Water booklet single pages.qxd - City of St. George

2 0 0 5 A N N U A L W A T E R R E P O R T
QUAIL CREEK WATER TREATMENT PLANT
MILLION GALLONS
500
450
400
350
300
250
200
150
100
50
0
2004 / 2005
PRODUCTION TOTAL
77.4
109.5
219.7
60
247.2
277.9
351.9
435.6
428.6
488
433
0 0 0 0 0
0 00
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV
422
321
294.5
259
180
50
DEC
2004
2005
The QCWTP is the first culinary water treatment plant built by the City of St. George. The Virgin
River is the water source for the plant. The plant began operating in 1988 with a production capacity
of ten million gallons a day (MGD). The plant was expanded in the year 1995 to a capacity of 20
MGD. In the fall of the year 2004, construction began to expand plant production capacity to 40
MGD. Treated water from the QCWTP will be fed into the regional pipeline as a resource for the City
of St. George as well as Ivins, Washington and Santa Clara cities. The current expansion project includes
several components.
DISSOLVED AIR FLOTATION SYSTEM (DAF)
The construction of a DAF system with the capacity to treat 40 MGD makes the QCWTP the largest
DAF plant in the western United States. The DAF system super saturates water with air at 90 pounds per
square inch (PSI) of pressure. The water is then injected into the water supply and allowed to return to
atmospheric pressure. In this process the dissolved air comes out of the solution and floats the particles in
the water. The floating particles are called sludge and are skimmed off of the water into a collection system
for drying and disposal. Because this system does not use filters, no backwashing is required, reducing
the amount of water that goes to "waste" in the treatment process.
NEW 9.5 MILLION GALLON STORAGE
Construction of a new 9.5 million gallon water storage tank combined with the existing five million gallon
storage provides the storage needed to supply water to the regional pipeline.
OTHER ASPECTS OF THE EXPANSION
Construction of a new pretreatment basin, flow control building, four new filters, four new sludge
lagoons and a new reclamation building. The computer program that monitors the levels in the
two water storage tanks as well as the treatment process is also being upgraded.
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