NCS000542_Henderson IDDE Plan_20220504

Illicit Discharge
Detection and
Elimination Plan
City of Henderson, North Carolina
March 2022 – FINAL
IDDE Plan Project Number: 60666154
March 2022 AECOM
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Quality Information
Prepared by Checked by Verified by Approved by
Kirstin Szogas, EIT Laurie Ruhlmann, EIT Alaina Armel, PE Alaina Armel, PE
AECOM Technical Services
Revision History
Revision Revision date Details Authorized Name Position
Distribution List
# Hard Copies PDF Required Association / Company Name
0 1 City of Henderson
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Prepared for:
City of Henderson
900 S. Beckford Drive
Henderson, NC 27536
Prepared by:
AECOM Technical Services
5438 Wade Park Boulevard
Suite 200
Raleigh, NC 27607
www.aecom.com
Copyright © 2022 by AECOM
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Table of Contents
1 Introduction...................................................................................................................1-1
1.1 Purpose of this Document .................................................................................1-1
2 Legal Authorities ...........................................................................................................2-2
3 Priority Areas ................................................................................................................3-1
4 Dry Weather Outfall Inspections ...................................................................................4-1
4.1 Major Outfalls ....................................................................................................4-1
4.2 Field Preparation...............................................................................................4-1
4.3 Dry Weather Inspections ...................................................................................4-1
5 Illicit Discharge Source Investigations...........................................................................5-1
5.1 Investigation Triggers ........................................................................................5-1
5.2 Source Determination .......................................................................................5-1
5.3 Twenty-Four Hour Reporting .............................................................................5-2
5.4 Documentation and Tracking.............................................................................5-2
6 Illicit Discharge Elimination ...........................................................................................6-1
7 Annual Reporting ..........................................................................................................7-1
8 Evaluation of IDDE Program .........................................................................................8-2
Appendices
Appendix A Illicit Discharge Source Investigation Log
Appendix B Inventory and Map of Major Outfalls
Appendix C Dry Weather Inspection Field Equipment Checklist
Appendix D Dry Weather Outfall Inspection Forms
Tables
Table 4-1. Dry Weather Screening Parameters and Equipment................................................4-3
Table 5-1. Parameters Action Criteria and Effluent Type ...........................................................5-1
Table 6-1. Methods to Eliminate Discharges ............................................................................6-1
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List of Acronyms
EPA Environmental Protection Agency
IDDE Illicit Discharge Detection and Elimination
IDP Illicit Discharge Potential
MS4 Municipal Separate Storm Sewer System
NCDEQ North Carolina Department of Environmental Quality
NPDES National Pollutant Discharge Elimination System
PPE Personal Protective Equipment
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1 Introduction
The City of Henderson (hereafter referred to as the “City”) is authorized by its National Pollutant
Discharge Elimination System (NPDES) Municipal Separate Storm Sewer System (MS4) Permit
NCS000542, issued February 20, 2017, to discharge stormwater from its MS4 to receiving
waters of the state. According to Part I.D.1.a of the MS4 permit, the permittee shall “implement
and enforce a program to detect and eliminate illicit discharges into the MS4.” An illicit discharge
is defined as any discharge to an MS4 that is not composed entirely of stormwater, except
discharges authorized under a separate NPDES permit, allowable non-stormwater discharges
identified in Part I.D.1.f that are not significant contributors of pollutants to the MS4, and
