NC0026051_Performance Report_20140902

The Durham County Collection System consists of gravity sewer lines, pump stations, and forcemains to
transport wastewater to the treatment plant. Durham County currently owns and maintains approxi-
mately 95 miles of sewer main with twelve pump stations. In the post 12 months, Durham County had
only one (1 ) reportable spill from a debris blockage which caused 3S0 gallons of sewage to spill into an
unnamed tributary of Northeast Creek. The line was cleaned and returned to normal operation.
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r74 NCAW'WA -WEA Collec-
tZf -� tion System of The Year Award
�rAA' recognizes utilities that protect
► �OLyFit
TIOV the public health and the natural
of IFI F beauty of the environment
` Ot 7 8
%w �RU through pro
- active practices of man-
agement, operations and mainte-
nance b4 tirond what is required of its
North Carolina Department of Environment
and Natural Resources collection system permit. Award
recipients have demonstrated that they have performed
quality collections system maintenance procedures and
innovative methods to keep its collection system in good
working condition. Examples of the innovative collection
system methods used by Durham County include a Geographical Information System
based asset management system and a comprehensive analysis of all manhole top eleva-
tions and their respective flood elevations.
It r the post year, the County Initiated a program to raise the manhole tops t
feet above the 100 year future condition base flood elevation. This on -going proje
reduces inflow of storm water into the collection system. Twelve manholes were rais
in the last year and positive results have already been seen.
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Triangle Wastewater Treatment Plant operates and maintains a 5.2 MGD recycled water system. The use of
recycled water can save a high percentage of the potable water used for non - potable purposes in the community. Some of
the uses of recycled water include landscape irrigation, industrial cooling, in-
Recycled Water Pump Station
dustrial process water and sewer cleaning. Within the Triangle Wastewater
Treatment Plant recycled water is used for a variety of purposes including
toilet flushing, the HVAC system in the administration building, power wash-
ing and yard hydrants. The recycled water system consists of the following
components: four turbine pumps, a hydropneumatic tank, a 500,000 gallon
storage tank. instrumentation and metering, a dual disinfection system and a
distribution system. The distribution system includes continuous monitoring
of chlorine, pressure and flow. Approximately 45.2 million gallons of recycled
water was distributed to customers during the fiscal year.
Treatment Systems
New Sludge Handling Facility
"7he TWWTP discliargle was compliant In all sampling events for the
pastyear, while treating almost 2.5 billion gallons of wastewater. "
Influent Pump Station - sized for 12 MGD average
flow, and located 2' above the 100 year flood eleva-
tion to reduce flooding risk.
Fine Screens - removes insoluble materials larger
than 114" prior to the beginning of the treatment
process.
Grit Removal - removes small dense inorganic mate-
rials prior to the beginning of the treatment process.
Five Stage Biological Nutrient Removal System -
provides the ability to biologically remove nitrogen
and phosphorous during treatment with carbon
source addition.
Chemical Polishing - sodium aluminate is used to
remove additional phosphorus from water by chemi-
cal precipitation.
Clarifiers - quiescent zone where biomass is separat-
ed from treated water.
Tertiary Filters - filtering to remove additional bio-
mass.
Ultraviolet Disinfection - disinfection process with-
out harmful by- products.
Reaeration - supplemental dissolved oxygen provid-
ed prior to discharge to Northeast Creek.
Effluent Annual Average Data
BIOCHEMICAL OXYGEN DEMAND (BOO s)
i . I - I
2.0 mg/I
(5.0 mg/1) Monthly Avg. Permit Limit
FEG4L COLIFORM
4.5 cfu /100ml
(200 cfu /100ml) Monthly Avg. Permit Limit
TOTAL SUSPENDED SOLIDS AMMONIA- NITROGEN
I < 2.5 mg/I 0.1 mg/1
(30 mg/1) Monthly Avg. Permit Limit (1.0 mg /I) MonthlyAvg. Permit Limit
TOTAL NITROGEN TOTAL PHOSPHORUS
90,073 lbs. 3,762 lbs.
