|
They look like small plastic Wiffle balls, and there are
thousands of them stacked inside a new water aeration tower in southeast
Redmond. The water cascades down through the plastic balls, which break
up the water into small droplets, so the extra carbon dioxide (CO2) can
escape the water. Air is blown up the tower to further help get rid of
the extra CO2 and keep filling the tower with fresh air. All this action
aerates the water and raises its pH level, which helps to protect your
household plumbing and the City's water mains.
The City operates five wells, which supply about 35 percent of the water
used in Redmond's service area. Redmond's well water has a moderately
high alkalinity level and much of that comes from dissolved carbon
dioxide (CO2), which can corrode metal pipes. Rainwater that percolates
down through the ground to replenish wells absorbs CO2 from microbes in
the soil. The new aeration technology removes about 90 percent of the
dissolved CO2 in the well water without the use of chemicals. The
current method used to raise the pH is to inject caustic soda into well
water, at a cost of about $200,000 a year. Caustic soda is used by many
drinking water municipalities to effectively adjust pH, but there are
drawbacks to its use. It is hazardous for operators to handle safely,
can cause water system equipment to wear out faster and can cause
calcium carbonate to build-up on the inside of water mains, which slowly
makes the pipe diameter smaller and restricts water flow.
The new tower is part of Well 5 near the Target and Home Depot
stores. Wells 1 and 2 in Anderson Park will start construction on one
shared tower later this year, and a new tower will be constructed at
Well 3 along Avondale Road in 2007. Redmond water operations will
stagger taking the wells out of service so we still get some water from
our wells. Well 4 next to City Hall is new and will continue to use
caustic soda for the near future.
All of Redmond's water supply meets or exceeds all Environmental
Protection Agency and Washington State Department of Health drinking
water regulations. Water from each well is treated before it enters the
City water supply system. Currently, Redmond provides three types of
treatments - fluoridation, chlorination, and pH adjustment - to comply
with these regulations.
Check out Redmond's most current
Water Quality Report
for more detailed reporting on Redmond's water and its latest lead and
copper testing.
If you have any questions about this project please contact Jeff
Thompson at 425-556-2884 or
jthompson@redmond.gov.
For questions about drinking water, please contact Tom Fix at
425-556-2847 or tfix@redmond.gov;
or contact our Drinking Water Program Administrator, Barbara Sullivan,
at 425-556-2845 or
bsullivan@redmond.gov.
|
