1. (a) An approved cover material shall be applied over all sides and working faces of the landfill in a manner and at a frequency required to achieve the following performance objectives:

   1. (1) Minimize the dispersal of offensive odors;
   2. (2) Minimize the potential to attract and harbor vectors;
   3. (3) Control drainage in accordance with Env-Sw 805.06, Env-Sw 805.09, Env-Sw 806.05, and Env-Sw 806.06;
   4. (4) Control unsightly conditions and windblown waste;
   5. (5) Reduce the potential for fire;
   6. (6) Provide stability; and
   7. (7) Assist in the proper development of final grades, as set forth in the facility’s approved fill sequencing plans.

2. (b) A material shall not be approved or used as cover material unless:

   1. (1) The material exhibits characteristics required to achieve the performance objectives in (a) above;

   2. (2) Use of the material will not:

      1. a. Cause equipment or operational problems;
      2. b. Contribute to the deterioration of leachate quality at lined landfills;
      3. c. Cause surface water or groundwater contamination; or
      4. d. Pose a hazard to human health through skin contact or respiration; and

   3. (3) The material itself:

      1. a. Is not a hazardous waste;
      2. b. Is physically and chemically consistent in nature; and
      3. c. Contains no free liquids.
3. (c) At landfills receiving MSW, cover material approved in accordance with Env-Sw 314 or Env-Sw 315 shall be placed over all exposed waste no less frequently than at the end of each operating day.
4. (d) Cover materials shall be placed over all exposed waste at a minimum thickness of 6-inches, except for geosynthetic tarps and alternate daily cover materials approved with a different thickness in accordance with Env-Sw 314 or Env-Sw 315.

5. (e) Subject to the requirements in (b) above, the following materials shall be approved as working face cover material:

   1. (1) Natural soils; and

   2. (2) The following alternate daily cover materials, provided that use of the material is approved as part of the facility operating plan or approved via a permit modification pursuant to Env-Sw 315:

      1. a. Geosynthetic tarps;
      2. b. Casting sands;
      3. c. A waste certified for distribution and use as landfill cover pursuant to the provisions of Env-Sw 1500 prior to the 2024 readoption of this chapter;
      4. d. A waste approved for distribution and use as landfill cover pursuant to the provisions of Env-Sw 806.03(f); and
      5. e. Contaminated soil, subject to the requirements of Env-Sw 903.05.

6. (f) Prior to using an alternate daily cover material in accordance with (e)(2)d. above, the permittee shall:

   1. (1) Obtain approval of a demonstration project meeting the requirements in (g) and (h) below pursuant to the permit modification process in Env-Sw 315;
   2. (2) Submit a report meeting the requirements of Env-Sw 806.03(h) to the department documenting the results of the demonstration project; and
   3. (3) Obtain approval of the alternate daily cover pursuant to the permit modification process in Env-Sw 315.
7. (g) A demonstration project shall be conducted for a period of no less than 60 days.

8. (h) The demonstration project required by (f) above shall include the following information:

   1. (1) The proposed cover material type and name;
   2. (2) Specifications for the material and, if available, a safety data sheet (SDS);
   3. (3) Test methodology, including procedures for placement and evaluation;
   4. (4) A contingency plan for the use of natural soils or geosynthetic tarps if the alternate material cannot be used, is not available, or is not performing adequately;
   5. (5) Analytical characterization testing; and
   6. (6) Any available documentation of the material’s use at other landfills which addresses the material’s performance and regulatory status.

9. (i) Following completion of the demonstration project in (f) above, the permittee shall submit a report to the department that includes:

   1. (1) The proposed cover material type and name;

   2. (2) The results of the project, including an assessment of;

      1. a. The performance of the material for each criterion listed in (a) above; and
      2. b. Whether the material meets the requirements in (a) and (b) above; and

   3. (3) A determination as to whether the material is suitable for use as cover material and recommendations for its use as cover material, including:

      1. a. The material specifications for acceptance; and
      2. b. The weather conditions during which the material can or cannot be used.
10. (j) A permittee may rely on a demonstration project completed by others when seeking a permit modification in accordance with Env-Sw 315, provided such demonstration project meets the requirements of (g) and (h) above.

11. (k) At landfills receiving MSW, an intermediate cover shall be placed over all waste no later than 90 days following the last day waste was added to the area and shall consist of at least:

    1. (1) Twelve inches of soil, which may contain regulated contaminants at concentrations that do not exceed the soil remediation standards specified in Env-Or 606.19; or
    2. (2) A temporary geomembrane cap underlain by 6 inches of soil that may contain regulated contaminants at concentrations that do not exceed the soil remediation standards specified in Env-Sw 606.19.

12. (l) At landfills receiving MSW, a final cap system designed pursuant to Env-Sw 805.10, shall be constructed within 5 years of achieving final grade in any phase or portion of the landfill, unless an alternative schedule is approved in accordance with Env-Sw 314 or Env-Sw 315 based on information provided in the application which demonstrates:

    1. (1) The intermediate cover used will meet the performance standards in Env-Sw 805.10(a) for the duration of time requested in the alternative schedule; and
    2. (2) The alternative schedule for placing final cap will not result in problems relating to the conditions identified in Env-Sw 1005.01(d).

Source. #5172, eff 7-1-91; ss by #6535, INTERIM, eff 7-1-97, EXPIRES: 10-29-97; ss by #6619-B, eff 10-29-97; ss by #6894-B, eff 12-1-98; (See Revision Note at chapter heading for Env-Sw 800); ss by #8459, eff 10-28-05 (formerly Env-Wm 2506.03); ss by #10597, eff 7-1-14; ss by #14156, eff 12-21-24