2018-2019 Annual Outfall Screening Plan

FY 2018-2019 Outfall Screening Plan
Introduction
Northeast Creek will be targeted initially and for the majority of screening work during FY 2018-2019,
because the watershed has a Total Maximum Daily Load (TMDL) developed by the NC DWR due to
exceedances of the NC water quality standard for fecal coliform bacteria.
The City of Durham has collected data from three ambient stream monitoring stations in this watershed.
1. NE1.2NE: Northeast Creek at NC Hwy 54
2. NEO.ONE: Northeast Creek at Sedwick Road
3. NE2.2NP: Northeast Creek at Meridian Parkway
During the period 2007 through 2016, ambient monitoring results show that all three sites had greater
than 20% of samples with values in excess of 400 cfu/100mL. The NC water quality standard for fecal
coliform bacteria is: for five consecutive samples taken in a 30-day period, the geometric mean shall not
exceed 200 cfu/100mL and no more than 20% of the samples shall exceed 400 cfu/100mL. One station,
NE1.2NE, showed a significant trend of increasing fecal coliform bacteria concentrations. There was no
significant trend observed for the other two stations.
Summer 2018 Outfall Screening
For the period July 1 through August 31, 2018, the outfall screening team goal requires 25 screenings.
Summer screening will begin with outfalls discharging into the NE1.2NE catchment area and be
complete once the summer screening goal is reached. A preliminary survey of the GIS outfall dataset
suggests that this catchment has 50 available outfalls.
Winter 2018-2019 Outfall Screening
Outfall Screening Methods
Investigation and Lab Sample Collection Triggers
Table 1. Lab sample conductivity triggers for FY2018-2019.
Conductivity Triggers

Summer 2018 Winter 2018-2019
800 µS/cm 1,000 µS/cm
No Is outfall flowing? Yes
Are there indicators Calculate flow rate
N of pollution?H-
No
Condud Water Is conductivity a
fuller action Quality Investigation No 800 (summer) Ye
1,000 (winter)
PS/cm')
Called lab samples
Are any other field from ouflall
No- measurements (pH, Yes (Nutrients, Fecal,
NH3, etc.) at GODS, Wetals, TSS)
triggers?
Conduct ther field
No further action ents (pH,at triggers?
If Sewage Discharge: No
I i
Collect lab samples Await Ia0 results to
from outfall tletermine if Water
(Nutrients, Fecal, Quality Investigation
Ammonia, Nitrate+Nitrite necessary
TKN,TP)
Figure 1. Flowchart for directing investigation or lab sample collection during outfall screening.

NU[UledbL ldtl t�K VULldll IVldp LU 10-LU lt�
N/ � _ . _ J t _ - 1
TF4.4TC
�1 1 RC
�` JJ OTF5.31RC
O
O -
TF3.4TCAo
p e !" •�
Third Fork Cre° o 0°0°oTF2.5TCTC O 0® Oo o e
6I ®o
0
00 O
O %
0
to Oo 0 0
/ 0 °
°° o
i °
� 1/�,�
OB O O m
00NE2.2NP
O 00 Oo p0 o orthbast Creek
p p NE1.2NE
O 0.00
O 00O °SI1.6SIC
° o0 O
00
YO O 8 °OL O°O NE&ONEOO 0O
p 0CI'B
&� tr m
reek m sed O6 Vdis 201 a-291 F-W
• DurhamAmhient LAKE; RESERVOIR
RIVER 0 0.5 1 2 Miles
QNortheast Creek WatershedI I I I I I I I I
O Storm Sewersheds -_-' SWAMP
- Streams
City Lim its
RTP Roads
Mounty Boundary
Figure 2. Stormwater discharge outfalls located in the Northeast Creek watershed. Spatial data as of 6/5/2018.