Section 327IAC8-2.5-13. Monitoring plan; stage 2 disinfection byproducts requirements

   (a) The following are PWS requirements for completion of a monitoring plan under sections 11 and 12 of this rule, this section, and sections 14 through 20 of this rule:

(1) A PWS shall develop and implement a monitoring plan to be kept on file at the system for review by the commissioner and the public. The monitoring plan must be completed not later than the date initial monitoring is conducted under sections 11 and 12 of this rule, this section, and sections 14 through 20 of this rule, and it must contain the following elements:

(A) Monitoring locations.

(B) Monitoring dates.

(C) Compliance calculation procedures.

(2) For selection of monitoring locations, the following apply:

(A) If a PWS was not required to submit an IDSE report under either 40 CFR 141.601, as incorporated by reference in section 10(a)(2) of this rule, or 40 CFR 141.602, as incorporated by reference in section 10(a)(3) of this rule, and the PWS does not have sufficient monitoring locations as required under sections 4 through 9 of this rule to identify the required number of compliance monitoring locations indicated in 40 CFR 141.605(b), as incorporated by reference in section 10(a)(6) of this rule, the PWS shall do the following:

(i) Identify additional monitoring locations by alternating selection of locations representing high TTHM levels and high HAA5 levels until the required number of compliance monitoring locations have been identified.

(ii) Provide the rationale for identifying the locations, required under item (i), as having high levels of TTHM or HAA5.

(B) If a PWS has more monitoring locations, as required under sections 4 through 9 of this rule, than required for compliance monitoring in 40 CFR 141.605(b), as incorporated by reference in section 10(a)(6) of this rule, the PWS shall identify the locations that will be used for compliance monitoring under sections 11 and 12 of this rule, this section, and sections 14 through 20 of this rule by alternating selection of locations representing high TTHM levels and high HAA5 levels until the required number of samples under section 12 of this rule have been identified.

  (b) A Subpart H system serving greater than three thousand three hundred (3,300) people shall submit a copy of the monitoring plan to the commissioner prior to the date initial monitoring is conducted under sections 11 and 12 of this rule, this section, and sections 14 through 20 of this rule, unless the initial distribution system evaluation report submitted under section 10 of this rule contains all the information required by this section.

  (c) Revision of a monitoring plan may be allowed if the following are met:

(1) A PWS may revise its monitoring plan after consultation with the commissioner regarding the need for changes and the appropriateness of changes to reflect one (1) or more of the following:

(A) Changes in treatment.

(B) Changes in distribution system operations and layout (including new service areas).

(C) Other factors that can affect TTHM or HAA5 formation.

(D) Reasons approved by the commissioner.

(2) A PWS making changes to monitoring locations shall replace existing compliance monitoring locations having the lowest LRAA with new locations that reflect the current distribution system locations with expected high TTHM or HAA5 levels.

(3) Modifications to a monitoring plan required by the commissioner.

(4) Subpart H systems serving greater than three thousand three hundred (3,300) people shall submit a copy of the modified monitoring plan to the commissioner prior to the date the PWS is required to comply with the revised monitoring plan.

(Water Pollution Control Division; 327 IAC 8-2.5-13; filed May 7, 2010, 9:30 a.m.: 20100602-IR-327080198FRA)