1. (1) Rule Applicability.

   1. (a) This rule applies to public drinking water systems categorized as community water systems as defined by rule R309-100-4(2), and to non-transient non-community water systems that have system demands higher than required by R309-510 or with demands for fire suppression. All public drinking water systems are still required to comply with R309-550-5 with respect to water main design, which may require a hydraulic analysis. Submission of the Hydraulic Model Report, as defined in R309-511-7 and 8, is not required for projects meeting one of the following criteria:

      1. (i) public drinking water projects that will not result in negative hydraulic impact, such as, but not limited to;

         1. (A) addition of new sources in accordance with R309-515;
         2. (B) adding disinfection, fluoridation, or other treatment facilities that do not adversely impact flow, pressure or water quality;
         3. (C) storage tank repair or recoating;
         4. (D) water main additions with no expansion of service (e.g., looping lines);
         5. (E) adding transmission lines to storage or sources without adding service connections;
         6. (F) adding pump station(s) from source or storage upstream of distribution service connections; or,
         7. (G) public drinking water projects that have negligible hydraulic impact as determined by the Director.
      2. (ii) public drinking water projects that are a part of a planned phase of a master plan previously approved by the Director per R309-500-6(3)(a);
      3. (iii) the water system maintains and updates a hydraulic model of the system, and has designated a professional engineer responsible for overseeing the hydraulic analysis in meeting the requirements of R309-511 in writing to the Director; or,
      4. (iv) the water system has a means that is deemed acceptable by the Director to gather real-time data indicative of hydraulic conditions in model scenarios of R309-511-5(9), and the real-time data show the system is capable of meeting the flow and pressure requirements for the additional demands placed on the existing system.
   2. (b) Professional Engineer's certification of the hydraulic modeling results, as defined in R309-511-4(2)(c) and R309-511-6(1), shall be part of the submission of plans for any public drinking water project as defined in R309-500-5(1) except for the projects listed under R309-511-4(1)(a)(i).
   3. (c) A public water system must clearly identify the reason in the plan submittal if it wishes to demonstrate that R309-511 does not apply to a new construction project. In some cases, supporting documentation may be needed.
   4. (d) If there are existing deficiencies in the water system, the Director may allow a new construction project to proceed in accordance with the plan review requirements in R309-500 through 550 as long as the public water system demonstrates that the new construction project is located in a hydraulically separated area and does not adversely impact the existing deficiencies, or does not create new deficiencies within the water system.

2. (2) Rule Elements.

   1. (a) conduct a hydraulic modeling evaluation consistent with the requirements as set forth in this rule and R309-510. This model shall include either the entire public drinking water system or the specific areas affected by the new construction if hydraulically separated areas exist within the water system;
   2. (b) calibrate the model using field measurements and observations;
   3. (c) certify in writing to the Director that the design complies with the sizing requirements of R309-510 and the minimum water pressures of R309-105-9;
   4. (d) prepare and submit a Hydraulic Model Design Elements Report (see R309-511-7); and,
   5. (f) prepare a System Capacity and Expansion Report if required (see R309-511-8).

   The public water system or its agent, in connection with the submission of plans and specifications to the Director, shall perform the following:

KEY: drinking water, hydraulic modeling

Date of Last Change: January 21, 2014

Notice of Continuation: February 10, 2025

Authorizing, and Implemented or Interpreted Law: 19-4-104