NC0024911_Report_20191206

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OF BUNCOMBE COUNTY, NORTH CAROLINA
yBP U°UNTY NOP GP RECEIVED
DEC 162019
December 6, 2019 NCDEQ/DWR/NPDES
NCDEQ/Water Quality NCDEQ/Water Quality
NPDES Complex Permitting Asheville Regional Office
1617 Mail Service Center 2090 US 70 Highway
Raleigh, North Carolina 27699-1617 Swannanoa, NC 28778-8211
Re: Wastewater Treatment Optimization and Improvement Plan
NPDES Permit# NC0024911—Section A. (8) Ammonia Schedule of Compliance
Dear Sir/Madam:
This report is written to maintain compliance with Metropolitan Sewerage District (MSD) of
Buncombe County's NPDES discharge permit issued October 1, 2018. Section A. (8) [Ammonia
Schedule of Compliance] of the NPDES Permit requires submission of a Wastewater Treatment
Optimization and Improvement Plan by December 31, 2019. The Plan must define steps being
taken by MSD to achieve the future ammonia limits as defined in Section A. (1) of the permit.
As outlined below, compliance will be achieved by following sound engineering design,
permitting, bidding, planning, scheduling and construction practices. These tasks will be
incorporated with operational strategies and sampling protocols to attain the October 1, 2030
ammonia limits deadline. The following items satisfy the requirements of reporting:
• MSD issued a Notice to Proceed for the new Water Reclamation Facility (WRF)
Headworks Improvements project on April 3, 2018. The headworks improvements
provide improved screening and grit removal at the plant, and a significant reduction
in solids deposition in the downstream biological basins. The result is increased
treatment volume and hydraulic residence time (HRT).
Prior to the project, the existing climber screens passed a significant amount of rags
and large debris that caused maintenance problems for downstream processes and
impacted the ability of these processes to perform at their peak efficiency. The poor
performance of the grit and grease removal facility also contributed to the
aforementioned maintenance problems and have been upgraded as well.
In addition, the existing abandoned anaerobic digester tanks were utilized for
emergency storage to allow peak flow mitigation during storm events. Equalizing
flow through the plant provides a more stable, reliable treatment system.
-Protecting Our Natural Resources-
2028 RIVERSIDE DRIVE, ASHEVILLE,NORTH CAROLINA 28804 TELEPHONE:[phone] FAX:[phone] WEBSITE:www.msdbc.org

The Headworks Improvements project included the following:
• Replacement of the existing 3/" influent climber screens with new 1/2"
traveling rake type screens.
• A new X" fine screening facility to be used in conjunction with the new
coarse influent screens
• A new vortex grit removal facility
• A new surge pumping station utilizing the existing out of service digesters for
4.2 MG of wet-weather storage
• A flow split/diversion structure that will serve as a point of return for flow
from the surge pumping station, and will be utilized in the Phase 2 upgrade
to tie-in to the new high rate primary treatment process. The diversion
structure will also facilitate maintenance of plant operations during
construction of the HRPT system.
• Demolition of the existing grit and grease removal facility.
• It should be noted that this upgrade raised the plant hydraulic grade line in
preparation for future plant upgrades. To allow this, MSD replaced their existing
pump impellers with a higher impeller trim as part of their normal pump
maintenance/replacement cycle. This project improved reliability of plant
equipment and reduced equipment maintenance, improved overall operational
efficiency, helped extend the lives of the existing RBCs, and established the hydraulic
profile for the planned future upgrades. This project did not change plant design
flowrate, biological treatment processes, filtration, disinfection, or solids handling at
the existing facility. The new WRF headworks was placed in service February 19,
2019.
• The volume of screenable and settleable material removed from the bar screens,
fine screens and vortex grit removal systems are measured and recorded for
comparison to historical data. (see attached graph)
• NPDES influent and effluent compliance sampling are conducted per the Permit
which for this annual report are adequate. A new sampling point will be established
beginning January 1, 2020 at the splitter box located north of the vortex grit removal
system prior to entering Rotating Biological Contractor (RBC) Basin number one (1).
This location is the influent for the High Rate Primary Clarifier (HRPC) when
construction is completed. The samples will be collected on a weekly basis for NH3-
N, total N, total BOD and soluble BOD.
• The sampling of NH3-N, total N, total BOD and soluble BOD will continue as specified
in the Ammonia Schedule for Compliance as outlined in the NPDES Permit. (Copy of
Ammonia Schedule of Compliance attached for you convenience)
• The optimization and improvements will be reported annually as construction
projects are completed and sampling results are summarized. The overall
optimization of the WRF will be achieved through operational strategies, sampling
analysis and planned construction project completion.

