20220790 Ver 1_SWPPP_TimbermillWind_November2022_20221104

Timbermill Wind, LLC
Chowan County, North Carolina
Stormwater Pollution Prevention Plan (SWPPP)
In compliance with:
The provisions of the Clean Water Act
General Permit to Discharge under the National Pollutant Discharge Elimination
System (NPDES):
',V N
Construction General Permit (CGP) NO. NCGO10000
NO
Timmons Group
Legacy Circle, Suite
Plano, TX 75024
imb rmill Wina, LLC
Garrett Street, Suite 700
lottesville, VA 22902
November 2022

Timbermill Wind, LLC
Chowan County, North Carolina
Stormwater Pollution Prevention Plan (SWPPP)
In compliance with:
The provisions of the Clean Water Act
General Permit to Discharge under the National Pollutant Discharge Elimination
System (NPDES):
Construction General Permit (CGP) NO. NCG010000
%Ih'-
I certify under penalty of law; this document an (misnquiry
chments were prepared under my direction or
supervision in accordance with the system designre that qualified personnel properly gathered
and evaluated the information submitted. Based oof the person or p ns who manage the
system, or those persons directly responsible for gathering the information, the in ation submitted is,
to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are
significant penalties for submitting false information, inquding the possibility of a fine and
imprisonment for knowing violations.
Respc
Comp
Respc
Mailit
Date:
Signal
Stormwater Pollution Prevention Plan Page I ii
Timbermill Wind, LLC
Chowan County, North Carolina

Timbermill Wind, LLC
Chowan County, North Carolina
Stormwater Pollution Prevention Plan (SWPPP)
In compliance with:
The provisions of the Clean Water Act
General Permit to Discharge under the National Pollutant Discharge Elimination
System (NPDES):
Construction General Permit (CGP) NO. NCG010000
I certify under penalty of law that I understand the terms and conditions of the general National
Pollutant Discharge Elimination System (NPDES) General Construction permit that authorizes the storm
water discharges associated with industrial activity from the &ction site ident feed as part of this
certification.
Stormwater Pollution Prevention Plan Page I iii
Timbermill Wind, LLC
Chowan County, North Carolina

Note to Contractor:
In North Carolina, the SWPPP consists of the NCGO10000 Construction General Permit (CGP) and
approved Erosion and Sedimentation Control Plans. This Compilation of documents is for use by the
Contractor, Owner and Inspectors during Construction.
Construction within any section of this project cannot begin until an Erosion and Sedimentation
Control Permit has been obtained for that area.
This site will be subject to implementing a Spill Prevention and Response Plan based on the
minimum requirements listed below. A more detailed report will be provided once materials are on site in
order to ensure adequate containment is put in place. Plan should be made available on site for quick
reference.
The purpose of the Spill Prevention and Response Plan is to Ndesthemeasures implemented by
Contractor to prevent the discharge of oil into navigable waters of thes or their adjoining
shorelines, and to respond in a safe, effective, and timely manner to azards to human health and
the environment should such an event occur. The SPCC plan will bmeet the requirements set
by the U.S. Environmental Protection Agency (EPA) contained in Title 40, Code of Federal Regulations,
Part 112 (40 CFR part 112). A non -trans UZ
related facility is subject to SPCC regulations if
• the total aboveground storage capacity exceeds 1,320 gallons;
or the underground oil storage capacity exceeds 42,000 gallons; and, if due to its location, the facility
could reasonably exp harge oilyoruponhe navigable waters of the United States.
Contents:
Appendix A CDENR DWQ GeneralGO10000
(Eff ve April 01, 2019 & Expires March 31, 2024)
Appendix B Self Ins n Program
Appendi Approved cculants
1%
Appendix D rosion and Sediment Control Inspector's Guide
Appendix E Post Construction BMP
Appendix F Erosion and Sedimentation Control Permits
References:
North Carolina Erosion and Sediment Control Plannin4 and Design Manual:
A complete design manual that provides extensive details and procedures for developing site -specific
erosion and sedimentation control plans, consistent with the requirements of the North Carolina
Sedimentation and Pollution Control Act and Administrative Rules. Revised Jan. 2017.
2. North Carolina Erosion and Sediment Control Field Manual
Stormwater Pollution Prevention Plan Page I iv
Timbermill Wind, LLC
Chowan County, North Carolina

Appendix A
NCDENR DWQ General Permit — NCGO10000
(Effective April 01, 2019 & Expires March 31, 2024)

STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENTAL QUALITY
DIVISION OF ENERGY, MINERAL, AND LAND RESOURCES
GENERAL PERMIT NO. NCG010000
TO DISCHARGE STORMWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
for:
Construction Activities that are also Subject to the
North Carolina Sedimentation Pollution Control Act of 1973
In compliance with the provisions of North Carolina General Statute (G.S.) 143-215.1, other lawful standards
and regulations promulgated and adopted by the North Carolina Environmental Management Commission
and the Federal Water Pollution Control Act, as amended, this permit is hereby issued to all owners or
operators, hereinafter permittees, which are covered by this permit as evidenced by receipt of a Certificate
of Coverage by the Environmental Management Commission to allow the discharge of stormwater to the
surface waters of North Carolina or to a separate storm sewer system conveying discharges to surface
waters in accordance with the terms and conditions set forth herein.
Coverage under General Permit No. NCG010000, hereafter referred to as NCG01, is applicable to:
All owners or operators of stormwater point source discharges associated with construction activities
including clearing, grading, or excavation activities resulting in the disturbance of land greater than or equal
to one acre, or that are part of a common plan of development of that size that are also subject to the North
Carolina Sedimentation Pollution Control Act of 1973 (SPCA), are hereby authorized to discharge
stormwater to the surface waters in accordance with the terms and conditions set forth herein. Failure to
receive coverage under this permit or violations of any of the conditions listed may result in assessment of
state or federal civil or criminal penalties for each day of each violation.
The General Permit shall become effective on April 1, 2019.
The General Permit shall expire at midnight on March 31, 2024.
Signed this day March 29, 2019.
S. Daniel Smith
Interim Director, Division of Energy, Mineral and Land Resources
By the Authority of the Environmental Management Commission

Permit No. NCG010000
TABLE OF CONTENTS
PART I NCGO1 PERMIT COVERAGE
PART II STORMWATER POLLUTION PREVENTION PLAN
Section A: Required Components of the Erosion and Sedimentation Control Plan
1. Location Information
2. Narrative and Construction Sequence
3. General Site Features
4. Site Drainage Features
5. Plans Showing E&SC Measures
6. Calculations
7. Vegetative Stabilization Shown on Plans
8. Documentation
Section B: Design and Construction Standards for Erosion and Sediment Control
Measures
1.
Objective of E&SC Measures
2.
Area to Be Covered by the E&SC Plan
3.
Angle for Graded Slopes
4.
Upslope Areas
S.
Design Standard for E&SC Measures
6.
Calculation Method
7.
Stormwater Outlets
8.
Stormwater Conveyances
9.
Sediment Basin Outlet Structures
9.
Lower Portions of the Site
Section C: Additional Design and Construction Standards in High Quality Water
(HQW) Zones
1. Extent of the HQW Zone
2. Disturbed Area Limits in HQW Zones
3. Additional Sediment Basin Requirements in HQW Zones
4. Open Channels in HQW Zones
Section D: Construction Activity Buffers
1. Buffers in Non -Trout Waters
2. Buffers in Trout Waters

Permit No. NCGO10000
Section E: Ground Stabilization
1. Ground Stabilization Timelines
2. Permanent Ground Stabilization Timeline
Section F: Materials Handling
1. Polyacrylamides (PAMS) and Flocculants
2. Equipment Fluids
3. Waste Materials
4. Herbicide, Pesticide, and Rodenticides
S. Concrete Materials
6. Earthen Material Stock Piles
Section G: Operation and Maintenance
1. Plan Deviations
2. Operation and Maintenance
3. Corrective Actions
4. Maintenance of Sediment Basins
5. Bypass of E&SC Measures
6. Upset of E&SC Measures
7. Compliance with the Turbidity Standard
PART III SELF -INSPECTION, RECORDKEEPING AND REPORTING
Section A: Self -Inspection
Section B: Recordkeeping
1. E&SC Plan Documentation
2. Additional Documentation to be Kept on Site
3. Documentation to he Kept for Three Years
Section C: Reporting
1. Occurrences that Must be Reported
2. Reporting Timeframes and Other Requirements
PART IV STANDARD CONDITIONS FOR NPDES STORMWATER GENERAL PERMITS
Section A: Compliance and Liability
1. Continuation of Previously Permitted Projects
2. Projects Submitted Prior to this Permit's Effective Date
3. Duty to Comply
4. Non-Stormwater Discharges
ii

Permit No. NCGO10000
S. Test Procedures
6. Duty to Mitigate
7. Need to Halt or Reduce Not a Defense
8. Civil and Criminal Liability
9. Oil and Hazardous Substance Liability
10. Property Rights
11. Severability
12. Duty to Provide Information
13. Inspection and Entry
14. Penalties for Tampering
15. Penalties for Falsification of Reports
16. Onshore or Offshore Construction
17. Duty to Reapply
18. Planned Changes
19. Anticipated Noncompliance
Section B: Permit Administration
1. General Permit Expiration
2. Transfers
3. When an Individual Permit May be Required
4. When an Individual Permit May he Requested
S. Impacts or Potential Impacts to Surface Waters or Wetlands
6. Signatory Requirements
7. General Permit Modification, Revocation and Reissuance, or
Termination
8. Certificate of Coverage Actions
9. Annual Administering and Compliance Monitoring Fee Requirements
10. Availability of Reports
11. Omissions
PART V DEFINITIONS

Permit No. NCG010000
PART I - NCGO1 PERMIT COVERAGE
This permit applies to all owners or operators of stormwater discharges associated with construction
activities such as clearing, grading, and excavation, that result in the disturbance of a land area greater
than or equal to one acre, or that are part of a common plan of development of that size or greater that
are also subject to the North Carolina Sedimentation Pollution Control Act of 1973 (SPCA). This
permit may also be issued to stormwater discharges from like activities deemed by the Division of
Energy, Mineral, and Land Resources (DEMLR) to be similar to these operations in process or
stormwater discharges. This permit shall not apply to land -disturbing activities that are covered under
the NCG020000 (Mining Activities) permit or the NCG120000 (Landfills) permit.
The SPCA requires that the persons engaged in subject construction activities develop and adhere to an
Erosion and Sedimentation Control (E&SC) Plan. The Sedimentation Control Commission and DEMLR
have created and adopted a North Carolina Erosion and Sediment Control Planning and Design Manual
describing recommended sedimentation control techniques for construction activities.
A person seeking coverage under this permit shall take the following steps in the following order:
1. Develop an E&SC plan that adheres to the SWPPP requirements of this permit, the SPCA and 15A
NCAC 048 .0101-.0132. The North Carolina Erosion and Sediment Control Planning and Design
Manual shall be used as guidance in meeting the applicable requirements.
2. Obtain approval of the E&SC plan by either DEMLR or the appropriate state delegated local
entity (hereafter known as the "E&SC plan authority").
3. Submit an electronic Notice of Intent (e-NOI) to DEMLR with documentation of the E&SC plan
approval scanned and uploaded. The e-NOI is available at https:lldeq.nc.gov/NCGO1. In
addition, pay the general annual permit fee provided for in § 143-215.31). DEMLR shall email
the COC within three business days (or 24 business hours for a project being reviewed under
DEMLR's Express review program) after the submittal of a complete and correct a-NOI and the
receipt of the general permitting fee.
4. Commence the construction activity after receipt of the COC.
S. Abide by the conditions of both the NCGO1 permit and the E&SC plan until completion of the
construction activity and establishment of permanent ground stabilization.
6. Contact the E&SC plan authority after construction is complete and the site is permanently
stabilized, contact the E&SC plan authority for the final/close out inspection of the E&SC plan.
7. Submit an electronic Notice of Termination (e-NOT) with a scan of the close-out inspection
report uploaded. The e-NOT is available at https://de-q.nc.gov/NCG01. DEMLR shall email
confirmation of the close-out of the COC within three business days after the submittal of a
complete and correct e-NOT.
The discharges allowed by this General Permit shall not cause or contribute to violations of North
Carolina Water Quality Standards for surface waters and wetlands (15A NCAC O213.0200). Discharges
allowed by this permit must meet all applicable water quality certification or permit requirements as
outlined in 15A NCAC 02H .0500 and 02H .1300. This permit does not relieve the permittee from
responsibility for compliance with any other applicable federal, state, or local law, rule, standard,
ordinance, order, judgment, or decree. This General Permit does not cover any other point source
discharge to surface waters of the state, nor does it cover activities or discharges that are covered by an
individual NPDES permit.
Any owner or operator of a subject construction activity not wishing to be covered or limited by this
General Permit may apply for an individual NPDES permit in accordance with NPDES procedures in 15A
NCAC 02H .0100, stating the reasons supporting the request. Any application for an individual permit
Page 1 of 26

Permit No. NCG010000
should be made at least 180 days prior to the time the permit is needed unless waived by the Director
(see Part IV Section B of this permit).
PART II - STORMWATER POLLUTION PREVENTION PLAN
The Stormwater Pollution Prevention Plan for this permit shall include the approved Erosion and
Sedimentation Control (E&SC) Plan as well as any requirements in this Part that exceed the approved
E&SC Plan. Items that are required in the SWPPP but are not part of the approved E&SC Plan may
include, at a minimum, Section E, Item (2) [Required Timeframesfor Temporary Ground Stabilization],
Section F [Materials Handling]. DEMLR provides two sample plan sheets that permittees may add to
their E&SC Plan set to fulfill Sections E(2) and F of this permit at https:,(Jdeq.nc.goy/NCG01.
Recommendations for preparing the E&SC plan as well as for designing, constructing, and maintaining
the erosion and sedimentation control practices are contained in the North Carolina Erosion and
Sediment Control Planning and Design Manual.
SECTION A: REQUIRED COMPONENTS OF THE STORMWATER POLLUTION
PREVENTION PLAN
The E&SC Erosion and Sedimentation Control Plan shall include, at a minimum, the following
components and those components shall be in compliance with all conditions of this permit. Hard
and/or digital copies shall be submitted in accordance with the specifications of the E&SC plan
authority.
1. Location Information
Project location & labeled vicinity map (roads, streets, landmarks)
North arrow and scale
Identification of the River Basin
A copy of site disturbed area located on applicable USGS quadrangle and hardbound copy of the
NRCS Soils maps to scale
Latitude and longitude (in decimal degrees) at the project entrance
2. Narrative and Construction Sequence
Narrative describing the nature & purpose of the construction activity
Construction sequence related to erosion and sediment control (including installation of critical
measures prior to the initiation of the land -disturbing activity & removal of measures after areas
they serve are permanently stabilized). Address all phases of construction and necessary
practices associated with temporary stream bypasses and/or crossings
Estimated start and end dates
3. General Site Features
Property lines
Existing and proposed contours (topographic lines)
Stockpiled topsoil or subsoil locations
Limits of disturbed area (with acreage labeled) within which all construction, material storage,
grading, and related activities occur, including the following items as applicable:
• Access to E&SC measures, lots that will be disturbed, and utilities that may extend offsite.
• Temporary access and haul roads, other than public roads, constructed or used in
connection with the land -disturbing activity
Page 2 of 26

Permit No. NCG020000
* Borrow and waste areas created by the applicant. If the land -disturbing activity and any
related borrow or waste activity are not conducted by the same person, they shall be
considered separate land -disturbing activities
+ Offsite borrow pits if the borrow pit is a construction support activity to the development
Planned and existing building locations and elevations, if applicable
Planned & existing road locations & elevations, including temporary access roads, if applicable
Profiles of streets, utilities, and permanent ditch lines, if applicable
Lot lines and/or building numbers, if applicable
Easements and drainageways, particularly required for offsite affected areas, if applicable
Location and details associated with any onsite stone crushing or other processing of material
excavated, if applicable. A mining permit will be required if the affected area associated with
excavation, processing, stockpiles and transport of such materials comprises one or more acres,
and materials will be leaving the development tract
4. Site Drainage Features
Existing and planned drainage patterns (include off -site areas that drain through project and
address temporary and permanent conveyance of stormwater over graded slopes)
Drainage area map
Surface waters, including the limits of wetlands, streams, lakes and ponds and all required local
or state buffer zones as well as impact maps by the construction activity to these sensitive areas.
Method used to determine acreage of land being disturbed and drainage areas to all proposed
E&SC measures (e.g. delineation map)
Size, pipe material and location of culverts and sewers
Soil information throughout the site and below culvert storm outlets, including soil type and
special characteristics
Name and classification of receiving water course where discharges are to occur
S. Plans Showing E&SC Measures
Legend (provide appropriate symbols for all measures and reference them to the construction
details)
Location of temporary and permanent E&SC measures
Location of permanent stormwater quality and quantity control measures
Construction drawings and details for temporary and permanent measures, including outlet
structures. Show measures to scale on plan and include proposed contours where necessary.
Ensure design storage requirements are maintained through all phases of construction.
Specifications for ground stabilization
Maintenance requirements for measures
Contact person responsible for maintenance, if the permittee wishes to designate one. If not, the
financially responsible organization will be the contact for maintenance.
A note stating that material handling procedures for the items required in Part II, Section F will
be followed.
Standard details for structural BMPs to be installed to manage the anticipated materials listed in
Part 11, Section F such as construction debris management, concrete washout, paint washout,
petroleum product storage and pesticide/herbicide handling, along with spill prevention
practices.
6. Calculations
Calculations for peak discharges of runoff from each outlet at pre -development, during
construction and at completion. Provide all supporting data for the computation methods used
(rainfall data for required storm events, time of concentration/storm duration, and runoff
coefficients).
Page 3 of 26

Permit No. NCG010000
Design calculations for culverts and storm sewers (include headwater, tailwater and outlet
velocities)
Discharge and velocity calculations for open channel and ditch flows (easement & rights -of -way)
Design calculations for cross sections and method of stabilization for existing and planned
channels (include temporary linings). Include appropriate permissible velocity and shear stress.
Design calculations and construction details for energy dissipaters below culvert and storm
sewer outlets (include stone/material specs & apron dimensions). Avoid discharges on fill
slopes.
Design calculations and dimensions for sediment traps and basins
Total and disturbed drainage areas for silt fencing and other sediment controls
7. Vegetative Stabilization Shown on Plans
Area & acreage to be stabilized with vegetation
Method of soil preparation
Seed type & rates (temporary & permanent)
Fertilizer type and rates
Mulch type and rates (include mulch anchoring methods)
S. Documentation
Completed, signed & notarized Financial Responsibility/Ownership Form
Certificate of assumed name, if the owner is a partnership
Name of Registered Agent (if applicable)
Copy of the most current Deed for the site. Please mare sure the deed(s) and ownership
information are consistent between the plan sheets, local records and this form.
Provide latitude & longitude (in decimal degrees) at the project entrance.
Army Corps 404 permit and Water Quality 401 certification, if required for project, or a
complete application if these items are not yet issued.
DWR Buffer Authorization, if required for project
Copies of any recorded easements and/or agreements with adjoining property owners for
landlocked parcels
SECTION B: DESIGN AND CONSTRUCTION STANDARDS FOR EROSION AND
SEDIMENT CONTROL MEASURES
1. Objective of E&SC Measures
E&SC Measures shall be designed and constructed to prevent off -site sedimentation damage.
2. Area to Be Covered by the E&SC Plan
The E&SC plan shall include the limits of disturbed area within which all construction, material
storage, grading, and related activities occur, including the following items as applicable:
(a) Access to E&SC measures, lots that will be disturbed, and utilities that may extend offsite,
(b) Temporary access and haul roads, other than public roads, constructed or used in connection
with the land -disturbing activity
(c) Borrow and waste areas created by the applicant. If the land -disturbing activity and any related
borrow or waste activity are not conducted by the same person, they shall be considered
separate land -disturbing activities
(d) Offsite borrow pits if the borrow pit is a construction support activity to the development
3. Angle for Graded Slopes
Page 4 of 26

Permit No. NCGO10000
The angle for graded slopes and fills shall be no greater than the angle that can be retained by
vegetative cover or other erosion control devices or structures. (NCGS 113A-57(2))
4. Upslope Areas
Runoff originating upslope of the disturbed areas shall be either diverted away from the
construction activity or E&SC measures shall be sized sufficiently to handle the runoff. Any
diversion measures shall be shown on the plans.
5. Design Standard for E&SC Measures
Plans shall include measures necessary to prevent erosion at the limit of disturbance during the 10-
year storm or the 25-year storm in HQW Zones and the Falls Lake Watershed.
6. Calculation Method
Hydrologic calculations for designing E&SC measures shall be in accordance with the procedures in
the United States Department of Agriculture, Natural Resources Conservation Service's "National
Engineering Field Manual Handbook 630" which is herein incorporated by reference including
subsequent amendments and editions, and may be accessed at:
https: //www.nres.usda.gov/wps/portal/nres/detailfull/national/water/manage/hydrology/?cid=s
tell2rdbl043063 or according to procedures adopted by any other agency of this state or the United
States or any generally recognized organization or association.
7. Stormwater Conveyances
Any increase in stormwater runoff velocity resulting from a land -disturbing activity shall not result
in accelerated erosion of the receiving stormwater conveyance during the 10-year storm or the 25-
year storm in HQW Zones. The following additional requirements apply to stormwater
conveyances:
(a) The velocity in the receiving stormwater conveyance shall not exceed the maximum permissible
velocity per Table 1 except for sinuous channels. For sinuous channels, multiply allowable
velocity in Table 1 by 0.95 for slightly sinuous, by 0.9 for moderately sinuous channels, and by
0.8 for highly sinuous channels
Table 1: Maximum Permissible Velocities
Stormwater conveyance in -situ material
Maximum Permissible Velocity
Feet per second
Meters per second
Fine sand (noncolloidal)
2.5
0.8
Sandy loam (noncolloidal)
Silt loam (noncolloidal)
3.0
0.9
Ordinary firm loam
3.5
1.1
Alluvial silts (noncolloidal)
Fine gravel
5.0
1.5
Stiff clay (very colloidal)
Alluvial silts (colloidal)
Graded, silt to cobbles (colloidal)
5.5
1.7
Cobbles and shingles
Coarse gravel (noncolloidal)
6.0
1.8
Shale and hard pans
(b) Conveyances may be stabilized by planting vegetation, enlarging cross sections, and/or
providing erosion -resistant lining. Any erosion -resistant linings shall be shown on the plans.
8. Sediment Basin Outlet Structures
Sediment basins and traps with drainage areas of one acre or greater shall use outlet structures
that withdraw water from the surface.
Page 5 of 26

