1.5 Facility Classification & Minimum Operator Attendance
Key Takeaways
- 12VAC5-590-461 A classifies waterworks by population served, water treatment plant capacity, and treatment technology, and VDH retains discretion to assign a higher or lower class.
- A Class 1 waterworks must have at least two operating staff in attendance whenever the water treatment plant is in operation, and at least one of them must be a licensed operator.
- Class 5 and Class 6 waterworks must be attended at least twice a month when no treatment is provided and at least once per week when treatment is provided.
- Transient non-community waterworks are normally unclassified and need no operator unless VDH determines one is necessary; operators are not required at unclassified waterworks.
- Table 1 of 9VAC25-790-290 classifies wastewater treatment works as Class I above 5 MGD, Class II from above 0.5 through 5 MGD biological, Class III from above 0.04 through 0.5 MGD biological, and Class IV at 0.04 MGD or less.
Facility Classification & Minimum Operator Attendance
A license class and a facility class are two different ratings assigned by two different agencies. DPOR classifies the person. VDH and DEQ classify the plant. The operator requirement is simply the join between the two: the licensee's class must equal or exceed the facility's class.
1. Waterworks Classification (12VAC5-590-461 A)
All community and non-transient non-community (NTNC) waterworks, including consecutive systems, that fit the protocol below are designated classified waterworks. Systems that fit none of the classes are unclassified. A transient non-community (TNC) waterworks is normally not classified and is not required to have an operator unless VDH determines one is necessary to ensure satisfactory operation of installed treatment. VDH keeps discretion to assign a higher or lower class than the protocol suggests, and where a waterworks contains multiple treatment facilities, each facility may be classified individually.
| Class | Population served / plant capacity | Treatment technology |
|---|---|---|
| Class 1 | 50,000 or more persons, or plant capacity 5.0 MGD or more | Conventional filtration, or chemical coagulation combined with membrane filtration |
| Class 2 | 5,000 to fewer than 50,000 persons, or 0.5 to less than 5.0 MGD | Rapid rate conventional filtration, or chemical coagulation with membrane filtration |
| Class 2 (alt.) | Fewer than 50,000 persons, or less than 5.0 MGD | High rate conventional filtration |
| Class 3 | Fewer than 5,000 persons, or less than 0.5 MGD (whichever is greater) | Conventional filtration, or chemical coagulation with membrane filtration |
| Class 3 (alt.) | 5,000 or more persons, or 0.5 MGD or more | Disinfection other than hypochlorination, caustic soda feed, iron and manganese removal, ion exchange, slow sand filtration, aeration, rechlorination other than hypochlorination, activated carbon contactors, membrane or other filtration without chemical coagulation, or fluoridation with a saturator or acid feed |
| Class 4 | Fewer than 5,000 persons, or less than 0.5 MGD | The same technology list as Class 3 (alt.), including fluoridation with a saturator |
| Class 5 | 400 or more persons | No treatment, or hypochlorination for disinfection, corrosion control with calcite or magnesium oxide contactors or solution feed (except caustic soda), or sequestration by solution feed |
| Class 6 | Fewer than 400 persons | The same short treatment list as Class 5 |
Two discriminators do most of the work on the exam:
- Class 5 versus Class 6 is decided purely by the 400-person line, given the same simple treatment. Nothing about flow or MGD enters the Class 5/6 test.
- Fluoridation is a class splitter. Fluoridation with other than a saturator pushes a system to at least Class 3; fluoridation with a saturator at a small system lands at Class 4.
2. Minimum Waterworks Operator Attendance (12VAC5-590-461 C)
These are floors, not targets. VDH may increase required attendance on a case-by-case basis to protect public health, and may consider reduced attendance for Class 3 through Class 6 systems.
| Waterworks class | Minimum attendance |
|---|---|
| Class 1 | At least two operating staff in attendance whenever the water treatment plant is in operation; at least one must be a licensed operator |
| Class 2 | At least one operator in attendance whenever the plant is in operation |
| Class 3 | One operator whenever the plant is in operation if it uses conventional filtration or chemical coagulation with membrane filtration; all other Class 3 facilities may follow Class 4 attendance |
| Class 4 | At least three days per week - except that plants using membrane filters on surface water or GUDI sources must be attended daily |
| Class 5 and Class 6 | No treatment: at least twice a month. Treatment provided: at least once per week. Attendance must be long enough to perform necessary operations, monitoring, and maintenance |
When VDH weighs increased or reduced attendance it considers operational history, type of treatment, capacity and hours of operation, population served, the type and reliability of remote monitoring and alarms, staff communications, and emergency response plans and procedures. Note what this list implies: SCADA and telemetry can justify a reduction request, but they never substitute for the baseline attendance automatically.