discharges from fire-fighting activities (MS4 Permit Part VIII.10).
Improper discharges to the MS4 may be the result of misconnection of a portion of the sanitary
sewer system to the storm sewer system, failure of sewer infrastructure allowing infiltration of
public drinking water or sanitary sewer effluent into the storm sewer system, inadvertent or
deliberate discharges of prohibited effluent to the MS4, or other causes.
Pursuant to Part II.D. of the MS4 permit, major outfalls will be annually inspected, and any
flowing water will be assessed for indicators of an illicit discharge. Section 4.1 of this plan
includes details on the definition and delineation of major outfalls within the MS4 area.
1.1 Purpose of this Document
The City MS4 permit requires the development of a written Illicit Discharge Detection and
Elimination (IDDE) Plan within 12 months of permit coverage. The purpose of this IDDE Plan is
to provide standard procedures and documentation to: (a) locate priority areas likely to have
illicit discharges, (b) conduct routine dry weather outfall inspections, (c) identify illicit discharges
and trace sources, (d) eliminate the source(s) of an illicit discharge, and (e) evaluate and assess
the IDDE Program. The recommendations and best practices detailed in this document are
based on industry standards.
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2 Legal Authorities
The City maintains an IDDE ordinance that provides the legal authority to prohibit illicit
connections and discharges. The IDDE Ordinance is available under Subtitle C, Chapter 16,
Division 3, Section 16-37.8 of the City of Henderson Code of Ordinances. This ordinance
regulates the discharge of substances which may contaminate or cause pollution of stormwater,
stormwater conveyances, or waters of the state; regulates connections to the stormwater
conveyance system; provides for the proper handling of spills; and provides for the enforcement
of same.
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3 Priority Areas
As identified in the City’s Stormwater Management Plan (SWMP), the IDDE Plan shall provide
standard procedures to locate priority areas likely to have illicit discharges. As of the date of this
plan, the City has identified priority areas to be the areas draining to major outfalls. Section 4.1
of this plan includes details on the definition and delineation of major outfalls within the MS4
area.
Within 12 months of receiving 2022 MS4 permit coverage, the City will begin to solicit public and
staff reporting illicit discharges, illegal dumping, and spills through a statement on the City
stormwater web site, located at https://ci.henderson.nc.us/departments/engineering
/stormwater_program.php.The City will investigate reports as specified in Section 5 of this plan
and determine if the area specified in the report is a priority area with potential for future illicit
discharge.
Throughout the permit year, the City will continue to evaluate and add additional locations to its
list of priority areas likely to have illicit discharges. When determining whether to add a location
as a priority area, the City will consider:
Recurring Discharge Complaints and Reports: Repeated reports and complaints
indicate chronic violators of the illicit discharge ordinance.
Poor Dry Weather Water Quality: Refer to Section 4 of this plan.
Age of Subwatershed Land Development: Developments older than 50 years can
experience high illicit discharge potential (IDP).
Sewer Conversion: Subwatersheds with septic systems that have been connected
to the sanitary sewer system in the last 30 years have high IDP.
Presence of Older Industrial Operations: Subwatersheds with more than 5% of its
area in industrial sites that are more than 40 years old are considered to have high
IDP.
Aging or Failing Sewer Infrastructure: High IDP can be present in infrastructure
exceeding its design life or in need of repair.
All priority areas will be logged within a City-developed IDDE tracking Excel spreadsheet (See
Appendix A) with the date it was added.
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4 Dry Weather Outfall Inspections
Part II.D.2.d of the MS4 permit requires the City to conduct annual dry weather inspections of all
major outfalls. Identification of major outfalls and dry weather screening procedures are
described in the subsequent sections. For the purposes of this plan, “dry weather conditions”
are identified as less than a cumulative 0.10 inches of rainfall in 48 hours. The United States
Environmental Protection Agency (EPA) promotes the use of the Illicit Discharge Detection and
