Colo. Rev. Stat. § 31-35-617
In the event any user of said sewerage system neglects, fails, or refuses to pay the rates and charges fixed by said governing body for the connection with and use of said sewer, said user shall not be disconnected from said sewerage system or refused the use of said sewer unless the user is outside the municipal limits, but the rates and charges due therefor may be certified by the clerk or the proper authority of the district to the board of county commissioners of the county in which said delinquent user's property is located and shall become a lien upon the real property so served by said sewer connection. The amount due shall be collected in the manner as though they were part of the taxes.
C.R.S. § 31-35-617
This section is similar to former § 31-35-517 as it existed prior to 1975.