If a classified waterworks is without a required operator, the owner must notify VDH as soon as practical and no later than 24 hours (12VAC5-590-461 B).
3. Wastewater Treatment Works Classification (Table 1, 9VAC25-790-290)
DEQ classifies treatment works by design flow crossed with process type - biological, advanced waste treatment (AWT), or natural. The same table also publishes recommended attendance hours.
| Facility class | Design capacity | Process family |
|---|---|---|
| Class I | Greater than 10 MGD | Biological treatment methods |
| Class I | Over 5 MGD through 10 MGD | Biological treatment methods |
| Class I | Greater than 5 MGD | Advanced waste treatment |
| Class I | Over 2.5 MGD through 5 MGD | Advanced waste treatment |
| Class II | Over 2.5 MGD through 5.0 MGD | Biological treatment methods |
| Class II | Over 0.5 MGD through 2.5 MGD | Biological treatment methods |
| Class II | Over 0.1 MGD through 2.5 MGD | Advanced waste treatment |
| Class III | Over 0.04 MGD through 0.5 MGD | Biological treatment methods |
| Class III | Greater than 1.00 MGD | Natural treatment methods |
| Class III | Over 0.001 MGD through 0.1 MGD | Advanced waste treatment |
| Class IV | Over 0.001 MGD through 0.04 MGD | Biological mechanical methods |
| Class IV | Over 0.001 MGD through 1.00 MGD | Natural treatment methods |
The biological rows list five process subtypes - suspended growth reactors, aerated lagoons or constructed wetlands, filters or other attached growth contactors, processes using biological nutrient control, and processes using land treatment. The AWT rows list ammonia stripping, breakpoint chlorination, carbon adsorption, chemical coagulation/flocculation/precipitation, filtration, demineralization (ion exchange, reverse osmosis, electrodialysis), and microstraining or screening.
Recommended attendance from the same table
Attendance is expressed as recommended licensed-operator hours and hours the works should be manned. Representative entries:
- Class I, over 10 MGD, suspended growth: 24 licensed-operator hours, manned 24 hours.
- Class I, over 5 through 10 MGD, suspended growth: 16 licensed-operator hours, manned 24 hours.
- Class II, over 0.5 through 2.5 MGD, suspended growth: 8 licensed-operator hours, manned 16 hours.
- Class III, over 0.04 through 0.5 MGD, biological: 8 and 8.
- Class IV: 4 and 4.
- Land treatment processes: attendance "during land application."
Table 1 is expressly a starting point: the number of licensed operators and the qualifications of operating staff are evaluated case by case against operational reliability and permit compliance data, in consultation with and with the concurrence of the director, and the resulting requirement is written into the facility's Operation and Maintenance Manual.
4. Putting the Two Ratings Together
A worked classification chain, the way an exam item is usually built:
A municipality operates a 3.2 MGD activated sludge plant with biological nutrient removal, and a 0.35 MGD groundwater waterworks that adds sodium hypochlorite and caustic soda and serves 2,900 people.
- Wastewater side: 3.2 MGD, biological, falls in the "over 2.5 through 5.0 MGD, biological" row = Class II treatment works. Under 18VAC160-30-360 C, a Class 2 wastewater works licensee may operate it.
- Water side: fewer than 5,000 persons and less than 0.5 MGD, employing caustic soda feed (a listed Class 4 technology) = Class 4 waterworks, requiring a Class 4 or higher waterworks licensee and attendance at least three days per week.
- The operator running both must hold two licenses - a Class 2 (or higher) wastewater works license and a Class 4 (or higher) waterworks license - and renew them in alternating years.
A groundwater waterworks serves 380 people and adds sodium hypochlorite for disinfection. Under 12VAC5-590-461, what is its classification and its minimum operator attendance?
What is the minimum staffing requirement whenever a Class 1 waterworks treatment plant is in operation?
A wastewater treatment works has a design flow of 0.30 MGD and uses an extended aeration suspended growth process. How is it classified under Table 1 of 9VAC25-790-290, and which operator license class is the minimum required?