“Renew or Replace” is the
question York Region
was facing with the
Aurora Wells 1- 4 treatment
facility. York Region is among a
number of municipalities that are dealing
with the problem of aging infrastructure
and technology in their water
supply system, and are facing this
decision. Under the new provincial
regulations for drinking water supply,
the Region is currently providing
upgrades to the Yonge Street Aquifer
Water Supply System, which supplies
water to the Ontario municipalities of
Aurora, Holland Landing, Newmarket,
Queensville, and Sharon.
The Aurora Wells 1 – 4 are one of
the larger producing wells on the
Yonge Street Aquifer and are the major
water supply for the town of Aurora.
They are located near the Aurora
Community Centre, just west of
Tannery Creek. This facility was one
of the oldest operational facilities in
the distribution system. Due to the limited
space on site, and the room constraints,
an expansion or upgrade to
add new equipment or additional
equipment (for redundancy) was not
possible.
The Yonge Street Aquifer Water
Supply System is a confined natural
underground reservoir with the water
treated for iron sequestration and disinfected
with chlorine before being
sent to the distribution network.
A majority of the facilities in the
distribution system were upgraded
during 2003 and 2004, with the exception
of the Aurora Wells 1-4 facility.
The author at the new Aurora treatment plant.
As a result of space constraints in
the old facility, York Region decided
to replace it with a new water treatment
plant, located to the east of
Tannery Creek, directly opposite the
well site. The new plant features a
fully automatic operation, computer
monitoring and control system, an
office and a laboratory. Water produced
at the well sites will be
pumped across Tannery Creek, in the
new facility, where it will receive
treatment:
Iron sequestration with sodium
silicate.
Disinfection with gaseous chlorine.
Chloramination with ammonium
sulphate.
The contact time will be achieved in
contact tanks, which are large diameter
(16.5 m long x 3.6 m diameter) in
ground concrete pressure tanks.
Each tank has a volume of 330 m3,
which represents 50% of the required
capacity, to provide the required contact
time for disinfection. Other equipment/
features included with the chlorine
system for safety, are a chlorine
scrubber and various alarms.
To provide additional safety to the
water supply system, a diesel generator
set is supplied for stand-by power,
as are primary and secondary discharge
water mains and multiple
redundancies.
Melissa Weber is with R.V. Anderson
Associates Ltd., Toronto.
Contact email: mweber@rvanderson.com
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