HomeMy WebLinkAboutWQCS00060_NOV-2022-DV-0271 Rsp_20220930Johnston County
DEPARTMENT OF PUBLIC UTILITIES
PO BOX 2263
SMITHFIELD, NC 27577
(919) 989-5075
September 30, 2022
Mr. Scott Vinson
Raleigh Regional Office
NCDEQ DWR
1628 Mail Service Center
Raleigh, NC 27699-1628
Re: Response to NOV-2022-DV-0271
Permit No. WQCS00060 - Johnston County Collection System
Dear Mr. Vinson:
In response to NOV-2022-DV-0271, the County offers the following information:
Incident Number 202201300:
Staff at Johnston County Public Utilities received a call at approximately 10:45 am on August 16,
2022 about a potential sewer main leak in the vicinity of 2677-2745 US Hwy 70 W, Smithfield,
NC.
Johnston County staff immediately responded and shut-off the multiple pumps pumping into
the force main on US Hwy 70 stopping the sewer spill. The spill ended at 12:31 pm.
County staff excavated the force main and determined the spill was caused by material failure of
the 12 year old ductile iron 20” force main.
The spill was recovered by vacuum truck to the extent possible, and staff lightly limed the area.
While the force main was shut-down upstream pump stations remained off and pumper trucks
were used to pump and haul until the repair was completed and the force main was placed back
in service. In addition, an industrial customer utilized available equalization storage during the
repair.
County staff removed and replaced the failed ductile iron pipe with C905 PVC pipe.
The accidental and unintentional spill was a result of ductile iron pipe failure of the force main
pipe material.
The County has a project in our approved 2022 Capital Improvements Plan to replace this force
main due to past failures of sections of DIP on this main. However, due to the recent failure, the
County plans to modify the plan and begin replacement of the most critical ductile iron sections
as soon as possible. The County has advertised a Request for Qualifications for “On-Call” Water
and Sewer Main Repairs and has an engineering firm on stand-by to assist with the project, as
needed. Furthermore, the County has some funds already allocated to sewer main
rehabilitation/replacement.
Johnston County works aggressively to prevent sanitary sewer overflows and help protect the waters of
our area. Preventative measures include the following:
All air release valves along this force main was inspected on March 22, 2022.
Page 2
Mr. Vinson
September 30, 2022
Extensive staff training ensures staff is prepared for system operation and response related to
potential sewer spills.
Updated County construction standards have been updated to minimize the use of ductile iron
pipe within the County’s sewer system. All ductile iron pipe installed contains an interior
corrosion resistant interior coating.
Staff use laptops to log into the SCADA system and monitor system operation from any location.
Furthermore, staff is on-call and prepared to respond to any event.
The County maintains an in-house supply of repair materials for all pipe sizes and many
electrical components and implements a detailed protocol for emergency response.
The County maintains a close working relationship with several local contractors who provide
emergency response repairs, as needed.
Johnston County takes seriously our responsibility to protect public health and the environment and
strives to prevent sewer spills. Please contact me at (919) 209-8333 or
chandra.farmer@johnstonnc.com if you have any questions or need additional information regarding
this issue.
Sincerely,
Chandra C. Farmer, PE
Director of Utilities
cc: Rick J. Hester, County Manager
Eric Narron, Johnston County
Vanessa Manuel, Raleigh Regional Office
Mitchell Hayes, Raleigh Regional Office