Elimination Guidance Manual, developed by The Center for Watershed Protection (Brown et al.
2004). The technical guidance and resources provided in the manual have been integrated into
this plan.
4.1 Major Outfalls
The North Carolina Department of Environmental Quality (NCDEQ) defines an outfall as: “A
point where the MS4 discharges from a pipe or other conveyance (e.g., a ditch) directly into
surface waters.” A “Major Outfall” is a “36-inch diameter pipe or discharge from a drainage area
larger than 50 acres; and for industrial zoned areas a 12-inch diameter pipe or a drainage area
larger than 2 acres.” Major outfalls are required to be mapped to meet permit requirements. The
City maintains a major outfall map and inventory, which are included in Appendix B of this plan.
4.2 Field Preparation
Proper field preparation is an important aspect of conducting thorough inspections, and the
necessary equipment and preparation may vary between sites. Some outfalls may be located at
secure facilities or on private property and will require inspectors to notify and coordinate access
with the City departments, the facility, and/or the land owner prior to inspection. Some sites will
require facility and/or device-specific preparation, and inspectors should develop a checklist of
field items needed to complete inspections. An example field materials checklist can be found in
Appendix C.
Prior to performing field inspections, safety precautions should be taken as needed, including,
but not limited to: conducting a vehicle check before traveling to the site, avoiding hazardous
weather conditions, wearing the appropriate personal protective equipment (PPE), and taking
frequent breaks for water. Inspectors should avoid confined spaces unless trained and equipped
with the proper PPE and required certifications. Inspectors should be aware of their
surroundings at all times while performing inspections.
4.3 Dry Weather Inspections
Dry weather MS4 screening programs involve monitoring both physical and chemical
characteristics of dry weather flows. If flowing water is present at a major outfall during dry
weather, the quality of the flowing water is assessed in the field. If flowing water is not present at
a major outfall during dry weather, physical indicators of a potentially improper discharge are
assessed. These physical indicators include but are not limited to: outfall damage, deposits or
stains, unfavorable colors or odors in standing water, deposits of material in receiving channels,
and algal growth in pipes.
Water quality testing for characteristics such as pH, ammonia levels, and temperature provides
on-the-spot information to help distinguish between improper discharges and other possible
sources of dry weather flow, such as groundwater infiltration. Physical indicators in flowing water
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include odor, color, turbidity, and the presence of floating material such as oil, sewage, or suds
(Brown et al. 2004).
Initial dry weather screening activities include assessing the physical characteristics of the
outfall and any discharge and performing screening chemistry tests on the discharge (if
present). Field screening will not proceed unless less than 0.10 inches of rainfall has fallen in
the preceding 48 hours. Field crews will verify that this dry-time criterion has been met before
beginning field operations. The field staff will obtain and gather the materials listed in Appendix
C prior to field work.
For the City of Henderson dry weather field effort, screening of outfalls consists of the following:
 Locate outfalls using Appendix B and GPS.
 Inspect the selected outfalls for physical evidence of illicit discharge.
 If flowing water is present, perform water chemistry tests in the field.
 Record data on the Dry Weather Outfall Inspection Form, included as Appendix D.
 If the presence of suspected illicit discharge is detected, notify the City Stormwater
Engineer.
Data gathered during the dry weather screening field effort will be recorded on pre-printed field
data sheets (Appendix D), which were developed by the Center for Watershed Protection
(Brown et al. 2004). The following screening information will be entered onto field data sheets:
1. Background Data: Record subwatershed, outfall ID, current date, investigators, GPS
location, land use and other background data.
2. Outfall Description: Enter information describing the outfall, including physical
dimensions, shape, material type, whether closed pipe or open channel, whether
subsurface or open to daylight etc. Indicate if water is flowing from the outfall and
