Section 277.233. Final cover and grading

(a) The operator shall provide final cover in the following manner:

(1) A cap shall be placed and graded over the entire surface of each final lift. The following performance standards for the cap shall be met:

(i) The cap shall have a permeability less than or equal to the permeability of the primary liner or a permeability no greater than 1 x 10^-7 cm/sec, whichever is less.

(ii) The cap shall be resistant to physical and chemical failure.

(iii) The cap shall cover all areas where waste is disposed.

(2) A drainage layer capable of transmitting flow and preventing erosion of the soil layer shall be placed over the cap.

(3) A uniform and compacted layer of soil at least 2 feet in thickness shall be placed over the drainage layer.

(4) For a construction/demolition waste landfill permitted prior to December 23, 2000, that does not have a liner, the Department may waive or modify the cap and drainage layer.

(b) The operator shall place final cover within 1 year after disposal in the final lift ceases or as soon thereafter as weather permits, unless the Department, in the permit, allows a later period based on a demonstration that a later period is necessary to protect the final cover from differential settlement of waste at the facility. The Department will not allow a later period unless, at a minimum, delayed installation will not cause or allow a violation of this article, the act or the environmental protection acts. For a construction/demolition waste landfill constructed with attenuating soil and permitted prior to December 23, 2000, or for an expansion of a landfill under § 277.122 (relating to modification to expand existing landfill), the Department may waive the final cover requirements in subsection (a) when the approved postclosure land use makes a cap and drainage layer unnecessary.

(c) Unless alternative design requirements to meet the performance standards in subsection (a)(1)(i)—(iii) are approved as part of the permit under § 271.231 (relating to equivalency review procedure), the cap shall meet the design requirements set forth for caps in Table I in § 277.255 (relating to liner) which will not result in a permeability greater than that of the primary liner.

(d) The layer of material described in subsection (a)(3) shall meet the following performance standards. The layer shall:

(1) Be capable of allowing loaded vehicles to successfully maneuver over it after placement.

(2) Be capable of controlling fires.

(3) Be capable of supporting the germination and propogation of vegetative cover as required by § § 277.234 and 277.235 (relating to revegetation; and standards for successful revegetation).

(4) Ensure slope stability.

(e) Unless alternative design requirements to meet performance standards in subsection (d) are approved as part of the permit under § 271.231 (relating to equivalency review procedure), the layer of material described in subsection (a)(3) shall meet the following design requirements:

(1) The cover soil shall fall within the United States Department of Agriculture textural classes of sandy loam, loam, sandy clay loam, silty clay loam, loamy sand and silt loam as defined in the Soil Survey Manual published by the United States Department of Agriculture, Soil Conservation Service (available from the Department or the Northeast National Technical Center of the Soil Conservation Service, 160 E. 7th Street, Chester, Pennsylvania 19103-6092).

(2) At least 40% by weight of the cover soil shall be capable of passing through a 2 millimeter, no. 10 mesh sieve.

(f) The grade of final slopes shall be designed, installed and maintained to:

(1) Ensure permanent slope stability.

(2) Control erosion due to rapid water velocity and other factors.

(3) Allow compaction, seeding and revegetation of cover material placed on the slopes.

(4) Ensure minimal percolation of precipitation and surface runoff into the disposal area.

(g) Unless the Department authorizes a different slope design in the permit based on a demonstration that the different design can meet the requirements of subsection (f), slopes shall be designed, installed and maintained as follows:

(1) The grade of the final surface of the facility may not be less than 3%.

(2) If the Department approves final grades of more than 15%:

(i) The operator shall construct a horizontal terrace at least 15 feet wide on the slope for every 25 feet maximum rise in elevations of the slope. The terrace width shall be measured as the horizontal distance between slope segments.

(ii) The gradient of the terrace shall be 5% into the landfill.

(iii) Drainage ditches shall be constructed in each horizontal terrace to convey flows.

(3) An operator may not leave final slopes that have a grade exceeding 33%, including slopes between benched terraces.

The provisions of this § 277.233 amended December 22, 2000, effective December 23, 2000, 30 Pa.B. 6685. Immediately preceding text appears at serial pages (226295) to (226296) and (266309).

Notation

Cross References

This section cited in 25 Pa. Code § 277.113 (relating to closure plan); and 25 Pa. Code § 277.141 (relating to compaction and cover plan).