Permit No. NCG010000
9. Lower Portions of the Site
Portions of a site that are lower in elevation than adjacent discharge locations and are not
expected to discharge during construction may be exempt from the temporary ground cover
requirements if identified on the approved E&SC plan or added by the E&SC plan authority.
SECTION C. ADDITIONAL DESIGN AND CONSTRUCTION STANDARDS IN HIGH
QUALITY WATER (HQW) ZONES
1. Extent of the HQW Zone
HQW Zones are those areas in the 20 Coastal Counties that are within 575 feet of High Quality
Waters and for the remainder of the state, areas that are within one mile of and drain to HQWs.
2. Disturbed Area Limits in HQW Zones
Disturbed areas in HQW zones shall be limited at any time to a maximum total area within the
boundaries of the tract of 20 acres. Only the portion of the construction activity within a HQW zone
shall be subject to the 20-acre limit. Larger disturbed areas may be allowed with the written
approval of the Director upon providing adequate engineering justification with a specific
construction sequence that addresses phasing, limited exposure, weekly submitted self -inspection
reports and/or more conservative design than the 25-year storm. The Director may also include
other conditions as necessary based on specific site conditions.
3. Additional Sediment Basin Requirements in HQW Zones
Sediment basins that discharge to HQW Zones shall be designed and constructed to meet the
following criteria unless the permittee demonstrates to the E&SC plan authority that meeting each
of the basin design conditions below would result in design or operational hardships. Alternative
control measures, such as quicker application of ground cover or use of sediment flocculants, shall
be allowed as a substitute on a case -by -case basis if it can be shown that use of the alternate
practices is expected to result in an equal or better sediment discharge reduction from the site.
(a) Use a surface withdrawal mechanism except when the basin drainage area is less than 1.0 acre.
(b) Have a minimum of 1800 cubic feet per of storage area per acre of disturbed area.
(c) Have a minimum surface area of 325 square feet per cfs for the peak flow from the 25-year
storm.
(d) Have a minimum dewatering time of48 hours.
(e) Incorporate three baffles unless the basin is less than 20 feet in length, in which case two baffles
are sufficient.
4. Open Channels in HQW Zones
Newly constructed open channels in HQW zones shall be designed and constructed with side slopes
DO steeper than two horizontal to one vertical if a vegetative cover is used for stabilization unless soil
conditions permit a steeper slope or where the slopes are stabilized by using mechanical devices,
structural devices or other acceptable ditch liners. The angle for side slopes shall be sufficient to
restrain accelerated erosion.
Page 6 of 26

Permit No. NC6010000
SECTION D: CONSTRUCTION ACTIVITY BUFFERS
The requirements in Section D below shall not apply to a land -disturbing activity in connection with the
construction of facilities to be located on, over, or under a lake or natural watercourse (NCGS 113A-57).
1. Buffers in Non -Trout Waters
Unless wider buffers are required per NC rules or statutes, the width of the buffer shall be sufficient
to confine visible sedimentation to the 25 percent of the strip closest to the land -disturbing activity.
The width of a buffer adjacent to a non -trout water shall be measured from the edge of the water to
the nearest edge of the disturbed area.
Recommended buffer widths to achieve this standard are shown in Table 2 below.
Table 2: Recommended Buffer Widths
Slope of Suffer (a/o}
Recommended Width of Undisturbed Vegetation
Adjacent to Non -Trout Waters
0-1
15 feet
1-3
20 feet
3-5
25 feet
>5
25 feet + (% of slope - 5)
2. Buffers in Trout Waters
Unless wider buffers are required per NC rules or statutes, the minimum width for an undisturbed
buffer adjacent to trout waters shall be 25 feet. The width of a buffer adjacent to a trout water shall
be measured horizontally from the top of bank to the nearest edge of the land -disturbing activity.
However, the Sedimentation Control Commission may approve plans that include land -disturbing
activity along trout waters when the duration of said disturbance would be temporary and the
extent of said disturbance would be minimal. (NCGS 113A-57(1)).
SECTION E: GROUND STABILIZATION
1. Ground Stabilization Timelines
Ground stabilization shall be achieved on any area of a site where land disturbing activities have
ceased within the timeframes listed in Table 3 below. It is recommended to stabilize the ground
more quickly if practicable. Extensions of time may be approved by the E&SC plan authority based
on weather or other site -specific conditions that make compliance impracticable. Portions of a site
that are lower in elevation and not expected to discharge during construction may be exempt from
the temporary ground cover requirements if identified on the E&SC plan and approved by the E&SC
plan authority.
Page 7 of 26

Permit No. NCGO10000
Table 3: Required Ground Stabilization Timeframes
Stabilize within
Site Area
this many calendar
Timeframe Variations
Description
days after ceasing
land disturbance
(a) Perimeter dikes,
7
None
swales, ditches, and
perimeter slopes
7
None
(b) High Quality Water
(HQW) Zones
N7
• If 10' less in length
slopes are or and are not
(c) Slopes steeper than
steeper than 2:1, 14 days are allowed
3:1
• 7 days for slopes greater than 50' in length
and with slopes steeper than 4:1
14
. 7 days for perimeter dikes, swales, ditches,
(d) Slopes 3:1 to 4:1
perimeter slopes, and HQW Zones
• 10 days for the Falls Lake Watershed
• 7 days for perimeter dikes, swales, ditches,
14
perimeter slopes, and HQW Zones
(e) Areas with slopes
• 10 days for the Falls Lake Watershed unless
flatter than 4:1
there is zero slope.
2. Permanent Ground Stabilization Timeline
After the permanent cessation of construction activities, any areas with temporary ground
stabilization shall be converted to permanent ground stabilization as soon as practicable but in no
case longer than 90 calendar days after the last land disturbing activity. Temporary ground
stabilization shall be maintained in a manner to render the surface stable against accelerated
erosion until permanent ground stabilization is achieved.
SECTION F: MATERIALS HANDLING
Any structural controls installed to manage construction materials stored or used on site shall be
included in the field copy of the E&SC plan. Requirements for handling materials on construction sites
shall be as follows:
1. Polyacrylamides (PAMS) and Flocculants
Polyacrylamides (PAMS) and flocculants shall be:
(a) stored in leak -proof containers that are kept under storm -resistant cover or surrounded by
secondary containment structures designed to protect adjacent surface waters,
(b) selected from the NC DWR List ofApproved PAMS/Fioccuiants list, available at:
https://files.nc.gov/nedeq/Water° 20 uali Environmentalti 2OSciences /ATU/ApprovedPAM
S4 1 2017.12df, and
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Permit No. NCGO10000
(c) used at the concentrations specified in the NC DWR List ofApproved PAMS/Flocculants and in
accordance with the manufacturer's instructions.
2. Equipment Fluids
(a) Fuels, Iubricants, coolants, and hydraulic fluids, and other petroleum products shall be
handled and disposed of in a manner so as not to enter surface or ground waters and in
accordance with applicable state and federal regulations. Equipment used on the site must be
operated and maintained properly to prevent discharge of fluids.
(b) Equipment vehicle, and other wash waters shall not be treated in a sediment basin or
sediment trap. Alternative controls should be provided such that there is no discharge of soaps,
solvents, or detergents.
3. Waste Materials
(a) Building material and land clearing waste shall be disposed of in accordance with North
Carolina General Statutes, Chapter 130A, Article 9 - Solid Waste Management, and rules
governing the disposal of solid waste (15A NCAC 1313). Areas dedicated for managing building
material and land clearing waste shall be at least 50 feet away from storm drain inlets and
surface waters unless it can be shown that no other alternatives are reasonably available.
(b) Paint and other liquid building material waste shall not be dumped into storm drains. It is
recommended to locate paint washouts at least 50 away from storm drain inlets unless there is
no alternative. Other options are to install lined washouts to use portable, removable bags or
bins.
(c) Hazardous or toxic waste shall be managed in accordance with the federal Resource
Conservation and Recovery Act (RCRA) and NC Hazardous Waste Rules at 15A NCAC,
Subchapter 13A.
(d) Litter and sanitary waste shall be managed in a manner to prevent it from entering waters and
shall be disposed of offsite.
4. Herbicide, Pesticide, and Rodenticides
Herbicide, pesticide, and rodenticides shall be stored and applied in accordance with the Federal
Insecticide, Fungicide, and Rodenticide Act and label restrictions.
S. Concrete Materials
Concrete materials onsite, including excess concrete, shall be controlled and managed to avoid
contact with surface waters, wetlands or buffers. No concrete or cement slurry shall be discharged
from the site. (Note that discharges from onsite concrete plants require coverage under a separate
NPDES permit - NCG140000.) Any hardened concrete residue will be disposed of, or recycled on
site, in accordance with local and state solid waste regulations.
6. Earthen Material Stock Piles
Earthen material stock piles shall be located at least 50 feet away from storm drain inlets and
surface waters unless no other alternatives are reasonably available.
SECTION G: OPERATION AND MAINTENANCE
1. Modifications to the E&SC Plan
Modifications to the approved E&SC plan that require changes to the E&SC measure designs, the
drainage areas, or the disturbed areas draining to E&SC measures shall be approved by the
E&SC plan authority. Deviations from the approved E&SC plan, or approved revised E&5C plan,
shall constitute a violation of this permit unless the deviation is to correct an emergency
situation where sediment is being discharged off the site. The E&SC plan authority may allow
deviations from the F&SC plan on a case -by -case basis if the deviations are minor adjustments to
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Permit No. NCGO10000
address minor deficiencies. A minor adjustment shall be the addition of E&SC measures (e.g.,
silt fence, inlet protection, check dams, rolled erosion control practices, etc.), or the relocation of
E&SC measures that would improve the overall stormwater management and sediment control
onsite. Minor adjustments shall be noted on the approved E&SC plan and maintained at the job
site.
2. Operation and Maintenance
The permittee shall install and maintain all temporary and permanent E&SC measures as required
by this permit and the approved E&SC plan.
3. Corrective Actions
If self -inspections required by this permit identify a need for maintenance of control measures,
modifications or additions to control measures, or corrective actions to control sediment or other
pollutants, these actions shall be performed as soon as possible considering adverse weather and
site conditions.
4. Draw Down of Sediment Basins for Maintenance or Close Out
Sediment basins and traps that receive runoff from drainage areas of one acre or more shall use
outlet structures that withdraw water from the surface when these devices need to be drawn
down for maintenance or close out unless this is infeasible. The circumstances in which it is not
feasible to withdraw water from the surface shall be rare (for example, times with extended cold
weather). Non -surface withdrawals from sediment basins shall be allowed only when all of the
following criteria have been met:
(a) The E&SC Plan authority has been provided with documentation of the non -surface withdrawal
and the specific time periods or conditions in which it will occur. The non -surface withdrawal
shall not commence until the E&SC plan authority has approved these items,
(b) The non -surface withdrawal has been reported as an anticipated bypass in accordance with Part
III, Section C, Item (2)(c) and (d) of this permit,
(c) Dewatering discharges are treated with controls to minimize discharges of pollutants from
stormwater that is removed from the sediment basin. Examples of appropriate controls include
properly sited, designed and maintained dewatering tanks, weir tanks, and filtration systems,
(d) Vegetated, upland areas of the sites or a properly designed stone pad is used to the extent
feasible at the outlet of the dewatering treatment devices described in Item(c) above,
(e) Velocity dissipation devices such as check dams, sediment traps, and riprap are provided at the
discharge points of all dewatering devices, and
(f) Sediment removed from dewatering treatment devices described in Item(c) above is disposed of
in a manner that does not cause deposition of sediment into waters of the United States.
5. Bypass of E&SC Measures
Diversions of stormwater from E&SC measures when the design storm has not been exceeded are
not allowed. Bypasses of E&SC measures shall be reported in accordance with Part III, Section C,
Item (2)(c) and (d) of this permit.
6. Unavoidable Bypass for Public Safety
A bypass may be allowed by the Director if the Director determines that all of the following
conditions were met:
(a) The bypass is unavoidable to prevent loss of life, personal injury or severe property damage,
(b) There were no feasible alternatives to the bypass, such as the use of auxiliary control
facilities, retention of stormwater or maintenance during normal periods of equipment
downtime or dry weather. This condition is not satisfied if adequate backup controls should
have been installed in the exercise of reasonable engineering judgement to prevent a bypass
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Permit No. NCGO10000
which occurred during normal periods of equipment downtime or preventative
maintenance, and
(c) the permittee submitted a notice of the bypass per the record -keeping requirements in Part
111, Section C, Item (2)(c) and (d) of this permit.
7. Upset of E&SC Measures
Diversions of stormwater from E&SC measures may be considered as an upset if the permittee
can demonstrate that all of the following conditions have been met. In any enforcement
proceeding, the permittee seeking to establish the occurrence of an upset has the burden of
proof.
(a) The permittee submitted notice of the upset as required in this general permit and identifies
the cause(s) of the upset.
(b) The permittee demonstrates that the upset was not caused by operational error, improperly
designed treatment or control facilities, lack of preventive maintenance, or careless or
improper operation.
(c) The permittee agrees to take remedial measures if necessary.
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Permit No. NCGO10000
PART III
SELF -INSPECTION, RECORDKEEPING AND REPORTING
SECTION A: SELF -INSPECTIONS
Self -inspections are required during normal business hours in accordance with the table below. When
adverse weather or site conditions would cause the safety of the inspection personnel to be in jeopardy,
the inspection may be delayed until the next business day on which it is safe to perform the inspection.
In addition, when a storm event of equal to or greater than 1.0 inch occurs outside of normal business
hours, the self -inspection shall be performed upon the commencement of the next business day. Any
time when inspections were delayed shall be noted in the Inspection Record.
Table 4: Self -Inspection Requirements
Frequency
Inspect
(during normal
Inspection records must include:
business hours
(1) Rain gauge
Daily
Daily rainfall amounts.
maintained in
If no daily rain gauge observations are made during weekend or
good working
holiday periods, and no individual -day rainfall information is
order
available, record the cumulative rain measurement for those un-
attended days (and this will determine if a site inspection is
needed). Days on which no rainfall occurred shall be recorded as
"zero." The permittee may use another rain -monitoring device
approved by the Division.
(2) E&SC
At least once per
1. Identification of the measures inspected,
Measures
7 calendar days
2. Date and time of the inspection,
and within 24
3. Name of the person performing the inspection,
hours of a rain
4. Indication of whether the measures were operating
event > 1.0 inch
properly,
in 24 hours
5. Description of maintenance needs for the measure,
6. Description, evidence, and date of corrective actions taken.
(3) Stormwater
At least once per
1. Identification of the discharge outfalls inspected,
discharge
7 calendar days
2. Date and time of the inspection,
outfalls (SDOs)
and within 24
3. Name of the person performing the inspection,
hours of a rain
4. Evidence of indicators of Stormwater pollution such as oil
event > 1.0 inch
sheen, floating or suspended solids or discoloration,
in 24 hours
S. Indication of visible sediment leaving the site,
6. Description, evidence, and date of corrective actions taken.
(4) Perimeter
At least once per
If visible sedimentation is found outside site limits, then a record
of site
7 calendar days
of the following shall be made:
and within 24
1. Actions taken to clean up or stabilize the sediment that has left
hours of a rain
the site limits,
event :1.0 inch
2. Description, evidence, and date of corrective actions taken, and
in 24 hours
3. An explanation as to the actions taken to control future
releases.
(5) Streams or
At least once per
If the stream or wetland has increased visible sedimentation or a
wetlands onsite
7 calendar days
stream has visible increased turbidity from the construction
or offsite
and within 24
activity, then a record of the following shall be made:
(where
hours of a rain
1. Description, evidence and date of corrective actions taken, and
accessible)
event > 1.0 inch
2. Records of the required reports to the appropriate Division
in 24 hours
Regional Office per Part III, Section C, Item (2) (a) of this permit
of this permit.
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Permit No. NCG010000
(6) Ground
After each phase
1. The phase of grading (installation of perimeter E&SC
stabilization
of grading
measures, clearing and grubbing, installation of storm
measures
drainage facilities, completion of all land -disturbing
activity, construction or redevelopment, permanent
ground cover).
2. Documentation that the required ground stabilization
measures have been provided within the required
timeframe or an assurance that they will be provided as
soon as possible.
NOTE; The rain inspection resets the required 7 calendar day inspection requirement.
SECTION B: RECORDKEEPING
1. E&SC Plan Documentation
The approved E&SC plan as well as any approved deviation shall be kept on the site. The
approved E&SC plan must be kept up-to-date throughout the coverage under this permit. The
items listed in Table 5 pertaining to the E&SC plan shall be kept on site and available for
inspection at all times during normal business hours.
Table 5: Recordkeeping Requirements
Item to Document
Documentation Requirements
(a) Each E&SC measure has been installed and
Initial and date each E&SC measure on a copy of the
does not significantly deviate from the
approved E&SC plan or complete, date and sign an
locations, dimensions and relative elevations
inspection report that lists each E&SC measure
shown on the approved E&SC plan.
shown on the approved E&SC plan. This
documentation is required upon the initial
installation of the E&SC measures or if the E&SC
measures are modified after initial installation.
(b) A phase of grading has been completed.
Initial and date a copy of the approved E&SC plan or
complete, date and sign an inspection report to
indicate completion of the construction phase.
(c) Ground cover is located and installed
Initial and date a copy of the approved E&SC plan or
in accordance with the approved E&SC
complete, date and sign an inspection report to
Plan.
indicate compliance with approved ground cover
specifications.
(d) The maintenance and repair
Complete, date and sign an inspection report.
requirements for all E&SC measures have
been performed.
(e) Corrective actions have been taken to
Initial and date a copy of the approved E&SC plan or
E&SC measures.
complete, date and sign an inspection report to
indicate the completion of the corrective action.
2. Additional Documentation to he Kept on Site
In addition to the E&SC plan documents above, the following items shall be kept on the site and
available for inspections at all times during normal business hours, unless the Division provides a
site -specific exemption based on unique site conditions that make this requirement not practical:
(a) This General Permit as well as the Certificate of Coverage, after it is received.
(b) Records of inspections made during the previous twelve months. The permittee shall record
the required observations on the Inspection Record Form provided by the Division or a similar
inspection form that includes all the required elements. Use of electronically -available records
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Permit No. NCG010000
in lieu of the required paper copies will be allowed if shown to provide equal access and utility
as the hard -copy records
3. Documentation to be Retained for Three Years
All data used to complete the e-NOI and all inspection records shall be maintained for a period of
three years after project completion and made available upon request [40 CFR 122.41]
SECTION C: REPORTING
1. Occurrences that Must be Reported
Permittees shall report the following occurrences:
(a) Visible sediment deposition in a stream or wetland.
(h) Oil spills if:
• They are 25 gallons or more,
• They are less than 25 gallons but cannot be cleaned up within 24 hours,
• They cause sheen on surface waters (regardless of volume), or
• They are within 100 feet of surface waters (regardless of volume).
(c) Releases of hazardous substances in excess of reportable quantities under Section 311 of the
Clean Water Act Ref: 40 CFR 110.3and 40 CFR 117.3) or section 102 of CERCLA (Ref; 40 CFR
302.4) or G.S. 143-215.85.
(d) Anticipated bypasses and unanticipated bypasses.
(e) Noncompliance with the conditions of this permit that may endanger health or the
environment.
2. Reporting Timeframes and Other Requirements
After a permittee becomes aware of an occurrence that must be reported, he shall contact the
appropriate Division regional office within the timeframes and in accordance with the other
requirements listed in Table 6 below. Occurrences outside normal business hours may also be
reported to the Department's Environmental Emergency Center personnel at [phone].
Table 6: Reporting Requirements
Occurrence
Reporting Timeframes After Discovery) and Other Requirements
(a) Visible sediment
• Within 24 hours, an oral or electronic notification.
deposition in a
. Within 7 calendar days, a report that contains a description of the
stream or wetland
sediment and actions taken to address the cause of the deposition.
Division staff may waive the requirement for a written report on a case -
by -case basis.
• If the stream is named on the NC 303 d list as impaired for sediment -related
causes, the permittee may be required to perform additional monitoring,
inspections or apply more stringent practices if staff determine that additional
requirements are needed to assure compliance with the federal or state
impaired -waters conditions.
(b) Oil spills and
. Within 24 hours, an oral or electronic notification. The notification shall
release of hazardous
include information about the date, time, nature, volume and location of
substances per Item
the spill or release.
1 b c above
(c) Anticipated
• A report at least ten days before the date of the bypass, if possible. The
bypasses [40 CFR
report shall include an evaluation of the anticipated quality and effect of
122.41 m 3)
the bypass.
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Permit No. NCGO10000
(d) Unanticipated • Within 24 hours, an oral or electronic notification.
bypasses [40 CFR • Within 7 calendar days, a report that includes an evaluation of the
122.41(m)(3)1 quality and effect of the bvnass.
(e) Noncompliance
. Within 24 hours, an oral or electronic notification.
with the conditions
. Within 7 calendar days, a report that contains a description of the
of this permit that
noncompliance, and its causes; the period of noncompliance, including
may endanger health
exact dates and times, and if the noncompliance has not been corrected,
or the
the anticipated time noncompliance is expected to continue; and steps
environment[40 CFR
taken or planned to reduce, eliminate, and prevent reoccurrence of the
122.41(1)(7)]
noncompliance. [40 CFR 122.41(1)(6).
• Division staff may waive the requirement for a written report on a case-
e basis.
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Permit No. NCGO10000
PART IV STANDARD CONDITIONS FOR NPDES
STORMWATER GENERAL PERMITS
SECTION A: COMPLIANCE AND LIABILITY
L Continuation of Previously Permitted Projects
Projects and their corresponding activities permitted under the previous version of the NC
general permit for construction activities will automatically be considered covered under this
general permit without the submittal of a Notice of Intent form. In addition, an annual general
permit fee shall not be required for projects covered under the previous version of the NC
general permit for construction activities.
2. Projects Submitted Prior to this Permit's Effective Date
Complete project applications that were received prior to the effective date of this permit, but
not approved by the E&SC plan authority until after approval of this NPDES permit, can rely on
design and management practices effective at the time of application submittal.
3. Duty to Comply
The permittee must comply with all conditions of this general permit. Any permit noncompliance
constitutes a violation of the Clean Water Act (CWA) and is grounds for enforcement action; for
permit termination, revocation and reissuance, or modification; or denial of a permit upon renewal
application. [40 CFR 122.41]
(a) The permittee shall comply with standards or prohibitions established under section 307(a)
of the CWA for toxic pollutants within the time provided in the regulations that establish these
standards or prohibitions, even if the general permit has not yet been modified to incorporate
the requirement. [40 CFR 122.41]
(b) The CWA provides that any person who violates section[s] 301, 302, 306, 307, 308,318 or 405
of the Act, or any permit condition or limitation implementing any such sections in a permit
issued under section 402, or any requirement imposed in a pretreatment program approved
under sections 402(a)(3) or 402(b)(8) of the Act, is subject to a civil penalty not to exceed
$37,500 per day for each violation. [33 USC 1319(d) and 40 CFR 122.41(a)(2)]
(c) The CWA provides that any person who negligently violates sections 301, 302, 306, 307, 308,
318, or 405 of the Act, or any condition or limitation implementing any of such sections in a
permit issued under section 402 of the Act, or any requirement imposed in a pretreatment
program approved under section 402(a)(3) or 402(b)(8) of the Act, is subject to criminal
penalties of $2,500 to $25,000 per day of violation, or imprisonment of not more than 1 year,
or both. In the case of a second or subsequent conviction for a negligent violation, a person
shall be subject to criminal penalties of not more than $50,000 per day of violation, or by
imprisonment of not more than 2 years, or both. (33 USC 1319(c)(1) and 40 CFR 122.41(a)(2)]
(d) Any person who knowingly violates such sections, or such conditions or limitations is subject
to criminal penalties of $5,000 to $50,000 per day of violation, or imprisonment for not more
than 3 years, or both. In the case of a second or subsequent conviction for a knowing violation,
a person shall be subject to criminal penalties of not more than $100,000 per day of violation,
or imprisonment of not more than 6 years, or both. 133 USC 1319(c)(2) and 40 CFR
122.41(a)(2)]
(e) Any person who knowingly violates section 301, 302, 303, 306, 307, 308, 318 or 405 of the Act,
or any permit condition or Iimitation implementing any of such sections in a permit issued
under section 402 of the Act, and who knows at that time that he thereby places another
person in imminent danger of death or serious bodily injury, shall, upon conviction, be subject
to a fine of not more than $250,000 or imprisonment of not more than 15 years, or both. In the
Page 16 of 26

