NCG030504_Outfall Update_20230510

SwSG Stormwater Services Group, LLC
8916 Oregon Inlet Court
Raleigh, North Carolina 27603
Phone: [phone]
Fax: 919.661.810S
May 8, 2023 RECEIVED
MAY 10 2023
Mike Lawyer
Stormwater Permits Supervisor DEMLR-Stormwater Program
NCDEQ/DEMLR
1612 MSC
Raleigh NC 27699-1612
RE: Flowserve USA Inc
NPDES General Permit NCG030504
Elimination of SDO-005
Dear Mr. Lawyer:
By this letter, we are notifying NCDEQ/DEMLR, that the Permittee is eliminating SDO-005 as
a location subject to outfall monitoring.
SDO-0051 was designated as an outfall by one of your field inspectors in late 2017. However,
this "outfall" does not discharge into waters of the State.
SDO-005 is at the end of a curb & gutter which discharges into a wooded area on Flowserve's
property (see Figure 1). There is no defined conveyance that meets the definition of Point
Source Discharge of Stormwater as indicated in General Permit NCG030000. The flow from the
end of the SDO-005 gutter disperses into this wooded area as sheetflow.
The sheetflow from SDO-005 commingles with the flow in the SDO-002 conveyance east of the
public greenway (see Figure 2). The SDO-002 sample collection point is at the end of a pipe
passing under the greenway (see Figure 3)which discharges into Walnut Creek.
The industrial activity within the SDO-002 drainage area includes the same as within the SDO-
005 drainage area. Prior to the NCDEQ inspector making his designation, neither the Permittee
nor this Consultant ever considered that SDO-005 would be a separate outfall. We believe some
erroneous assumptions were made when this additional outfall was designated.
Map 1 is enclosed to show the outfalls in question.
' The label "SDO-005"follows the outfall numbering scheme established by the Permittee in 2005.

NCDEQ/DEMLR wQG
May 8, 2023 S S
Page 2
Therefore, in accordance with General Permit NCG030000 Part H Section H-3, we are providing
notification of this change to eliminate SDO-005 as an outfall subject to monitoring.
In the meantime, if you have any questions, do not hesitate to call us.
S' ely,
TO S ERVICEs GROUP, LLC
ames D. Frei
Project Manager
cc: Adams Moraldnyo, Flowserve
File

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Open conveyance is downstream from pipe outlet.
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Map 1 —Partial Site Plan
North is at Top of Plan.