Ind. Admin. Code tit. 410, r. 6-2.1-31 – Water quality standards

Sec. 31. (a) At all times, the water in a pool shall have sufficient clarity so that the main drain or a black disc, six (6) inches in diameter placed at the deepest part of the pool, is readily visible from the deck.

(b) The water temperature in spas may not exceed one hundred four (104) degrees Fahrenheit.

(c) One (1) water sample must be collected weekly from each pool and submitted for bacteriological examination. Samples may not be collected from any portion of the recirculation system.

(d) Sampling shall start at least one (1) week prior to the opening of the pool.

(e) Bacteriological examinations performed on each sample shall include the heterotrophic thirty-five (35) degree Centigrade plate count, and a total coliform test using either the:

(1) multiple tube fermentation test;
(2) membrane filter test; or
(3) one hundred (100) milliliter presence/absence test.

Tests shall be performed by a state-approved laboratory in accordance with the procedures outlined in Standard Methods.

(f) A copy of each water sample report must be submitted to the local health department by the pool owner or operator within four (4) days of receiving such a report from the laboratory. No two (2) consecutive samples or three (3) samples collected in a six (6) week period shall demonstrate the following:

(1) Contain more than two hundred (200) bacteria colonies per milliliter as determined by the heterotrophic thirty-five (35) degree Centigrade plate count.
(2) Test positive (confirmed test) for coliform organisms in any of the five (5) to ten (10) milliliter portions of a sample when the multiple tube fermentation tube test is used.
(3) Test positive for more than one (1) coliform organism per fifty (50) milliliters when the membrane filter test is used.
(4) Show the presence of any coliform when the one hundred (100) milliliter presence/absence test is used.

Failure to collect and analyze weekly water samples during the period that a pool is open for use is considered an unsatisfactory report for the applicable week.

(g) When the pool must be closed due to an unsatisfactory sample report, an additional water sample must be submitted to an approved laboratory. The pool may be reopened upon receipt of a satisfactory report.

(Indiana Department of Health; 410 IAC 6-2.1-31; filed May 19, 2003, 8:30 a.m.: 26 IR 3329; readopted filed Jul 8, 2009, 1:44 p.m.: 20090805-IR-410090209RFA; filed Jul 26, 2010, 2:16 p.m.: 20100825-IR-410090006FRA; readopted filed Sep 30, 2015, 2:45 p.m.: 20151028-IR-410150169RFA; readopted filed Nov 12, 2021, 8:42 a.m.: 20211208-IR-410210386RFA; readopted filed Nov 14, 2025, 11:18 a.m.: 20251210-IR-410240588RFA)