Indiana Administrative Code
Title 327 - WATER POLLUTION CONTROL DIVISION
Article 2 - WATER QUALITY STANDARDS
Rule 1 - Water Quality Standards Applicable to All State Waters Except Waters of the State Within the Great Lakes System
Section 1-13 - Development of site-specific aquatic life criteria using the recalculation procedure
Current through March 20, 2024
Authority: IC 13-14-8; IC 13-14-9; IC 13-18
Affected: IC 13-18-4
Sec. 13.
(a) The definitions in section 9 of this rule and 327 IAC 2-1.5-2 and the following apply throughout this section:
(b) The recalculation procedure is intended to allow site-specific criteria to differ from the aquatic life criteria in this rule and 327 IAC 2-1.5. The site-specific criteria may be allowed if justified by demonstrated pertinent toxicological differences between the aquatic species that occur at the site and those that were used in the derivation of the criteria in this rule or 327 IAC 2-1.5. The recalculation procedure involves the recalculation of water quality criteria for a given site through the modification of the toxicity data set used to originally calculate the criteria. The process of modifying a toxicity data set for this procedure involves one (1) or more of the following steps:
(c) Except as provided in subsection (g), the following MDRs must be available to calculate site-specific aquatic life criteria using the recalculation procedure:
(d) If a specific requirement in subsection (c) cannot be satisfied, after deletion of toxicity data described in subsection (e), because that kind of species does not occur at the site, toxicity data from a taxonomically similar sensitive species must be substituted in order to meet the MDRs. The following procedures, listed in order of preference, shall be used to substitute a taxonomically similar species in order to meet the MDRs under subsection (c):
(e) The following procedures in this subsection shall be used to develop the toxicity data set that must be used to recalculate a site-specific aquatic life water quality criterion:
STEP 1. Does the genus occur at the site?
If "No", go to STEP 2.
If "Yes", is there one (1) or more species in the genus that occurs at the site but is not in the data set?
If "No", delete the uncircled species*.
If "Yes", retain the uncircled species*.
STEP 2. Does the family occur at the site?
If "No", go to STEP 3.
If "Yes", is there one (1) or more genera in the family that occurs at the site but is not in the data set?
If "No", delete the uncircled species*.
If "Yes", retain the uncircled species*.
STEP 3. Does the order occur at the site?
If "No", go to STEP 4.
If "Yes", does the data set contain a circled species that is in the same order?
If "No", retain the uncircled species*.
If "Yes", delete the uncircled species*.
STEP 4. Does the class occur at the site?
If "No", go to STEP 5.
If "Yes", does the data set contain a circled species that is in the same class?
If "No", retain the uncircled species*.
If "Yes", delete the uncircled species*.
STEP 5. Does the phylum occur at the site?
If "No", delete the uncircled species*.
If "Yes", does the data set contain a circled species that is in the same phylum?
If "No", retain the uncircled species*.
If "Yes", delete the species*.
* = Continue the deletion process by starting at STEP 1 for any remaining species unless all species in the data set have been considered. The species that are circled and those that are retained constitute the site-specific data set.
(f) The following procedures in this subsection must be used to calculate the site-specific final acute value (FAV), the acute aquatic criterion (AAC) or criterion maximum concentration (CMC), and the chronic aquatic criterion (CAC) or criterion continuous concentration (CCC) using the site-specific data set developed using the procedures in subsection (e):
Where: eA = natural logarithm (ln) of A
GMAV = genus mean acute value
S2 = variance (S = standard deviation)
P = cumulative probability for each GMAV at rank (R)/(n + 1)
[SUMMATION] = summation
(g) If the variety of aquatic invertebrates, amphibians, and fish is so limited that species in fewer than eight (8) families occur at the site, the following procedures must be used: