Section 329IAC10-17-3. Landfill subgrade; design, construction, and quality assurance/quality control requirements

   (a) The subgrade surface under the liner systems described in section 2 of this rule must:

(1) be constructed with on-site soils, or a select soil specified in the approved construction plan or otherwise approved by the commissioner;

(2) be constructed with material that is free of organic material, except that organic material naturally occurring in the soil;

(3) be prepared using procedures and equipment specified in:

(A) the approved construction plan; or

(B) otherwise approved by the commissioner;

(4) meet the stable foundation criteria as defined in 329 IAC 10-16-7(b); and

(5) meet any additional requirements necessary to obtain adequate design and construction, as specified in the construction plans or as determined by the commissioner.

  (b) Before any material is placed over the subgrade, the project engineer shall ensure the following:

(1) The subgrade was tested for density and moisture content as specified in the approved construction plans.

(2) The exposed surface was inspected to:

(A) evaluate the suitability of the subgrade;

(B) ensure that the surface is properly compacted, smooth, and uniform; and

(C) ensure that elevations are consistent with the approved construction plans.

(3) Any additional requirements necessary to obtain an adequate subgrade, as specified in the construction plans or as determined by the commissioner, are met.

(Solid Waste Management Division; 329 IAC 10-17-3; filed Mar 14, 1996, 5:00 p.m.: 19 IR 1832; filed Mar 19, 1998, 11:07 a.m.: 21 IR 2775)