NC0069761_Response to Notice_20240723

Permit No. NC0069761
Pond Creek WWTP
Watauga County

May 2024 Nitrogen, Ammonia Total Monthly Average Exceeded
NOV-2024-LV-0646

Mr. Snider,

I have received the NOV for ammonia as listed above.  The Pond Creek WWTP had a major mechanical failure of the air lift line in the primary clarifier unit.  This required the full shutdown
and draining of the primary unit to make repair some 16 feet underwater.  The work for repairs began the second week of May 2024 and were completed and return to service was achieved
July 5th, 2024.  Photo and documents attached.

The was the end result of a problem presenting in March of 2024 at which time the aeration basin and clarifier unit were essentially interconnected resulting in poor treatment in the
clarifier unit.  We took action quickly, identified the issue, contracted the repairs and finished repairs as quickly as possible.   In the between time we had to alter our normal treatment
process and route through makeshift aeration to the secondary clarifier so we could work in the primary clarifier as we do not have a redundant system built in to bypass the primary.
 I reached out to Ron Boone on 3/21/2024 with notification of the situation via email and through telephone conversation in accordance with Condition 6 in Section E. 

The failure in the plant was found to be a catastrophic failure (complete pipe burst) of the 6” hydro-pneumatic lift for clarifier solids to return inside of the aeration basin allowing
the two tanks to transfer water.  Cause of the pipe failure is not clear as it showed no sign of corrosion damage, although a large pipe section broke free. (pictured)  Work in the
unit required many days of shutdown, alternative treatment and contract work effort at a large expense to the town.  As the NOV included the intent to assess civil penalty, I would
ask that this be considered.  I am attaching the cost already paid to make this repair by the town to remediate the primary clarifier.  During the process of repairs we also identified
a point that we could install additional valve works that will allow us to work in this basin in the future with less lead time for shutdown of the primary clarifier and allow for in
house repair in lieu of requiring a contractor.

This is the second monthly NOV consecutive beginning in April 2024 during which planning and contracting for repairs were underway. The final repair was completed in the last week of
July 5th, 2024.

All of these things said, the problem has now been corrected, the plant has returned to normal operation, and I expect no further issues with compliance. 

Thank you,

Daniel Davis
Director of Utilities
108 Bark Park Way
Beech Mtn, NC, 28604
[e-mail]
Office 828-387-9282

Attachments: see below

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