Permit No. NCGO10000
case of a second or subsequent conviction for a knowing endangerment violation, a person
shall be subject to a fine of not more than $500,000 or by imprisonment of not more than 30
years, or both. An organization, as defined in section 309(c)(3)(B)(iii) of the CWA, shall, upon
conviction of violating the imminent danger provision, be subject to a fine of not more than
$1,000,000 and can be fined up to $2,000,000 for second or subsequent convictions. [40 CFR
122.41(a)(2)]
(f) Under state law, a civil penalty of not more than $25,000 per violation may be assessed
against any person who violates or fails to act in accordance with the terms, conditions, or
requirements of a permit. [North Carolina General Statutes § 143-215.6A]
(g) Any person may be assessed an administrative penalty by the Administrator for violating
section 301, 302, 306, 307, 308, 318 or 405 of this Act, or any permit condition or limitation
implementing any of such sections in a permit issued under section 402 of this Act.
Administrative penalties for Class I violations are not to exceed $20,628 per violation, with the
maximum amount of any Class I penalty assessed not to exceed $51,570. Penalties for Class lI
violations are not to exceed $20,628 per day for each day during which the violation
continues, with the maximum amount of any Class 11 penalty not to exceed $257,848. [33 USC
1319(g)(2) and 40 CFR 122.41(a)(3)]
4. Non-Stormwater Discharges
If storm event monitored in accordance with this general permit coincides with a non-stormwater
discharge, the permittee shall separately monitor all parameters as required under all other
applicable discharge permits and provide this information with the stormwater discharge
monitoring report.
S. Test Procedures
Test procedures for the analysis of pollutants shall conform to the EMC regulations published
pursuant to NCGS 143-215.63 et. seq, the Water and Air QualityReporting Acts, and to regulations
published pursuant to Section 304(g), 33 USC 1314, of the Federal Water Pollution Control Act, as
Amended, and Regulation 40 CFR 136.
To meet the intent of the monitoring required by this general permit, all test procedures must
produce minimum detection and reporting levels and all data generated must be reported down to
the minimum detection or lower reporting level of the procedure. If no approved methods are
determined capable of achieving minimum detection and reporting levels below general permit
discharge requirements, then the most sensitive (method with the lowest possible detection and
reporting level) approved method must be used.
6. Duty to Mitigate
The permittee shall take all reasonable steps to minimize or prevent any discharge in violation of
this general permit which has a reasonable likelihood of adversely affecting human health or the
environment. [40 CFR 122.41(d)]
7. Need to Halt or Reduce Not a Defense
It shall not be a defense for a permittee in an enforcement action that it would have been necessary
to halt or reduce the permitted activity in order to maintain compliance with the condition of this
general permit. [40 CFR 122.41(c)]
8. Civil and Criminal Liability
Except as provided in Part II, Section B of this general permit regarding bypassing of stormwater
control facilities, nothing in this permit shall be construed to relieve the permittee from any
responsibilities, liabilities, or penalties for noncompliance pursuant to NCGS 143-215.3,143-215.6A,
143-215.613, 143-215.6C, or Section 309 of the Federal Act, 33 USC 1319. Furthermore, the
Page 17 of 26

Permit No. NCG010000
permittee is responsible for consequential damages, such as fish kills, even though the responsibility
for effective compliance may be temporarily suspended.
9. Oil and Hazardous Substance Liability
Nothing in this general permit shall be construed to preclude the institution of any legal action or
relieve the permittee from any responsibilities, liabilities, or penalties to which the permittee is or
may be subject to under NCGS 143-215.75 et seq. or Section 311 of the Federal Act, 33 USC 1321.
10. Property Rights
The issuance of this general permit does not convey any property rights in either real or personal
property, or any exclusive privileges, nor does it authorize any injury to private property or any
invasion of personal rights, nor any infringement of Federal, State or local laws or regulations [40
CFR 122.41(g)],
11. Severability
The provisions of this general permit are severable, and if any provision of this general permit, or
the application of any provision of this general permit to any circumstances, is held invalid, the
application of such provision to other circumstances, and the remainder of this general permit, shall
not be affected thereby [NCGS 15013-23].
12. Duty to Provide Information
The permittee shall furnish to the Division, within a reasonable time, any information which the
Division may request to determine whether cause exists for modifying, revoking and reissuing, or
terminating the general permit issued pursuant to this general permit or to determine compliance
with this general permit. The permittee shall also furnish to the Division upon request, copies of
records required to be kept by this general permit [40 CFR 122.41(h)].
13. Inspection and Entry
The permittee shall allow the Director, an authorized representative (including an authorized
contractor acting as a representative of the Director), or an authorized representative of a municipal
operator or the separate storm sewer system receiving the discharge (if applicable), upon the
presentation of credentials and other documents as may be required by law, to:
(a) Enter upon the permittee's premises where a regulated facility or activity is located or
conducted, or where records must be kept under the conditions of this general permit;
(b) Have access to and copy, at reasonable times, any records that must be kept under the
conditions of this general permit;
(c) Inspect at reasonable times any facilities, equipment (including monitoring and control
equipment), practices, or operations regulated or required under this general permit; and
(d) Sample or monitor at reasonable times, for the purposes of assuring permit compliance or as
otherwise authorized by the Clean Water Act, any substances or parameters at any location. [40
CFR 122.41(i)]
14. Penalties for Tampering
The Clean Water Act provides that any person who falsifies, tampers with, or knowingly renders
inaccurate, any monitoring device or method required to be maintained under this general permit
shall, upon conviction, be punished by a fine of not more than $10,000 per violation, or by
imprisonment for not more than two years per violation, or by both. If a conviction of a person is for
a violation committed after a first conviction of such person under this paragraph, punishment is a
fine of not more than $20,000 per day of violation, or by imprisonment of not more than 4 years, or
both [40 CFR 122.41].
Page 18 of 26

Permit No. NCG010000
15. Penalties for Falsification of Reports
The Clean Water Act provides that any person who knowingly makes any false statement,
representation, or certification in any record or other document submitted or required to be
maintained under this general permit, including monitoring reports or reports of compliance or
noncompliance shall, upon conviction, be punished by a fine of not more than $10,000 per violation,
or by imprisonment for not more than two years per violation, or by both [40 CFR 122.41].
16. Onshore or Offshore Construction
This general permit does not authorize or approve the construction of any onshore or offshore
physical structures or facilities or the undertaking of any work in any navigable waters.
17. Duty to Reapply
Dischargers covered by this general permit need not submit a new Notice of Intent (NOI) or renewal
request unless so directed by the Division. If the Division chooses not to renew this general permit,
the permittee will be notified to submit an application for an individual permit. [15A NCAC 02H
.0127(e)]
18. Planned Changes
The permittee shall give notice to the Director as soon as possible of any planned changes at the
permitted facility which could significantly alter the nature or quantity of pollutants discharged [40
CFR 122.41(l)]. This notification requirement includes pollutants which are not specifically listed in
the general permit or subject to notification requirements under 40 CFR Part 122.42 (a).
19. Anticipated Noncompliance
The permittee shall give advanced notice to the Director of any planned changes at the permitted
facility which may result in noncompliance with the general permit. [40 CFR 122.41(1)(2)]
SECTION B: PERMIT ADMINISTRATION
1. General Permit Expiration
General permits will be effective for a term not to exceed five years, at the end of which the Division
may renew them after all public notice requirements have been satisfied. If a general permit is
renewed, existing permittees do not need to submit a renewal request or pay a renewal fee unless
directed by the Division. New applicants seeking coverage under a renewed general permit must
submit a Notice of Intent to be covered and obtain a Certificate of Coverage under the renewed
general permit. [15A NCAC 02H .0127(e)]
2. Transfers
This general permit is not transferable to any person without prior written notice to and approval
from the Director in accordance with 40 CFR 122.61. The Director may condition approval in
accordance with NCGS 143-215.1, in particular NCGS 143-215.1(b)(4) b.2., and may require
modification or revocation and reissuance of the Certificate of Coverage, or a minor modification, to
identify the new permittee and incorporate such other requirements as may be necessary under the
CWA [40 CFR 122.41(l)(3), 122.61] or state statute. The Permittee is required to notify the
Division in writing in the event the permitted facility is sold or closed.
3. When an Individual Permit May be Required
The Director may require any owner/operator authorized to discharge under a certificate of
coverage issued pursuant to this general permit to apply for and obtain an individual permit or an
alternative general permit. Any interested person may petition the Director to take action under
this paragraph. [15A NCAC 02H ,0127(i)-(j)] Cases where an individual permit may be required
include, but are not limited to, the following:
Page 19 of 26

Permit No. NCGO10000
(a) The discharger is a significant contributor of pollutants;
(b) The receiving stream is of a unique duality and the standard conditions may not provide
adequate protection;
(c) Conditions at the permitted site change, altering the constituents and/or characteristics of the
discharge such that the discharge no longer qualifies for a general permit;
(d) The discharge violates the terms or conditions of this general permit;
(e) A change has occurred in the availability of demonstrated technology or practices for the
control or abatement of pollutants applicable to the point source;
(f) Effluent limitations are promulgated for the point sources covered by this general permit;
(g) A water quality management plan containing requirements applicable to such point sources is
approved after the issuance of this general permit;
(h) The Director determines at his or her own discretion that an individual permit is required.
4. When an Individual Permit May be Requested
Any permittee operating under this general permit may request to be excluded from the coverage of
this general permit by applying for an individual permit. When an individual permit is issued to an
owner/operator the applicability of this general permit is automatically terminated on the effective
date of the individual permit. [15A NCAC 02H .0127(h)]
S. Impacts or Potential Impacts to Surface Waters or Wetlands
If evidence indicates that the stormwater discharges from the site are impacting or have the
potential to impact surface waters or wetlands, then the Division may take appropriate actions
including any or all of the following:
a) take compliance and enforcement action;
b) require the permittee to include and implement appropriate control and restoration
measures;
c) require the permittee to develop and implement additional site -specific stormwater
pollution prevention measures;
d) require the permittee to obtain an individual permit.
6. Signatory Requirements
All applications, reports, or information submitted to the Permitting Issuing Authority shall be
signed and certified. [40 CFR 122.41(k)]
(a) All Notices of Intent to be covered under this general permit shall be signed as follows:
• For a corporation: by a responsible corporate officer. For the purpose of this Section, a
responsible corporate officer means: (a) a president, secretary, treasurer or vice
president of the corporation in charge of a principal business function, or any other
person who performs similar policy or decision making functions for the corporation, or
(b) the manager of one or more manufacturing, production, or operating facilities,
provided, the manager is authorized to make management decisions which govern the
operation of the regulated facility including having the explicit or implicit duty of making
major capital investment recommendations, and initiating and directing other
comprehensive measures to assure long term environmental compliance with
environmental laws and regulations; the manager can ensure that the necessary systems
are established or actions taken to gather complete and accurate information for permit
application requirements; and where authority to sign documents has been assigned or
delegated to the manager in accordance with corporate procedures.
• For a partnership or sole proprietorship: by a general partner or the proprietor,
respectively; or
Page 20 of 26

Permit No. NCGO10000
• For a municipality, State, Federal, or other public agency: by either a principal
executive officer or ranking elected official. [40 CFR 122.22]
(b) All reports required by the general permit and other information requested by the Director
shall be signed by a person described in paragraph a. above or by a duly authorized
representative of that person. A person is a duly authorized representative only if:
• The authorization is made in writing by a person described above;
The authorization specified either an individual or a position having responsibility for the
overall operation of the regulated facility or activity, such as the position of plant manager,
operator of a well or well field, superintendent, a position of equivalent responsibility, or
an individual or position having overall responsibility for environmental matters for the
company. (A duly authorized representative may thus be either a named individual or any
individual occupying a named position.); and
The written authorization is submitted to the Director. [40 CFR 122.22]
(c) If an authorization under paragraph (b) of this section is no longer accurate because a different
individual or position has responsibility for the overall operation of the facility, a new
authorization satisfying the requirements of paragraph (b) of this section must be submitted to
the Director prior to or together with any reports, information, or applications to be signed by
an authorized representative. [40 CFR 122.221
(d) Any person signing a document under paragraphs a. orb. of this section shall make the
following certification [40 CFR 122.22]. NO OTHER STATEMENTS OF CERTIFICATION WILL BE
ACCEPTED:
"I certify under penalty of law that this document and all attachments were prepared under
my direction or supervision in accordance with a system designed to assure that qualified
personnel properly gather and evaluate the information submitted. Based on my inquiry of
the person or persons who manage the system, or those persons directly responsible for
gathering the information, the information submitted is, to the best of my knowledge and
belief, true, accurate, and complete. 1 am aware that there are significant penalties for
submitting false information, including the possibility of fine and imprisonment for knowing
violations. "
7. General Permit Modification, Revocation and Reissuance, or Termination
The issuance of this general permit does not prohibit the Division from reopening and modifying the
general permit, revoking and reissuing the general permit, or terminating the general permit as
allowed by the laws, rules, and regulations contained in Title 40, Code of Federal Regulations, Parts
122 and 123; Title 15A of the North Carolina Administrative Code, Subchapter 2H .0100; and North
Carolina General Statute 143-215.1 et al.
After public notice and opportunity for a hearing, the general permit may be terminated for cause.
The filing of a request for a general permit modification, revocation and reissuance, or termination
does not stay any general permit condition. The Certificate of Coverage shall expire when the
general permit is terminated.
8. Certificate of Coverage Actions
The general permit may be modified, revoked and reissued, or terminated for cause. The
notification of planned changes or anticipated noncompliance does not stay any general permit
condition [40 CFR 122.41(f)].
Page 21 of 26

Permit No. NCGO10000
9. Annual Administering and Compliance Monitoring Fee Requirements
The permittee must pay the administering and compliance monitoring fee within 30 (thirty) days
after being billed by the Division. Failure to pay the fee in timely manner in accordance with 15A
NCAC 2H .0105(b)(2) may cause this Division to initiate action to revoke coverage under the general
permit.
10. Availability of Reports
Except for data determined to be confidential under NCGS 143-215.3(a)(2) or Section 308 of the
Federal Act, 33 USC 1318, all reports prepared in accordance with the terms shall be available for
public inspection at the offices of the Division. As required by the Act, analytical data shall not be
considered confidential. Knowingly making any false statement on any such report may result in the
imposition of criminal penalties as provided for in NCGS 143-215.613 or in Section 309 of the Federal
Act.
11. Omissions
Where the Permittee becomes aware that it failed to submit any relevant facts in a Notice of Intent
to be covered under this general permit, or submitted incorrect information in that Notice of Intent
application or in any report to the Director, it shall promptly submit such facts or information. [40
CFR 122.41(1)(8)]
Page 22 of 26

PART V DEFINITIONS
1. Act
See Clean Water Act.
Permit No. NCG010000
Adverse Weather
Climate conditions that are dangerous or create inaccessibility for personnel, such as local flooding,
high winds, electrical storms, winter weather conditions, or situations that otherwise make
inspections impractical. When adverse weather or site conditions prevent or restrict access to
complete a regular or rain event inspection, this should be clearly documented on the next issued
report. Documentation should include the inspector's name, the date and time, and a written
narrative of the adverse weather or site condition. Adverse weather or site conditions do not
exempt the permittee from having to file an inspection report in accordance with Section 11. B of this
permit.
3. Allowable Non-Stormwater Discharges
This general permit regulates stormwater discharges. Non-stormwater discharges which shall be
allowed in the stormwater conveyance system are:
(a) All other discharges that are authorized by a non-stormwater NPDES permit.
(b) Uncontaminated groundwater, foundation drains, air -conditioner condensate without added
chemicals, springs, discharges of uncontaminated potable water, waterline and fire hydrant
flushings, water from footing drains, and irrigation waters, flows that do not result in a water
quality standards violation.
(c) Discharges resulting from fire -fighting or fire -fighting training, or emergency shower or eye
wash as a result of use in the event of an emergency.
4. Best Management Practices (BMPs)
Measures or practices used to reduce the amount of pollution entering surface waters. BMPs may
take the form of a process, activity, or physical structure
S. Bypass
The known diversion of stormwater from any portion of stormwater control facility including the
collection system, which is not a designed or established operating mode for the facility.
6. Certificate of Coverage
The cover sheet that accompanies a general permit upon issuance and lists the facility name,
location, receiving stream, river basin, effective date of coverage under the general permit and is
signed by the Director.
7. Clean Water Act
The Federal Water Pollution Control Act, also known as the Clean Water Act (CWA), as amended, 33
USC 1251, et. seq.
8. Common Plan of Development
A contiguous area where multiple separate and distinct land disturbing activities may be taking
place at different times and on different schedules under one common plan. The "common plan" of
development or sale is broadly defined as any announcement or piece of documentation (including a
sign, public notice or hearing, sales pitch, advertisement, drawing, permit application, zoning
request, computer design, etc.) or physical demarcation (including boundary signs, lot stakes,
surveyor markings, etc.) indicating construction activities are planned to occur on a specific plot
regardless of ownership of the parcels..
Page 23 of 26

Permit No. NCG010000
9. Concrete Washout
Wastewater resulting from the washing of equipment such as trucks, chutes, hoses, mixers, hoppers,
wheelbarrows, and tools that are used to produce, handle, or store concrete and other cementitious
materials such as mortar, plaster, stucco, or grout.
10. Control Measure
Any BMP or other structural or non-structural practice or procedure used to prevent or reduce
the discharge of pollutants including practices to control erosion and sedimentation.
11. Division or DEMLR
The Division of Energy, Mineral, and Land Resources of the NC Department of Environmental
Quality (DEQ).
12. Director
The Director of the Division of Energy, Mineral, and Land Resources of the NC Department of
Environmental Quality (DEQ).
13. EMC
The North Carolina Environmental Management Commission.
14. Erosion and Sedimentation Control (E&SC) Plan
A plan developed in compliance with the North Carolina Sedimentation Pollution Control Act of
1973 in G.S. 113A-50 et seq. to prevent sediment resulting from accelerated erosion from being
transported off the site of the land -disturbing activity or in waters.
15. Erosion and Sedimentation Control (E&SC) Plan Authority
The entity responsible for reviewing and approving the Erosion and Sediment Control Plan.
Within some local governments' jurisdictions, this will be a delegated program. Elsewhere, it
will be the Division.
16. Erosion and Sediment Control (E&SC) Measure
Temporary and permanent practices and devices to prevent sediment resulting from accelerated
erosion from being transported off the site of the land -disturbing activity or in waters of the State
of North Carolina. E&5C measures, include, but are not limited to, sedimentation traps,
sedimentation ponds, rock dams, temporary diversions, temporary slope drains, rock check dams,
sediment fence or barriers, all forms of inlet protection, storm drainage facilities, energy
dissipaters and stabilization methods of open channels.
17. Ground Cover
Any vegetative growth or other material which, when applied to the soil surface, renders the soil
surface stable against accelerated erosion.
18. Hazardous Substance
Any substance designated under 40 CFR Part 116 pursuant to Section 311 of the Clean Water Act.
19. Landfill
A disposal facility or part of a disposal facility where waste is placed in or on land and which is not a
land treatment facility, a surface impoundment, an injection well, a hazardous waste long-term
storage facility or a surface storage facility.
20. Normal Business Hours
These are generally considered to be between the hours of 6 a.m. and 6 p.m., or when workers are
normally present on the construction site. Weekends, state and federal holidays are not considered
normal business hours unless construction activities are taking place on the site during those times.
Page 24 of 26

Permit No. NCGO10000
21. Notice of Intent
The state application form which, when submitted to the Division, officially indicates the facility's
notice of intent to seek coverage under a general permit.
22. Permanent Stabilization
When all soil disturbing activity is completed and exposed soils have been stabilized with a
vegetative cover with a density of at least 80% or covered with a structural stabilization method.
Permanent perennial vegetation may include the use of sod, shrubs and ground cover plants mixed
with mulching, aggregate or other landscaping techniques. Structural methods include concrete,
asphalt, retaining wall or other stabilization techniques.
23. Permittee
The person, firm or organizational entity that signed as the financially responsible party on the
Erosion and Sedimentation Control Plan.
24. Point Source Discharge of Stormwater
Any discernible, confined and discrete conveyance including, but not specifically limited to, any pipe,
ditch, channel, tunnel, conduit, well, or discrete fissure from which stormwater associated with
industrial activity is or may be discharged to waters of the state.
2 S. Secondary Containment
Spill containment for the contents of the single largest tank within the containment structure plus
sufficient freeboard to allow for the 25-year, 24-hour storm event.
26. Section 313 Water Priority Chemical
A chemical or chemical category which:
(a) Is listed in 40 CFR 372.65 pursuant to Section 313 of Title III of the Superfund Amendments
and Reauthorization Act (SARA) of 1986, also titled the Emergency Planning and Community
Right -to -Know Act of 1986;
(b) Is present at or above threshold levels at a facility subject to SARA title III, Section 313
reporting requirements; and
(c) Meets at least one of the following criteria:
Is listed in appendix D of 40 CFR part 122 on Table I1 (organic priority pollutants), Table
III (certain metals, cyanides, and phenols) or Table IV (certain toxic pollutants and
hazardous substances);
Is listed as a hazardous substance pursuant to section 311(b)(2)(A) of the CWA at 40 CFR
116.4; or
Is a pollutant for which EPA has published acute or chronic water quality criteria.
27. Soil Stabilization
The use of vegetative, physical or chemical coverage techniques that will restrain accelerated
erosion on disturbed soils for temporary or permanent control needs.
28. Stormwater Discharge Outfall (SDO)
The point of departure of Stormwater from a discernible, confined, or discrete conveyance, including
but not limited to, storm sewer pipes, drainage ditches, channels, spillways, or channelized
collection areas, from which stormwater flows directly or indirectly into waters.
29. Stormwater Runoff
The flow of water which results from precipitation and which occurs immediately following rainfall
or as a result of snowmelt.
Page 25 of 26

