium. The medium is charged, attracting and removing the radium particles as the water flows through.
The treated material removed from the water will be taken away by WRT. Combest estimated the company will change out the ion exchange filters every few years.
Under the terms of the city's contract, WRT will dispose of the material away from the city.
Once the iron and the radium have been removed from the water, Combest said, the Hickory water in fact is purer than what
"It's a lot better than what we're drinking," he said.
Water quality typically is measured by its content of total dissolved solids. Water from
THE HICKORY BLEND
An extra connection in the pipeline would allow the Hickory water to be combined with water from
In March, the TCEQ gave the city the green light to blend surface water with the Hickory water if necessary at a 5:1 ratio -- because the average radiation level was lower than officials initially thought.
There are nine existing wells in the Hickory Aquifer, and each well has a different level of radiation. The water extracted from the wells ranges in radium levels from 17 picocuries per liter to 38 picocuries per liter, Combest said.
Radium tests take about a month, Combest said. Officials originally thought the average radiation level was 35 picocuries -- it turns out the average concentration in those nine wells is closer to 25 picocuries per liter.
Bringing the concentration within the federal standard of 5 picocuries per liter is a simple 5:1 ratio, but Combest said city crews can blend it to an even lower concentration.
If the city draws from the three wells with the lowest radiation level, for instance, Combest said, the concentration will be far lower than even federal limits.
"You're blending more like 18 picocuries per liter," he said. "You're getting a number that's a lot lower."
The city began blending surface water with small amounts of the Hickory water early May, at a 10:1 ratio, to set transducer pressures and ensure everything is running well.
Combest said the blending was smooth overall.
By comparison, the city uses about 15,000 acre-feet -- or 4.9 billion gallons -- of water per year.
In light of this, Dickson hopes to save as much of the Hickory water that
If the city brings the Hickory water in at its projected capacity of 9 million gallons per day, this banked water only would last five years before
The Groundwater Treatment Facility is estimated for completion by the fall and the expansion to 15 wells at the
If the well field expansion is complete as scheduled in
According to Standard-Times archives, city officials were considering development of the Hickory Aquifer, faced with drought conditions but were daunted by the almost
In a 1984 article,
"The only dependable water supply for the city would be in
Right now -- until the city makes significant progress on some long term water projects down the pipe -- the Hickory remains that final source.
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