NC0026051_Performance Annual Report (July 2023-June 2024)_20240828

DURHAM , •
COUNTY
O •
NC
1 1 �
Triangle Wastewater + 1
Treatment Plant
5926 NC Hwy. 55 E.
Durham, NC 27713 ID YOU KNOW there is a North Carolina law that mandates underground
[phone] utilities to be located before any excavation occurs?
NC General Statute Chapter 87, Article 8A, Damaged Pipes E
Permits: requires existing facilities be identified in T-,.•-UU9
•
T-100
Wastewater advance of any excavation in North Carolina.
Treatment Plant: The reason being, many utilities
NCO026051 provided to you, such as water,
sewer, cable, gas, etc. are often
buried underground close to the /
Collection System: -
surface. The law requires a notifica- ..,
WQCS00038 . • r� .- .
tion prior to digging to NC811,
which will alert utility owners in that
stormwater: area so they can be located and 'NCG110054 marked prior to any digging. ' •'
Reclaimed Water: Durham County Utilities has ,. .
wQ0032821 dedicated staff that locates County ' '
owned utilities so contractors, home
Owned and Operated
by: + • UNIFORM COLOR CODE
FOR MARKING UNDERGROUND
Durham County • • • OR
•••. •EXCAVATION
Engineering 4
GNAL LINES,CABLES OR CONDUIT
& • ••. POTABLE
Environmental Services MARKINGS 0 1 and business owners, etc.
RECLAIMEDELECTRIC POWER LINES,CABLE IRRIGATION,
Utilities Division 0 CONDUIT AND LIGHTING CABLF,, AND SLURRY LINES know where to excavate safely.
• • .• Sometimes this is not the case,
GASEOUS OR and lines may be damaged
Contact: For all locate requests,call Need that can result in sanitary
Stephanie Brixey 911 or ' •'• ' ' sewer overflows (SSO) and
Deputy Director • . Resources . . costly repairs. Often, County
staff determine sewer pipes
have been affected by watching videos taken within the pipe. If the responsible party
cannot be determined, repairs are paid for by the County which may result in higher
sewer and water rates for customers.

Collection System
Projects &
urham County owns and maintains a
wastewater collection system which includes Rehabilitation
110 miles of gravity sewer, 11 miles of pres-
surized force mains, and 13 lift stations.
In the past 12 months Durham County had two hroughout the last year, the County has
reportable sewer spills. continued its efforts to rehabilitate aging
On July 26, 2023, a spill estimated at 5,000 gallons collection system infrastructure and
• of wastewater occurred because of a blockage in increase sanitary sewer capacity to facilitate
the line. economic growth in our service area.
• September 1, 2023, a spill estimated at 180 gallons
of wastewater occurred at a step system in the zz> Replaced 500 linear feet of 16" DIP force main with
Wexford Development due to a broken discharge 16" PVC on Hopson Road.
line. => Lake Park Lift Station was rehabilitated.
Durham County Utilities prides itself on providing a => Bypass connections were installed at Page Park and
high level of customer service. All commercial, indus- Fairfield Lift Stations.
trial, and residential customers' questions and concerns => Six manholes were rehabilitated.
are responded to in a timely manner. If you have a
question or concern regarding the collection system, => TWWTP BNR Train #3 - Cleaned the interior basin,
services, or any item covered in this report, please call repaired the seams, replaced the flapper valves,
[phone] or send an e-mail to [e-mail]. installed two new adjustable weirs, and four new
rotors with variable frequency drives.
Aim*
' .. :- �•
4W
Reclaimed Water
r
t
• r,H
include:(TWWTP) operates a reclaimed water
system. Some of the uses of this water
irrigation, .. •
industrialprocess •
Approximatelygallons of reclaimed
water was distributed to customers during theBiosolids System
averageThe reclaimed water annual .. is
reflected the - ,.- •, . -• T WWTP generates biological residuals
• following: 1 (approximately 6,389 wet tons per year), which are
• Fecal • • 00 ml dewatered by centrifuges. The dewatered cake
Turbidity:• 60 NTU (approximately 1 ,213 dry tons per year) is transport-
- Total • Chlorine: • ed to McGill Environmental Systems, where it under-
goes further biological treatment to produce a Class
There were no reportable reclaimed water A biosolid. These biosolids are beneficially used as
spills ..st12 months . m soil amendments in commercial landscaping and
agricultural activities.