Permit No. NCGO10000
30. Stormwater Associated with Industrial Activity
The discharge from any point source which is used for collecting and conveying stormwater and
which is directly related to manufacturing, processing or raw material storage areas at an industrial
site. Facilities considered to be engaged in "industrial activities" include those activities defined in
40 CFR 122.26(b)(14). The term does not include discharges from facilities or activities excluded
from the NPDES program.
31. Stormwater Pollution Prevention Plan (SWPPP)
The elements of the States stormwater pollution prevention program that provide the technology -
based requirements designed to protect the state's waters from the adverse impacts of sediments.
In North Carolina, the SWPPP for construction activities includes the Erosion and Sedimentation
Control Plan, Ground Stabilization, Materials Handling, and Disturbed Area Limit for Special and
Threatened Waters.
32. Temporary Stabilization
When the establishment of ground cover over all disturbed areas (such as mulching, rolled erosion
control products, vegetation, or other material) renders the surface stable against accelerated
erosion. Stabilization shall be achieved with the establishment of a uniform and evenly -distributed
(i.e., without large bare areas) ground cover with a cover density of at least 80%.
33. Toxic Pollutant
Any pollutant listed as toxic under Section 307(a)(1) of the Clean Water Act.
34. Upset
An exceptional incident in which there is unintentional and temporary noncompliance with
technology -based permit effluent limitations because of factors beyond the reasonable control of the
permittee. An upset does not include noncompliance to the extent caused by operational error,
improperly designed treatment or control facilities, inadequate treatment or control facilities, lack
of preventive maintenance, or careless or improper operation.
35. Visible Sedimentation
Solid particulate matter, both mineral and organic, that has been or is being transported by water,
air, gravity, or ice from its site of origin that can be seen with the unaided eye.
36. 25-year, 24-hour Storm Event
The maximum 24-hour precipitation event expected to be equaled or exceeded, on the average, once
in 25 years.
Page 26 of 26

Appendix B
Self -Inspection Program

The North Carolina
erosion control program
Responsibilities
of
Local Erosion & Sedimentation Control Programs
Local governments (a.k.a. "Local Programs") with authority delegated to them by the
Sedimentation Control Commission for administering and enforcing the state Sedimentation
Pollution Control Act of 1973 ("Sediment Act") must adhere to the mandatory standards and
other provisions of this law, including its exemptions and exclusions of power. Below are some
common responsibilities under which Local Programs are expected to adhere to satisfy this
state law and effectively manage their programs.
WTI ►■ ilk] ikyIIiMAM
1. Plans are to be reviewed and a decision rendered to the applicant within 30 calendar
days of receipt of a complete plan. Unlike with other permits, there is no pausing this
"review clock". A complete plan is defined as follows:
a. An erosion and sediment control plan
b. Calculations in support of the design, if applicable
c. An authorized statement of financial responsibility
d. A letter of consent or permission letter from the landowner for the land -
disturbance, if the landowner and the Financially Responsible Person/Party are
not the same entity
e. Documentation of property ownership (e.g., deed)
f. Fees paid in full
2. Plans are to be reviewed and a decision rendered to the applicant within 15 calendar
days of receipt of a revised plan. There is no pausing this "review clock" once it has
started.
Reference: G.S. 113A-61(b)
Page 1 of 5

The North Carolina
erosion control program
3. Local Programs must require homebuilders to apply for an erosion and sediment
control plan approval once their cumulative land -disturbance in a subdivision is
planned to exceed one acre (or the Local Program's threshold for requiring a plan,
whichever is less*).
Each homebuilder within a subdivision must have their own erosion and sediment
control plan once their land disturbance exceeds or is reasonably expected to exceed
one (1) acre within the subdivision. This is a per subdivision requirement, and not a
per lot requirement. This is regardless of whether those lots are contiguous. The
Sediment Act refers to the land -disturbing activity as that occurring on a tract of land.
By definition, a "Tract" means all contiguous land and bodies of water being disturbed
or to be disturbed as a unit, regardless of ownership. Thus, the subdivision is the Tract
of land which is to be permitted. Individual lots are not tracts if they are within a
subdivision.
*Local Programs can require a plan when this exceedance equals something less than
one acre.
Reference: G.S. 113A-52 & 113A-57(4)
4. Local Programs are not to accept erosion control plans from publicly -funded projects
Local Programs are excluded from administering the Sediment Act (i.e., reviewing and
monitoring projects) on the following types of land -disturbing activities:
a. Those conducted by the state of North Carolina (e.g., NCDOT, public schools)
b. Those conducted by the federal government (e.g., DOD)
c. Those conducted by themselves or another Local Program (e.g., public schools)
d. Those conducted by parties having the power of eminent domain
(e.g., pipelines, railroads, public works projects)
e. Those conducted for oil and gas exploration and development on a well pad site
Broadly stated, this exclusion would apply to all publicly -funded projects, whether
funded in whole or in part.
Reference: G.S. 113A-56(a) and MOA Part II.D.
Page 2 of 5

The North Carolina
erosion control program
5. Local Programs shall only approve a plan upon determining that it complies with all
applicable state and local regulations for erosion and sediment control.
Projects that call for work within a jurisdictional waterbody or a riparian buffer may
require a USACE 404 permit or a 401 Water Quality Certification from DEQ's Division of
Water Resources (DWR). These permits or certifications should be sought when
reviewing plans. These waterbodies and buffers should be clearly delineated on the
plans, and the terms of the permit or certification should be considered when
reviewing the plans. Because these permits and certifications may take longer than 30
days to be issued, Local Programs shall condition approval of plans upon compliance
with these permits and certifications or with any federal or state water quality laws or
rules. A Local Program shall disapprove an erosion and sediment control plan if
implementation of the plan would result in a violation of the riparian buffer rules.
Reference: G.S. 113A-61(b) & (b1)
6. Waivers must be sought for desired land disturbances greater than 20 acres when in
a High Quality Water Zone
Projects located within sensitive watersheds known as High Quality Waters (HQW),
have more restrictive design standards. Uncovered areas involved with the land -
disturbing activity inside HQW zones shall be limited to 20 acres within the boundaries
of the tract. Larger areas may be uncovered within the boundaries of the tract with
written approval of the DEQ-DEMLR Director upon providing engineering justification
with a construction sequence that considers phasing, limiting exposure, weekly
submitted self -inspection reports, a more conservative design than the 25-year storm,
and other site -specific conditions as stipulated by the Director. The plans may have to
be disapproved in the interim, if larger areas have been submitted for approval within
the 15 or 30 day review period with no waiver granted.
Reference: 15A NCAC 048.0124
Page 3 of 5

The North Carolina
erosion control program
SITE MONITORING & COMPLIANCE
7. Local Programs are to review documents provided on the project site.
Before construction begins, certificates or letters of plan approvals shall be posted at
the primary entrance of the job site or other location that is observable to the public or
inspectors. Local Program staff are to verify these postings with each visit.
Contractors, developers, homebuilders, financially responsible parties, or their
consultants are to conduct their own inspections after each phase of the plan (and
weekly or within 24 hours of a precipitation event equal to or greater than 1 inch for
projects covered under the NPDES NCG01 permit). The name, address, organization
affiliation, telephone number, signature of the person conducting the inspection, and
the date of the inspection shall be included, whether on a copy of the approved
erosion and sedimentation control plan or an inspection report. If documentation of
inspections occurs on a copy of the approved erosion and sedimentation control plan,
then that plan shall be kept onsite. (NPDES inspection reports must be made available
during normal business hours.) Local Program staff are to review self-inspection/self-
monitoring records and ensure that inspections are being conducted, properly
documented, and are accessible.
Reference: 15A NCAC 048.0127 & .0131
8. Local Programs are to provide for inspections of land -disturbing activities at a
frequency sufficient to ensure compliance with the Sediment Act and the local
ordinance, and to determine whether the measures required in an erosion and
sedimentation control plan are effective in controlling erosion and sedimentation
resulting from the land -disturbing activity.
If it is determined that the party engaged in the land -disturbing activity has failed to
comply with the Sediment Act or with the local government, the Program will
immediately service a notice of violation upon the responsible party. The notice may
be served by any means authorized under G.S. 1A-1, Rule 4.
Reference: G.S. 113A-61.1(a) & (c) and MOA Part III.D.1.
Page 4 of 5

The North Carolina
erosion control program
FTI11 A I101NIIWI1[*101
9. Local Programs are to report on their activities
Local Programs are to provide monthly activity reports to the DEQ, Division of Energy,
Mineral & Land Resources (DEMLR), Land Quality Section on behalf of the
Sedimentation Control Commission.
Reference: MOA Part/H. B.1.
10. Local Programs are to notify the DEQ regional office of issuance of NOVs
Local Programs are to notify the appropriate DEQ regional office of issuance of
Notices of Violation at the time the violator is notified.
Reference: MOA Part 111.8.2.
11. Local Programs are to maintain current contact information on file with the Land
Quality Section.
Local Programs are to notify the State Sedimentation Program Specialist or their
assistant of at least one Program administrator. The name, address, phone number,
and email address for a main contact is to be kept current with the state program.
A list of all local program administrators will be maintained on the DEQ website.
Reference: MOA Part 111.8.3.
Page 5 of 5

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Appendix C
Approved Flocculants

NORTH CAROLINA
RCY COOPER Enkrronmental Quality
MICHAEL S. RECAP
secrcrary
LINDA CULPEPPER
hrrerfm &lrffror
North Carolina DWR List of Approved PAMS/Flocculants
Current as of 08/30/2018
Company
Product
Maximum Recommended Concentration
Applied Polymer System
APS 712
59.3 ppm
Applied Polymer System
APS 730
5.6 ppm
Applied Polymer System
APS 740
5.2 ppm
Applied Polymer System
APS 703d
**
Applied Polymer System
APS 703d#3
**
Applied Polymer System
APS 706b
**
Applied Polymer System
APS 705
27.7 ppm
Aquamark, Inc
AQ100
Land surface application only at 39.7 ppm
Aquamark, Inc
AQ109
Land surface application only at 0.180g/I
Ashland Hercules Water Tech
Ashland Charge Pac 55
10 mg/L
Ashland Hercules Water Tech
Ashland Zalta MC 9500
10 mg/L
Cape Fear Consulting
PAX-CFC39A
5 ppm
Cape Fear Consulting
CFC-4330
4.5 ppm
Carolina Hydrologics
HYDROLOC PAM
Land surface application only at 3.0 mg/I
Carolina Hydrologics
Floc Roll/Line/Flat
50 mg/L
Chemical Solutions, Inc.
CS-1234 and/or CS-1234D
500 mg/L per 18% solids *(see below)*
Chemical Solutions, Inc
MK7154DP
10 mg/L
Green Techniques
Soil Defender
Land surface application only at 0.008%
HaloSource, Inc.
GelFloc
2.56 mg/L
HaloSource, Inc.
LBP-2101
500 mg/L
Hanes Geo Components
TerraGuard Granular PAM
3.25mg/L
Innovative Turf Solutions
EnviroPam
200 mg/L
Innovative Turf Solutions
Erosion Guard Powder, Erosion
Guard Logs/Erosion Guard Flats
200 mg/L
Innovative Turf Solutions
FLOC
650 mg/L
Leaner Meaner Greener, Inc
L.M.G. Dust Magnet 281 Solution
0.05%
Leaner Meaner Greener, Inc
L.M.G. Dust Magnet 163 powder
0.5 mg/L
Leaner Meaner Greener, Inc
DBP-2100
28.125 mg/L
Nalco
Nalco 8187
100 ppm
NTU
GeoScrub 10, 13, 20, 23, 34
10 mg/L
NTU
GeoScrub Bubbles
1 mg/L
Paschal Associates Sales
PFR P251
25 ppm
Southeastern Laboratories
SEL FLOC 6026
7.5 ppm
Storm Klear
3% Liqui-Floc
9.4 mg/L
Terra Novo
EarthGuard
.000625 mL/L
All these products should be used per the manufacturer's instruction and with Best Management Practices.
See next page for additional information.
, 9 A-S: 45
North Carolina Department of Environmental Quality I Division of Water Resources/ Water Sciences Section
4401 Reedy Creek Road 11621 Mail Service Center I Raleigh, North Carolina 27699-1621
919-743-8400

Additional information for specific products:
• For use and toxicity guidance regarding CS-1234 and/or CS-1234D and about toxicity
testing requirements, please contact Cindy Moore with the DWR Aquatic Toxicology
Branch at [phone] or atcindy.a.moorea-ncdenr.gov.
A list of laboratories that have been approved by the DWR to perform toxicity testing can be found at:
httgs://files.nc.gov/ncdeg/Water%20Quality/Environmental%2OSciences/ATU/4 18CertList.pdf.

Appendix D
Erosion and Sediment Control Inspector's Guide

May,1992
A cooperative effort
between the Nortli
Carolina Department
of Environment,
and Natural Resources,
and the Nortli Carolina
Cooperative Extension
Service, supported by
the Nortli Carolina
Sedimentation Control
Commission
Erosion and
Sediment
Control
Inspector's Guide

Disclaimer
The contents of this publication were prepared by the authors and should not be
interpreted as necessarily representing the policies or recommendations of other
referenced agencies or organizations. Additional information is available in the
North Carolina Erosion and Sediment Control Planning and Design Manual,
and the North Carolina Erosion and Sediment Control Field Manual.
The mention of trade names, products, or companies does not constitute an
endorsement.
This manual is intended for periodic update. Section may be changed as
practices for erosion and sedimentation control evolve.

Project Director and Editor
Jon A. Arnold Ph.D., PE
Water Quality Group,
Biological and Agricultural
Engineering, North Carolina
State University
Engineering/Technical
Consultants
Robert G. Jessup, PE
SCS State Conservation
Engineer, Retired
Joseph A. Phillips, Ph.D.
Professor Emeritus,
Department of Soil
Science, Cooperative
Extension Service,
North Carolina State
University
Acknowledgments
This manual was prepared by the NCSU Water Quality Group in cooperation with
the North Carolina Department of Environment, Health, and Natural Resources
(DEHNR). The project was made possible by funding from the North Carolina
Sedimentation Control Commission.
We wish to acknowledge the roles of Charles Gardner, PE, Francis M. Nevils, Jr.,
PE, S. Craig Deal, PE, Stephen T. Reid, and Randy Cotten of the DEHNR, who
guided the planning, development, and review of this manual.
We especially acknowledge the regional engineers and the inspector -technicians
from the regional offices for their very important input, ideas and reviews of this
guide.
The authors express their gratitude to the numerous reviewers in state and
local government, federal agencies, and the private sector whose generous help
improved the content and appearance of this manual.
We would like to acknowledge Karl E. Larson, of the NCSU Department of
Agricultural Communications, for design and page layout.
Sandy Sullivan, graphic artist for the Water Quality Group, illustrated the manual
and provided assistance in production.

Table of Contents
1 The Inspector and the Law
Overview of the Law and Rules, program structure and the inspector's
duties under the Law and to the public.
2 Erosion and Sediment Control Principles
Scheduling, protecting the land surface, keeping runoff velocities low,
capturing sediment near the source, inspection and maintenance.
3 Inspecting Sites
How to prepare for an inspection, preconstruction conferences, methods
for inspecting sites, causes of noncompliance.
4 Inspecting Vegetation Used for Erosion Control
Proper selection, preparation and use of vegetation.
5 Inspecting Erosion and Sediment Control Practices
GroundCovers............................................................................................ 5.2
Entrances and Exits.............................................................................. 5.4
Runoff Control — Diversions...............................................................
5.5
Runoff Conveyances — Channels, Drains and Chutes .........................
5.6
OutletProtection...................................................................................
5.7
InletProtection.....................................................................................
5.8
Sediment Traps and Barriers..............................................................
5.10
Stream Crossings................................................................................
5.12
BufferZones........................................................................................
5.13
Maintenance.......................................................................................
5.14
6 Appendices
A. Human Relations............................................................................. 6.1
Dealing with Angry People.............................................................. 6.1
Being the Bearer of Bad News ......................................................... 6.3
B. Soil and Vegetation.......................................................................... 6.6
C. Water and Runoff Management....................................................... 6.9
Concrete and Corrugated Metal Pipe Full Flow Values ................. 6.9
Problems with Improperly Installed Channels .............................. 6.10
D. Erosion and Sedimentation............................................................ 6.11
Damages from Erosion and Sedimentation ................................... 6.11
Estimating and Measuring Erosion and Sediment Volumes .......... 6.12
E. Tools of the Inspector..................................................................... 6.13
F. Conversions, Tables and Reference Information ...........................
6.14
Slope Measurement........................................................................
6.15
Soil Textural Classification............................................................
6.16
Crushed Stone Reference...............................................................
6.17
Riprap and Erosion Control Stone, NC DOT Sizes .......................
6.19
Crushed Stone Sizes and Uses, NC DOT Sizes ..............................
6.20
Notes About Crushed Stone Used
for Erosion and Sediment Control .................................................
6.21
G. Construction Plan and Aerial Photos ............................................
6.22

e

The Sedimentation Pollution Control Act of 1973
authorized the program and set the standards for
erosion and sediment control in North Carolina.
This chapter discusses the program structure and
how the law is carried out. Refer to the Act and
the Rules governing Sedimentation Control, Title
1 SA NCAC Chapter 4, for more details.
rin The Inspector and
the Law
The Sedimentation The North Carolina Erosion and Sedimentation Control Program was created
Pollution Control Act by the Sedimentation Pollution Control Act of 1973. This legislation authorizes
the North Carolina Department of Environment, Health and Natural Resources
to provide staff to the Sedimentation Control Commission to operate a program
to limit erosion and sediment from land -disturbing activities. It allows local
governments, state agencies and federal agencies to conduct their own erosion
and sedimentation control programs with the approval of the state. The Act does
not apply to forestry using Best Management Practices, agriculture or mining
activities.
The Act is performance -oriented; that is, the measures used at a construction site
must be effective in controlling erosion and preventing off -site sedimentation for
the site to be in compliance. Following an approved plan and installing the control
measures may not be enough. If erosion and sediment damage occurs, the person
responsible must install additional measures to correct the problem.
The law is flexible, allowing the responsible parties to determine the most
economical, effective means for erosion control. This encourages the use of
innovative techniques and specifically designed erosion control systems. The law
emphasizes that the system must control accelerated erosion and prevent off -site
sedimentation.
1.1

n
The Act contains four mandatory standards to control erosion and
sedimentation.
GS 113A-54(d)(4), 113A-54.1(a),
1. Prior to beginning any land -disturbing activity, a plan must be approved for
113A-57(4)
sites on which more than one acre on a tract will be disturbed. This plan must
be submitted 30 days before the land -disturbing activity is to begin. If the Land
Quality Section has not acted on plan by the end of the 30 day period, the plan
is automatically considered to be approved under the law.
GS 113A-57(1)
2. Buffer zones must be provided along all natural watercourses and lakes.
These buffer zones must retain all visible sediment within the first 25 percent of
the buffer zone nearest the disturbed area. Along trout streams, the buffer zone
must be a minimum of 25 feet in width or of sufficient width to retain all visible
sediment within the first 25 percent, whichever is greater.
GS 113A-57(2)
3. All disturbed areas must be able to be stabilized by vegetation or other
suitable erosion control methods. These areas must be stabilized within 30
working days after completing any phase of grading.
GS 113A-57(3)
4. All land -disturbing activities on a tract comprising more than one acre, when
more than one acre on a tract is disturbed, must retain all sediment on -site. In
addition, the responsibile party must provide permanent ground covers within
30 working days or 120 calendar days, whichever is shorter, after completion of
construction.
Program Authority The North Carolina Sedimentation Control Commission is the final authority for
the Erosion and Sedimentation Control Program. The commission consists of
volunteers, appointed by the Governor, who represent a wide range of interests
in erosion and sedimentation. The commission meets every 90 days to conduct
business and review the overall program.
Figure 1.1 Erosion and
Sediment Control Program
Structure
Regional
Office
North Carolina Sedimentation
Control Commission
Land Quality Section
(Department of Environment,
Health, and Natural Resources)
Local
Programs
State Agency
Programs
1.2

The Inspector and the Law
The Land Quality Section, Division of Land Resources, Department of
Environment, Health, and Natural Resources, administers the Erosion and
Sedimentation Control Program. The Land Quality Section operates a central
office in Raleigh and seven regional offices across the state.
Work in the field is administered by the regional offices and by approved local and
state agencies. Local and state agencies have their own staff for the implementation
of the programs, including inspections.
Sedimentation The Program operates by Rules given in Section 15A of the North Carolina
Control Rules Administrative Code.' These Rules, commonly called regulations, specify the
requirements and standards on construction sites that must be met.
The Rules are usually developed by the commission through its Technical Advisory
Committee with support from the Land Quality Section staff. Public hearing are
held on all proposed Rules, which are then presented to the Sedimentation Control
Commission for approval. Once approved by the Commission, the Rules become
law.
The Rules interpret and define the intent of the act and therefore are performance
oriented. The intent of the Rules is to prevent accelerated erosion and to control
sedimentation through the following procedures:
■ Identifying critical areas;
■ Limiting exposed areas;
■ Limiting time of exposure;
■ Controlling surface water;
■ Controlling sedimentation; and
■ Managing storm water runoff.
The use of these procedures to achieve compliance with the Rules is discussed in
Chapters 2-5.
The inspector should be familiar with the definitions of the terms used in the Rules
and in the laws governing erosion and sedimentation.2
Remember that the Act and the Rules are performance -based. If the measures used
at a site are not controlling erosion and sedimentation, the person responsible for
the site must install additional measures. The inspector is the key in making this
kind of performance -based law work because he is the first person to recognize
performance failures and report the problems.
The Inspector and The inspector's job is to:
the Public ■ Determine that an erosion and sediment control plan for the site has been
approved;
■ Determine that all specified practices have been installed and are being
maintained according to the plan
■ Determine that off -site sedimentation is being prevented.
115A NCAC 04A—E.500
2The definitions are listed in the Rules under 15A NCAC NCAC 04A.0005 and in the Act.
1.3

n
If the inspector finds deficiencies, appropriate action must be taken to attain
compliance.
The inspector must have technical expertise in erosion control. In addition, in
order to achieve full compliance, the inspector must be able to deal effectively
with people. For example, disputes sometimes arise about a site violation. The
person responsible for the site may disagree with your assessment of the site.
Neighboring landowners may be upset and demand that corrective action be
taken immediately. At times like these, it is easy to become overly emotional. No
matter what the situation, inspectors need to carry out their responsibilities in a
professional manner and in accordance with the rules. Inspectors must maintain
their integrity if they are to do the job well and be respected as professionals.
Inspectors need to know how to deal with people. See Appendix A for guidelines
in interacting with people who are angry or upset. The guidelines can be a big
help in your job.
In dealing with the public it is most important to follow proper legal procedures
and to remain courteous and fair. If you fail to follow proper legal procedures
you may not be able to prosecute a violator. By showing courtesy and fairness,
you encourage mutual respect among all persons involved. Parties responsible
for construction sites are less likely to violate the act if they see the inspector as
a competent professional.
Remember that the goal of the program is to prevent accelerated erosion and
off -site damage from sediment. As the inspector, you are the first person to
determine if the performance standards and intent of the act are met. You are the
key person ensuring that construction sites are evaluated fairly and consistently
and that the responsible party keeps the site in compliance.
Sites Subject to Law Any activity that disturbs land, except agriculture, mining and forestry using
Best Management Procedures, is subject to the Sedimentation Pollution Control
Act and may require inspection. Even a private homeowner installing a driveway
must comply with the law. However, most small projects cause few problems
and do not normally require the attention of an inspector.
Examples of sites that are usually inspected include:
■ all sizes of commercial and industrial developments;
■ housing subdivisions;
■ shopping centers;
■ public buildings;
■ utility construction;
■ highway construction and maintenance; and
■ recreational facilities.
Before construction begins, an approved plan must be developed for any site
where more than one acre of land on a tract is to be disturbed. You can find help
in determining the size of a project from the tax assessor's office, topographic
maps, and survey plats of the site.
1.4

