NC0064050_Approval_20220712

DocuSign Envelope ID: 6E063068-0E83-4217-A136-475142A1 A711
ROY COOPER
Governor
ELIZABETH S. BISER
Secretary
RICHARD E. ROGERS, JR.
Director
NORTH CAROLINA
Environmental Quality
Town of Apex
Attn: Lori Avent, Pretreatment Coordinator
P.O. Box 250
Apex, NC 27502
Email: [e-mail]
Dear Permittee:
7/12/2022
Subject: HWA-AT Approval
Program Name: Apex
NPDES Permit No NC0064050, 3.6 MGD
Class A Biosolids WQ0029376
Middle Creek WWTP
Wake County, RRO
The Municipal Unit of the Division of Water Resources has reviewed the Headworks Analysis
(HWA) for the Town of Apex for its wastewater treatment plant (WWTP) working under the
NPDES Permit No NC0064050 (effective on May 1, 2022). The HWA was initially received by
the Division on December 31, 2020, followed by more information received on March 29, 2022,
and June 29, 2022.
The Division concurs with the HWA calculations for all pollutants of concern, with the
observation discussed below. The approved Maximum Allowable Headworks Loadings
(MAHLs), Maximum Allowable Industrial Loadings (MAILs), and the basis for these values are
found in the enclosed HWA and Allocation Table (AT) spreadsheet, which has the updates and
corrections highlighted. Please ensure to replace or update the POTW's HWA AT spreadsheets
with this approved one.
1. HWA Observations
a. Silver has been reinstated in the HWA' s uncontrollable concentration section and the
LTMP due to the reported detections for silver.
Next HWA Due date: The HWA approved today is based on DMR/LTMP data for the period of
February 2019 through May 2022. Unless conditions at the POTW change significantly and thus
warrant an earlier submittal (see Comprehensive Guide, Chapter 5, Section B), the POTW must
submit an updated site -specific HWA by July 1, 2027 (or after the reissue of the next NPDES
permit renewal/modification. Whichever comes first).
Federal and State pretreatment regulations require the local delegated pretreatment program to
effectively control and document the discharge of wastewater from Significant/Categorical
Industrial Users to the POTW. It is the POTW' s responsibility to ensure that these objectives are
consistently met.
Thank you for your continued support of the Pretreatment Program. If you have any questions or
comments, please contact the Pretreatment Coordinator Keyes [[e-mail]], or the
Unit Supervisor, Michael, at [[e-mail]].

DocuSign Envelope ID: 6E063068-0E83-4217-A136-475142A1 A711
Sincerely,
DocuSigned by:
C464531431644FE...
for Richard E. Rogers Jr., Director
Division of Water Resources
dy/Apex.64050_HWA approval_2022
Attachments:
Apex.64050. HWA-AT.2022.approved (xlsx and pdf)
cc with attachments:
Town of Apex, Director of Water Resources/ Michael Deaton
DWR Raleigh Regional Office — Pretreatment/ Cheng Zhang
DWR - Raleigh Regional Office - Water Quality/ Scott Vinson
Municipal Unit File and Central Files (Laserfiche)