WQ0036327_CLOSURERESPONSE_20200725

July 25, 2020

Laurence Harwood Jr., General Partner
PO Box 1327
Hixson, TN 37343

Subject: High-Rate Infiltration Basin Closure Plan Response
Permit No. WQ0036327
Mystic Meadows WWTP
Swain County

Dear Mr. Harwood,

The Division of Water Resources, Asheville Regional Office (ARO), received a written closure plan from
Mountain Solis Inc. on July 20, 2020 for the permanent closure of the Mystic Meadows WWTP high-rate
infiltration basin. The submitted plan indicated the basin walls would be incorporated into the final cap.
Please note, as stated in the Closure Requirements issued by the ARO on January 2, 2020, the basin wall
material is too coarse and cannot be used, in any form, to construct the earthen cap. The following is
required to close out the basin and rescind the permit.

 The performance cap will be comprised of a sufficient volume of clay of no less than 3 feet in
thickness, free of coarse material, and extending beyond the boundaries of the infiltration
gallery. The clay loam material identified by Mountain Soils was determined to be suitable by
the ARO as a capping material for this closure;
 The performance cap will be sufficiently compacted and shaped to limit infiltration and promote
positive drainage away from the infiltration gallery;
 The performance cap will be stabilized by a vegetative cover and appropriately maintained so as
to prevent the establishment of woody vegetation;
 Surface drainage will be diverted away from the infiltration gallery between the basin and US
HWY 19/74;
 The closure plan must be sealed by a North Carolina licensed engineer demonstrating all the
above requirements have been met;
 The ARO will conduct a final inspection before approving the permit rescission.

The closure plan must be submitted to the ARO for review within 30 days upon receipt of this letter.
Please be aware that failure to adequately address the closure requirements may result in a Notice of
Violation and potential enforcement. Should you have any questions or wish to clarify any of the
requirements, please feel free to contact Brett Laverty ([e-mail]) or me
([e-mail]) at 828-296-4500.

Sincerely,

Mikal Willmer, Environmental Specialist II
Water Quality Regional Operations Section
Asheville Regional Office
Division of Water Resources, NCDEQ

Ec: LF