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Cheat sheet

Water Treatment Operator Cheat Sheet

Treatment Process

33%of exam

Laboratory Analysis

16%of exam

Equipment Operation

23%of exam

PumpsValvesMetersSCADAEquipment Picker

Source Water

15%of exam

Surface WaterGroundwaterWatershedSeasonal ChangesSource Picker

Safety + Administration

13%of exam

Chemical SafetySOPsPublic NoticeRecordsSafety Picker

Quick Facts

Exam body
WPI / states
Questions
100 scored
Pretest
Up to 10
Time
3 hours
Pass
Often 70%
Calculations
12%
Cognitive
70% application
Formula sheet
Provided

Treatment Train Order

Coagulate, grow, settle, filter, disinfect.

CoagulationFlocculationSedimentationFiltrationDisinfection

Coagulation vs Flocculation

Coagulation

  • Rapid mix
  • Neutralizes charge
  • Chemical dose

Flocculation

  • Slow mix
  • Builds floc
  • Contact time

Dose first, grow second

Process Picker

  1. Fine particlesCoagulation(Neutralize charge)
  2. Weak flocFlocculation(Gentle mixing)
  3. Heavy flocSedimentation(Settle solids)
  4. Turbid effluentFiltration(Polish water)
  5. Pathogen riskDisinfection(Meet CT)
  6. Low residualIncrease dose(Check demand)

Treatment Train

Screening
Remove large debris
Coagulation
Destabilize particles
Flocculation
Build settleable floc
Sedimentation
Gravity settling
Filtration
Polish turbidity
Disinfection
Inactivate pathogens
Clearwell
Storage plus contact
Residual
Distribution protection

Chlorine Balance

Dose minus demand leaves residual.

DoseDemandResidualCT

Dose vs Residual

Dose

  • Chemical applied
  • Before demand
  • Operator controlled

Residual

  • Chemical remaining
  • After demand
  • Compliance measured

Demand consumes dose

Coagulation Control

Alum
Common coagulant
Ferric salts
Iron coagulants
Polymer
Coagulant aid
pH
Controls charge
Alkalinity
Buffers pH
Rapid mix
Chemical dispersion
Zeta potential
Particle charge
Streaming current
Charge monitor

Free vs Combined Chlorine

Free

  • Stronger disinfectant
  • Shorter persistence
  • Breakpoint target

Combined

  • Weaker disinfectant
  • Longer persistence
  • Chloramine residual

Free kills faster

Filtration

Rapid sand
Conventional filter
Slow sand
Biological layer
Anthracite
Coarse top media
Headloss
Clogging indicator
Breakthrough
Turbidity spike
Backwash
Clean filter bed
Ripening
Postwash stabilization
Filter aid
Improves capture

Disinfection

CT
Concentration times time
T10
Effective contact time
Demand
Dose minus residual
Free chlorine
Strong primary
Chloramine
Longer residual
Ozone
Strong oxidant
UV
No residual
DBPs
Disinfection byproducts

Operator Math

lbs/day
Dose x flow x 8.34
Dose
lbs/day / flow / 8.34
Demand
Dose minus residual
Detention
Volume divided flow
Pressure
Feet divided 2.31
Volume
Area times depth
Percent
Part divided whole
MGD
Million gallons daily

Lab Quality Checks

Calibrate, blank, duplicate, document.

CalibrationBlankDuplicateChain custody

Recall vs Application

Recall

  • Definitions
  • Recognition
  • 30% exam

Application

  • Calculations
  • Troubleshooting
  • 70% exam

Practice decisions most

Data Picker

  1. Coagulant doseJar test
  2. Filter healthTurbidity trend
  3. Disinfection proofResidual + time
  4. Corrosion controlpH/alkalinity
  5. Instrument driftCalibration standard
  6. Questionable resultDuplicate sample

Routine Tests

Turbidity
Particle cloudiness
pH
Acid/base condition
Alkalinity
Buffer capacity
Hardness
Calcium/magnesium
Color
Organic signal
Temperature
Reaction speed
Residual
Disinfectant remaining
Bacteria
Microbial indicator

Jar Testing

Purpose
Find best dose
Rapid mix
Simulate coagulation
Slow mix
Simulate flocculation
Settling
Compare clarity
pH series
Find optimum
Turbidity check
Measure performance
Sludge volume
Settling clue
Plant trial
Confirm cautiously

Sampling + QA

Grab sample
Instant condition
Composite
Time blended
Chain custody
Sample tracking
Preservation
Protect integrity
Calibration
Instrument accuracy
Blank
Contamination check
Duplicate
Precision check
Standard
Known value

Equipment Picker

  1. No flowCheck pump(Prime first)
  2. High ampsCheck load(Motor stress)
  3. VibrationCheck bearings(Alignment clue)
  4. Erratic analyzerClean/calibrate(Verify grab)
  5. Remote alarmSCADA trend(Confirm field)
  6. Wrong chemical feedStroke setting(Verify drawdown)

Pumps + Motors

Centrifugal
Flow by velocity
Positive displacement
Fixed volume
Cavitation
Vapor bubble damage
Priming
Remove air
Seal
Leak control
Bearing
Supports rotation
Amps
Motor load
VFD
Speed control

Controls + Instruments

SCADA
Remote monitoring
PLC
Local controller
Flow meter
Measure flow
Analyzer
Online chemistry
Telemetry
Signal transmission
Alarm
Abnormal condition
Setpoint
Control target
Trending
Pattern review

Surface vs Groundwater

Surface

  • Turbidity swings
  • Pathogen exposure
  • Watershed driven

Groundwater

  • Stable quality
  • Minerals common
  • Wellhead driven

Source controls treatment

Source Water

Surface water
Rapidly variable
Groundwater
Mineral rich
GUI
Surface influence
Watershed
Drainage area
Algae
Taste/odor risk
Runoff
Turbidity spike
Wellhead
Groundwater protection
Reservoir turnover
Seasonal mixing

Safety Order

Read SDS before handling chemicals.

SDSPPEVentilationSpill plan

MCL vs MCLG

MCL

  • Enforceable standard
  • Feasibility considered
  • Compliance limit

MCLG

  • Health goal
  • Not enforceable
  • Safety margin

MCL is enforceable

Safety Picker

  1. Chemical unloadingSDS + PPE
  2. Tank entryConfined permit
  3. Repair energized gearLOTO
  4. Water violationPublic notice
  5. Cyber alertIncident plan
  6. Process upsetEmergency SOP

Safety + Compliance

SDS
Chemical hazards
PPE
Worker protection
LOTO
Energy isolation
Confined space
Permit entry
SOP
Standard procedure
Public notice
Violation communication
CCR
Annual water report
MCL
Enforceable limit

Common Traps

Dose Is Not Residual

Chemical added Chemical remaining

Turbidity Is Not Color

Suspended particles Dissolved appearance

Detention Is Not CT

Hydraulic time Disinfection exposure

Calibration Is Not Cleaning

Adjusts accuracy Removes fouling

MCL Is Not MCLG

Legal limit Health target

SOP Is Not SDS

Work procedure Chemical hazard

Last Minute

  1. 1.Treatment Process = 33%
  2. 2.Equipment O&M = 23%
  3. 3.Lab Analysis = 16%
  4. 4.Source Water = 15%
  5. 5.Safety/Admin = 13%
  6. 6.Dose - demand = residual
  7. 7.CT = concentration x time
  8. 8.8.34 converts mg/L-MGD
  9. 9.MCL enforceable; MCLG goal
  10. 10.Jar tests guide dosing
  11. 11.Surface water changes quickly
  12. 12.Use SDS before chemicals