describe.
3. Quantitative Characterization: If flowing water is observed, measure flow
characteristics as well as temperature, pH and ammonia levels following equipment-
specific methodology records provided by the manufacturer.
4. Physical Indicators for Flowing Outfalls Only: Collect information on physical
features of flowing outfalls (e.g., odor, color, turbidity, sheens, floating materials).
5.Physical Indicators for Flowing and Dry Outfalls: Collect information on physical
features of both flowing and dry outfalls. Examine outfall for presence and type of
algae, abnormal vegetation (if applicable), damage, stains, sheens, and condition of
plunge pool (if applicable). Structural problems (e.g., cracking, holes in corrugated
metal pipes, dissolved concrete) should also be noted.
Table 4-1 identifies the dry weather screening parameters and the equipment and materials
used to screen for those parameters.
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Table 4-1. Dry Weather Screening Parameters and Equipment
Recommended Analyte Screening Equipment/Material
Temperature Thermometer
pH pH strips or pH meter
Ammonia Nitrogen/Ammonia Test Kit
Following dry weather screening, the inspection forms with screening results will be maintained
with IDDE program records. If any source investigations are initiated, the IDDE tracking excel
spreadsheet will be updated accordingly.
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5 Illicit Discharge Source Investigations
The MS4 Permit requires that permittees investigate the sources of illicit discharges (MS4
Permit Part I.D.2.e) and track and document investigations of illicit discharges (MS4 Permit Part
I.D.2.f).
5.1 Investigation Triggers
Any suspected illicit discharge, including spills entering the MS4 and outfalls that fail physical or
chemical parameter screening, will be reported to City staff via one of two methods:
1. During field investigations, any active pollution discharge (elevated flow,
discoloration, and abnormal odor) observed will be reported to the City Stormwater
Engineer.
2. A public reporting mechanism will be established on the City’s website so that
members of the public will be able to report suspicious flows.
The City will investigate suspected illicit discharges and document them in the City’s IDDE
tracking Excel spreadsheet.
5.2 Source Determination
The source of some illicit discharges may be easy to identify. However, some discharges may
require further investigation for source determination. The course that the investigation will take
will vary according to the nature of the discharge. Potential means of investigation are described
below:
Source Isolation – Field personnel work upstream from the point of the initial observation,
inspecting stormwater structures (e.g., manholes, catch basins, junctions) for the presence of
the same indicators, until a structure is found that does not exhibit evidence of the illicit
discharge. This indicates that the source of the discharge is likely located between the clean
structure and the last structure to exhibit an indicator. Once the source area has been identified,
field personnel should inspect the drainage area near the point of entry to identify the source.
This means of investigation may be undertaken by field personnel immediately upon discovery
of an illicit discharge during the annual field screening.
Effluent Analysis – Field personnel will compare the results of dry weather screening to the
criteria presented in Table 5-1 to assist in identifying the possible source of a suspected
improper discharge or illicit connection. Table 5-1 identifies the dry weather screening
parameters and their ability to aid in detecting the type of illicit discharge. Selection was based
primarily on information provided in Brown et al. (2004).
Table 5-1. Parameters Action Criteria and Effluent Type
Recommended
Analyte
Effluent Type Indicated Recommended Action
Criterion
Ammonia Industrial; washwater; sewage ≥ 1 mg/l
pH Industrial; washwater ≤ 5
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Dye Testing – Dye testing is often used to confirm sanitary sewer cross connections but may
be used to confirm other sources of an illicit discharge. Dye is introduced into plumbing fixtures
or at the suspected source of an illicit discharge. Stormwater structures are then monitored for
the presence of the dye. The presence of the dye in the MS4 confirms that the source was
correctly ascertained.
Laboratory Analysis – Samples may be collected and submitted for laboratory analysis, if
