AQ_F_1300002_20180815_CEM_RptRvwLtr (3)

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ROY COOPER NORTH CAROLINA
Governor Environmental Quality
MICHAEL S.REGAN
Secretary
MICHAEL ABRACZINSKAS August 15, 2018
Director
Mr. Timothy Kiser
Engineering Director
WSACC Rocky River Regional WWTP
P.O. Box 428
Concord, NC 28025
SUBJECT: Review of 2018 Semiannual CEMS Report, First Half
WSACC Rocky River Regional WWTP
Concord, Cabarrus County,North Carolina
Permit No. 04475T20
Facility ID: 1300002
Dear Mr. Kiser:
Thank you for your timely submittal of the subject report, dated July 23, 2018, from the Water
and Sewer Authority of Cabarrus County(WSACC) Rocky River Regional Wastewater
Treatment Plant(WWTP). Additional clarification regarding monitor downtime was provided
upon request by Chad VonCannon of your staff. The report included an assessment of the total
hydrocarbon(THC)/oxygen(02) continuous emissions monitoring systems (CEMS) operating
on the sewage sludge incinerator(ID No. 1) during the first half of 2018. The Division of Air
Quality(DAQ)has completed its review and offers the following comments:
1. The report was reviewed for compliance with the THC emission limit(100 ppmvd, corrected
to 7% 02,monthly average)pursuant to 15A NCAC 02D .1204 -Sewage Sludge and Sludge
Incinerators, 40 CFR Part 503, Subpart E -Standards for the Use or Disposal of Sewage
Sludge, and Air Permit No. 04475, Specific Condition 2.1.A.5.a. There were no reported
exceedances of the THC limit.
2. A review was also conducted for compliance with proper operation and maintenance(O&M)
practices pursuant to permit Specific Conditions 2.1.A.5.e, 2.1.A.7.c, and 15A NCAC
02D .1204,which includes the monitoring provisions of 02D .0600 and 02D .0611(d). When
expressed as a percentage of the total operating time of the sewage sludge incinerator,
percent excess emissions (%EE) were reported as 0.0% for both quarters and percent monitor
downtime(%MD)was reported as 1.7% for the first quarter and 0.5% for the second quarter.
NORTH CAR'U � Y
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North Carolina Department of Environmental Quality I Division of Air Quality
217 West)ones Street 11641 Mail Service Center I Raleigh,North Carolina 27699-1641
919.707.8400

Mr. Timothy Kiser
August 15, 2018
Page 2
The THC/02 monitors appear to indicate the use of proper O&M practices since%EE and
%MD did not exceed 6% for any single calendar quarter and did not exceed 3% for two
consecutive quarters.
3. Quarterly cylinder gas audits (CGAs) were reviewed for each monitor. The quality
assurance(QA)results appear to have met the 15%accuracy requirement of 40 CFR Part
60, Appendix F—Quality Assurance Procedures, as referenced in your facility's Quality
Assurance Program(QAP) and Specific Condition 2.1.A.7.d.
If you should have any questions, please contact me at [phone] or [e-mail].
Sincerely,
Alan Drake, Environmental Engineer
Division of Air Quality, NCDEQ
c: Bruce Ingle, MRO
Gary Saunders, RCO
IBEAM Documents, 1300002
Central File, Cabarrus County