Ultraviolet(UV)System
Treatment System & Process
The Influent Pump Station (IPS) is used to pump raw wastewater
(sewage) to the treatment process to be biologically treated. The IPS is
sized for 12 million gallons per day average flow.
• • The Fine Screens are used to remove fine materials from the wastewater
such as grit, sand, egg shells, etc. All of the organic materials are washed
off and used in the biological treatment process.
The Five Stage Biological Nutrient System is where all biological treatment
takes place, such as removing ammonia through nitrification and
denitrification processes as well as the removal of phosphorus.
The Chemical Polishing process removes any phosphorus that is remaining
after the biological treatment process. Methanol is used in this polishing
process to add additional BOD to support the denitrification treatment
process.
The Clarifiers are where the biomass is separated from the treated
wastewater and then is returned to the BNR for further treatment.
' The Tertiary Filters are next in the clarification process which removes all
Aerator remaining unsettled biomass in the treatment process.
JL
The Ultraviolet Disinfection
treatment process is used to
remove all disease causing
Jill U
• . ' • •
bacteria without creating
harmful by-products.
5.0mg/I Monthly Avg.Permit Limit 200cfu/100ml Monthly Avg.Permit Limit
The Reaeration stage of the
treatment process adds
<2.0mg/I 2 cfu/100 m1 dissolved oxygen to the treated
wastewater to meet required
BIOCHEMICAL OXYGEN DEMAND FECAL COLIFORM permit limits before it is
discharged to Northeast Creek.
30 mg/I Monthly Avg.Permit Limit 1.0 mg/I Monthly Avg.Permit Limit
Clarifier
i
<2.5mg/I <0A0mg/I
TOTAL SUSPENDED SOLIDS AMMONIA-NITROGEN
� 1
111,207lbs.Annual Permit Load Limit 8,432lbs.Annual Permit Load Limit
55,492lbs.
TOTAL NITROGEN TOTAL PHOSPHORUS

Auqust 31,2024
Lab Notification:
• This Performance Annual
• Report covering July 1,
• 2023 through June 30,
2024, was forwarded to
the NC Department of
Triangle Wastewater Treatment Environmental Quality.
Public Notice of the report
Plant's (TWWTP) laboratory staff was advertised in the
• " �` • Durham Herald Sun
Collects and analyzes wastewater _ .. newspaper and is availa-
samples as required by the NPDES ble for review at the
•• � •• • •permit and the reclaimed water permit. following locations:_ _ _
Currently, the laboratory is certified by • _ _ - • _
the Division of Water Resources •_• ~_~ _ _• Clerk to the Board
• •• • •• •Laboratory Certification Branch to 200 East Main St.
_
analyze ammonia, biochemical oxygen
demand, total residual chlorine, Main Library
conductivity, dissolved oxygen, fecal 300 N.Roxboro St
coliform, pH, temperature, and total
suspended solids. Staff determines the
• :. - • • r . - South Regional Library
age and health of the activated sludge 4505 S.Alston Ave.
and identifies microorganisms, such as
amoebae, bacteria, ciliates, flagellates,
- - - i •- -• - - . • - Website
nematodes, rot hers, and water bears.
• • •" www.dconc.gov/utilities
-• • • - C •+, - Certification:
Fats, >Rags Oil 1 certify under penalty of law
••• • • • that this report is complete and
& Grease accurate to the best of my
• , , - • • • • •_ • knowledge. I further certify that
this report has been made
isposing of Fats, Rags, available to the users or cus-
Oils, and Grease (FROG) > t' tomers of the named system
down the drain or toilets + and that those users have
causes build up inside pipes and tI i been notified of its availability.
could result in a complete
blockage.Clogged pipes overflow
in your home and in the
environment resulting in costly ` Stephanie Brixe
maintenance and repairs to Deputy Director
residents. - • •
...- . - • W. .. - .- - .. • . -
F �
Pipe with Congealed F.O.G. _ - -• - •. • • .•- •• -• •• I • .•