The Division will utilize a two-step process for classifying wastewater collection systems as follows:
Step 1: The first step will be to classify based on population served which is a surrogate for number of connections, system volume/flow, and pipe size/quantity. Increasing number of connections, volume, and flow implies increased complexity.
Step 1 Collection 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 wastewater collection system based on system specific factors as outlined in the Step 2 Collection 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 Collection Table. However, a class 1 or class 2 collection 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 Collection Table
Collection System Feature | Minimum Classification |
Lift stations1: designed capacity to receive greater than 2,000 gpd (domestic wastewater treatment works) and firm capacity2 less than 150,000 gpd (0.15 MGD). Includes 1 or 2 lift stations with one or both having firm capacity 150,000 gpd (0.15 MGD) or greater, but less than 0.35 MGD. | Class 1 |
Lift stations: 3 to 5, each with designed capacity to receive greater than 2,000 gpd (domestic wastewater treatment works) and one or more with firm capacity 150,000 gpd (0.15 MGD) or greater. | Class 2 |
Lift stations: 6 or more, each with designed capacity to receive greater than 2,000 gpd (domestic wastewater treatment works) and one or more with firm capacity 150,000 gpd (0.15 MGD) or greater. | Class 3 |
Lift station: any single lift station with firm capacity 0.35 MGD to 2.49 MGD. | Class 2 |
Lift station: any single lift station with firm capacity 2.5 MGD or more. | Class 3 |
Two significant industrial users (SIU)3 in collection system service area | Class 2 |
Three or more significant industrial users (SIU) in collection system service area | Class 3 |
Notes:
5 CCR 1003-2-100.9