2021-2022 Annual Outfall Screening Plan

2021-2022 Outfall Screening Plan
Introduction
Outfalls in the Ellerbe Creek subwatershed will be targeted for screening work during the 2021-2022
screening season due to historically high colony counts of fecal coliform bacteria in this drainage area.
Outfall Screening Plan
Screening Goals
This session's goals were calculated based upon conditions and performance over the past five years.
o Effective — 115 structures
o Highly Effective — 145 structures
o Exemplary — 175 structures
Field Measurements
Field measurements shall be conducted in situ, according to standard procedures. Each outfall with
active discharge or a suspect pool shall have the following measurements run:
1) pH
2) temperature
3) conductivity
4) Dissolved oxygen (mg/L and saturation)
5) Ammonia
At your discretion, you may run detergents if you suspect a wastewater discharge.
Sampling and Special Projects
Routine Outfall Program Lab Sampling
All grab samples collected for analysis shall be delivered to ENCO Labs, Inc. in Cary. Sample IDs for
samples are to be the structure FID as identified in GIS.
Sample container availability will be arranged by the IDDE supervisor.
Lab samples shall be collected under the following circumstances:
1) Conductivity measures greater than 1,000 µS/cm and no other field measurement meets a
trigger
a. OR
2) A sewage discharge is identified

Lab samples must be packed on wet ice and delivered to ENCO no later than 1:00 p.m. on the day they
are collected. Samples may not be delivered on a Friday.
Canine Ship-n-Sniff Project Sampling
A sample from all discharging outfalls shall be collected in a fresh Whirl-pak bag for this study. Samples
shall be stored double -bagged (in a zip top bag) and in the WQ lab refrigerator for weekly shipment, to
be handled by the IDDE supervisor. Sample IDs shall be the structure FID identified by GIS. Sample bags
shall be labeled as follows:
• Sample ID [CS-XXXX] (where XXXX is the facility ID)
• Date of collection [MM-DD-YYYY]