NC0024911_NOV-2019-PC-0083 Response_20190301

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Metropolitan Sewerage District
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OF BUNCOMBE COUNTY, NORTH CAROLINA
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March 1, 2019
G. Landon Davidson, P.G.
Regional Supervisor —Asheville Regional Office
Water Quality Regional Operations Section
NCDEQ— Division of Water Resources
2090 U.S. Hwy. 70
Swannanoa, N.C. 28711
Dear Mr. Davidson:
We received your correspondence regarding the December 21, 2018, bypass on Thursday, February 21, 2019.
Regarding Permit condition Part II.C.4.c.1; this bypass occurred during a heavy rain event when the 180 square
mile service area was previously saturated from prior rainfall events. The French Broad River was flowing
approximately 12,000 cu. ft. /sec (90,000 gallons per second) at the time of the bypass and occurred at the
Grit/Grease (Schreiber system) removal process. The reported bypassed amount represented a small percentage
of the total wastewater being pumped at the time and an extremely small percentage of our receiving stream
(less than 0.000004% of the French Broad River flowrate). The wastewater, in this case, had been screened
through % inch bar screen equipment prior to entering the Schreiber system and no immediate or on -going
harmful effect was noticed. The slide gate for one of the grit removal channels was damaged in attempting to fully
open it (a downward push instead of an upward pull is employed to operate this gate). Photos taken show how
the threaded stem bent under the pressure with a net result of being only partially opened. The restricted flow
created by this partially opened slide gate forced a rise in water level resulting in some water exiting relief ports
that had never been breached.
At that time, final phase for new headworks construction to replace this system was underway (the Schreiber
system was permanently taken offline on February 5th). The same location occurrence can never reoccur due to
the complete replacement of the grit removal/headworks system. The new $10 million system consisting of three
(3) separate six -millimeter fine screens, two (2) vortex grit removal systems and a two (2) 2.1-million gallon surge
tanks is part of an extensive effort and investment by MSD to rehab and improve treatment. The new headworks
is on-line at the time of this letter and the old system is in process of being demolished.
Permit Condition Part ILE. 6. a: 24-hour reporting. We failed to make the 24-hour oral report as required by this
regulation. This was an oversight simply due to the Christmas Holiday season. This should not have happened and
would not have happened should it not have been the holidays. Everyone experiences staff on leave during the
holidays and when something out of the ordinary occurs the issue is dealt with and the details are sometimes
missed. This detail was missed however, no environmental damage occurred due to the failure to make this phone
call.
Sini'�PjeIy,
Peter C. Weed
Director of Treatment, MSD
Cc: Thomas E. Hartye, P. E.
Division of Wator Resoul
MAR - 1 2019 -
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Water Quatfir Rppional operations
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Protecting Our Natural Resources -
2028 RIVERSIDE DRIVE, ASHEVILLE, NORTH CAROLINA28804 TELEPHONE: [phone] FAX: [phone] WEBSITE: www.msdbc.org