New Census and Possible Changes to Population Served

Knock, knock! Oh, is that the census volunteer at my door?

It is the year 2020 and we all know what that means. Sometime in 2021, cities and towns across the country will have updated population counts. You may be asking yourself, why is this relevant to your public water system? The simple answer is that the monitoring requirements established for your water system by Regulation 11 of the Colorado Primary Drinking Water Regulations and the department are based on the total population served by the public water system. The regulation categorizes populations into three different types: resident, non-transient, and transient populations. 

1. Resident populations are identified as the people regularly served year-round by the water system. This applies to people whose primary residence is in the service area and applies even if the individuals do not live in the service area year-round.
2. Non-transient populations are identified as the people that regularly commute into a supplier’s service area throughout the year and have a regular opportunity to consume the water. The non-transient population is generally made up of working professionals or students who travel into the service area but do not live in the service area. Regular opportunity means four or more hours per day, for four or more days per week, for six or more months out of the year.
3. Transient populations are determined by attempting to identify the daily average of individuals served by the public water system that are neither resident nor non-transient in nature. This generally applies to tourists and visitors to your water system service area, along with customers of businesses in your water system that do not live in the water system’s service area. 

Many community water systems rely on census counts to better determine the resident population served. The department is aware that there are many instances where not all of the town or city residents are served by the same public water system; however, generally in Colorado, many systems have relied on the census population to better determine the resident population served by the system.

What could change?

The department anticipates various changes to the suppliers’ population types, which can trigger increased or decreased monitoring requirements for total coliforms, lead and copper, disinfection byproducts, and turbidity. 

Many of the population-specific monitoring requirements can be found in the following tables in regulation 11:

     

The most likely impact change will be to the total coliform rule sampling requirements:

For many systems, now may be an opportune time to evaluate any anticipated population increases and how it may impact the supplier’s monitoring requirements. Many suppliers may have to adjust future budgets in order to account for increases in sampling requirements.

It is the responsibility of the supplier to notify the department, via an updated monitoring plan, of any identified changes to the system’s population and/or inventory within 30 days of the effective date. For many systems, this date may likely occur sometime in 2021.

➽ Jorge Delgado, P.E., North Unit Compliance Manager