Download South Fork Field Trip

South Fork WT Plant Tour
5/1/2007
Water Source:
The Clackamas River
Tour Guide Mark Cage
South Fork WT Plant
15962 S Hunter Ave. Oregon City,
Oregon 97045,
(503) 657-5030
The Control Room:
Where all Plant data is recorded
SCADA
Supervisory Control And Data Acquisition
SCADA Stats:
• Plant during tour is running at 10.3 MGD
• Plant runs at approximately 6 MGD in
Winter, 18 MGD in Summer
• Current Alum dosage at 4.5 parts in the
Rapid Mix
• Pre-feed Polymer #LT7990 dosage at .8
parts
Dual media filters
4’ Anthracite coal
1’ Garnet sand
Pilot Filters:
Conveniently located in the Control Room
Pilot Filters:
• Miniature replicas of the main filters
• Sampled daily
• Help avoid plant shut down
• Save about ½ hour per day on the work load
Stream Current Monitor
Stream Current Monitor
Optimizes coagulant dosage
Chlorine Spikes or “Slugs”
• Plant start-up causes 5 minute chlorine
spike
• Spike goes down as plant comes on-line
Rapid Mix Injection Order:
• Polymer
• Alum
• Pre-Chlorination with Sodium
Hypochlorite
• Flash Mixed by use of pump
turbulence, (no mechanical mixing
takes place)
Factoid:
One pound Liquid Alum equals 5.3 LBS
of dry Alum
Pretreatment
Polymer Delivery
•#LT7990 dosage at .8 parts
Pretreatment
Alum Pumps
•Current
Alum dosage
at 4.5 parts
in the Rapid
Mix
Alum Tank
Pretreatment
Corrosive Material
Post welded measurements
Pretreatment: Sodium Hypochlorite
Chlorine Pre-feed at 0.7
Chlorine Residual at 1.0
Pretreatment
Alum, Polymer and Sodium hypochloritee
Rapid Mix well
Chlorine
Alum
Polymer
Flocculation Chamber with
Serpentine Baffles
Sedimentation/Contact Basin
$100 Plastic Tube used to prevent wave
vibration caused buy pumping
– Savings: $100,000 in repairs!
Dual Media Filter:
•4’ Anthracite Coal - 1’ Garnet Sand.
•Backwash after approximately 70hrs
depending on turbidity.
•Filter Aid Polymer is used.
•Flow approximately 2000 GPM
during tour.
View of Pipe gallery While Standing over
Clear Well (.55 Million Gallons)
Disinfection:
Sodium Hypochlorite Generation:
Injection of salt water reacts with 700 amps of
electricity and titanium plates. Produces 600 lbs 0.8%
NaOCl per day (300 lbs per cell).
On-site Generation of Disinfectants
(OSG)
Sodium Hypochlorite Generation:
Injection of salt water reacts with 700 amps of
electricity and titanium plates. Produces 300 lbs 0.8%
NaOCl per day.
Two cells= 600 lbs
On-site Generation of Disinfectants
(OSG)
Anode
Hydrogen bubbles
Cathode
NaCl + H2O >>>NaOCl + H2
2Cl- >> Cl2 + 2e-
Water
Softener cell
Brine tank
2H2O + 2e->>H2 + 2OH-
HOCl + OH->>H2O +OCl-
On-site Generation of Disinfectants
(OSG)
Advantages:
Operator safety: No toxic chlorine gas
handling, safety and regulation
Greener solution: No chemical
shipments (all you need is pure NaCl)
Minimal storage
On-site Generation of Disinfectants
(OSG)
Disadvantages:
Hydrogen gas generation: Toxic,
colorless, flammable (vent) regulation
Need steady water composition and
have to soften water
Cell maintenance: Need to wash with
muriatic acid (HCl)
Chlorine Meters
Chlorine Stats:
• Chlorine Pre-feed at 0.7
• Chlorine Residual at 1.0
High Turbidity:
• The technique used at South Fork for dealing
with extremely high turbidity is to use both
Polymer and Alum in increased dosages.
Soda Ash Delivery
•Dry hopper
•Lead and Copper Rule
Soda Ash mixer
Soda Ash in bags used for pH adjustment
End