S.C. Code Regs. § § 61-107.19.V.F.258.60

Current through Register Vol. 48, No. 10, October 25, 2024

Section 61-107.19.V.F.258.60 - Closure Criteria

a. Owners/operators of all Class Three landfills shall install a final cover system that is designed to minimize infiltration and erosion. The final cover system shall be designed and constructed to:

(1) Have a permeability less than or equal to the permeability of any bottom liner system or natural subsoils present, or a permeability no greater than 1 x 10^-5 cm/sec, whichever is less;

(2) Minimize infiltration through the closed Class Three landfill by the use of an infiltration layer that contains a minimum eighteen (18) inches of earthen material;

(3) Minimize erosion of the final cover by the use of an erosion layer that contains a minimum one (1) foot of earthen material that is capable of sustaining native plant growth; and,

(4) Have a storm water conveyance system for the landfill cap designed to ensure that the hydraulic head at any point does not exceed one (1) foot for a 24-hour period as the result of a 24-hour, 25-year storm event on all areas that have received final cover.

b. The Department may approve an alternative final cover design that includes:

(1) An infiltration layer that achieves an equivalent reduction in infiltration as the infiltration layer specified in paragraphs a. (1) and a. (2) above; and,

(2) An erosion layer that provides equivalent protection from wind and water erosion as the erosion layer specified in a. (3) above.

c. The permittee shall prepare a written closure plan that describes the steps necessary to close all Class Three landfills at any point during their active life in accordance with the cover design requirements in Section258.60.a. or b., as applicable. The closure plan, at a minimum, shall include the following information:

(1) A description of the final cover, designed in accordance with Section258.60.a. and the methods and procedures to be used to install the cover;

(2) An estimate of the largest area of the Class Three landfill ever requiring a final cover as required in Section258.60.a. at any time during the active life;

(3) An estimate of the maximum inventory of wastes ever on-site over the active life of the landfill facility; and,

(4) A schedule for completing all activities necessary to satisfy the closure criteria in Section258.60.

d. Prior to permit issuance, the permittee shall submit to the Department a closure plan. The closure plan shall be updated if any changes occur at the facility which require a deviation from the approved closure plan.

e. Prior to beginning closure of each Class Three landfill as specified in Section258.60.f., a permittee shall submit a notice of intent to close to the Department to include a schedule outlining closure activities.

f. The permittee shall begin closure activities of each Class Three landfill no later than 30 days after the date on which the Class Three landfill receives the known final receipt of wastes, or if the Class Three landfill has remaining capacity and there is a reasonable likelihood that the Class Three landfill will receive additional wastes, no later than one year after the most recent receipt of wastes. Extensions beyond the one-year deadline for beginning closure may be granted by the Department if the permittee demonstrates that the Class Three landfill has the capacity to receive additional wastes and the permittee has taken and will continue to take all steps necessary to prevent threats to human health and the environment from the unclosed Class Three landfill.

g. The permittee of all Class Three landfills shall complete closure activities of each Class Three landfill in accordance with the closure plan within 180 days following the beginning of closure as specified in Section258.60.f. Extensions of the closure period may be granted by the Department if the permittee demonstrates that closure will take longer than 180 days and they have taken and will continue to take all steps to prevent threats to human health and the environment from the unclosed Class Three landfill.

h. Following closure of each Class Three landfill, the permittee shall submit to the Department for approval certification, that is signed by a South Carolina registered professional engineer other than the design engineer, verifying that closure has been completed in accordance with the closure plan. A copy of this certification shall be placed in the operating record. The certification testing shall be conducted at a minimum rate of one (1) permeability test per acre and four (4) density/thickness tests per acre.

i. Within 30 days of the Department's issuance of final closure approval of a Class Three landfill, and using a form approved by the Department, the permittee shall record with the appropriate Register of Deeds, a notation in the record of ownership of the property - or some other instrument which is normally examined during title search - that will in perpetuity notify any potential purchaser of the property that the land or a portion thereof was used for the disposal of solid waste. This notice shall define the final boundaries of the waste disposal area including the latitude and longitude, identify the type, location, and quantity of solid waste disposed on the property, and advise potential owners of the property that there are land use restrictions.

j. The permittee may request permission from the Department to remove the notation from the deed if all wastes are properly removed from the facility and there is no environmental impact.

k. All facilities constructed with liner systems in accordance with this regulation shall install a final cover system which, at a minimum, consists of:

(1) A gas management layer or layers, or other gas management design, as necessary;

(2) Eighteen (18) inches of soil with a maximum permeability of 1 x 10^-5 centimeters per second, and capable of providing a suitable foundation for the flexible membrane liner specified in paragraph (3) below;

(3) A 20-mil flexible membrane liner with a maximum permeability equal to or less than the bottom liner system, if HDPE is used as the FML, then a sixty (60) mil thickness is required;

(4) A drainage layer; and,

(5) A minimum of two feet of soil capable of supporting native vegetation.

l. All Class Three landfills closed utilizing a flexible membrane cover system shall be constructed to preclude precipitation migration into the landfill. All flexible membrane cover systems shall be constructed in accordance with the requirements of the approved engineering plans, reports, specifications and manufacturer's recommendations.

m. The erosion layer shall be designed to maintain vegetative growth over the landfill by seeding with native grasses or other suitable cover. A 75% or greater vegetative ground cover with no substantial bare spots shall be established and maintained throughout the post-closure period.

n. The final cover system shall promote positive drainage by grading to create at least a 3%, but not greater than 5%, surface slope and a side slope that does not exceed three horizontal feet to one vertical foot, i.e., a 3:1 slope.

o. The Department may, on a case-by-case basis, approve other landfill closure designs, provided there is adequate information to demonstrate that the proposed design meets or exceeds the environmental and public health protection standards outlined in Subparts B, D and E of this regulation.

S.C. Code Regs. § 61-107.19.V.F.258.60