NC0020214_Variance Request_20210630

MCGILL ASSOCIATES 55 BROAD STREET, ASHEVILLE, NC 28801 / 828.252.0575 / MCGILLASSOCIATES.COM
Shaping Communities Together
June 30, 2021
Mr. Jeff Poupart
Water Quality Permitting Section Chief
North Carolina Department of Environmental Quality
Division of Water Resources
512 North Salisbury Street (9th Floor Archdale Building)
Raleigh, North Carolina 27604

Re: Variance Request
Request for Authorization to Construct
TWSA WWTP No. 2 (NC0020214)
Tuckaseigee Water and Sewer Authority
Jackson County, North Carolina
Dear Mr. Poupart,
Tuckaseigee Water and Sewer Authority (TWSA) hereby requests a variance from the setback
requirements laid out in 15A NCAC 02T .0506 (b) for the following reasons:
1. The facility already violates the setback requirement.
As shown in the attached Figure V-1, the existing package plant, grit chamber, and sludge
drying beds already violate the setback requirement.
2. Site constraints, as well as the construction sequence, dictated the placement of
the SBRs.
a. In order to reuse the existing package treatment plant as a post-equalization basin,
the SBRs should be located as close as possible to the package treatment plant.
The SBR nearest the package treatment plant can be located no closer than 15
feet as measured from outside wall to outside wall in order for post-tensioned
prestressed concrete panel construction to be feasible. The same clearance is
needed between SBR tanks. This establishes a zone of ideal placement for the
SBRs, which should be constructed within an annulus with an inside radius of 50
feet and an outside radius of 131 feet. (see Figure V-2, top)
b. Treatment basins should be constructed with 50’ setbacks from surface waters and
property lines. Additional 15’ clearances are required from the headworks and
influent pump station. (see Figure V-2, bottom)
c. Vehicular access to the headworks must be maintained for the removal of
screenings by truck. (see Figure V-3, top)
d. The chemical feed building, which also requires vehicular access for chemical
delivery, must be located near the roadway. (see Figure V-3, bottom)
e. Since the chemical feed building will be constructed before the SBRs, an additional
15’ of clearance is required between the chemical feed building and the outside
walls of the proposed SBR tanks, leaving insufficient space to construct the SBRs
outside the 50’ setback from surface waters. (see Figure V-4, top)
f. The proposed SBR tanks are the only structures proposed to be constructed within
the 50’ setback. Their alignment has been shifted slightly to accommodate yard
piping. (see Figure V-4, bottom)
Mr. Jeff Poupart, Water Quality Permitting Section Chief
June 30, 2021
Page 2 of 2

g. All erosion control measures are to remain in place until construction is completed,
and the entire site is stabilized. Due to both the existing and proposed design
grades of the site, the erosion control basin location must remain in its current
location to capture all potential sediment runoff from the site. The post-construction
stormwater treatment device will need to occupy the same location as the sediment
basin to continue treating stormwater runoff after the project is completed.
3. The proposed design provides better treatment and better protection of the waters
of the state than the existing facility.
The existing package treatment plant exhibits small leaks at multiple locations as shown
in the attached process tank structural condition assessment. New SBR tanks and
rehabilitation of the package treatment plant tank will reduce leaking and the potential of
failure.
4. The proposed design has been modified to provide additional spill protection.
While the SBRs cannot overflow unless the influent pump station is used to overfill them
while their decanters are closed, and all pump and SBR control devices have failed or
have been turned off, additional overflow pipes have been added for additional protection
of the environment. These 12” pipes (shown in the attached Plans) are capable of directing
a flow greater than the capacity of the influent pumps back to the influent pump station
wet well.
This submittal includes one hard copy and one digital copy of the following:
 Engineering Calculations
 Engineering Plans
 Engineering Specifications
 Setback and Clearances Figure V-1 and Site Constraints Figures V-2 through V-4
 Structural Engineer’s Process Tank Structural Condition Assessment
Please contact me if you have any questions or require any additional information.

Sincerely,
McGILL ASSOCIATES, P.A.
Kyle Seaman, PE
Project Manager
Enclosure
Cc: Daniel Manring, TWSA (w/ electronic attachment)
Min Xiao, NCDEQ
Ken Pohlig, NCDEQ
Tesfu Tsadwa, NCDEQ