The Inspector and the Law
Some construction sites require extra care to ensure that they are in compliance,
especially those near or crossing watercourses, trout waters or high -quality waters.
These sites must meet more stringent requirements for the user of buffer zones and
for the general protection of water. High -quality water zones in coastal counties
mean those areas within 575 feet of the High Quality Water. For the rest of the
state, High Quality Water zones include those areas within one mile that drain to
the High Quality Water. (See definitions 24, 25 and 27 of the rules, 15A NCAC
04A.0005.)
Handling Violations As the inspector on the site, you play a central role in providing details of
violations and subsequent corrections. The policy for handling violations depends
on whether the state or a local government has jurisdiction. The policy for state
programs may be obtained from the Sedimentation Control Commission. Violation
policies for local programs or state agencies may be obtained from the appropriate
office. These policies outline the actions that are required under each program to
bring the site into compliance. We recommend that you insert a copy of the proper
policy for your program into this guide for quick and easy reference.
The inspection records that you write are the basis for hearings and assessing
fines, You are the first person to determine whether the measures on the site
are preforming properly; thus you are the first link in enforcing the erosion and
sedimentation Rules. Inspectors are often called to appear at hearings as witnesses
to document a violation. For information on hearing procedures and on how to
conduct yourself as a witness, refer to the Enforcement Manual, available from
the Land Quality Section.
You should write a report for every inspection of a site. When writing your
inspection report, remember that it is a legal document. Your report must be written
accurately, consistently and in clear and concise language. Report all violations
observed each time you visit a site even if you have reported some of them on
previous visits, Always write inspection reports while you are on the site so that
you will not forget items and can recheck conditions if you have doubts.
Field notes are very effective in hearings. They should be organized, thorough,
concise and legible. Make a habit of taking organized, well -written notes. It will
pay off the next time you are in court.
1.5

1.6

a

Accelerated erosion and sedimentation can be
controlled by following five basic principles.
Erosion control practices are simple, effective
and inexpensive if implemented before a
problem occurs. The key is to install a system
that makes all erosion and sediment control
practices work together.
Erosion and Sediment
Control Principles
Controlling Erosion Accelerated erosion takes place when wind, rainfall and runoff act upon disturbed
and Sedimentation soil. Normal construction activities, such as clearing and grading, leave the soil
bare and compacted. With no protective cover, soil particles are easily washed or
blown away. Grading smooths and usually compacts the soil, reducing the amount
of rainfall that infiltrates into the ground. Because less rainfall is absorbed, the
volume of runoff is increased. The smooth, compacted surface further increases
the velocity of the runoff. These conditions lead to accelerated erosion on the
construction site and may cause off -site sedimentation, streambank sloughing and
flooding problems.
It is much less expensive and less damaging to the environment to prevent erosion
and sedimentation than to clean up after it has happened. Carefully following these
principles of erosion and sediment control will help in preventing environmental
damage:
■ Coordinate sediment control with construction activities;
■ Protect the land surface from erosion;
■ Manage runoff and keep velocities low;
2.1

n
■ Capture sediment near the source; and
■ Inspect and maintain the erosion and sediment control system.
As an erosion and sediment control inspector, you should be familiar with these
principles and know how to apply them on construction sites.
Scheduling The key to efficient and cost-effective erosion control is to plan construction
activities in phases to reduce the erosion potential of the site. Each phase
exposes only small areas of land, making it much easier to control erosion than
if the entire site were exposed at once.
Erosion and sedimentation can be controlled most effectively by coordinating
the construction schedule with the installation of erosion control measures.
Before any site disturbance occurs, sediment traps, basins and diversions should
be in place to control runoff and catch sediment. Graded areas should be seeded
and mulched immediately, according to the schedule, rather than waiting until
all the grading has been completed. A well -planned construction entrance with
stabilized construction roads can prevent major erosion and sediment problems,
complaints from neighbors and future aggravations.
Protecting the Land Erosion can be greatly reduced by simply covering the soil to protect it from
Surface the effects of rainfall, runoff and wind. By paying attention to the following
principles, erosion can be limited and the cost of maintaining sediment control
devices reduced.
■ Construction activities should be scheduled to reduce the duration of
exposure of bare soil.
■ The size of the disturbed area should be kept as small as practical. The
construction schedule should be planned to limit the area graded at any one
time. Buffers should be left around all working areas. No areas outside the
designated work area should be disturbed.
■ Runoff should be diverted away from slopes to be graded.
■ Construction roads, parking areas and the construction entrance should be
stabilized immediately. Equipment operators should use the designated routes
to limit ruts, erosion and tracking of sediment and debris from the site.
■ All streams, lakes and natural watercourses should be protected by buffers.
All drainage channels should be stabilized as soon as they are constructed.
■ Graded surfaces should be covered with temporary vegetation and mulch
when work is interrupted for extended period.
Measures to protect the soil surface are described in the following sections
of the North Carolina Erosion and Sediment Control Planning and Design
Manual:
■ Temporary Seeding, 6.10;
■ Permanent Seeding, 6.11;
■ Mulching, 6.14;
■ Riprap, 6.15;
■ Temporary Gravel Construction Entrance/Exit, 6.06;
2.2

Erosion and Sediment Control Principles
■ Construction Road Stabilization, 6.80;
■ Sodding, 6.12;
■ Trees, Shrubs, Vines and Ground Covers, 6.13;
■ Temporary Diversions, 6.20;
■ Grass -lined Channels, 6.30;
■ Dust Control, 6.84;
■ Runoff Control Measures, 6.20-6.23;
■ Runoff Conveyance Measures, 6.30-6.33; and
■ Stream Protection Measure, 6.70-6.73
Keeping Runoff Erosion is greatly increased if runoff is allowed to flow at high velocities.
Velocities Low Control measures, installed properly and at the proper times, keep runoff
velocities low and prevent erosion. Where practical, measures should be taken
to divert water from flowing onto the site from outside the area. Energy
dissipators should be used to reduce the flow velocity of water leaving the site.
Certain areas, such as constructed fill slopes and newly cut channels, need special
attention. The following practices will help control runoff velocities.
■ The work area should be protected from off -site water with perimeter dikes or
temporary diversions.
■ Runoff water should be diverted into stabilized channels with stable outlets.
■ Runoff from disturbed areas should be diverted to sediment traps or basins.
■ Where practical, runoff from undisturbed areas should be diverted around
sediment basins and traps to stable areas and protected outlets. This reduces the
volume of water that flows into the sediment basins and traps, increasing their
efficiency and reducing their costs
■ Long slopes must be broken up with temporary or permanent diversions to
prevent the buildup of runoff and reduce runoff velocity.
■ The permanent storm water drainage system should be installed during early
stages of construction and used to manage runoff. All inlets should be protected
with appropriate measures to prevent sediment from entering the storm drains.
■ Critical construction areas should be protected from unexpected rain by
installing temporary diversions at the end of each work day.
Practices for controlling runoff velocities are discussed in the following sections
of the North Carolina Erosion and Sediment Control Planning and Design
Manual:
■ Temporary Diversions, 6.20;
■ Diversion Dike (Perimeter Protection), 6.22;
■ Permanent Diversions, 6.21;
■ Right -of -Way Diversions (Water Bars), 6.23;
■ Level Spreader, 6.40;
■ Outlet Stabilization Structure, 6.41;
2.3

n
■ Temporary Slope Drains, 6.32;
■ Riprap, 6.15
■ Grass -lined Channels, 6.30; and
■ Riprap-lined Channels, 6.31;
Capturing Sediment Generally it is easier, safer and more practical to capture sediment near the
Near the Source source than to install a single large sedimentation basin and try to capture the
sediment from an entire site. A few small, well -maintained sediment traps or
barriers properly located at the edges of the graded area will control sediment
better and take up less space than a single large sediment basin farther away.
Also, large sediment basins present a greater hazard if they fail.
Remember that sediment traps, sediment basins and barriers such as silt fences
remove sediment by pooling water and allowing the sediment to settle out. Silt
fences and rock structures do not filter the water effectively because they clog
too easily. These fences and structures are used to form a pool where the water
velocity is slowed, allowing the sediment to settle.
The other key to capturing sediment is to inspect and maintain the devices
frequently. The pools created by these devices will fill with sediment. This
sediment must be removed so the device will have adequate capacity for the next
rainfall. Occasionally the overflow structure will need to be repaired or rebuilt.
The devices should be inspected frequently to ensure they are functioning
properly.
Adequate access to the sediment control devices may not be provided for in
the plans or may be blocked by construction. If the contractor cannot get in
to clean out the trapped sediment and make repairs, violations may occur. All
sediment control devices must be accessible so that cleaning, inspections and
maintenance can be performed.
Inspection and Erosion and sediment control measures, practices and devices should work as
Maintenance a system —all the components should work together to prevent erosion and off -
site sediment damage. Regular inspections and maintenance of all devices are
necessary for the system to work effectively.
Lack of maintenance is the most common reason for failures. Contractors and
the responsible parties cannot know that a device needs maintenance unless they
inspect it regularly. A low point in a dike or diversion can lead to the formation
of a major gully after the next rain. A collapsed sediment fence or inadequate
inlet protection device and allow large amounts of sediment to move off -site.
The failure of a large sediment basin could have severe consequences.
The erosion control inspector must insist that contractors and the responsible
parties regularly inspect erosion and sediment control measures. The owners
are responsible for ensuring that all erosion and sediment control measures are
frequently inspected and repaired.
2.4

a

Inspections don't "just happen;" A lot of planning
and preparation go into a proper and thorough
inspection. Inspectors need to review construction
plans, attend preconstruction conferences and be
knowledgeable of the law and standards. Knowing
why a site is or is not in compliance is a key part of
the inspector's duty.
Inspecting Sites
The Inspection An erosion control plan is designed to control erosion; however, components of
the plan may fail or the responsible party may not adhere to the plan. For these
reasons, the Sedimentation Pollution Control Act of 1973 includes provisions for
the inspection of sites where land -disturbing activities are taking place. As the
inspector of these sites, your job is;
■ to be certain that all erosion and sediment control measures in the approved
plan have been properly installed and maintained;
■ the erosion is being controlled; and
■ that off -site sedimentation is being prevented.
It takes time to learn how to inspect a construction site properly. Project sites are
often large and can have many land -disturbing activities occurring at any one
time, which can be confusing. Also, there are many considerations to keep in
mind while conducting the inspection. You must be familiar with the law, the
rules and many erosion and sedimentation control practices. With some experience,
3.1

n
however, you will soon feel comfortable about making an official erosion
control inspection. This guide will help by providing some ideas on how to
make a thorough inspection.
A proper inspection requires planning and a systematic approach. With careful
preparation, you can carry out your duty and work cooperatively with the
responsible parties and the contractors so that all those involved can do their
jobs efficiently.
Preparing for an The first step in inspecting a project is to review plans when first submitted.
Inspection This review will alert you to potential problems at the site and weaknesses in the
erosion and sedimentation control system design. Make a list of comments for
the engineer who will approve the plan so that he can benefit from your review.
By working together, you and the engineer will complement one another's
skills, making for a sound review and approval process.
While at your office, look for the following items in the plan. (There are other
items that you may want to include as you gain more experience.)
■ Check contour maps and available aerial photos to see how the water flows
through the site. Note where water enters and leaves the site. Determine the
direction of flow in the general area and in the watershed where the project is
located.
■ Note if the site borders a sensitive area such as a stream or high quality
water body. The perimeter should be especially well protected against off -site
sedimentation.
■ Pay particular attention to critical areas such as steep cut -and -fill slopes,
stream crossings, channels, outlets of pipes and diversions, construction access
routes and highly erodible soils.
■ Look for adequate access to and space to maintain erosion and sediment
control measures.
3.2

Inspecting Sites
■ Make sure that the plan provides an installation sequence for measures to
control erosion and sediment, with measures for one phase being installed before
grading of the next phase begins.
■ Study the construction schedule to determine whether long periods of time
exist between phases of construction. If so, temporary seeding or other temporary
soil stabilization may be required.
■ Check to make sure that the plan requires all surfaces to be stabilized as soon
as possible after completion of the project and within the mandatory 30 working
days or 120 calendar days (15 days and 60 days if in a High Quality Waters Zone).
Temporary and permanent seeding should also be specified.
■ Remember that when the contractor is finished, the entire site should be
stabilized —no accelerated erosion and no off -site sedimentation should occur.
■ Note if the measures are designed for the 10-year storm. Some measures should
provide for safe bypass of flows greater than the 10-year storm. High Quality
Waters Zones require design and safe bypass for the 25-year storm.
■ Be sure that the perimeter of the site is protected to prevent off -site
sedimentation and keep off -site runoff from flowing across highly erodible areas
during construction.
■ Make sure that maintenance plans are adequate and the contractor's procedure
in monitoring the performance of control measures is specified. For example, it
should be clear whether the contractor or someone else is to do the inspection and
maintenance.
■ Note any proposed borrow or waste areas and proposed measures for controlling
erosion and sedimentation there.
■ Watch for existing areas that may not be in compliance, such as old highways
and abandoned railroad rights -of -way. Those parties responsible for the land
disturbance are responsible for erosion control even if ownership of the property
has changed.
■ Check tree -cutting operations to ensure compliance with Forest Practice
Guidelines Related to Water Quality (Best Management Practices, or BMP's).
■ Make a list of the specific items of the plan that you want to inspect closely
when you get to the site. This list can speed your inspection and remind you to
check certain important points.
■ Determine the owner(s) of the site itself and of the adjoining property. Though
this sometimes may be difficult to determine, you can get useful information from
the county register of deeds or tax records.
Reviewing the erosion and sedimentation control plan should provide you with a
solid grasp of the proposed project. From the review you can identify parts of the
erosion control system that may need to be strengthened and parts that should be
watched carefully to see if the performance requirement is met. Your experience
in the field and in the geographical area will provide valuable assistance in the
approval or revision of the submitted plan.
Inspectors must also be familiar with the construction plans. In Appendix G you
will find two views of a highway project. The upper view is an aerial photo of a
construction site. Below the aerial phoyo is the corresponding construction plan
of the site. Compare the two views to find out if the measures called for on the
plans have been installed at the site and if they are in the proper locations. The
3.3

n
captions will help you see the control measures. Study these plans, paying
attention to the highlighted items, so that you become better able to read
construction plans.
The ability to read aerial photos is important because many construction projects
now use aerial photos on which to draw the construction plans. It will take some
practice to be able to recognize ordinary objects from the air.
Many experienced people have found that aerial photos and topographic maps
can help greatly in determining the effects of a project on the surrounding area.
Aerial photos can be obtained from the local ASCS (Agricultural Stabilization
and Conservation Service) office or the state Department of Transportation
(DOT). The 1:660 scale is usually used. The USGS (United States Geological
Survey) is a good source for topographic maps. These maps are drawn on a
scale of 1:24,000.
Reviewing the construction plan provides information needed for the next step
of the inspection process, the preconstruction conference. Use the suggestions
below to ensure that you are fully prepared for the conference.
P R E CO N ST R U CTI O N A preconstruction conference is one of the most valuable vehicles by which
CONFERENCES you can address and divert many potential erosion and sedimentation problems
before they become catastrophes. For complex projects, a preconstruction
conference should be mandatory. This conference provides an opportunity for
you to meet face-to-face with the responsible party and the contractor. In this
way, you establish the expectations for the project and start a good working
relationship with the job superintendent. While holding the conference, keep
the following suggestions in mind:
■ Clarify the objectives of erosion and sediment control and inform all parties
about the specific requirements for compliance in this project. Also, discuss
the inspection procedures and establish communications and scheduling so that
everyone knows what will be happening during the project.
■ Designate a contact person for communicating concerns about erosion
control. This will make future contacts much easier.
3.4

Inspecting Sites
■ Be sure that all parties review a copy of the approved erosion and sediment
control plan so that they know what is expected and are prepared to initiate the
plan. An approved copy of the plan must be available on the site at all times.
■ Inform the responsible party and the contractor that the program is performance
oriented and that the plan may need to be changed during the course of construction.
Inform all parties about procedures for changing the plans. Remember that all
revisions to erosion and sediment control plans must be approved before they are
put into effect.
■ Try to hold the conference on the site. There, the group can walk the site and
compare the plans to see if the measures are appropriate, are located properly, and
can be maintained once installed. Note areas where sediment from the sediment
traps and basins can be placed and stabilized when the devices are cleaned. The
site is also the best place to determine if adequate access will be available to
maintain the erosion control measures.
■ Discuss the scheduling of clearing and grading. Emphasize that sediment
control measures should be installed before the actual grading begins in order to
capture sediment as it is generated. Be sure that the schedule allows for stabilizing
surfaces with temporary and permanent measures during and between phases of
grading and construction.
■ Discuss the maintenance requirements so that the responsible party and the
contractor know who is responsible for inspecting, cleaning and repairing the
measures. Regular inspection and maintenance may need to be supplemented with
extra work if there is a large storm.
■ Establish open communications at the preconstruction conference; this pro-
vides a good foundation for your relationship with the responsible parties during
the project.
Before you Leave ■ Take the time to review the plans thoroughly before you go to the site, even if
the Office you have already reviewed them when they were first submitted.
■ Outline your approach for each inspection. It is necessary to know in detail the
erosion control system and why each measure is specified.
■ Always take a copy of the approved plans with you to the site for quick
referral.
■ Always bring the project file and necessary reporting forms.
3.5

n
Inspecting the Site At the construction site, ask yourself the following four questions:
(1) Is the erosion and sediment control system installed as shown on the
approved plans?
(2) Is erosion being controlled on the site? and
(3) Is sediment being contained on the site?
(4) Are the four mandatory requirements of the Sedimentation Control Act
being met?
If the answer to all of these questions if YES, then the site is in compliance. File
an inspection report stating that the site is in compliance and take field notes to
support the inspection report. It is a good idea to keep track of the sites where
the erosion and sedimentation control plan works well so that you can show
others an example of a good site.
If the answer to any of the above questions is NO, then the site is not in
compliance. File an inspection report listing the items that are not in compliance.
Your field notes should describe precisely the noncompliance and its location.
Remember that others may need to use your field notes, so make them readable
and understandable.
The following points will help you in checking for compliance.
■ Carry a set of the approved plans to the site for your reference. They are
necessary to determine what measures make up the erosion control system and
how they are to be installed and maintained.
■ Take detailed, orderly field notes as you do the inspection. In the long run,
this procedure will save you time and possibly a second trip to the site. Be sure
that your notes are neat, concise and complete. (Remember, your notes may be
needed as evidence in court.)
■ Check in with the job superintendent when you arrive so that the contractor
knows who you are and what you are doing. When possible, schedule
appointments so that the contractor and responsible party know when to expect
you.
■ Walk the perimeter of the site on your first inspection. This procedure will
give you a good idea of the terrain and will alert you to any problems occurring
from off -site water and off -site sedimentation
3.6

Inspecting Sites
■ You may want to start your inspection from the lowest point at the perimeter
and work your way upstream. This helps to make you aware of the amount of
sediment leaving the site and can help you in locating its source.
■ If sediment is flowing off the site, go far enough downstream to see the extent
of the damage. In these situations, it is very important to document the damage.
Make an estimate of the sediment volume. Photos and videotapes make very good
evidence. Be sure to write the time, date and other items in your notes and on the
inspection report.
■ Bring necessary tools to measure the devices and disturbed areas in the field. Be
sure that basins and traps are fixed according to the plans, channels and diversions
have the proper grade, and contributing areas for the control devices are no larger
than those used in the design.
■ Pay particular attention to the maintenance of erosion and sediment control
measures. All measures require regular maintenance and may require special
attention after severe storms.
■ Keep in mind that when certain structural measures fail from improper
installation or maintenance, more off -site sediment damage may occur than if the
device had not been installed.
■ Always fill out an inspection report for each trip to a site while you are still at
the site. The pertinent inspection points are still fresh in your mind and you can
easily re -check items that may be in question.
Causes of when you find a site that is not in compliance, it is important to determine why.
Noncompliance By determining the cause(s), solutions become more apparent.
Problems of erosion and sediment control on sites fall into three categories:
1. The responsible party has not made efforts to comply with the law;
2. There are design errors in the erosion control system or the site conditions
have changed; or
3. The installation or maintenance of a measure is faulty or inadequate.
Little or No Effort Noncompliance in the first category is easy to spot. The responsible party may
to Comply believe that the project does not come under the jurisdiction of the law or may
3.7

n
intentionally disregard the provisions of the law. Quite often these sites are
found by inspectors while driving by. Therefore, be observant in your territory.
Once you have found a noncomplying site, inform the responsible party
that compliance is mandatory by law. On the inspection report, note that the
responsible party has been informed of the law and list the items that are not in
compliance.
These are some of the causes of noncompliance within this category:
■ not submitting a plan;
■ starting work without an approved plan; or
■ failing to follow the approved plan.
Inadequate Design or Violations and failures may occur because the design was inadequate or the
Changes in Site site conditions have changed since the plan was prepared. In this case, the plan
Conditions needs to be revised and approved. The inspection report should note all items of
non-compliance and the need for a revised plan.
Faulty Installation and/or
Poor Maintenance
Compare the original design in the plan to conditions in the field. Look for
changes in the site, conditions and construction plan. Ask yourself the following
questions when checking for violations caused by design errors and changes.
■ Are the planned measures retaining the sediment on the site?
■ Are there modifications to the plan? Have they been approved?
■ Are ground covers adequate for the slope and orientation of the areas to be
protected? Is the slope too steep for the ground cover chosen?
■ Is the perimeter protected, given the conditions at the site?
■ Do the measures with impoundments have a safe bypass installed for storms
larger than the 10-year storm?
■ Have the contributing drainage areas changed significantly, thereby
potentially overloading the control measures? Are additional control measures
needed?
■ Is dust control needed?
■ Is the planned and ongoing maintenance adequate for the existing
conditions?
Most noncompliance occurs because measures were not installed correctly or
maintained properly, or both. Determining the reasons why the measures are
failing requires technical knowledge about the devices and how to construct
them properly.
In the following two chapters, you will find ideas on how to inspect erosion
control devices and what to look for in their construction. Chapter 4 presents
information on inspecting vegetation used for erosion control and Chapter 5
presents information on inspecting erosion control practices. These practices
are listed in the same order as they appear in the North Carolina Erosion
and Sediment Control Planning and Design Manual and the North Carolina
Erosion and Sediment Control Field Manual. The references in the sidebars
direct you to specific sections of the Design Manual and the Field Manual for
more detailed information.
3.8

Co]

