We are hiring a new Water Treatment Specialist or Plant Operator to join our incredibly talented and dedicated team plant operators! Our ideal candidate will have a CO water plant operator A certification. If you are a person that likes variety, challenges, and accomplishments, is team oriented but can work individually to deliver a common goal, this is the place for you.
2026 Salary Ranges for specific positions below DOE and certification level
Water Treatment Specialist: $37.80-$49.90/hr
Water Plant Operator III: $33.01-$43.58/hr
Water Plant Operator II: $30.85-$40.72/hr
Water Plant Operator I: $28.83-$38.06/hr
Compensation & Benefits
$Base hourly pay rate + shift differential pay + overtime pay
11 Paid Holidays plus up to 2 Floating Holidays
Generous Vacation & Sick Leave
Health Insurance (Cigna or Kaiser)
Dental Insurance (Delta)
Vision Insurance (VSP Vision)
Life, Dependent Life & Supplemental Life Insurance Options
Flexible Spending Plan
Retiree Health Savings Plan
Pension Plan & Deferred Compensation Plans with up 7.6% Employer Match
Multilingual Incentive Pay
Recreation Center Pass for you and your immediate family members
Wellness Program - Learn more here
In-House Training Opportunities
Tuition Reimbursement
Employee Assistance Program
The Community
Thornton is a diverse community with a strong commitment to quality of life. The community’s location provides an ideal environment for business and recreation. Located in the Denver metropolitan area, the City of Thornton is adjacent to Westminster, Broomfield, Northglenn, Federal Heights, and Commerce City. The community’s natural setting of ridgelines, wildlife, waterways, rolling hills, and undeveloped land provide Thornton residents with amenities that contribute to a unique quality of life.
The City of Thornton is the sixth largest city in Colorado. Located in the northeast quadrant of the Denver metropolitan area and comprising 37 square miles, Thornton is only 10 minutes from downtown Denver, 35 minutes from Denver International Airport (DIA) and less than 2 hours from the Breckenridge and Vail ski areas. Thornton offers convenient access to Interstate 25, Interstate 70, Interstate 76, E-470, and U.S. 36 and is serviced by the Denver Regional Transportation District (RTD), which provides public transportation.
The Infrastructure Department
The Infrastructure Department is a dedicated team of approximately 200 that provides a variety of services, including raw water rights and accounting; water treatment; water quality testing; water distribution; sanitary sewer collection; stormwater conveyance and flood control; street maintenance and snow plowing; trash and recycling collection; traffic engineering and operations; engineering services including capital project management, surveying, MS4 Program management, ArcGIS services, ROW permitting, and utility locates; and real estate/real property management. The Departments' total annual operating budget is approximately $45M, funded through various general government and enterprise funds (water, sewer, stormwater, sanitation).
The Position
The city of Thornton is seeking a Water Plant Operator/Water Treatment Specialist who represents a culture of health and is committed to providing high quality drinking water to our diverse customer base of 160,000 people and growing. Our system is also diverse, with multiple source waters including the South Platte River, Clear Creek, and a developing source on the Cache la Poudre River; two water plants; multiple pump stations; and plenty of capital improvement projects on the horizon, all making Thornton a very exciting place to work. Some job duties include:
Operate one of two High Performance Water Treatment plants - Learn more here
50 mgd ultrafiltration plant
20 + mgd ozone/biofiltration plant
Monitoring Raw, Process and Finished Water Quality
Adjusting Water Treatment Chemicals
Perform Lab Bench Tests
Adjusting Raw and Finished Water Flows
Ordering and Receiving Chemicals
Filter and Membrane Surveillance
Rotating Shifts
Under specified supervision, monitors water plant operations and computerized control systems, and adjusts plant-operating conditions to provide a safe and adequate treated water supply.
Positions in this class are flexibly staffed and are normally filled by advancement from level I or, when filled from the outside, require prior directly related experience.
Water Plant Operator I:
Under immediate supervision, this is the entry-level class in the Water Plant Operator series. Incumbents entering the class are required to have little directly related work experience. Generally, work is observed and reviewed both during performance and upon completion, and changes in procedures or exceptions to rules are explained in detail as they arise.