• Shook Construction is the General Contractor for the new High Rate Primary
Treatment (HRPT) project. The HRPT project Notice to Proceed was issued January
7, 2019 with a contract completion date of January 9,2021.
If there are questions or concerns regarding this report please, do hesitate to contact Roger
Edwards, Water Reclamation Facility ORC, at [e-mail] or 828-225-8224.
Sincere) ,
d
Thomas E. Hartye, PE
General Manager
MSD of Buncombe County

Grit Removal Daily Average
80
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60 -
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150
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20
10
Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sept Oct
2018 2018 2018 2018 2018 2018 2018 2018 2018 2018 2018 2018 2019 2019 2019 2019 2019 2019 2019 2019 2019 2019
•Schreiber System ■Pista Grit

Permit NC0024911
submit the modified plan to DWR Ashville Regional Office for approval,and submit the approved Sampling Plan
to the Division at the following address:
NCDEQ/Water Quality
NPDES Complex Permitting
1617 Mail Service Center
Raleigh,NC 27699-1617
A. (7) ASH STORAGE LAGOON
MSD Buncombe is permitted to operate a 17-acre lagoon for the purpose of storing incinerator ash. Effluent from
this lagoon is sent to the head of the plant for treatment. No other materials may be stored in the lagoon without
prior Division notification and approval.
A. (8) AMMONIA SCHEDULE OF COMPLIANCE
[G.S. 143-215.1(b)]
In accordance with Federal Regulations 40 CFR 122.47 the permit shall specify interim dates for the submission of
reports of progress toward completion of the interim requirements and indicate a projected completion date. The
Permittee shall submit the following interim reports until the new ammonia-nitrogen limitations specified in
Section A.(1)Effluent Limitations and Monitoring Requirements become effective by October 1,2030.
1. By December 31,2019,the Permittee shall submit a Wastewater Treatment Optimization and Improvement
Plan to define the steps to be taken to achieve the ammonia limits.The Permittee shall also commence
construction of the High Rate Primary Treatment improvement system;
2. By December 31,2020,the Permittee shall submit a progress report summarizing the Headworks
performance testing,and the status of the optimization and improvements plan.Testing to include NH3-N,
Total N,Total BOD,and Soluble BOD at influent and effluent locations;
3. By December 31,2021,the Permittee shall complete the installation of the High Rate Primary Treatment
system,and initiate performance testing.Testing to include NH3-N,Total N,Total BOD,and Soluble BOD
at influent and effluent locations.The Permittee shall submit a progress report confirming installation and
the status of the optimization and improvements plan;
4. By December 31,2022,the Permittee shall continue High Rate Primary Treatment performance testing and
begin the Biological Treatment consultant selection.Testing to include NH3-N,Total N,Total BOD,and
Soluble BOD at influent and effluent locations.The Permittee shall submit a progress report on
performance testing results and the status of the optimization and improvements plan;
5. By December 31,2023,the Permittee shall complete High Rate Primary Treatment system performance
testing,and begin Biological Treatment Alternatives Evaluation.The Permittee shall submit final results on
the performance testing, and the status of the optimization and improvements plan.Testing to include NH3-
N,Total N,Total BOD,and Soluble BOD at influent and effluent locations;
6. By December 31,2024,the Permittee shall submit a completed Biological Treatment Alternative
Evaluation report including the chosen alternative along with a design and construction timeline and
specific steps to be taken to achieve the ammonia-nitrogen limits;
7. By December 31,2025,the Permittee shall submit an annual report identifying the steps that have been
taken and the progress towards completing the Biological Treatment design;
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