1.2 Facility Classification & Operator in Responsible Charge (ORC) Requirements

Principles of Facility Classification

Colorado matches the complexity of water infrastructure to the certified competency of the people operating it. Under Regulation 100 (5 CCR 1003-2), facilities are grouped into operating categories, each divided into four progressive tiers:

• Water Treatment (WT) — Class D (lowest) through Class A (highest), section 100.4.
• Domestic Wastewater Treatment (WWT) — Class D through Class A, section 100.5.
• Industrial Wastewater Treatment (IWT) — Class D through Class A, section 100.7. Industrial facilities use the same D/C/B/A letters as domestic facilities, not Roman numerals.
• Water Distribution (WD) — Class 1 (lowest) through Class 4 (highest), section 100.8.
• Wastewater Collection (WC) — Class 1 through Class 4, section 100.9.
• Reclaimed water and graywater treatment and distribution — section 100.6.

Two hybrid operator certificates exist for small systems. A Class S water certificate is valid only where the system serves no more than 3,300 persons and the works would be classified Class D treatment and/or Class 1 distribution. A Class S wastewater certificate applies on the same 3,300-person basis to Class D wastewater treatment and Class 1 collection. A Class T certificate is narrower still: it is valid only for a transient non-community public water system on groundwater that is not under the direct influence of surface water, serving fewer than 100 individuals per day, using non-gaseous chlorine disinfection only, that would classify as Class D treatment and/or Class 1 distribution.

Treatment Facility Classification: Treatment Type by Design Flow

A very common exam trap is the belief that Colorado adds up "points" for source water, flow, and processes. It does not. The Board deleted the old point tables in the November 2018 rulemaking (effective March 1, 2019) and refined the replacement tables effective May 30, 2021. Today the Division reads a matrix: find the treatment process in the left-hand column, read across to the column for the plant's design flow rate, and take the class shown.

For water treatment (section 100.4.2), the flow columns are less than 350 gpm, 350 to 1,400 gpm, and more than 1,400 gpm. A sample of the table:

For domestic wastewater treatment (section 100.5.2) the columns are design hydraulic capacity bands: below 0.5 MGD, 0.5-1.00, 1.01-2.00, 2.01-4.00, and above 4.00 MGD. Rows run from coarse solids reduction and screening through secondary and advanced treatment to solids handling — for example, thickening and conditioning is Class C below 0.5 MGD but Class A above 4.00 MGD, and thermal hydrolysis is Class B at the smallest sizes and Class A at 1.01 MGD and above.

The controlling rule in sections 100.4.4, 100.5.4, and 100.7.4: when a facility uses two or more listed processes, it is classified at the highest class produced by any of them. The Division may also raise a classification for facility-specific complexity — unusual design features, a difficult source of supply, a hard-to-treat waste, or receiving-water standards demanding an unusually high degree of operational control.

Worked classification example

A drinking water plant has a design flow of 900 gpm and runs conventional granular media filtration with alum, gas chlorine disinfection, and caustic soda for pH adjustment.

1. Granular media filtration with coagulants at 350-1,400 gpm → Class A.
2. Gas chlorine at 350-1,400 gpm → Class B.
3. pH adjustment at 350-1,400 gpm → Class C.

The highest class governs, so the facility is a Class A water treatment facility and its ORC must hold an active Colorado Class A water treatment certificate. Notice that no arithmetic was performed: one qualifying process was enough.

Distribution and Collection: The Two-Step Process

Linear systems are classified in two steps under sections 100.8.2 and 100.9.2.

Step 1 — population served. "Population served" means the average daily population during the busiest month of the year or normal operating periods, including resident, non-transient, and transient population.

The same Step 1 table applies to both water distribution and wastewater collection. Memorize the two break points — 3,300 and 25,000 and 100,000 — because guessing "10,000" or "50,000" is the most common error candidates make on this item.

Step 2 — complexity uplift. The Division then raises a Class 1 or Class 2 system based on listed features. A system already Class 3 or Class 4 by population is not further increased, and a classification can never be lower than Step 1.

Distribution uplifts include 3 to 5 pressure zones (minimum Class 2), 6 or more pressure zones (Class 3), normal operating pressures greater than 150 psi (Class 3), chloramine residual instead of free chlorine (Class 2), booster chlorine stations inside the distribution system (Class 2), more than 2 percent of system pipe length at 24 inches diameter or larger (Class 3), 5 to 9 entry points (Class 2), and 10 or more entry points (Class 3). A pressure zone counts only if it serves at least 15 service connections.

Collection uplifts are keyed to lift stations and industrial users: 3 to 5 qualifying lift stations with at least one at 0.15 MGD firm capacity or greater (Class 2); 6 or more (Class 3); any single lift station with firm capacity of 0.35 to 2.49 MGD (Class 2); any single lift station at 2.5 MGD or more (Class 3); two significant industrial users (Class 2); three or more significant industrial users (Class 3). Firm capacity means installed pumping capacity with the largest unit out of service.

Operator in Responsible Charge (ORC)

Under sections 100.10 and 100.12, every owner of a regulated facility must have at least one designated Operator in Responsible Charge. The ORC holds the technical authority — and the personal liability — for process control and system integrity.

+-------------------------------------------------------------------------+
|                     MANDATORY ORC QUALIFICATION RULE                    |
+-------------------------------------------------------------------------+
| The ORC must hold a VALID certificate in the SAME certification         |
| category, at a class EQUAL TO OR HIGHER THAN the facility class.        |
|                                                                         |
|   Class A facility  -> A                                                |
|   Class B facility  -> A or B                                           |
|   Class C facility  -> A, B, or C                                       |
|   Class D facility  -> A, B, C, D, or S (S only per 100.10.5(e))        |
|   Class 4 system    -> 4                                                |
|   Class 1 system    -> 4, 3, 2, 1, or S (S only per 100.10.5(e))        |
+-------------------------------------------------------------------------+

Duties reserved to the ORC

1. Process control and system integrity decisions. Sections 100.12.2 and 100.12.3 reserve drinking water quality and effluent quality process-control decisions to the certified ORC — chemical dosing, filter and backwash sequencing, sludge wasting, and disinfection setpoints.
2. Written operating plan. Section 100.12.6 requires the ORC to develop and maintain a written operating plan so that other staff can run the facility correctly when the ORC is not on site.
3. Availability. Section 100.10.3 requires the ORC to be available to the facility as needed to make timely decisions, including outside normal hours.
4. Compliance oversight. Supervising regulatory sampling, verifying data, and signing operating reports submitted to CDPHE.
5. Reasonable care. Section 100.11.1 holds certified operators to the level of reasonable care and skill ordinarily exercised by others in the profession.

Owner obligations

• 30-day reporting (section 100.10.4). The owner must submit the division contact update form no later than 30 days after a facility goes online, and thereafter within 30 days of any change to the legal representative's contact information, the name and operator identification number of the ORC, the facilities each ORC covers, or the PWSID or CDPS permit number.
• Site-specific ORC (section 100.10.8). A limited site-specific designation exists to give owners temporary flexibility when specific conditions are met.
• Enforcement (section 100.10.6). The Division investigates owner violations of sections 100.10.1 through 100.10.5 and enforces under section 25-9-110, C.R.S.