needed, to aid in source identification. This will be determined by the City on a case-by-case
basis.
5.3 Twenty-Four Hour Reporting
The MS4 permit requires that any illicit discharges that may constitute an imminent threat to
health or the environment be reported to the Division of Energy, Mineral and Land Resources,
Department of Environmental Quality. The report should be provided orally within 24 hours from
the time the permittee became aware of the circumstances, and then in writing within 5 days.
5.4 Documentation and Tracking
The City will maintain documentation to track the status of source investigations conducted for
illicit discharges. Appendix A includes a log for this purpose and allows space to document the
following, per Part II.D.2.f of the MS4 Permit:
 The dates that the illicit discharge was initially observed, reported, or both;
The results of the investigation;
 Any follow-up to the investigation; and
 The date that the investigation was closed.
Summaries of these documents are to be included in the annual report, as described in Section
7 of this plan.
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6 Illicit Discharge Elimination
Once the source of an illicit discharge has been identified, steps should be taken to eliminate
the discharge. Ultimate responsibility for removing the source of a discharge is generally that of
either the property owner or the municipality.
Illicit discharges generally originate from one of the following sources (Brown et al. 2004):
 An internal plumbing connection (e.g., the discharge from a washing machine is
directed to the building’s storm lateral; the floor drain in a garage is connected to the
building’s storm lateral)
 A service lateral cross-connection (e.g., the sanitary lateral from a building is
connected to the MS4)
 An infrastructure failure within the sanitary sewer or MS4 (e.g., a collapsed sanitary
line is discharging into the MS4)
 An indirect transitory discharge resulting from leaks, spills, or overflows
Internal plumbing repairs are to be corrected by the property owner. Other repairs are to be
addressed by the City. Some common examples are included in Table 6-1, originally presented
in Brown et al. (2004).
Table 6-1. Methods to Eliminate Discharges
Technique Application Description
Service Lateral
Disconnection,
Reconnection
Lateral is connected to
the wrong line
Lateral is disconnected and reconnected to
appropriate line
Cleaning Line is blocked or
capacity diminished
Flushing (sending a high-pressure water jet
through the line); pigging (dragging a large
rubber plug through the lines); or rodding
Excavation and
Replacement
Line is collapsed,
severely blocked,
significantly misaligned,
or undersized
Existing pipe is removed, new pipe placed in
same alignment; Existing pipe abandoned in
place, replaced by new pipe in parallel
alignment
Manhole Repair Decrease ponding;
prevent flow of surface
water into manhole;
prevent groundwater
infiltration
Raise frame and lid above grade; install lid
inserts; grout, mortar or apply shortcrete inside
the walls; install new precast manhole
Pipe Bursting Line is collapsed,
severely blocked, or
undersized
Existing pipe used as guide for inserting
expansion head; expansion head increases
area available for new pipe by pushing existing
pipe out radially until it cracks; bursting device
pulls new pipeline behind it
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Slip Lining Pipe has numerous
cracks, leaking joints,
but is continuous and
not misaligned
Pulling of a new pipe through the old one
Fold and
Formed Pipe
Pipe has numerous
cracks, leaking joints
Similar to sliplining but is easier to install, uses
existing manholes for insertion; a folded
thermoplastic pipe is pulled into place and
rounded to conform to internal diameter of
existing pipe
Inversion
Lining
Pipe has numerous
cracks, leaking joints;
can be used where
there are misalignments
Similar to sliplining but is easier to install, uses
existing manholes for insertion; a soft resin
impregnated felt tube is inserted into the pipe,
inverted by filling it with air or water at one end,
and cured in place
After the repairs have been made to correct a discharge, satisfactory removal of the discharge
should be verified both at the source and downstream, to ensure that it is the only local
discharge present.
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7 Annual Reporting
Part IV.B. of the MS4 permit requires the City to submit an annual report to NCDEQ. The City
SWMP identifies annual reporting metrics for each measurable goal associated with IDDE
program best management practices. This section specifies the annual requirements pertaining