More area is protected from erosion with vegeta-
tion than with any other erosion control means.
Knowing how to choose and establish the prop-
er vegetation can prevent soil loss and sediment
problems.
Inspecting Vegetation
Used for Erosion
Control
Vegetation for Vegetation cover is the principal means used to stabilize soil surfaces. With
Erosion Control the selection of the proper species and appropriate maintenance, vegetative
cover provides inexpensive, long-term protection with moderate maintenance.
Construction projects present a wide range of conditions for vegetation. This
chapter describes what to look for when vegetation is used for short and long-term
erosion control.
A vegetative plan is one of the keys to a well -executed project. An effective plan
specifies the appropriate plants for each disturbed area, describes proper soil
preparation methods and indicates when to plant. Vegetation should be established
as soon as possible after grading. Planting should be coordinated with construction
so that areas do not remain uncovered, thus producing unnecessary amounts of
runoff and sediment.
Consider the Site and Vegetation works well only if the plant species selected suits the climate, soil,
Its Intended Uses and the intended use for the area. Remember that at certain times of the year or
under special conditions it may be necessary to use temporary vegetation before
establishing permanent vegetation. Ask these questions when you inspect sites
using vegetation for erosion control.
Is the plant type appropriate for the soil and the slope?
■ Plants must have fertile, well -prepared soils to grow properly, a requirement
rarely met on a graded slope.
4.1

0
■ Heavy, dense subsoils may be too infertile to support certain plants.
■ Graded slopes may be too steep or too rocky to prepare adequate seedbeds.
■ Steep slopes may need to be sodded or covered with riprap or concrete.
Is the plant properly chosen, given the climate and orientation for the area?
You may want to review the following sections in the North Carolina Erosion
and Sediment Control Planning and Design Manual:
■ Temporary Seeding, (6.10);
■ Permanent Seeding, (6.11);
■ Sodding, (6.12); and
■ Trees, Shrubs, Vines and Ground Covers, (6.13).
Is the vegetated area being maintained?
■ Frequently the degree of maintenance required to keep a certain type of plant
growing is overlooked. The responsible party must provide higher maintenance
for some ornamental shrubs and grasses.
■ Also, see if the maintenance crews can reach the planted area to provide the
necessary care.
■ Is the area subject to high velocity flow? Some areas such as channels and
steep slopes may require sod, riprap or concrete linings to prevent erosion.
Check Seedbed Graded areas are usually compacted and have little topsoil left when planting
Preparation is started. Lime and fertilizer must be properly incorporated into the soil to
establish an adequate seedbed for vegetative cover. If practical, the soil should
be tested so that the proper amounts of lime and fertilizer can be added.
Check the following points to determine if the vegetation will be adequate.
■ Slopes that have been graded are too compacted and smooth to establish
plants. It is necessary to apply fertilizer and lime, prepare a proper seedbed and
roughen the surface to provide required nutrients and adequate rooting depth.
■ Keep in mind the essentials for plant growth; an adequate supply of nutrients,
water and air in the root zone. These conditions are frequently lacking in graded
soils. Therefore, fertilizer and lime must be added and incorporated to a depth
of 4 or more inches by chiseling, plowing or roto-tilling. This preparation also
enhances water and air infiltration to the root zone.
Check for Proper Seeded areas should be mulched to protect and help establish erosion control
Mulching vegetation. Mulching holds the seed and fertilizer in place, protects the soil,
and conserves moisture. Mulching also encourages rapid seed germination by
preventing soil crusting and insulates the soil against rapid temperature changes.
The following points will help you determine if mulching is adequate.
■ Look for a proper thickness for thick mulch. Few areas can develop a strong
growth of vegetation without mulching, and mulches are often too thin to be of
much help. See the Planning and Design Manual section on mulching (6.14)
for more information.
4.2

Blade
W
Inspecting Vegetation Used for Erosion Control
■ Mulch needs to be well -anchored to work properly. This requirement is often
overlooked, causing many failures and much added expense for re -seeding. On
flatter slopes, mulches can be tacked by spraying on tacking agents that bind the
mulch, preventing it from being washed or blown away. Crimping also works well
on flatter slopes and level areas.
■ For steeper slopes mulches should be overlaid with netting. Mats can also be
used. Netting and mats should be anchored with long staples at the proper spacing
to provide the best resistance to washing. Thicker and more durable mats should
be used on steep slopes, areas that are exposed to high -velocity flows, and areas
where vegetation needs more help to become established.
Ensure Maintenance of The key to an adequate vegetative cover that will result in good erosion control
Vegetative Cover is maintenance. For vegetation, seeding, and the early stages of plant growth are
especially critical. The inspector must ensure that the vegetation is protected to
allow the best germination and strongest growth. Even after the vegetation has
emerged, mulches and mats must be maintained to prevent washing during the
next rain.
Watch for areas where the mulch is too light —the mulch can blow away or wash
away in the next rain. The owner/developer must have new mulch applied and
Seedhead
Spikelet must anchor it to prevent washing.
/l Damage to seeded areas usually happens where the mulch is improperly anchored.
These areas will require immediate repair. The responsible party should fill
the eroded area if needed, apply new seed, lime, and fertilizer, and apply an
adequate layer of mulch that is well -anchored. If the area is in a zone where the
erosion potential is high or if the practice called for in the plans is inadequate, the
responsible person may need to use a heavier mat to provide more protection for
Auricles --fir. the vegetation.
Look for a means of access to the vegetated areas. The responsible party cannot
provide maintenance if crews cannot get to the area. This is especially important for
Node areas while ornamental shrubs and turf grasses, which require high -maintenance,
have been planted.
1 For more information on temporary and permanent vegetating, see Appendix B.
Sheath ll
I .. ♦�l O `
Leaf Bud
Figure 4.1 Typical Grass Plant
4.3

0
4.4

0

In this chapter you will find advice on what
to look for when inspecting various erosion
and sediment control practices. The topics are
presented in the same order as they appear in
the Planning and Design Manual and the Field
Manual. Check the appropriate sections of those
manuals for more detailed information as you
encounter practices installed in the field.
Inspecting Erosion
and Sediment
Control Practices
Inspecting Individual The effectiveness of an erosion and sediment control system depends on the
Practices design, installation and maintenance of the individual practices. It is only when
all three efforts have been done properly that the system will function to prevent
accelerated erosion and off -site sedimentation.
Each practice has specific requirements to function properly. Inspectors must be
familiar with these requirements to ensure that each practice has been designed,
installed and maintained properly. When you are inspecting a practice in the field,
first check that the practice has been installed according to the design specifications
on the approved plan. If the practice has been installed as shown on the plan, then
check the appropriate section in this chapter for items that should be given special
attention for each practice group.
5.1

n
RIPRAP
Ground Covers Types of ground cover can be divided into three groups —(1) hard surfaces, (2)
(Surface Stabilization) semi -hard surfaces and (3) soft (vegetative) covers. This section provides some
ideas on what to look for when you are inspecting a site using ground cover for
erosion control.
Hard Surfaces Hard surfaces are those that include pavement, concrete and revetment. Some
of these surfaces can be cast in place using wooden or fabric forms or they can
be installed in large mats.
See sections 6.10-6.16 of the ■ Look for proper hydrostatic pressure relief for solid slabs or liners.
Planning and Design Manual, and Make sure that liners on channel slopes extend far enough up or away
sections 6.10-6.16 of the Field from the water to prevent water from cutting under, around or overtopping the
Manual for more information and
common trouble points. liners.
■ Be certain that proper vegetation is planted in the hollows of the surface.
Also, the soil filling the hollows should be well -prepared to provide the best
growing conditions for the plants.
■ Watch for accelerated erosion and high water velocities at the toe and top of
hard -surfaced slopes and at the outlets from hard surfaces.
Semi -hard Surfaces Semi -hard surfaces consist of layers of large stone, crushed aggregate or
gravel. These surfaces are often used to line channels and cover slopes.
■ Semi -hard surfaces can be washed away by high water velocities; therefore,
be certain that the water velocity is within the limits for the D50 aggregate size
See section 6.84 of the Planning and gradation.
and Design Manual for more on Stone should be placed to blend with surrounding land surface to ensure
dust control. that water will flow into the channel without erosion, not along the side of the
lining.
■ Check to see if the riprap is installed according to the plan and is performing
properly.
■ Ensure that adequate flow area has been provided.
■ Semi -hard surfaces should have geotextile fabric or a crushed stone filter
underneath to prevent washing of the fine soil particles.
■ Make sure that dust control is being practiced for areas covered with stone
aggregates or gravel.
5.2

Inspecting Erosion Control Practices
Points most vulnerable to erosion
T thickness of riprap layer
T
minimum
Smooth foundation
under filter
1=76i 1.5Tminimurn
Geotextile fa•ic
Figure 5.1 Semi -hard Surface Keyway at toe of slope
Soft Ground CoverS Soft ground covers (such as vegetative ground covers) are the most common and
are used on moderate slopes not exposed to high water velocities. Mulches are
See Chapter 4 and section 6. 10- sometimes used alone as ground cover but require frequent maintenance. Address
6.16 of the Planning and Design the following questions as you inspect sites where soft ground covers are used.
Manual and the Field Manual for 0 Are the plants appropriate for the site conditions?
more information on vegetation 0 Has the soil been properly amended and prepared for planting?
and soft ground covers.
0 Does the area have adequate mulch and is the mulch well anchored?
0 Are the stands of vegetation adequate?
0 Have vegetative specifications been followed (appropriate seeding rates and
mixtures)?
0 Are the established ground covers being maintained? Have provisions been
made to maintain the ground covers indefinitely?
Mulch with netting to protect vegetation and soil
T
until vegetation is established.
kLL;L�
Grass growing on slope
Soil prepared for seedbed;
4" minimum
Figure 5.2 Vegetative Ground Cover
5.3

n
Entrances and Exits
See sections 6.06 and 6.80 of the
Planning and Design Manual for
more information on entrances/
exits and construction roads,
respectively.
See the Field Manual, section
6.06, for other common trouble
points.
Figure 5.3 Typical Entrance
i
Erosion can be a special problem around all entrances and exits, access roads and
construction roads. Erosion in these places can cause mudholes, gullies, muddy
pavement, sediment being tracked offsite, dust and complaints from neighboring
landowners. Construction roads, even temporary roads, need to be stabilized to
prevent erosion. Look for the following while conducting your inspection.
■ Entrance and exit pads should be built with coarse gravel and stone that are
sufficient to prevent tracking of sediment onto streets or other public rights -of -
way and prevent the pad from sinking into the soil.
■ Sites with heavy clay soils may require the installation of a wash rack in
order to control tracking of sediment onto roads.
■ On unstable or wet soil, the stone should be spread over a layer of geotextile
fabric to keep the stone from being pressed into the soil.
■ Pads may need to be extended to be effective.
■ All runoff from construction roads should be diverted to sedimentation traps
retain sediment on the site.
■ Pads and roads must be maintained (adding more clean stone) to ensure
proper functioning.
Geotextile fabric to stabilize "
foundation (especially needed
where soils are wet
5.4

Inspecting Erosion Control Practices
Runoff Control — Diversions (dikes and channels) should be constructed as shown on the approved
Diversions Plans or failure of these measures is likely to occur. The most important factors
in installing a diversion are its size, the grade, the elevation of the dike above the
channel, compaction of the dike and stabilization of the channel. To help assure
compliance, the following should be evaluated:
■ A dike and its channel must be on the proper grade to ensure that the water
flows in the desired direction. Watch for abrupt changes or reversal of grade on
diversions — overflows and failures occur at these places.
See sections 6.20-6.23 of the ■ Dikes must be large enough to meet the design water flow with 6 inches of
Planning and Design Manual and freeboard. Be sure that they are sufficiently wide at the top (a minimum of 2 feet)
the same section in the Field and the side slopes are 2:1 of flatter.
Manual for more information.
■ Dikes must always be compacted or the loose soil will wash out.
■ Channels must have a large enough flow area to carry the expected volume of
water.
■ Channels on steep grades must be lined to withstand the expected water
velocity.
■ Diversions should generally parallel the site contours.
■ Diversions must be maintained routinely for proper performance, with special
attention after severe storms.
Figure 5.4 Typical Diversion
Channel: 18" min below top of dike
Dike: 2' wide at top, min; with 6" of freeboard at design flow
stabilized with vegetation
�yll.lt'„��rit'Yi .�yl�...�1"4'�Artlt�it ............w..u...r ^r.... .. ..
�����R tli.- 1t7/. r�l �l,� V•���"Y' �."art .....,..,.�•,".• � ^..
*::= }z :x;,�`` f, ♦ Channel lining for high velocities
IIII-.�Illll=1111�-�,�-.-,,,,,__--r,ll-,1�111-�I�11=f1(II_-11111=11I
Compacted soil6'wide=l�111��1111-11!(�IIIE- I1!!1 =III►I-=1II11=(IIII=I�III=(I11=
at bottom, min
5.5

n
Runoff Conveyance —
Runoff must be controlled to ensure that it will not cause accelerated erosion or
Channels, Drains
off -site sedimentation. Channels, drains, and chutes must carefully follow the
design specifications. Check these key points as you conduct your inspection.
and Chutes
Vegetated channels require protection until the vegetation is fully established.
Well -anchored mulch, mats or netting should be used.
■ Make sure that the flow cross-section is not reduced when riprap is used
to line a channel. The channel excavation must be increased (or overcut) to
compensate for the thickness of the riprap
■ Look to see that channels lined with riprap have a layer of geotextile fabric
(filter cloth) under the riprap. Also, the riprap should be inlaid into the channel
See sections 6.30-6.33 of the
bank to a depth of 1.5 times the D.- size of the riprap and set into the soil
Planning and Design Manual and
surface to prevent undercutting.
the same section in the Field
Manual for more information.
■ Inspect outlets of all runoff conveyances to ensure proper outlet protection.
■ Be sure that the slope drains have watertight joints in the pipe and that the
pipe is well anchored to prevent movement.
■ Slope drains frequently fail because the water "pipes" around the inlet to the
pipe. Check to see that the soil at the inlet is compacted to prevent piping.
■ Chutes have steep slopes and carry water at very high velocities. Check that
the outlets are stabilized to prevent erosion and that the inlets are designed to
prevent water from washing around or under the chute.
■ Determine if the chutes have subdrains, necessary to prevent hydrostatic
uplift.
■ Bends in chutes are difficult to design and build and should be avoided if
possible. Check any bends in a chute for signs of overtopping or erosion.
Problem Assessment
0 Gullies in the channel bottom mean that the velocities are too high. In this
case, the channel must be redesigned by either lining the channel to withstand
the flow velocities, changing the grade or altering the channel cross-section to
lower the velocity.
■ Sloughing from the channel sides indicates stability problems. Causes of
sloughing include a high water table, unstable soils, channel banks that are too
steep or water velocities that are too high.
■ Overbank erosion, or flooding, may result from debris and sediment
accumulation. The damaged areas should be rebuilt and the channel restabilized
according to plan specifications.
■ Sediment below the channel outlet indicates that erosion is occurring either
in the channel or its watershed. The problem should be located and corrected.
5.6

Inspecting Erosion Control Practices
Outlet Protection Outet protection is used to reduce high velocity flows from channels, culverts,
pipes and other high velocity structures. Concrete stilling basins may be required
for outlets that have overfills or where a riprap apron would be too long. Check the
following points of outlet protection practices.
■ The installation of riprap is often problematic for outlet stabilization structures.
The riprap should be inlaid into the soil to a depth of 1• times the D.- size and
See sections 6.40-6.41 of the have a layer of geotextile fabric under the stone.
Planning and Design Manual and
section 6.41 in the Field Manual The finished structure should be large enough to handle the full volume that
for more information. the outlet was designed to carry. The cross -sectional flow area can be seriously
reduced if no compensation is made for the thickness of the riprap.
Figure 5.5 Riprap Outlet
Protector
■ The riprap should extend far enough downstream to reach a stable section of
the stream. The purpose of the stabilization structure is to dissipate the energy of
the water and slow water movement to keep the channel from eroding.
■ The apron of the outlet structure must be level to prevent the water from
undercuttting the downstream edge of the apron.
■ Level spreaders must be constructed on undisturbed soil; no fill is allowed (the
fill will settle and the lip no longer will be level). Also, the lip must be level if the
spreader is to work.
■ The natural discharge area of the level spreader should handle the flow without
eroding and not reconcentrate the flow (which will cause rills or gullies).
Length of apron to achieve
non -erosive velocity
07.
III IIIdIII-�_IiII1�
Geotextile fabric or
aggregate filter blanket
Riprap level with ground
surface to prevent overfall
'00X
5.7

n
Inlet Protection Inlet protection prevents sediment from entering the storm drains and leaving
the construction site. By using inlet protectors (excavated, fabric, gravel or
block and gravel), the designers can make use of the storm drains to discharge
storm waters during construction. Look for problem areas within each of these
practices.
Excavated Drop -inlet
Protectors
Fabric Drop -inlet
Protectors
Figure 5.6 Excavated and
Fabric Drop -inlet Protectors
■ If sediment has filled the excavated pool around the inlet, the contributing
area for the inlet may be too large or the inlet protection structure may not have
been maintained properly.
■ The capacity of the excavation around the drop -inlet protectors must be
adequate for the contributing area. Also, the excavated area should be frequently
cleaned and maintained.
■ These structures frequently fail because the posts are not set against the
inlet and the tops of the posts are not supported or braced to on another.
■ Water should fall directly into the inlet opening, not onto the unprotected
soil around the inlet box.
■ The fabric must always be buried at the bottom to prevent undercutting and
to provide structural strength. The fabric should be set a minimum of 12 inches
in the soil, and the trench backfilled with compacted earth or crushed stone.
f �// Main flow
Flow
Flow
Flow
1.5' max Drop inlet with
height: grate
Fabric reinforced
with wire mesh backing
and set 12" into ground
— compact backfill against fabric
2x4 posts set
against inlet and
braced at top —
use 3 foot posts
Nith minimum
1.5' in ground
5.8

Inspecting Erosion Control Practices
■ Drop -inlet protectors should be set low (no more than 1.5 feet high) to allow
water to flow over them without collapsing.
■ Also, drop -inlet protectors should be set low (less than 1.5 feet) to prevent
water from overflowing the pool behind the fabric, thus bypassing the storm inlet.
In some cases a dike may be required to prevent bypassing.
Gravel and 0 Gravel and block and gravel inlet protectors should be set low (no more than 2
Block and Gravel feet high) to prevent water from overflowing the pool and bypassing the structures.
The blocks must be set against the base of the inlet for support and to prevent
Inlet Protectors erosion between the blocks and the inlet. A few blocks must be set on their sides
to allow the pool to drain.
■ The stone used for the gravel inlet protector should be large enough that it will
not wash into the inlet. The slope of the inside face of the gravel must not be too
steep or the gravel will fall into the inlet. A few blocks must be set on their sides
See sections 6.50-6.53 of the to allow the pool to drain.
Planning and Design Manual and
sections 6.50-6.52 in the Field ■ The fine, "washed stone" must be on the outside face of the gravel inlet
Manual for more information. protector in order to slow the flow of the water through the larger stone. (The fine
stone does not filter the sediment from the water. Sediment drops out of the water
because the water is pooled behind the inlet protector.)
■ Gravel and block and gravel inlet protectors require flat approaches with
adequate storage to allow sediment to settle.
■ A dike may be required on the low side of the pool to prevent runoff bypassing
the protector.
Figure 5.7
Block and Gravel Inlet Protector
Compacted dike to prevent
Holes set for by-pass flow, 6" higher
dewatering than top of blocks
—�_
Slope
2:1 slope, gravel blanket'
of washed stone ��-
5.9

n
Sediment Traps and Sediment traps, basins and barriers are used to retain sediment on the site to
Barriers protect streams, lakes, drainage systems and adjacent property. These devices
are used at the outlets of channels, diversions and other runoff conveyance
measures to allow sediment -filled water to pool and sediment to settle. These
measures are often used as the last line of defense to stop sediment from leaving
the site; therefore, inspect them closely.
Sediment Traps
■ The drainage area must be limited to 5 acres or less.
■ The size of the sediment pool must be adequate for the disturbed area.
■ The spillway of sediment traps must be large enough to carry the design
flow. The crest of the spillway should be level to distribute the flow evenly.
See sections 6.60-6.63 of the
0 Geotexitle fabric (filter cloth) must be installed under the outlet section to
Planning and Design Manual and
prevent undercutting.
the same sections in the Field
■ The slopes of the inside and outside faces of the outlet section must not be
Manual for more information.
greater than 2:1 to prevent the stone from washing away.
■ The earth dike forming the basin must be compacted to prevent it from
failing when the pool is full. The height and top width must be adequate to hold
the water in the pool.
■ The dike must be higher than the outlet weir section or the water will wash
Figure 5.8 Sediment Trap
out the dike at its the lowest point.
■ Sediment traps should be cleaned when the sediment is one-half the design
depth to maintain adequate storage volume.
SEDIMENT TRAP
CROSS SECTION
5' minimum 1.5'
Flood pool
Set stake at
— — — — Apron — 5' min
cleanout level
must be level
Washed stone `L 2.j
facing 5' max
Size: 1800 cubic feet/acre
SEDIMENT TRAP
1'thickfacing * 1111=
OUTLET
Geotextile fabric
Design elevation
of top after
21 „ min Overfill 6"
settling r
for settlement Emergency bypass
6" below top
of settled dam
I11) I 1 5' A
iUl—
l
4' min
i R 21 slope (Illlli—Illl=Itl�
-«l _
=111
Geotextile 1:1 slope max 1=P�'
fabric max I I
5' max fill
.c s Undisturbed
5.10
T min soil

