Water treatment plant operators need knowledge in the following areas:

• Chemistry: The properties of substances and the changes that occur when they interact.
• Biology: Cells, plants, and animals and how they function.
• Mechanical: The design, use, and repair of machines and tools.
• Mathematics: The rules and uses of numbers.
• Public Safety and Security: How to protect people and property.
• Production and Processing: How products are made and distributed.
• Engineering and Technology: How to use computers and rules of engineering to design and produce goods and services.
• Administration and Management: How to run a business or group.
• Computers and Electronics: Computer hardware and software.
• Education and Training: The methods of teaching and learning.
• Clerical: General office work such as filling and storing information.
• English Language: The meaning and use of the English language.
• Customer and Personal Service: Providing special services to customers based on their needs.