to the IDDE minimum measures only (MS4 Permit Part II.D) and corresponds to the annual
reporting metrics identified in Table 15 of the City SWMP. The report should include:
 The date that the major outfall map was finalized;
 The type and number of enforcement actions issued;
 The type and number of enforcement actions issued to chronic violators;
 The total number of outfalls screened;
 The number of outfalls with dry weather flow;
Source investigation findings;
 The number of investigations, potential illicit discharges, verified illicit discharges,
remedied illicit discharges, and enforcement actions;
 Employee and Contractor training date, topics, and number trained on identification
and reporting of illicit discharges;
 The number of public and staff reports of illicit discharges, illegal dumping, and spills;
and
 A summary of City responses to public and staff reports.
The City should maintain records of the above information throughout the year to facilitate ease
of annual reporting.
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8 Evaluation of IDDE Program
Review and evaluation of the IDDE program is key to ensuring that illicit discharges are
eliminated in the most cost-effective way. Program components should be reviewed annually to
identify possible efficiencies, cost-savings, and revised milestones/goals. During this annual
review, the City will take into consideration the following:
 Accuracy of the Major Outfall Map;
 Indicator sampling results for specific streams, outfalls, or storm drains that indicate
poor water quality;
 Frequency of hotline use and associated number of “hits” or confirmed illicit
discharges;
 Number of discharges corrected;
 Success rate of source determination and illicit discharge elimination; and
 Effectiveness of enforcement actions.
Regular analysis of the IDDE Program sheds light on program strengths and deficiencies and
improves targeting of limited program resources.
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Appendix A – Illicit Discharge Source Investigation Log
Illicit Discharge Source Investigation Log
City of Henderson
Date Outfall ID (If applicable)Location
Investigation Status (Pending Investigation,
Investigation Completed)Investgation Results Follow-up Needed?Follow-up Results Date Investigation was Closed
5438 Wade Park Blvd, Suite 200
Prepared by: AECOM
Tel: [phone] Fax: [phone]
Raleigh, NC 27607
IDDE Plan Project Number: 60666154
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Appendix B – Inventory and Map of Major Outfalls
M a r t i n C r e e kNutbush CreekPounder BranchRed Bud CreekSandy Cr
eekRuin CreekRose St
Marketplace Plaza
Anne St/David Ave
Henderson Square SCM Henderson Laundromat
Henderson Ops Facility #2Henderson Ops Facility #1
Birch Circle (Bircle Circle)
Americal Road Industrial FacilitySandy CreekRed Bud CreekInd
ian
CreekRuin CreekPounder BranchAnderson CreekNutbush CreekM a r t i n C r e e k We
a
v
e
r
C
r
e
e
k
Sandy Cr
eekR uin C reekMartin CreekRed Bud Cr
eekSandy CreekRuin Creek Nutbush CreekRed Bud CreekSource: Esri, Maxar, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA, USGS, AeroGRID, IGN,
and the GIS User Community
Legend
Major Outfalls
NCDENR Named Streams
MS4 Area Boundary
Tributaries
Lakes and Ponds
City of Henderson MS4 Major Outfall Map ¯
0 0.5 1 1.5 20.25
Miles
Prepared by: AECOM Major Outfall Inventory
5438 Wade Park Blvd, Suite 200 City of Henderson
Raleigh, NC 27607 March 17th, 2022
Tel: [phone] Fax: [phone]
Outfall ID/Description Location Land Use Approximate Drainage Area (acres)*Pipe Diameter Pipe Material Latitude Longitude Name of Receiving Waters Describe Surrounding Area (e.g. woods, roadside, nearby businesses, etc.)Other Comments
Henderson Ops Facility #1 900 S Beckford Dr, Henderson, NC 27536, on the northeast side B4 - Neighborhood Commercial 2.0 36 Concrete 36.33564 -78.430762 Tributary to Nutbush Creek Roadside ditch in front parking lot at Operations Facility.Meets definition of major outfall due to pipe size. Pipe collects stormwater from front parking lot of Ops Facility and discharges into
vegetated channel upstream of stream flowing behind Ops Facility.
Henderson Ops Facility #2 900 S Beckford Dr, Henderson, NC 27536, on the northeast side B4 - Neighborhood Commercial 7.4 42 Concrete 36.336116 -78.431532 Tributary to Nutbush Creek Located behind the Operations Facility, collects stormwater from the back parking lot.Meets definition of major outfall due to pipe size. Pipe discharges into riprap channel flowing to stream. Site is zoned commercial
