By Mai Ling Slaughter, The Chronicle, 8/26/99
Centralia's new $1.2 million well is the most technologically advanced of the city's wells, including a filter system that protects and prepares the water supply for the future.
The Tennis Court Wells, named for their location near the tennis courts in Fort Borst Park, make up one of the projects the city's water rate increase supports.
City employees and contractors are now making the finishing touches on the Tennis Court Wells after almost three months of work.
Although the city still uses the nearby Borst Well during water shortages, Centralia Utilities Director Richard Southworth said the well was not producing enough water to sustain its maintenance.
''The Borst Well was not as effective as we hoped,'' he said.
Studies were done to find a new well site in the area, and a test well was built where the larger Tennis Court Wells and their facility now lie.
At about the same time, the issue of corrosion in the city's water supply became apparent, as officials focused on the ability of copper, lead and other metals to leach into the water.
''It's a requirement under federal regulations to get the pH to balance so that doesn't occur,'' Southworth said.
Another concern of the city was the possibility of perchloroethylene entering the water supply in the future. PCE is a contaminant known to cause cancer, liver damage and other ailments. In 1988, the city closed the Eshom Well on Fords Prairie after environmental agencies found PCE in its water supply.
Although PCE has not been found in the Borst or Tennis Court wells, Southworth said it may be moving in the groundwater toward the Tennis Court Wells.
But the city is preparing to protect the wells from PCE, and to balance the pH level with the air filter process attached to the Tennis Court Wells.
No matter whether the contaminant appears in the new wells, the system pumps water from them into the top of the 30-foot-high air filter tower, which is filled with plastic structures similar to Whiffle balls. Air is blown upward through the filter and the water ''rains through the filter media,'' said project supervisor Russ Johnson of Boss Construction, Bellingham.
Through the process, any PCE would be vaporized into the air. Southworth said the level of PCE is too low to cause a problem in the atmosphere, although it would be a problem in the city's drinking water.
The Tennis Court Wells include the test well, found to be ''a very good producer,'' Southworth said, as well as an additional larger well. The city decided to use both wells to add to its water intake.
About 1,800 gallons of water are pumped out of the two wells every minute.
Fluoride is added to the water before the water goes through the air filter, and chlorine is added after the process. The ''clearwell,'' where the processed water is held before being pumped to one of the city's reservoirs, holds up to 13,000 gallons.
Steve Spurgeon, city water technician, said the chlorine used is much safer than the type used in the past. It is a salt-based hydrochloride that, he said, is less dangerous to those handling it.
The wells' entire system - run on an automated system with numerous alarms in case of an emergency - is programmed to pump water into the wells according to how much is needed in the city's two main reservoirs, the 4&Mac221;-million-gallon Seminary Hill and 2&Mac221;-million-gallon Davis Hill reservoirs.
City officials plan to build an air filter system similar to the Tennis Court Wells' system at the contaminated Eshom Well site within the next couple of years.
Next month, the city expects to publish the project's environmental impact statement to start cleaning the groundwater by the end of 2000.
The Department of Ecology has given the city a $5.2 million grant for the project and to help connect homes in the contaminated area to the city's water supply. The city's local match is $1.3 million, which is also being paid for with the water rate increase.
Although the well is used in emergencies, in its peak use, the Eshom Well distributed about 1,300 gallons of water a minute.
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Mai Ling Slaughter covers municipal government for The Chronicle. She can be reached by e-mail at news@chronline.com or by telephoning 807-8237.
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