Water Plant Operator II:
Under general supervision, this is the intermediate-level class in the Water Plant Operator series, which requires the appropriate Plant Operator's certification. Employees work with only occasional instruction or assistance.
Water Plant Operator III:
Under general supervision, this is the journey-level class in the Water Plant Operator series, which requires the appropriate Plant Operator’s certification. Employees receive minimal instruction and assistance. Incumbents assigned to this class are expected to perform the full range of work assigned to this class and to work with considerable independence and initiative. The Water Plant Operator III is flexibly linked to Water Treatment Specialist.
Water Treatment Specialist: Under direction, monitors water plant operations and computerized control systems and adjusts plant-operating conditions to provide a safe and adequate treated water supply.
(Essential functions, as defined under the Americans with Disabilities Act, may include the following tasks, knowledge, skills and other characteristics. The list of tasks is ILLUSTRATIVE ONLY, and is not a comprehensive listing of all functions and tasks performed by this position.)
Conducts daily inspections and monitors operations of drinking water plant facilities and equipment. Combines various data elements to make necessary changes to achieve optimal water treatment goals and provide a safe and adequate treated water supply.
Monitors and controls the water distribution system and wastewater collection system through the use of electronic and automated control systems. Observes variations in operating conditions by interpreting meter, gauge, and graph readings as well as water quality test results. Performs collection of water samples and related laboratory tests. Documents readings and results.
Combines various data elements to properly gauge the quantity of treated water needed to maintain sufficient storage tank levels for uninterrupted service to customers during high demand and fire flow conditions. Monitors and records all water storage tank levels.
Interprets data to properly maintain pressure zone balance in the distribution system. Calculates and maintains correct water flow (MGD) rate. Adjusts pumps and valves for plant flow conditions.
Maintains a thorough knowledge of federal and state laws, local statutes, ordinances, standards and procedures related to water plant operations, and ensures compliance and implementation.
Operates Supervisory Control and Data Acquisition (SCADA) computer system; understands the proper use of Plant Control Systems (PCS); understands function of Programmable Logic Controllers (PLCs), remote Inputs and Outputs (I/O) and Remote Terminal Units (RTUs). Interprets data, resolves errors, and performs rudimentary diagnostics.
Maintains proper use of in-line process instrumentation, including turbidimeters, pH monitors, suspended solids analyzers, chlorine analyzers, sludge blanket monitors and ORP probes. Conducts instrumentation calibration, interprets data, understands deviations, makes corrections and controls processes.
Responsible for the safe and proper operation of plant mechanical systems, including chemical feeders, centrifugal pumps, metering pumps, positive displacement pumps, electric motors, air blowers, mixers and air compressors. Reports any deviation from normal operation.
Creates and analyzes reports utilized to maintain compliance with the Safe Drinking Water Act; maintains oversight of water quality; develops cost of service; develops future plans and budgets.
Reviews engineering documents, including contract specification design reports, line drawings and construction diagrams.
Performs work that requires the use of specified respiratory equipment that guards against exposure to airborne hazards. Complies with all Municipal, State, and Federal physical requirements as per Self-Contained Breathing Apparatus (SCBA) guidelines.
Performs research on new methods and advances in water treatment through a variety of technical sources.
Responds and investigates customer questions and complaints regarding perceptions of water quality, such as dirty water, taste and odor, no water, low water pressure and frozen pipes. Resolves problems or refers to proper person or department. Tracks incoming calls in daily log.
Works a varying schedule and/or shift.
Understands the operation and use of the various raw water sources available.
May perform emergency dispatch duties for after-hours, weekends, and holidays, related to utilities emergencies such as water main breaks and sewer line backups.
May be required to work overtime.
Performs other duties as assigned.
Education/Experience:
Water Plant Operator I:
High school diploma or GED, with additional course work in chemistry, biology or related field. Equivalent combinations of education and experience may be considered.
Water Plant Operator II:
High school diploma or GED; two years’ experience performing water purification plant operations. In accordance with the Colorado Water & Wastewater Facility Operators Certification Board, postsecondary education may be substituted for up to 50 percent of the experience requirements.
