|
Process
|
Old
Plant
|
New
Plant
|
Comments
|
|
Capacity
|
22 million gallons
per day (MGD)
|
30 MGD expandible to
45 MGD
|
30 MGD design period
for 20 years to year 2015
|
|
Raw Water
Pump Station
|
22.5 MGD capacity
|
30 MGD capacity (Space
to add two pumps for another 15 MGD)
|
New intake & raw
water pump station. Increased reliability & capacity in new
plant.
|
|
Pre-treatment
|
Limited facility: 20
minutes detention frame
|
Large facility: More
than 20 hours detention time
|
Carbon only at old
plan. Carbon plus potassium permanganate at new plant (taste and
odor control). Increased ability to remove organics.
|
|
Pre-sedimentation
|
None
|
Yes
|
New presedimentation
will allow turbid waters during high runoff periods to be handled
much better.
|
|
Lime & Soda
Ash Softening Begins
|
Single stage softening
|
Two stage softening
|
More reaction time
in two-stage softening basins in new plant. Increases ability
to acheive targeted hardness levels year round.
|
|
PH Adjustment
|
Carbon dioxide
|
Carbon dioxide
|
No change except for
more capacity in new plant.
|
|
Primary Disinfection
|
Chlorine
|
Ozone
|
Ozone much more powerful
disinfectant than chlorine. Trihalomethanes not developed. Ozone
also effective against taste and odors.
|
|
Filters
|
10 mixed media filters
|
6 mixed media filters
|
Backwash system for
new filters use air and water - the old plant only water. New
filters may be changed to granular activated carbon if necessary.
|
|
Residual Disfection
|
Chloramine
|
Chloramine
|
Chloramines for residual
disinfaction used at both plants. Trihalomethanes not developed
with chloramine.
|
|
High Service Pump
Station
|
27 MGD capacity
|
30 MGD capacity
Space to add two pumps for another 15 MGD
|
New service pump station
much easier on fragile water distribution system because of adjustable
frequency drive pumps.
|
|
Residuals Handling
|
Vacuum drum dryers
with capacity of 25 MGD
|
Belt filter presses
with capacity to treat 45 MGD
|
Sludge facilities designed
to handle sludge drying for 45 MGD facility.
|
|
Computerization
|
None
|
Automated
|
Control system will
allow operators to control entire Water Treatment Plant from main
control room in new plant.
|
|
Laboratory
|
100 square feet
|
3,000 square feet
|
Full service laboratory
in new Water Treatment Plant. Testing capabilities will be substantially
increased.
|
