Authority: IC 13-14-8-7; IC 13-15-2-1; IC 13-19-3-1

Affected: IC 13-20-2; IC 36-9-30

Sec. 5. (a) Before soil liner construction, prior to soil compaction, the soil liner material must be tested at a frequency described in Table 1 of this subsection. During construction, after the soil material has been compacted, the soil liner material must be tested as described in Table 2 of this subsection. TABLE 1 TABLE 2

(b) To ensure proper soil compaction, the following factors must be controlled:

1. (1) The moisture content of the soil must be maintained within the range identified in the moisture-density curve and hydraulic conductivity relation that is developed for the proposed MSWLF unit, both prior to and during compaction of the soil lift, to ensure the remolded lift does not exceed allowable hydraulic conductivity.
2. (2) The density after compaction must be within the range identified in the moisture-density curve and hydraulic conductivity relation that is developed for the proposed MSWLF unit, to ensure that the remolded lift does not exceed allowable hydraulic conductivity.
3. (3) Lift thickness.
4. (4) Compactive energy/kneading action to ensure effective destruction of soil clods.
5. (5) Placement operations to ensure elimination of lift interfaces.
6. (6) Any additional factors necessary to obtain adequate soil compaction results as specified in the construction plan or as determined by the commissioner.

(c) Unless a waiver pursuant to subsection (e) is granted by the commissioner, test pads must be constructed and tested prior to construction of the full-scale compacted soil liner. Test pads must be constructed each time:

1. (1) the dry unit weight of the soil changes by at least five (5) pounds per cubic foot, based on a moisture density curve established by a standard or modified proctor test;
2. (2) construction equipment is changed; or
3. (3) construction practices are changed.

(d) The test pads required in subsection (c) must be used to verify that the specifications outlined in the approved construction plan, including density, moisture content, and hydraulic conductivity specifications, can be achieved. Tests must conform with the test standards established in section 17 of this rule. In addition, the following test methods pertaining to in situ hydraulic conductivity are acceptable:

1. (1) Sealed double-ring infiltrometer (SDRI).
2. (2) Boutwell borehole test, with a minimum of five (5) tests required.
3. (3) Shelby tube (carved block) test using a twelve (12) inch diameter tube, with a minimum of three (3) tests required.
4. (4) Other equivalent test methods approved by the commissioner.

(e) The requirements outlined in subsection (c) may be waived by the commissioner, provided the owner, operator, or permittee demonstrates, to the satisfaction of the commissioner, the following:

1. (1) The soil to be used in the soil component of the liner:

   1. (A) is of a unified soil classification of ML, CL, MH, CH, or OH;
   2. (B) contains a minimum of fifty percent (50%), by weight, of material that can pass through the number 200 sieve;
   3. (C) consists of a minimum of twenty-five percent (25%), by weight, of clay content, which is defined for the purposes of this subsection to mean soil particles that are less than or equal to five-thousandths (0.005) millimeter in diameter;
   4. (D) has a liquid limit (LL) of at least twenty-five (25); and
   5. (E) has a plasticity index (PI) of at least ten (10).

2. (2) Adequate compactive effort will be applied during soil liner construction. The following compaction curve data, obtained by plotting dry unit weight versus molding water content, must be submitted to the commissioner in order to demonstrate that adequate compactive effort will be applied:

   1. (A) At least five (5) compaction curves must be submitted, provided the soil does not vary in dry unit weight by more than five (5) pounds per cubic foot.
   2. (B) At least three (3) additional compaction curves must be submitted every time the soil varies in dry unit weight by more than five (5) pounds per cubic foot.

(Solid Waste Management Division; 329 IAC 10-17-5; filed Mar 14, 1996, 5:00 p.m.: 19 IR 1833; filed Aug 2, 1999, 11:50 a.m.: 22 IR 3814; readopted filed Oct 16, 2024, 11:58 a.m.: 20241113-IR-329230812RFA)