Water Plant Operator III:
High school diploma or GED; three years’ experience performing water purification plant operations. In accordance with the Colorado Water & Wastewater Facility Operators Certification Board, postsecondary education may be substituted for up to 50 percent of the experience requirements
Water Treatment Specialist: High school diploma or GED; four years’ experience performing surface water treatment plant operations. In accordance with the Colorado Water & Wastewater Facility Operators Certification Board, postsecondary education may be substituted for up to 50 percent of the experience requirements. Equivalent combinations of education and experience may be considered.
Licensing/Certification Requirements:
Water Plant Operator I:
State of Colorado Water Plant Operator's certification, Class D, or ability to obtain.
May need the ability to travel to various locations in a timely manner as the job requires.
Water Plant Operator II:
State of Colorado Water Plant Operator's certification, Class C.
May need the ability to travel to various locations in a timely manner as the job requires.
Water Plant Operator III:
State of Colorado Water Plant Operator’s certification, Class B.
May need the ability to travel to various locations in a timely manner as the job requires.
In addition to the above, progress through the State of Colorado Water Treatment Plant Operator’s certification testing per the following schedule as a condition of employment from date of hire.
Current Certification
Certification Schedule
No Certification
“D” level in one (1) year.
“C” level in two (2) years.
“B” level in three (3) years.
“A” level in four (4) years.
“D” Certification
“C” level in one (1) year.
“B” level in two (2) years.
“A” level in three (3) years.
“C” Certification
“B” level in one (1) year.
“A” level in two (2) years.
“B” Certification
“A” level in one (1) year.
Water Treatment Specialist: State of Colorado Water Plant Operator's certification, Class A.
May need the ability to travel to various locations in a timely manner as the job requires.
Knowledge, Skills and Abilities:
Knowledge of the policies, procedures and goals of the city of Thornton and the department.
Knowledge of water treatment and purification procedures and methods.
Knowledge of the principles of hydraulics and plumbing.
Knowledge of the methods, materials, and tools used in the operations of water facility equipment.
Knowledge of computer SCADA systems as used in water treatment systems.
Knowledge of Plant Control Systems and instrumentation.
Knowledge of mathematics relating to water treatment, e.g., the calculation of volumes, areas, flow rates, and dosage rates.
Knowledge of current regulatory requirements of the Safe Drinking Water Act, the Disinfectant, Disinfection Byproducts Rule and the Enhanced Surface Water Treatment Rule.
Knowledge of chlorination principles and disinfectant requirements as required by federal, state, and local policies, codes and regulations.
Knowledge of biology and bacteriology as related to water treatment.
Knowledge of the purpose, projects, organization, and employees' responsibilities of the department.
Knowledge of basic Colorado water law and the city of Thornton's water rights.
Skill in interpreting data and making treatment decisions.
Skill in manipulating water supplies to maintain distribution system viability.
Skill in converting abstract ideas into easily understood procedural guidance.
Skill in recalling specific facts and/or, as appropriate, quickly locating facts in designated references.
Ability to successfully complete all medical and fit testing as required for the use of personal protective respiratory equipment.
Ability to wear SCBA gear and/or respiratory protection.
Ability to understand complex chemical processes.
Ability to attend to detail for prolonged periods when following detailed and precise laboratory procedures and water quality testing.
Ability to understand and apply technical written material.
Ability to read and interpret charts, records, blueprints and drawing of water treatments plants and associated equipment.
Ability to consistently follow safety procedures.
Ability to maintain detailed and accurate records.
Ability to listen well and communicate effectively orally and in writing with various audiences.
Ability to establish and maintain effective working relationships with City employees, other governmental employees and the general public.
Ability to work days, nights, weekends and holidays in the context of rotating shift.
Ability to exercise independent judgment and discretion.
Physical and Mental Requirements:
This is a safety-sensitive position. While performing the duties of this job, the employee is required to stand for prolonged periods, perform repetitive motions, kneel, squat, stoop, and repeatedly twist the upper body a significant part of the time. The employee is also required to walk a major part of the time and to lift heavy objects (more than 25 pounds) on a regular basis. The employee is required to see, hear, talk, and sit. The employee is required to comply with all physical requirements of SCBA and/or any other respiratory protection equipment including passing all medical and fit testing.