but industrial activities such as vehicle washing, dry storage, fuel pumping occur in back parking lot of Ops Facility.
Americal Road Industrial Facility 389 Americal Rd, Henderson, NC 27537, southeast corner I2 - Industrial Non-Park 5.0 24 Concrete 36.313742 -78.384973 Tributary to Roland Pond Upstream of sewer easement behind warehouse parking lot, warehouse is no longer active except for used tire sales.Meets definition of major outfall due to pipe size in industrial zoned area. Appears large tree is growing on top of pipe, probably
caused the separation.
Rose St 993 Park Ave, Henderson, NC 27536, southwest corner I2 - Industrial Non-Park 2.0 24 Concrete 36.312942 -78.400506 Tributary to Roland Pond 24” pipe coming out of fenced industrial area, unsure what the pipe is draining. After stormwater discharges from pipe, stormwater enters a culvert, joins with a roadside
stormwater inlet to be discharged into unnamed stream behind the gas station.
Meets definition of major outfall due to pipe size in industrial zoned area. This outfall does not discharge directly to a body of water,
but joins with a body of water after joining a downstream storm network
Birch Circle 582 Birch Cir, Henderson, NC 27536, northeast of the parcel R8/R15 - Residential 9.0 36 Concrete 36.323436 -78.423839 Tributary to Red Bud Creek Concrete headwall on a residential street with two pipes discharging from it, one 18" and one 36".Meets definition of major outfall due to pipe size. Two pipes present onsite, one 36" and one 18". Only the 36" was considered to be
a major outfall.
Anne St/David Ave 1202 Anne St, Henderson NC, behind the property (north side)R8/R15 - Residential & B3 - Shopping Center Commercial 59.0 42 Corrugated Plastic 36.326595 -78.433975 Tributary to Red Bud Creek Behind a residential house on Anne St (last house on the left in cul-de-sac).Meets definition of major outfall due to pipe size. Stream is not labeled as such on any GIS or USGS website, but was observed in the
field.
Henderson Laundromat 341 N Chestnut St, Henderson, NC 27536, behind the property (northwest side)OI - Office/Institutional & B1 Retail/Central Business 10.0 54 Concrete 36.331181 -78.401901 Tributary to Nutbush Creek Behind abandoned laundromat.Meets definition of major outfall due to pipe size. Water appears to be draining elsewhere besides the stream, water observed
flowing under laundromat. Major Outfall status to be confirmed with pipe data information from the City of Henderson.
Henderson Square SCM N Cooper Dr, Henderson, NC 27537, south of Walmart, across the road B2/B2A - Highway Commercial & OI - Office/Institutional 94.0 36 Concrete 36.33225 -78.44202 Tributary to Red Bud Creek Outfall is the inlet pipe for the SCM located south of the Walmart parking lot (called Detention #2 in Walmart Site Plan).Meets definition of major outfall due to pipe size, determined using site plans provided by the City of Henderson. Verify pipe size
and material in the field.
Marketplace Plaza 885 S Beckford Dr, Henderson, NC 27536, behind the Jamaican restaurant B4 - Neighborhood Commercial 16.5 60 Concrete 36.33461 -78.43038 Tributary to Nutbush Creek Headwall with pipe located in woods behind Jamaican restaurant.Meets definition of majour outfall due to pipe size, determined using site plans provided by the City of Henderson. Verify pipe size
and material in the field.
*Drainage areas were delineated based on best available elevation contours and storm sewer data. Storm sewer mapping efforts are in progress throughout the city, and these drainage area estimates should be revised when data has been updated in the area. The Americal Road and Henderson Laundromat outfalls had particularly limited storm sewer data.
IDDE Plan Project Number: 60666154
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Appendix C – Dry Weather Inspection Field Equipment Checklist
Henderson Outfall Inspections - Field Work Checklist
SAFETY
Proper identification (drivers license, work ID/badge, etc.)
First Aid Kit
High visibility vest and/or shirt
Steel toe boots
Gloves - leather or similar for manual labor
Gloves – nitrile for performing chemical tests
Snake chaps (if necessary)
Sunscreen
Insect Repellant
Traffic cones (if necessary)
Sharps disposal container (for Ammonia Test Kit glass disposal)
OTHER EQUIPMENT/MATERIALS
Ammonia Test Kit
pH Test Strips
Thermometer
Outfall inspection forms or electronic device
Major Outfall Map and Inventory
Clipboard
Camera
Manhole hook (for source investigations)
Tape measure
Flashlight
Trash bag
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Appendix D – Dry Weather Outfall Inspection Forms