(111,207 lbs.) Annual Permit Load Limit (8,432 lbs.) Annual Permit Load Limit

August 31, 2014
Notification:
This Performance Annual Report
covering July I, 2013 through June
30, 2014, was forwarded to the NC
Department of Environment and
Natural Resources. Public notice of
the report was advertised in the
Durham Herald Sun newspaper and
is available for review at the fol
lowing locations:
Durham County Clerk To The Boarc
200 East Main Street, 2nd Floor
Durham County Main Library
300 North Roxboro Street
Durham. NC
Durham County South Regional Librar.
4SOS S. Alston Avenue
Durham, NC
Durham County Website :
www.dconc.gov
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Certification:
I certify under penalty of law
that this report is complete and
accurate to the best of my
knowledge. I further certify that
this report has been made available
to the users or customers of the
named system and that those users
have been notified of its availability.
Joseph R. Pearce, P.E.
Utility Division Manager
Engineering and Environmental
Services Depar* men,
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Lab : Pretreatment Program
The Triangle Wastewater Treatment Plant's ( TWWTP) laboratory staff collects and
analyzes wastewater samples as required by the NPDES permit and the Recycled Wa-
ter permit. Currently, the laboratory is certified by the Division of Water Resources
Laboratory Certification Branch to analyze ammonia, biochemical oxygen demand,
to
residual chlorine, conductivity, dissolved oxygen, fecal coliform, pH, temperature,
and total suspended solids.
The TWWTP implements an Industrial Pretreatment Program (IPP) to control pollu-
tants which may cause pass through or interfere with the treatment plant's' processes,
which may contaminate sewage sludge, or potentially be hazardous to workers health
and safety. Currently there are forty -eight permitted industries that are regularly in-
spected and monitored to ensure their discharges meet specific permit limits. Thir-
teen of these industries are Significant Industrial Users (SIUs).
or
I Extension of Recycled Water System: The first phase of the recycled water system h
been installed. The next phase will extend the distribution system further north to BASF a
terminating at the Research Triangle Park Phase One Redevelopment site. Future phases
extend the distribution system under Interstate 40 to RTI, IBM and the Research Trion
Park Phase Two Redevelopment site.
Waste to Energy: Wastewater treatment residual biomass is currently being dewatered
offsite composting into a Class A biosolid. Alternatives to use this biomass in a more sustai
able manner will be considered. Alternatives which may be considered include: thermophi
anaerobic digestion, hydrolysis, active solar drying, waste to energy conversion, or a combing-
tion of these alternatives. A
All photographs used in this report are not to be republished without Durham County approval.
Triangle Wastewater
Treatment Plant
5926 NC Hwy. 55 E.
Durham, NC 27713
(919) 560 -9033
I
Permits:
r
Wastewater
Treatment Plant:
NCO026051
J
Collection System:
I
WQCS00038
s
Stormwater :
NCG 110054
Reclaimed Water:
i WQ0032821
I'
Owned and Operated
s by:
i
Durham County
Engineering
&
r
Environmental Services
p Utility Division
Contact:
Ir Joseph R. Pearce, P.E.
Utility
Division Manager
(919) 560 -9035
1
RECEIVEDIDENRIDINR
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Durham County watt, .audoty
Permitti Section
Triangle Wastewater Treatment Pant
Performance Annual Report
July 2013— June 2014
the Durham County wastewater collection and treatment system serves over 10, 000 res-
idential, commercial, and industrial customers in Southeast Durham County,
ittrluding the Research Trian,Qle Park.
Environmental Stewardship is a goal of Durham County's Strategic Plan.
Our Environmental Stewardship is exemplified by:
A treated wastewater discharge in compliance
includes the future Jordan Lake nutrient load limits;
A US Geological Survey report on small North Carolina watersheds which credits a
64% reduction in the nitrogen load in the Northeast Creek watershed to
improvements at the facility,
The production and distribution of reuse water for non - potable purposes, including
cooling tower make -up water and landscape irrigation;
On -site dewatering of a wastewater treatment byproduct (waste activated sludge)
and stabilization at McGill Environmental Systems to produce a Class A compost for
agricultural and landscape use; and
A "Collection System of the Year Award" from the NC AWWA -WEA, related to
innovative methods for sewer maintenance and rehabilitation.