Inspecting Erosion Control Practices
Sediment basins 0 The size of the sediment pool must be adequate for the disturbed area. Limit
the drainage area to 100 acres.
■ Sediment basins require special attention because their large size makes them
very hazardous if they fail. Thus, it is important that sediment basins carefully
follow the dimensions, grades, elevations, pipe sizes, emergency spillway sections
and other specifications as shown on the approved plans.
■ The conduit must be installed and function properly. The conduit joints must
be watertight and must have antiseep collars or drainage diaphragms to prevent
piping along the conduit.
■ Anti -flotation weights must be used to prevent conduit movement.
■ The soil in the embankment and particularly around the conduit must be
compacted to prevent piping along the conduit. Hand tamping is necessary around
the conduit.
■ Trash racks can cause failures if they are improperly designed. They should
catch large debris to prevent the conduit from being clogged but should not have
such fine openings that they become clogged with leaves and cause water to
overtop the embankment.
■ There should be at least 1 foot of freeboard above the emergency spillway flow
depth to prevent overtopping the embankment.
■ The emergency spillway should be large enough to carry the 10-year storm
flow (25-year storm flow in High Quality Water Zones) safely without eroding. It
should be constructed in undisturbed soil and properly stabilized.
■ Large basins must be accessible to allow frequent cleaning. The sediment
removed from the basins should be placed where it will not be lost off -site.
Sediment fences 0 Sediment fences fail because they are improperly designed, installed or
maintained. Silt fences must be buried at least 12 inches and backfilled with
compacted soil or stone to prevent undercutting. These fences must be adequately
supported to prevent collapse from the pressure of the water and accumulated
Figure 5.9 Sediment Fence sediment.
■ Silt fences should never be placed across
streams, drainage channels or areas of concen-
trated flow. The flowing water will collapse or
Wire mesh reinforcement undermine the fence.
11
Fabric buried 12 inches and backfilled
with compacted soil or crushed stone
■ Silt fences cannot withstand flows from
large areas or steep slopes. The size of the con-
tributing area must be limited to • acre per 100
feet of fence.
■ Sediment fences require frequent mainte-
nance. The accumulated sediment should be
removed often.
5.11

n
STREAM
CULVERTS CROSSINGS BRIDGES
FORDS
Stream Crossing Inspect stream crossing carefully because any sediment will enter the stream
directly.
■ Culverts (or the overflow area) must be large enough to carry the storm flow.
■ The soil around culverts or conduit pipes must be compacted to prevent
water from piping along the length of the culvert or pipe. The fill over the pipe
should be higher than the stream banks. (This is called "island type" construction
for culverts.) Inlets and outlets should be well armored.
See sections 6.70 and 6.73 of the 0 Debris and construction material should be removed from the stream to
Planning and Design Manual and prevent water cutting around culverts and bridge abutments.
section 6.70 in the Field Manual for
more information. ■ Culverts cause additional soil disturbance when they are installed or
removed. Provisions should be made to reduce sedimentation in the stream
during installation and removal of the culvert.
■ Fords should be used only for shallow or intermittent streams. Use geotextile
fabric covered with properly sized stone to prevent the stone from being carried
downstream.
■ Bridges cause the least disturbance to the stream and should be used where
practical.
■ Banks should not be filled to shorten the length of bridge required. Fills
Figure 5.10 restrict the stream channel and can easily wash out.
Typical Stream Crossing 0Approaches to stream crossing should be stabilized and should have
diversions to prevent runoff from entering the stream.
Bank height 5' maximum
•�.1 `4�. r1r �. iY.
V
�� lll,fw
�( Stream channel
01
04
.err q,+u � •� + -• �
Approach covered with crushed stone,
5:1 slope maximum
PA
�J
Crushed stone over
geotextile fabric
A(
"+ Surface flaw
—diversion
5.12
IF

Inspecting Erosion Control Practices
Buffer Zones The law requires the use of buffer zones to protect streams, lakes and other bodies
of water. Check for the following points when buffer zones are required on a site.
(See GS 113A-57(1) 1 for the legal requirements.)
See the Sedimentation Control 0 Buffer zones along water bodies with no special classification must be wide
Rules. 15A NCAC 04B.0025, for enough to stop all visible sediment in the first one-fourth of the buffer nearest the
the required buffer zone widths construction work.
along various waters. ■ Buffer zones along designated trout waters must be a t least 25 feet wide
(measured from the top of the stream bank) or wide enough so that all visible
sediment is stopped in the first one-fourth of the buffer nearest the construction,
whichever dimension is greater.
m ILIL "n^
All sediment stopped in first 25%
of width. Minimum width along
trout waters is 25 feet.
■ Avoid the use of in -stream controls such as check dams, weirs and the like.
/V,
Figure 5.11 Buffer Zone Along Stream
5.13

n
Maintenance Maintenance of erosion control devices is frequently overlooked on many
construction sites. It is one of the most critical points in preventing accelerated
erosion and off -site sedimentation.
■ The responsible party should provide for continued inspection and
maintenance of erosion control practices. Maintenance for a disturbed site
should be planned to continue through the life of the project.
■ All devices in the erosion and sediment control system should be inspected
regularly (especially after storms). The erosion control plan should specify
regular inspections and proper maintenance, such as cleaning and repairs, for
each practice.
■ Sediment traps and basins should be cleaned when the settling pools are
half full.
■ Contractors frequently run over diversions with heavy equipment, breaking
down the dike and allowing overtopping. If the contractor must drive over the
diversion, it should be stabilized with gravel and built up to the design elevation
above the channel.
■ Silt fences should be repaired immediately if they are damaged.
More Information and For further information regarding proper erosion control practices, refer to the
References Planning and Design Manual and Field Manual. Also the Rules governing
sediment control can be helpful for many practices.
Remember that the Sedimentation pollution Control Act is performance -
oriented. Even if practices are installed on a site in accordance with the approved
plan, the site is only in compliance where erosion and sediment are effectively
controlled.
5.14

0

Appendices
APPENDIX A HUMAN RELATIONS
Human Relations The hardest part of an inspector's job is dealing with people. You will be working
with contractors, developers, neighbors and concerned citizens. All have rights as
citizens and as human beings.
To deal effectively with people, you must be fair and consistent. You must follow
the rules governing erosion and sediment control, and you must apply them
fairly. Fairness means treating all people with courtesy and respect. If you show
respect for the other person, that person is more likely to show respect for you. It
is important to be as consistent as possible. If you apply the rules consistently to
every situation, the people you deal with will know what to expect.
Perhaps the most challenging part of being an inspector is carrying out your
responsibilities in a professional manner. Sometimes you may feel pressured not to
cite violations, but it is your job to make sure all rules are followed. The objective
is to prevent accelerated erosion and off -site damage from sediment. To do this job
well and be respected as a professional, you must maintain your integrity.
You will visit many construction sites, offices and organizations. For these visits,
prepare a short introduction explaining who you are, what your job is and why
you are there. Give a business card to those you meet to help them remember your
name and the role of your organization.
Dealing With Angry or Individuals who have complaints frequently come to the inspector. Consequently,
Difficult People it is the inspector who has to handle heated confrontations.
When a person voices a complaint, you will not have time to prepare a response.
Therefore, you must resolve the situation spontaneously. You can be prepared,
however, by developing skills for dealing with conflict situations. The general
guidelines in the following section will help in handling angry people.
6.1

0
Key Steps A situation with an angry person should be handled in a manner that is
satisfactory to the person, yourself and the organization you represent. Your
organization relies on you to handle these situations effectively. Use these steps
as a guide for developing your skills in dealing with angry people. You can
tailor these skills to fit your own personality and style.
Step 1 Maintain a friendly and professional manner.
You are likely to be the first person an angry individual confronts. Be careful
not to argue because it will only make the person become defensive and even
more difficult.
■ Show an interest in the person's problem and communicate your desire to
solve it.
■ Do not let the person's anger arouse your desire to retaliate. Handling a
conflict situation diplomatically is your professional responsibility and can be
rewarding.
■ Do not take what the individual says personally. Though the anger may be
directed at you, the person is actually angry with the organization. The individual
probably feels that your organization has treated him or her unfairly.
Step 2 Acknowledge that a difficult situation exists.
Show that you take the complaint seriously. It is important that you help the
person maintain self-esteem. The complaint must not be viewed as unimportant.
The person would not be complaining if he or she did not consider the problem
important.
■ Choose words and use a tone of voice that show sensitivity to the parry's
situation. The person wants to know that you understand the situation. An angry
person does not want to hear (and probably is unable to hear) that he is wrong.
■ Express empathy by responding to what the person says and feels. Expressing
empathy does not mean you agree with the individual. It means simply that you
recognize and respond to what the person is experiencing.
■ If an apology is in order, apologize for the specific incident and no more.
Step 3 Calm the individual by questioning and verifying.
By asking questions, you can verify your understanding of the situation and
also demonstrate that you are willing to work with the person. This also helps
the person to work with you.
■ Ask questions to get specific information about the problem. Never assume
that you understand.
■ Give the person feedback to show that you understand the problem.
■ Be sure that you and the person fully understand the problem.
Step 4 Involve the person in solving the problem.
The next step is to get the person to cooperate in exploring alternative solutions.
Show thatyou are interestedin solving the problem. By discussing all alternatives
and the consequences of each solution, you can keep the party focused on the
problem and avoid side issues.
6.2

Appendix A
■ Ask the person to help you solve the problem. Request suggestions for
solving the problem, and offer your assistance to help correct the situation. Your
knowledge of erosion and sediment control can guide the party to a reasonable and
legal solution.
■ Continue to ask questions in order to keep the person focused on solving the
problem. If the individual is still angry, continue to empathize, showing that you
understand the problem.
Step 5 Handle the problem.
Having explored the possible solutions, focus on the most feasible and satisfying
solution. Be positive with the person. Explain what you are going to do in a way
that the person understands.
■ If he resists, go on to another alternative. Be as helpful as you can. Satisfying
the person's desire for service and special attention can sometimes turn an opponent
into an advocate.
■ Decide upon a follow-up action to ensure that the problem has been resolved
satisfactorily.
Being The Bearer of There will be times when you will have to be the bearer of bad news. You may
Bad News have to tell a person that you cannot solve a complaint to his or her satisfaction,
or you may have to inform a responsible party of a violation. These situations can
be very stressful for both you and the other person. The following section lists key
steps that will help prepare you to deliver bad news.
Key Steps
Step 1 Present the situation.
Explain the situation to the person with as few words as possible. When your
discussion is concise, direct, and to the point, the person is spared the anxiety of
wondering how bad the news is.
■ Prepare the person for the negative information. It maybe necessary to provide
a short background about the events leading up to the present situation.
■ Provide reasons why the situation has occurred. Your maybe able to show that
the person's actions were not responsible for the situation.
■ Don't try to give the person good news first and then the bad news —this can
appear patronizing.
■ Do not make the bad news seem insignificant; it probably isn't insignificant to
the person involved.
Step 2 Allow the person time to adjust.
Most people need a little time to collect their thoughts and react emotionally to
the bad news. Allow the person some time, but try not to leave long periods of
silence. Some people perceive silence as pressure to react and therefore may react
inappropriately.
6.3

0
■ Try discussing the positive aspects of the situation. The person may or may
not hear you, but positive comments can help keep the conversation constructive
and the outlook optimistic.
Step 3 Accept the person's reaction
Allow the person to express his or her feelings and opinions. It is normal to
react emotionally to bad news. Allowing people to ventilate their emotions
shows that you accept their feelings and helps to reduce the negative aspects of
the situation.
■ If the person does not offer a reaction, try talking about how you have felt
or would feel in a similar situation. Then ask for the person's reaction. Use
this technique to stress that you are empathetic to the other person's dilemma.
However, do not get caught up in discussing your own troubles.
Step 4 Demonstrate acceptance of the person's reaction.
A person may react emotionally in many different ways and may not clearly
express his or her feelings. By accepting their emotions you reaffirm them as
valuable and important. Most of us find it hard to talk about emotions in the
workplace, and we have trouble accurately identifying the emotions of others.
You must observe and listen carefully to determine if the person's true feelings
are being expressed
■ When receiving bad news, the person may feel a wide range of emotions,
such as anger, dissatisfaction, embarrassment or confusion. Respond to these
emotions by remaining calm, expressing empathy, offering reassurance, or
providing further explanation.
■ Try to mentally identify or name the emotion that the person is feeling.
Identifying the person's reaction allows you to accept the reaction for what it
is —that is, not a personal affront to you. Understanding how the other party
feels also helps you anticipate upcoming statements and remain in control of
your own emotions.
■ People often react by blaming another person, a group, or the system. The
person is simply reacting from his anger —try not to take it personally.
■ Avoid being caught in answering questions that are really meant as
statements. For instance, "Don't you think this is unfair?" really means "I
think this is unfair." Restate the question as "I understand that you think this is
unfair."
■ Sometimes you may be able to use self -disclosure to diffuse the situation. In
other words, state how you have felt in similar situations. Statements such as, "I
know just how you feel," can be taken as patronizing. Rather, say, "I know how
I've felt in situations like this."
Step 5 Restate position points.
Once the initial emotional reaction has passed, help the person put the situation
into perspective.
■ You can help the person see the situation more positively by expressing
confidence in his or her ability to meet the challenge and by providing genuine
praise for efforts put forth.
6.4

Appendix A
■ Reemphasize the basic facts about the situation and discuss any steps that can
be taken to address the problem.
Step 6 Offer assistance.
If appropriate, you can offer to assist the person in future actions or planning.
■ Do not offer to do something that you are not authorized to do.
■ Inform the person that it may be necessary to submit revised plans or seek
legal help.
Step 7 Clearly express that violations must be corrected.
An emotionally upset person may not be able to fully understand the situation
or may intentionally misunderstand the conversation. Be sure that the person
understands the information you have provided and knows what is expected to
correct or address the situation.
■ Repeat the actions that must be taken and the required time frames.
■ Discuss the required action. if you cannot change the requirements or time
frames, tell the person that you regret that you cannot change them.
■ A good way to ensure that the person understands the information you have
discussed is to ask the person to repeat the details of your discussion in his or her
own words. For example, "I want to be sure I haven't said something that might
be misunderstood. Would you tell me, in your own words, your understanding of
this discussion?"
Step 8 Allow for future contact and follow-up.
Give the person a chance to contact you for further discussion. You may need to
schedule a future meeting. You should always give the person your business card
and phone numbers where you can be reached.
■ Confirm, in writing, the conclusions reached so that all parties have a similar
basis for their understanding of the situation.
These lessons were adapted from material written by the North Carolina Office of
State Personnel, Division of Employee and Management Development, Personnel
Development Center. This center has additional information on human relations
and also offers workshops in dealing with angry people and other human relations
topics.
6.5

0
APPENDIX B SOIL AND VEGETATION
Plants Recommended for Revegetating Disturbed Soils
in North Carolina
Annuals
Perennials
Cool -season
Winter rye (grain)
Tall fescue
grasses
Kentucky bluegrass
Redtop
Warm -season
German millet
Bermudagrass
grasses
Sudangrass
Bahiagrass
Centipedegrass
Legumes
Annual lespedeza
Crownvetch
Sericea lespedeza
Marsh plants
Smooth cordgrass
Saltmeadow cordgrass
Giant cordgrass
Dune plants
American beachgrass
Sea oats
Bitter panicum
Saltmeadow cordgrass
Temporary Seeding recommendations for Late Winter and Early Spring
Seeding mixture
Species Rate (Ib/acre)
Rye (grain) 120
Annual lespedeza
(Kobe in Piedmont and Coastal
Plain, Korean in Mountains) 50
Omit annual lespedeza when duration of temporary cover is not to extend beyond June.
Seeding dates
Mountains — Above 2500 ft: Feb. 15 - May 15
Below 2500 ft: Feb. 1 - May 1
Piedmont — Jan. 1 - May 1
Coastal Plain — Dec. 1 - Apr. 15
Soil amendments
Follow recommendations of soil tests or apply 2,000 lb/acre ground agricultural limestone
and 750 lb/acre 10-10-10 fertilizer.
Mulch
Apply 4,000 lb/acre straw. Anchor straw by tacking with asphalt, netting, or a mulch anchoring tool.
A disk with blades set nearly straight can be used as a mulch anchoring tool.
Maintenance
Refertilize if growth is not fully adequate. Reseed, refertilize and mulch immediately following erosion
or other damage.
6.6

Appendix B
Temporary Seeding Recommendations for Summer
Seeding mixture
Species Rate (Ib/acre)
German millet 40
In the Piedmont and Mountains, a small -stemmed Sudangrass may be substituted at a rate of 50 lb/acre.
Seeding dates
Mountains — May 15 - Aug. 15
Piedmont — May 1 - Aug. 15
Coastal Plain — Apr. 15 - Aug. 15
Soil amendments
Follow recommendations of soil tests or apply 2,000 lb/acre ground agricultural limestone
and 750 lb/acre 10-10-10 fertilizer.
Mulch
Apply 4,000 lb/acre straw. Anchor straw by tacking with asphalt, netting, or a mulch anchoring tool.
A disk with blades set nearly straight can be used as a mulch anchoring tool.
Maintenance
Refertilize if growth is not fully adequate. Reseed, refertilize and mulch immediately following erosion
or other damage.
Temporary Seeding Recommendations for Fall
Seeding mixture
Species Rate (Ib/acre)
Rye 120
Seeding dates
Mountains —Aug. 15 - Dec. 15
Coastal Plain and Piedmont -- Aug. 15 - Dec. 30
Soil amendments
Follow soil tests or apply 2,000 lb/acre ground agricultural limestone
and 1000 lb/acre 10-10-10 fertilizer.
Mulch
Apply 4,000 lb/acre straw. Anchor straw by tacking with asphalt, netting, or a mulch anchoring tool.
A disk with blades set nearly straight can be used as a mulch anchoring tool.
Maintenance
Repair and refertilize damaged areas immediately. Topdress with 50 lb/acre of nitrogen in March.
If it is necessary to extend temporary cover beyond June 15, overseed with 50 lb/acre Kobe (Piedmont
and Coastal Plain) or Korean (Mountains) lespedeza in late February or early March.
Permanent Seeding You can find recommended permanent seeding mixtures in the North Carolina
Mixtures Erosion and Sediment Control Planning and Design Manual in Tables 6.1lc-v on
pages 6.11-31. Make copies of the seeding tables you use and insert them in this
appendix
6.7

0
Seeding Table Use this blank seeding chart for your own seeding mixtures. Copy this page and
write in the information about your mixtures on the copy.
Seedling No. for:
Seeding mixture
Species Rate (lb/acre)
Seeding notes
Nurse plants
Seeding dates
Best Possible
Soil amendments
Mulch
Maintenance
Notes
6.8

Appendix C
APPENDIX C WATER AND RUNOFF MANAGEMENT
The following two tables list the flowrate of water in circular concrete and circular
corrugated metal pipes for given slopes. The values listed are for pipes with no
entrance or exit restrictions or controls. Pipes with either restrictions or controls
will not carry the flowrates listed here.
Concrete Pipe Full Flow Values in cubic feet per second
where n (roughness coefficient) = 0.012
Slope (ft/ft)
Pipe
0.001
0.005
0.01 0.02
0.05
0.1
Diameter
(0.1%)
(0.5%)
(1.0%) (2.0%)
(5.0%)
(10%)
8 inches
0.4 cfs
0.9 cfs
1.3 cfs 1.8 cfs
2.9 cfs
4.1 cfs
12
1.2
2.7
3.9 5.4
8.6
12
15
2.2
5.0
7.0 10
16
22
18
3.6
8.1
11.4 16
25
36
24
7.7
17.3
24.5 35
55
77
30
14
31
44 63
99
140
36
23
51
72 102
161
228
1 cubic foot per second =
450 gallons per minute
Corrugated Metal Pipe
Full Flow Values -
Circular Cross-section
in cubic
feet per second where n
(roughness coefficient) = 0.025
Slope (ft/ft)
Pipe
0.001
0.005
0.01 0.02
0.05
0.1
Diameter
(0.1%)
(0.5%)
(1.0%) (2.0%)
(5.0%)
(10%)
8 inches
0.2
0.4
0.6 0.9
1.4
2.0
12
0.6
1.3
1.9 2.6
4.1
5.8
15
1.0
2.4
3.4 4.8
7.7
10.6
18
1.7
3.9
5.5 7.7
12
17
24
3.7
8.3
11.8 17
26
37
30
6.7
14.9
21 30
47
67
36
11
24
34 49
77
109
6.9

0
Problems with Many riprap-lined channels are not installed as the engineer designed them on
R i p ra p- I i n ed Channels the approved plans. Too often, these channels are greatly undersized in the field
because the contractor did not inlay the riprap. The riprap was simply dumped
on the surface of the excavated channel, thus reducing the cross sectional area
and restricting the flow in the channel.
Flow Restrictions vs The riprap must be inlayed to prevent undercutting and loss of soil around the
Extra Excavation stone. Proper installation of riprap requires the stone to be set one and one-half
times its maximum diameter (or Dm_) size into the soil. Setting the riprap into the
soil means that the channel must be excavated to a larger size to accommodate
the thickness of the riprap and not restrict flow in the channel.
Remember, riprap must always be inlayed a minimum of one and one-half times
its maximum diameter (D._) into the surrounding soil when it is installed and it
must have a geotextile fabric or a stone filter layer under it.
Figure 6.1
— 22'
1.0 16' 1
2:1 side slope
Geotextile fabric
4' No 118" depth of 8" (D50) riprap
In the illustration above, the approved plans call for a channel 3 feet deep, with
a 4-foot-wide bottom, 2:1 side slopes, and a top width of 16 feet which requires
excavating 1.1 cubic yards of soil per foot of channel. If the channel is lined with
8-inch (D50) riprap using a geotextile fabric under the stone, then the contractor
must increase the excavation size to 4.5 feet deep, and a top width of 22 feet,
which requires removing 2.2 cubic yards of soil per foot of channel.
Looking at it from the point of flow restriction, say the approved plans called
for a depth of 4.5 feet, a bottom width of 4 feet, 2:1 side slopes, a top width of
22 feet, and an 18-inch lining of 8 inch (D50) riprap. If the riprap is dumped on
the surface of the excavated soil, then the channel has only one-half the cross -
sectional flow area that was called for in the approved plans. This channel will
not carry the flow rate of water that it should carry.
6.10

Appendix D
APPENDIX D EROSION AND SEDIMENTATION
Damages from Erosion Most of the general public is unaware of the types, severity, and extent of damage
and Sediment that results from erosion and sediment. This section briefly explains how erosion
and sediment from construction activities damage the construction site, streams,
lakes, and public and private property.
Erosion on Construction More than a million acres of land in the United States are converted from
Sites agricultural use to urban use each year. What were once fields become the sites for
new houses, shopping centers, schools, industrial parks, highways and airports.
Construction sites are a significant source of the sediment that pollutes streams
and fills lakes. Studies show that erosion on land disturbed for construction is
much higher than on land in cultivated row crops and very much higher than on
land in pasture or timber.
The amount of erosion that occurs is determined by the kind of soil, the slope of
the terrain, the intensity of rainfall and construction methods. Much of the erosion
occurs during the construction period, but areas below a construction site may
erode after construction is completed because of increased runoff from compacted
soil, impervious pavement and parking lots.
Damage to the land does not come from erosion alone. Increased runoff from an
eroding site erodes stream banks and channels, and causes flooding downstream.
Sediment from the erosion pollutes streams, fills lakes, and damages the area
where it is deposited.
Damage to the Erosion damage to the construction site includes rilled and gullied slopes, gullies
Construction Site in waterways and channels, washed-out roads and streets, undercut pavements and
pipelines, clogged storm sewers, flooded basements and debris -laden work areas.
Damage of this kind must be repaired. It increases the cost of construction and
causes delays in work schedules.
Also, fertile topsoil is lost through erosion. This loss means that lawns and gardens
will be difficult to establish and landscaping costs will be higher.
Damage to Stream Streams in a stable environment have banks covered with vegetation, and clean,
Channels stable bottoms. They rarely flood. In contrast, stream channels below a construction
site can flood or become filled with sediment due to increased runoff and erosion
from the construction site. Larger flowrates of runoff erode streambanks, cause
sloughing of large parts of the streambank, and can force the stream to meander.
Streams that are stressed by increased runoff cut larger channels by widening or
deepening the channel, depending on the erodibilities of the soil layers. Active
erosion or sloughing of the streambanks is visible. The bottoms are covered
with sediment, either from the eroding construction site or the streambanks. The
aesthetic value of the stream is seriously reduced.
Land owners along such streams may find their property washing away or damaged
by thick deposits of sediment.
6.11