Illicit Discharge Detection and Elimination: Technical Appendices D-3
OUTFALL RECONNAISSANCE INVENTORY/ SAMPLE COLLECTION FIELD SHEET

Section 1: Background Data
Subwatershed: Outfall ID:
Today’s date: Time (Military):
Investigators: Form completed by:
Temperature (°F): Rainfall (in.): Last 24 hours: Last 48 hours:
Latitude: Longitude: GPS Unit: GPS LMK #:
Camera: Photo #s:
Land Use in Drainage Area (Check all that apply):

Industrial

Ultra-Urban Residential

Suburban Residential

Commercial

Open Space

Institutional

Other:

Known Industries:
Notes (e.g., origin of outfall, if known):

Section 2: Outfall Description
LOCATION MATERIAL SHAPE DIMENSIONS (IN.) SUBMERGED
Closed Pipe
RCP CMP

PVC HDPE

Steel

Other:
Circular

Eliptical

Box

Other:
Single

Double

Triple

Other:
Diameter/Dimensions:

In Water:
No
Partially
Fully

With Sediment:
No
Partially
Fully
Open drainage
Concrete

Earthen

rip-rap

Other:
Trapezoid

Parabolic

Other:
Depth:

Top Width:

Bottom Width:

In-Stream (applicable when collecting samples)
Flow Present? Yes No If No, Skip to Section 5
Flow Description
(If present) Trickle Moderate Substantial

Section 3: Quantitative Characterization
FIELD DATA FOR FLOWING OUTFALLS
PARAMETER RESULT UNIT EQUIPMENT
Volume Liter Bottle Flow #1
Time to fill Sec
Flow depth In Tape measure
Flow width ’ ” Ft, In Tape measure
Measured length ’ ” Ft, In Tape measure
Flow #2
Time of travel S Stop watch
Temperature °F Thermometer
pH pH Units Test strip/Probe
Ammonia mg/L Test strip
D-4 Illicit Discharge Detection and Elimination: Technical Appendices Outfall Reconnaissance Inventory Field Sheet Section 4: Physical Indicators for Flowing Outfalls Only Are Any Physical Indicators Present in the flow? Yes No (If No, Skip to Section 5) INDICATOR CHECK if Present DESCRIPTION RELATIVE SEVERITY INDEX (1-3) Odor Sewage Rancid/sour Petroleum/gas Sulfide Other: 1 – Faint 2 – Easily detected 3 – Noticeable from a distance Color Clear Brown Gray Yellow Green Orange Red Other: 1 – Faint colors in sample bottle 2 – Clearly visible in sample bottle 3 – Clearly visible in outfall flow Turbidity See severity 1 – Slight cloudiness 2 – Cloudy 3 – Opaque Floatables -Does Not Include Trash!! Sewage (Toilet Paper, etc.) Suds Petroleum (oil sheen) Other: 1 – Few/slight; origin not obvious 2 – Some; indications of origin (e.g., possible suds or oil sheen) 3 - Some; origin clear (e.g., obvious oil sheen, suds, or floating sanitary materials) Section 5: Physical Indicators for Both Flowing and Non-Flowing Outfalls Are physical indicators that are not related to flow present? Yes No (If No, Skip to Section 6) INDICATOR CHECK if Present DESCRIPTION COMMENTS Outfall Damage Spalling, Cracking or Chipping Peeling Paint Corrosion Deposits/Stains Oily Flow Line Paint Other: Abnormal Vegetation Excessive Inhibited Poor pool quality Odors Colors Floatables Oil Sheen Suds Excessive Algae Other: Pipe benthic growth Brown Orange Green Other: Section 6: Overall Outfall Characterization Unlikely Potential (presence of two or more indicators) Suspect (one or more indicators with a severity of 3) Obvious Section 7: Data Collection 1. Sample for the lab? Yes No 2. If yes, collected from: Flow Pool 3. Intermittent flow trap set? Yes No If Yes, type: OBM Caulk dam Section 8: Any Non-Illicit Discharge Concerns (e.g., trash or needed infrastructure repairs)?
IDDE Plan Project Number: 60666154
March 2022 AECOM
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