Authority: IC 13-14-8; IC 13-18-11-1.5; IC 13-18-11-13

Affected: IC 13-18-11

Sec. 2. (a) A water distribution system shall be classified in one (1) of three (3) classifications as follows:

1. (1) Class DSS (distribution system small) includes systems that:

   1. (A) serve a population of less than three thousand three hundred one (3,301); and

   2. (B) have no components other than:

      1. (i) pressure tanks; or
      2. (ii) storage tanks.
2. Nontransient noncommunity public water systems serving a population less than five hundred one (501) utilizing no treatment other than ion exchange or inline filtration are DSS systems.

3. (2) Class DSM (distribution system medium) includes systems that meet one (1) of the following:

   1. (A) Serve a population greater than three thousand three hundred (3,300) but less than ten thousand one (10,001) people and have no mechanical means of movement of water other than one (1) of the following:

      1. (i) Pressure tanks.
      2. (ii) Storage tanks.
      3. (iii) Booster pumps to storage tanks.

   2. (B) Serve a population of less than three thousand three hundred one (3,301) and consist of at least one (1) of the following:

      1. (i) Pumps, not including well pumps, before the entry point to the distribution system.
      2. (ii) Booster pumps to storage tanks.

4. (3) Class DSL (distribution system large) includes systems that meet one (1) of the following:

   1. (A) Serve a population greater than ten thousand (10,000) people.

   2. (B) Serve a population of less than ten thousand one (10,001) and consist of at least one (1) of the following:

      1. (i) Booster pumps in the distribution system other than booster pumps to storage tanks.
      2. (ii) Mechanical devices for movement of water beyond storage.

(b) A water treatment plant shall be classified in one (1) of six (6) classifications, based on population served and type of treatment, as follows:

1. (1) Class WT 1 includes systems that meet the following:

   1. (A) Serve a population less than five hundred one (501) people.
   2. (B) Are a community water system.

   3. (C) Acquire water from one (1) or both of the following:

      1. (i) Ground water.
      2. (ii) Purchase.

   4. (D) Have one (1) or both of the following:

      1. (i) Ion exchange softening process for cation removal.
      2. (ii) Inline filtration device with no chemical treatment.

2. (2) Class WT 2 includes, with no population limitations, systems that meet the requirements of clause (A) and either clause (B) or (C), or both, as follows:

   1. (A) Acquire water from one (1) or more of the following:

      1. (i) Ground water.
      2. (ii) Purchase.

   2. (B) Utilize chemical feed to achieve one (1) of the following:

      1. (i) Disinfection.
      2. (ii) Fluoride standardization.
      3. (iii) Water stabilization.

   3. (C) Have one (1) or both of the following:

      1. (i) An ion exchange softening process for cation removal if the population served is greater than five hundred (500) and less than three thousand three hundred one (3,301).
      2. (ii) An inline filtration device if the population served is greater than five hundred (501) and less than three thousand three hundred one (3,301).

3. (3) Class WT 3 includes systems that meet the following:

   1. (A) Acquire water from one (1) or both of the following:

      1. (i) Ground water.
      2. (ii) Purchase.
   2. (B) Utilize chemical feed.

   3. (C) Have one (1) or more of the following:

      1. (i) Pressure or gravity filtration.
      2. (ii) Ion exchange processes if the population served is greater than three thousand three hundred (3,300).
      3. (iii) Lime soda softening.
      4. (iv) Reverse osmosis.
      5. (v) Inline filtration if the population served is greater than three thousand three hundred (3,300).

4. (4) Class WT 4 includes systems that meet the following:

   1. (A) Serve a population less than ten thousand one (10,001) people.

   2. (B) Acquire water from one (1) or both of the following:

      1. (i) Surface water.
      2. (ii) Ground water under the direct influence of surface water.

5. (5) Class WT 5 includes systems that meet the following:

   1. (A) Serve a population greater than ten thousand (10,000) people.

   2. (B) Acquire water from one (1) or both of the following:

      1. (i) Surface water.
      2. (ii) Ground water under the direct influence of surface water.
6. (6) Class WT 6 includes systems that utilize newly emerging treatment technology not commonly in use for drinking water treatment in Indiana, as determined by the commissioner.
7. (7) The commissioner may determine the classification of a system based on system complexity and operational requirements where necessary.

(Water Pollution Control Division; 327 IAC 8-12-2; filed Sep 24, 1987, 3:00 p.m.: 11 IR 719; filed Sep 19, 1990, 3:00 p.m.: 14 IR 259; filed Dec 12, 1994, 4:39 p.m.: 18 IR 1230; errata filed Mar 9, 1995, 4:15 p.m.: 18 IR 1836; filed Nov 20, 2000, 4:11 p.m.: 24 IR 974; filed Oct 24, 2006, 3:03 p.m.: 20061122-IR-327050255FRA; readopted filed Oct 18, 2024, 1:57 p.m.: 20241113-IR-327230810RFA)