5 Colo. Code Regs. § 1003-2-100.8
The Division will utilize a two-step process for classifying water distribution systems as follows:
Step 1: The first step will be to classify based on population served which is a surrogate for number of taps and system volume/flow. Increasing number of taps, volume, and flow implies increased complexity.
Step 1 Distribution Table
CLASS | POPULATION SERVED1 |
Class 1 | 3,300 or Less |
Class 2 | 3,301 - 25,000 |
Class 3 | 25,001 - 100,000 |
Class 4 | Over 100,000 |
Note: 1. "Population served" means the average daily population that occurs during the busiest month of the year or normal operating period(s) including resident, non-transient, and transient population.
Step 2: The second step will be to account for additional system complexity not captured in step 1. The Division will increase the classification in accordance with the needs created by particular complexities of any specific water distribution system based on system specific factors as outlined in the Step 2 Distribution Table below. Note: A system classified as a class 3 or class 4 based on population would not increase classification based on the Step 2 Distribution Table. However, a class 1 or class 2 distribution system will be increased to a class 2 or class 3 based on a listed complexity. System classifications can never be lower than the classification determined in step 1.
Step 2 Distribution Table
Distribution System Feature | Minimum Classification |
Pressure zones1: 3 to 5 zones | Class 2 |
Pressure zones: 6 or more zones | Class 3 |
System pressures greater than 150 psi (normal operation) | Class 3 |
Chloramines residual (instead of free chlorine) | Class 2 |
Booster chlorine stations - within distribution (not at entry points) | Class 2 |
Substantial lengths of pipe within distribution (>2% of overall distribution system pipe length) with diameters greater than or equal to 24 inches | Class 3 |
Systems with 5 to 9 entry points | Class 2 |
Systems with 10 or more entry points | Class 3 |
Hand-pumped wells regulated under Colorado Primary Drinking Water Regulations, 5 CCR 1002-11 Alternatively can be operated by Level D or above Treatment operator without a distribution operator. | Class 1 |
Note: 1. Pressure zones must serve at least 15 service connections to be counted as a zone. A small booster pump serving a few houses should not be considered its own zone. Pressure zones can be served by a pump or pressure regulating valves.
5 CCR 1003-2-100.8