Free Online Course

Wastewater Disinfection Fundamentals

Learn how the last health barrier at the plant works: how chlorine and UV lower disease-causing organisms, and how operators check, adjust and troubleshoot the process.

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Time
About 65 minutes
Certificate
1.0 hour of completion
Credit
Not yet approved for continuing education credit
Price
Free
Format
72 narrated pages, checks and a final
Built by
A working wastewater operator (Washington Group III)

Who It's For

Wastewater operators at any level and people studying to become operators. No experience needed.

What You'll Learn

  • Explain why disinfection matters, what pathogens and indicator organisms are, and what can change results.
  • Describe the forms of chlorine, chlorine demand, residual and contact time.
  • Describe chlorine feed equipment: storage, metering pumps, drawdown checks, injection, contact basins and analyzers.
  • Operate chlorination through the shift: dose and residual, flow pacing, sampling points, high flow and residual problems.
  • Explain why and how chlorine is removed before discharge, and how to match and check the dechlorination feed.
  • Explain how UV disinfection works and how lamps, sleeves, intensity, transmittance, cleaning and alarms affect it.
  • Collect good samples, judge test quality, read trends, confirm alarms and keep clear records.
  • Recognize chemical, gas, energy, fall and spill hazards, and connect disinfection to the whole process.

It does not replace plant training or site-specific safety rules.

What's Inside

  1. Why Disinfection Matters 9 pages
    • Welcome
    • The Purpose
    • Pathogens
    • Indicator Organisms
    • Not Sterilization
    • Upstream Quality
    • What Changes
    • The Operator’s Job
    • Checkpoint
  2. Chlorine Basics 9 pages
    • Why Chlorine
    • Chlorine Forms
    • Gas Chlorine
    • Sodium Hypochlorite
    • Calcium Hypochlorite
    • Chlorine Demand
    • Chlorine Residual
    • Contact Time
    • Checkpoint
  3. Chlorine Feed Equipment 9 pages
    • Feed System
    • Chemical Storage
    • Metering Pumps
    • Pump Drawdown
    • Valves and Tubing
    • Injection and Mixing
    • Contact Basins
    • Online Analyzers
    • Checkpoint
  4. Operating Chlorination 9 pages
    • Start of Shift
    • Dose and Residual
    • Flow Pacing
    • Sampling Points
    • Process Timing
    • High Flow
    • Low Residual
    • High Residual
    • Checkpoint
  5. Dechlorination 9 pages
    • Why Remove Chlorine
    • Dechlor Chemicals
    • Feed Point
    • Matching the Feed
    • Final Residual
    • Underfeed
    • Overfeed
    • Safe Handling
    • Checkpoint
  6. Ultraviolet Disinfection 9 pages
    • How UV Works
    • UV Equipment
    • Lamps and Sleeves
    • UV Intensity
    • UV Transmittance
    • Flow and Exposure
    • Cleaning UV
    • UV Alarms
    • Checkpoint
  7. Monitoring and Troubleshooting 9 pages
    • Good Samples
    • Sample Care
    • Test Quality
    • Read the Trend
    • Confirm the Alarm
    • Find the Cause
    • Maintenance Clues
    • Clear Records
    • Checkpoint
  8. Safety and the Whole Process 9 pages
    • Know the Hazard
    • Gas Alarm
    • Lockout Tagout
    • Basins and Falls
    • Spill Response
    • Simple Process Math
    • Ozone Overview
    • Whole Process
    • Final Checkpoint

Sample Page

The Purpose

Wastewater can carry bacteria, viruses, protozoa, and other organisms. Some can cause illness. Earlier treatment steps remove many of them, but some may remain. Disinfection provides another barrier before the water reaches a river, lake, ocean, groundwater system, or reuse system.

Disinfection does not make wastewater into drinking water. It also does not remove every chemical or every solid. Its main purpose is to inactivate, or make unable to cause infection, the target organisms required by the facility’s permit.

For example, clear-looking effluent can still contain organisms too small to see. An operator cannot judge disinfection by appearance alone. Equipment readings, samples, lab results, and plant records are needed to show whether the process is working.

Think of disinfection as a controlled barrier. The operator cannot see the organisms being inactivated. Instead, the operator proves that the barrier is working by keeping the process inside its required conditions and checking the final water with an approved test.

What to remember: Disinfection protects people and the environment by reducing harmful organisms before discharge or reuse.

Questions

Does This Course Count Toward My Renewal?

Not yet. A course counts toward your continuing education credit only after your state approves it, and this one is not approved yet. This page will say which states approve it once they do.

Do I Need an Account?

Yes, to take the course. Signing in lets us record your time and issue your certificate. This page, the topic pages and the practice questions need no account.

Can I Skip Ahead?

No. Each page has a minimum time before the next one opens, and your time is recorded.

What Do I Get When I Finish?

A certificate of completion from Operator Master for 1.0 hour, once you pass the final with 80% or better. Your operator certificate or license always comes from your state, not from Operator Master.

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