0
Damage to Water Sediment is the greatest single pollutant of streams, lakes, ponds and reservoirs.
It lowers the quality of water for municipal and industrial uses and for boating,
fishing, swimming and other water -based recreation. Suspended sediment
increases the costs of water treatment and causes increased wear on equipment
such as turbines, pumps and sprinkler irrigation systems.
Sediment can destroy the habitat for fish and other aquatic animals and plants.
If the sediment loads are heavy, fish and shellfish can suffocate due to sediment
clogging their gills.
Many pollutants such as pesticides, phosphates, and other chemicals are
adsorbed on the sediment particles and carried with the sediment.
Damage to Public and Sediment damages the areas where it is deposited. It can bury lawns, fill
Private Property ditches, and clog storm sewers, culverts and drains. Thick deposits can make an
area unsuitable for use as a park or playground. Sediment reduces the storage
capacity or reservoirs and may fill small ponds and lakes. If sediment reaches
major waterways, it can block navigation channels, or fill harbors and estuaries
with silt.
Estimating and Estimating erosion or measuring sediment volumes can be difficult tasks. This
Measuring Erosion and section outlines two methods that have been used to estimate soil losses and find
Sediment Vo I u m e s sediment volumes —there is no widely accepted or standard method. Accuracy
of the methods is variable.
Measuring Soil Losses
Soil loss from a field can be measured with surveying equipment. To find
from a Field
how muck soil has been lost, the field is surveyed and contours of elevation
established. The present contours of the field are then compared with the original
contours. The volume of soil is calculated from the differences in elevation of
the soil surface and the areas over which the soil loss occurred.
The following points can help when using this method.
■ Sometimes it is difficult to obtain contoured site plans of a project. You
can check with the U.S. Geological Survey, Soil Conservation Service, the
Agricultural Conservation and Stabilization Service, the Forest Service or other
such organizations for topographic maps or site plans with elevation contours.
■ Roughness of the field soil surface greatly influences the measured volume
of soil loss. Be sure to measure the soil surface in a consistent manner so that
the soil loss volume is accurate.
■ All soil lost from a field may not flow off -site. Mush soil can be redeposited
in the same field, changing the shape of the field slope, but not violating the law
by losing sediment off -site.
■ If sediment is not being lost off -site, the site may still not be in compliance
with the provisions of the law requiring slopes to be stable and all surfaces
covered.
Measuring Sediment
Measured sediment volume is usually used in legal proceedings to prove
Volumes
damages and non-compliance with the law.
Surveying instruments can be used to find the total volume of sediment. A grid
pattern of transects, or straight lines, is established across each sediment deposit
6.12

Appendix D
and the sediment depth is measured at the points of the grid. The average depth
of sediment is multiplied by the area of the grid section to arrive at a sediment
volume lost.
The following points can help you in measuring sediment volume.
■ Sediment can be carried long distances; therefore, you may have to make
measurements far from the originating site to get an accurate measurement.
■ The total volume of sediment actually lost maybe much larger than the amount
you can measure. The sediment can be deposited in layers too thin to measure or
swept too far away to be found.
For further assistance, consult state regulatory agencies, the Soil Conservation
Service, the Cooperative Extension Service, and state university departments of
soil science, civil and agricultural engineering.
Appendix E
APPENDIX E TOOLS OF THE INSPECTOR
This section will help you in properly equipping your office and your vehicle to
do a thorough inspection. The items listed are suggested only; please add to the
list as necessary.
For Your Vehicle ■ Hand level —to measure slopes and elevations.
■ Measuring wheel.
■ Measuring tape, 100 feet.
■ One-man surveyor's rod and rod holders.
■ Surveying level or transit.
■ Surveying flags or stakes.
■ Camera.
■ Calculator.
■ Inspection reports.
For Your Office ■ Aerial photographs of your region of responsibility.
■ Topographic maps of your region of responsibility.
■ Engineering scales for appropriate scales of maps and photos.
■ Planimeters and other drafting tools to properly measure sites from plans,
topographic maps, and aerial photos.
■ Soils surveys or soils maps of your region of responsibility.
■ Calculator.
■ Video Camera.
6.13

APPENDIX F CONVERSIONS, TABLES, REFERENCE INFORMATION
Slope Measurements and Conversions
Ratio
Run: Rise
Percentage (%)
Degrees (°)
Sine of Slope
1:1
100%
45°
0.707
1.251
80
38.7
0.625
1.501
66.7
33.7
0.555
1.751
57
29.7
0.495
2:1
50
26.6
0.448
2.251
44.4
24.0
0.407
2.501
40
21.8
0.371
2.751
36.4
20.0
0.342
3:1
33.3
18.4
0.316
3.501
28.6
15.9
0.274
4:1
25
14.0
0.242
5:1
20
11.3
0.196
6.14

Appendix F
Slope Measurment
Use this slope measuring aid in the field. Hold the
dashed line horizontal and match the slope of the
embankment to one of the slopes here. A trans-
parent version of this aid, that can be lined up
directly on the slope, can be made by copying this
page onto clear transparency film.
51�
18.4
7
33%
250/0
4.1
100
10 0 0
14.0
11.3
6.15

Soil Textural
Classification
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6.16

Appendix F
Crushed Stone The following pages contain certain information about crushed stone, standard
References sizes and its use in erosion control. The first table lists National Stone Association
(NSA) sizes and the following tables list standard North Carolina Department of
Transportation sizes
Quarried Stone for Erosion and Sediment Control
GRADED RIPRAP STONE
Size Inches (sq. openings)
Wave Height3
Velocity4 Filter Stone
NSA No. Max. Avg.' Min .2
(ft.)
(ft./sec.) NSA Size No.
R-1 1.5 3/4 (No.8)
-
2.5 FS-1
R-2 3 1.5 1
0.3
4.5 FS-1
R-3 6 3 2
0.5
6.5 FS-2
R-4 12 6 3
1.0
9.0 FS-2
R-5 18 9 5
1.5
11.5 FS-2
R-6 24 12 7
2.0
13.0 FS-3
R-7 30 15 12
2.5
14.5 FS-3
R-8 48 24 15
4.0
- FS-3
ARMOR STONE*
Wt. in Short Tons
NSA No. Max. Avg. Min .2
Wave Height (ft.)5
Filter Stone
A-1 4.0 3.0 2.0
8.0
(See Supplemental
A-2 6.0 4.5 3.0
10.0
Engineering Notes)
A-3 8.0 6.5 5.0
12.0
*Due to the large size of armor stone, one or more underlayers may be required in addition to stone filter.
FILTER STONE
Size Inches (sq. openings)
NSA No. Maximum
Average
Min.(2)
FS-1 3/8
No. 30
No. 100
FS-2 2
No. 4
No. 100
FS-3 6.5
2.5
No. 16
The above tables assume a stone dry density of 165 pounds per cu.ft.
"`Average" is that size exceeded by at least 50 percent of the total weight
of the tonnage shipped;
i.e., 50 percent of the tonnage shall
consist of pieces larger than the "average" size (normally half the specified nominal top size).
2Pieces smaller than the minimum size shown shall not exceed 15 percent of the tonnage shipped.
'Wave height is the vertical distance from wave crest to wave trough.
The wave height given in the table is the average height of the
one-third highest waves in the incident wave train.
'The stream velocity is the velocity at mid -stream or at a point 10 feet
from the bank, whichever is
closest to the bank.
'The stone industry generally is unable to economically produce armor stone in sizes to fit the 6-ft.
wave height category. Therefore,
the reader should use NSA No. A-1.
6.17

0
Supplemental The National Stone Association (NSA) has devised the above Tables to define
Engineering N oteS a number of standard sizes from which the reader may select the one most
appropriate to the anticipated service situation. Designations R-1 through R-8
describe "graded" riprap or revetment stone —grading designed to produce a
well bonded mass heavy enough to resist the forces of waves or stream flows of
the magnitude shown.
The larger armor stones designated A-1 through A-3 are more closely sized,
usually "hand-picked" at the quarry and individually placed, piece by piece, by
well-equipped heavy construction contractors.
The proper size of filter stone for the underlayer or "filter pack" for revetment
stone depends upon the type of underlying soil as well as the size of protective
riprap or armor stone above. In brief, the filter layer must be fine enough to
prevent the underlying soil material from being washed up through it and yet
coarse enough to prevent its own finer particles from being washed out through
the voids in the protective cover layer above. In case the underlying soil is
very fine and the riprap or armor stone quite large, it may be necessary to place
two layers of filter stone —a finer layer at the bottom (FS-1 or FS-2, say) and
a coarser bedding layer immediately below the riprap (perhaps FS-3). A more
complete guide to stone sizes for filter layers may be found in the Army Corps of
Engineers' "Shore Protection Manual," Volume II, paragraph 7.377h, Reference
No. 15, page 32, as well as in various soil mechanics texts and other sources.
Adapted from, Quarried Stone for Erosion and Sediment Control. National
Stone Association, 1-91 SEC 5, Washington D.C., 1991.
6.18

Appendix F
Riprap and Erosion Control Stone Sizes
North Carolina Department of Transportation Specifications
Stone density is assumed to be 165 pounds per cubic foot. Stone shape
is assumed to be spherical. Percentages indicate amount passing given
screen size
Approx. Riprap Riprap
Weight of Class Class Approx. Class Class Slope
spheres 1 2 Size A B Protection
(pounds) (inches) Stone
290
250
200
170
140
110
86
66
50
36
26
21
17
15
11
6.2
5
3.2
1.5
0.8
0.4
0.05
0.02
100%
100%
0 - 40%
0-70% 0 - 5%
0%
0-10%
0%
18
17
16
15
14
13
12
11
10
9
8
7.5
7
6.5
6
5
4.5
4
3
2.5
2
1
0.75
Equally
distributed
Equally
distributed
i
90-100%
30 - 70%
10-35%
0-5%
Or use
Class A Riprap
Notes:
1) Slope Protection stone is to be used for control of splash erosion and surface erosion
only, it is not to be used to line channels or where water flows are concentrated.
2) Class 1 and Class 2 riprap are specified by weight of the individual pieces of stone.
3) Class A and Class B riprap are specified by sizes of the individual pieces of stone.
4) Class 1 and Class B riprap are equivalent for practical purposes.
Adapted from the North Carolina Aggregates Association
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Crushed Stone Sizes and Uses
North Carolina Dept. of Transportation Sizes
Coarse Aggregate
Size in inches, or
Standard
Size # Sieve Size (square openings)
Maximum Average*
Minimum
Best Uses
4
2 1
3/4
Bituminous Plant Mix Pavement
467M
2 3/4
#4
Bituminous Plant Mix Pavement
5
11/2 3/4
1/2
Bituminous Surface Treatment Mat Coat
57
11/2 1/2
#4
Structural Concrete Shoulder Drain,
Subsurface Drains
57M
11/2 3/4-1/2
#4
Portland Cement Concrete Pavement,
Subsurface Drains
6
1 1/2
3/8
Bituminous Surface Treatment
67
1 3/8
#4
Structural Concrete, Bituminous Plant Mix
Pavement
78M
3/4 #4
#8
Bituminous Plant Mix Pavement,
Bituminous Surface Treatment, Weep Hole
Drains, Structural Concrete
14
3/8 #4
$8
Bituminous Structural Treatment
All standard sizes of stone listed above are free of fines (washed stone);
therefore they will resist clogging.
Stone sizes SA, ABC and ABC(M)
contain significant
amounts of fines.
These standard sizes should not
be used for subsurface drains or facing
stone for rock dams or outlets for
sediment traps.
SA
2 #4
#50
Stabilizer Aggregate, Pothole Filler,
Soil Stabilizer, Sub -base Course
ABC
11/2 3/8
350
Aggregate Base Course, Bituminous
Plant Mix Pavement
ABC(M)
11/2 1/2
#40
Maintenance Stabilization, Pothole
Filler, Soil Stabilizer
Fine Aggregate
is
3/8 #16
#50
Blotting Sand, Bituminous Pavement
Retreatment
2S
3/8 #30
#50
Structural Concrete, Subsurface
Drainage, Blotting Sand
21VIS
3/8 #30
#100
Structural Concrete
4S
#4 #40
#80
Mortar Sand
*Average size represents the approximate 50% size for the standard size gradation.
NOTE: See the North Carolina Department of Transportation Standard Specifications for Roads and Struc
tures, Section 1005 for technical specifications for coarse and fine aggregate gradations.
6.20

Appendix F
Notes About Crushed Sizes #4 and #467M
Stone Used for Erosion Sizes #4 and #467M can be used to control splash or sheet erosion. Do not use
Control these sizes to line channels or where concentrated flows occur.
This stone provides excellent stabilization for construction roads and construction
entrances and exits in dry soils. If the soils are too wet, larger sizes may be
needed.
These sizes make excellent sub -base courses for parking lots and permanent
roads, providing better drainage and greater support for the final pavement.
These sizes are between NSA R-1 and R-2.
Sizes #5, #57 and #57M
Roughly equivalent to NSA size R-1, these sizes are excellent for use in subsurface
drains and as facing stone for rock dams, sediment trap outlets, and block and
gravel inlet protectors. There are no fines in these sizes; thus, they will resist
plugging.
Sizes SA, ABC and ABC(M)
These sizes are best used as the base course for permanent paving and to stabilize
wet soils. They closely approximate NSA FS-2.
Parking Areas
For sites that plan large permanent parking areas, much erosion can be prevented
by installing a base course of crushed stone just after the site is graded. This
prevents construction equipment from creating large areas of ruts and puddles.
Acceptable stone to use is ABC, ABC(M), SA, #467M, or #4, depending on the
soil and site conditions.
Class A Riprap
Class A riprap is the same as NSA R-3.
Class B and Class 1 Riprap
These sizes are approximately the same as NSA R-5.
Class 2 Riprap
This stone closely approximates NSA R-6.
Slope Protection Stone
Slope protection stone is between NSA R-3 and R-4.
Sizes 2S and 2MS
Fine aggregates #2S and #2MS are equal to NSA FS-1. Size #2S can be used in
subsurface drains.
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APPENDIX G CONSTRUCTION PLANS AND AERIAL PHOTOS
On the following pages, you will find two views of a highway construction
project. The lower portion of the pages are the construction plans, and the upper
portion of the pages are aerial photos of the same project. These plans and
photos are included here to allow you to gain experience in reading construction
plans and aerial photos.
The construction plan shows the "clearing and grubbing" phase for a new
highway. The aerial photos show the site at an interim stage of construction.
This project was chosen because the construction plans and aerial photos are
relatively clear and uncluttered. Except for its simplicity, this project is typical
of many other projects you will encounter as an inspector.
When you are studying these plans and photos, please note that the light gray
contour lines show the original topography of the site. The roadway has been
well -fitted to the original topography, requiring minimal fills and excavations;
however, the constructed roadway has changed the flow patterns significantly
from those originally at the site. Also the contours and the plans were taken
from two sources; thus there are a number of places where the flow paths of
the streams do not fit the contours exactly. Problems such as these are common
when the topographic and the construction plans are done at different times or
by different groups.
Study the plans to find the erosion and sediment control measures. The following
points can help your review.
■ Check the contours of the site to determine the higher and lower areas, and
the direction of flow of the runoff. The contours shown are for the undisturbed
site, before construction. The graded site will have only gradual slopes.
■ Note the perimeter protection, especially near the streams crossing the
project. Is it adequate?
■ Pay attention to critical areas, such as steep cut and fill slopes, stream
crossings, channels, outlets of pipes and diversions and construction access
routes.
■ Are the devices and measures properly placed?
■ Look for adequate access and space for constructing and maintaining the
erosion and sediment control measures.
■ The aerial photo can help you determine if the measures are adequate and/
or working. What would you look for to find out if an area is not adequately
protected?
■ The captions point out certain measures on the plans and on the aerial photo.
Can you find other measures not pointed out by the captions?
■ Have all the measures listed on the plans been is stalled (check the photo)?
■ What additional or alternative measures would you recommend?
6.22

G

Appendix E
Post Construction BMP

C-1. Infiltration System
An infiltration system captures stormwater runoff and allows it to infiltrate into the soil. This
SCM (along with permeable pavement) is typically the work horse of a runoff volume match
site because it helps the site to mimic pre -development hydrology and therefore helps to
protect the structure of the receiving stream. Infiltration systems work best when their
drainage areas are mostly impervious, as pervious surfaces can contribute fines that clog
the soil. This section discusses two types of infiltration devices: infiltration trenches (Figure
1) and infiltration basins:
• Infiltration Trenches are filled with stone or other media to store stormwater in the voids
between. Some infiltration trenches use precast concrete vaults with open bottoms to
provide a large storage volume to hold stormwater for infiltration into the soil. Infiltration
trenches are usually used to manage the runoff from parking lots and buildings.
• Infiltration Basins are depressions that capture, store and allow stormwater to infiltrate
into the soils.
The design volume for an infiltration device is equivalent to the volume that is completely
draw down to the bottom of the infiltration system within 72 hours.
Rule 15A NCAC 2H .1051. MDC for Infiltration
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Underground Infection Wells
Guidance on the MDC
MDC 1: Soil Investigation
MDC 2: Separation from the SHWT
MDC 3: Soil Subgrade Surface
MDC 4: Pretreatment
MDC 5: Drawdown Time
MDC 6: Observation Port
Recommendations
Recommendation 1: Trench Media
Recommendation 2: Trench Geotextiles
Recommendation 3: Pumoed Infiltration
Construction
Maintenance
Operation and Maintenance for Infiltration Trenches
Operation and Maintenance for Infiltration Basins
Old Versus New Desian Standards
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Figure 1: Infiltration Trench: Example Section View
CLEANOUT
TRENCH TOP
CAP
SOIL INVESTIGATION
PERFORM A SOIL INVESTIGATION
TO ESTABLISH HYDRAULIC
PROPERTIES OF SOIL
nPAW nNAIN TRAP:
(a) WITHIN 72 HOURS OR LESS.
(b) IN -SITU SOILS MAY BE REPLACED WITH INFILTRATION MEDIA OR
INFILTRATION MEDIA MAY BE PLACED ON TOP OF IN -SITU SOILS IF MODIFIED
SOIL ALLOWS FOR INFILTRATION WITHIN 72 HOURS
` EX. GRADE OUTLET STRUCTURE
l OUTLETINVERT
OVERFLOW PIPE
LENGTH VARIES
SEPARATION FROM THE SHWT
(a) PROVIDE A MINIMUM OF 2' OF SEPARATION FROM SHWT.
(b) SEPARATION MAY BE REDUCED TO NO LESS THAN T IF
HYDROGEOLOGIC WATER TABLE WILL SUBSIDE TO PRE -STORM
ELEVATION WITHIN 5 DAYS
PERFORATED UNDERDRAIN
SOIL SUBGRADE SURFACE
(a) SLOPES LESS THAN OR
EQUAL TO 2%
(b) TERRACES AND BAFFLES
MAY BE INSTALLED TO
ACHIEVE LEVEL SUBGRADE
• PROVIDE PRE-TREATMENT DEVICES TO PREVENT CLOGGING (E.G. SUMPS IN CATCH BASINS, GRAVEL VERGES, SCREENS ON
ROOF AND PATIO DRAINS, FILTER STRIPS, GRASSED SWALES, AND FOREBAYS). ROOFTOP RUNOFF DISCHARGED TO THE
SURFACE OF AN INFILTRATION SYSTEM DOES NOT REQUIRE PRETREATMENT
• FOR INFILTRATION DEVICES LOCATED UNDER THE GROUND SURFACE. PROVIDE A MINIMUM OF 1 INSPECTION PORT
Class V Stormwater Drainage Well Requirements
Class V stormwater drainage wells are defined in EPA's Underground
Injection Control regulations (40 CFR144.3) as:
A bored, drilled, or driven shaft whose depth is greater than the largest surface
dimension; or, dug hole whose depth is greater than the largest surface
dimension; or, an improved sinkhole; or, a subsurface fluid distribution system.
Class V wells are a specific type of well that are used to inject non -hazardous fluids,
including stormwater, underground. Infiltration systems can sometimes meet the
definition of Class V wells, in which case they are referred to as stormwater drainage
wells. Per the requirements of 15A NCAC 02C .0227, the owner of a stormwater
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infiltration system that meets the definition of a Class V Stormwater Drainage Well
must submit a notification form to the NC Division of Water Resources' Underground
Injection Control (UIC) Program in order to comply with federal injection well inventory
reporting requirements. The Stormwater Drainage Well Notification Form can be found
on DWR's Stormwater Iniectio page. The paragraphs below describe which types of
infiltration systems do not require notification, which ones are not allowed and which
ones do require notification.
Infiltration Systems that do not Require Notification
Infiltration basins without any pipes to convey stormwater into the ground do not
require notification. In addition, infiltration trenches designed in accordance with Figure
1 above are not stormwater drainage wells because the purpose of the underdrain pipe
system is for collecting overflow rather than for distributing stormwater.
Infiltration Systems that are not Allowed
Under NC rules, untreated stormwater is not allowed to be injected directly into any
aquifer. This includes injecting stormwater into an improved sinkhole or into a vertical
well into the ground as depicted in Figure 2 below.
Figure 2: An Example of a Class V Drainage Well (EPA)
CowrfGrate - 004or
- lT�TJ'/117�nZ
l.Li
Urbris
r A ---
Shield l
Oil Absorbent .. Dii Absorbent _
Cometc Chamber PVC Pipe PVC Pipe
.1� 1
.75'ta 3.5' �� _ ,J5' to 1,5'
Washed Rack I a Washed Rock
Infiltration Systems Requiring Notification to DWR's Stormwater Injection
Program
DEQ considers infiltration systems to be stormwater drainage wells if they meet one of
the following criteria:
An infiltration trench or subsurface infiltration system whose depth is larger than
its smallest surface dimension.
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2. The separation from the bottom of the infiltration system to the seasonal high
water table (SHWT) is less than 2 feet (note that additional requirements must
also be met to reduce the separation from the SHWT per MDC 2: Separation
from the SHWT).
3. The groundwater table is artificially lowered to create sufficient separation from
the SHWT for infiltration to occur.
4. A stormwater infiltration system that uses pipes to distribute stormwater (rather
than collect and bypass stormwater overflow), such as the one shown in Figure
3 below.
Figure 3: An Example of an Infiltration System with Piped Stormwater
Distribution (Storm Tech)
AMP AW
Stormwater infiltration systems that fall into one of the four criteria listed above do not
need a separate permit from the DWR Underground Injection Control (UIC) Program;
however, a notification form must be submitted to the UIC Program in order to comply
with federal injection well inventory reporting requirements. The Stormwater Drainage
Well Notification Form can be found on DWR's Stormwater Infection page.
Guidance on the MDC
INFILTRATION MDC 1: SOIL INVESTIGATION.
A site -specific soil investigation shall be performed to establish the hydraulic
properties and characteristics of the soil within the proposed footprint and at the
proposed elevation of the infiltration system.
See Part A-2 for guidance on soil investigation. It is recommended to provide a
minimum of one soil test hole per 5,000 square feet of infiltration surface area.
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INFILTRATION MDC 2: SEPARATION FROM THE SHWT.
The lowest point of the infiltration system shall be a minimum of two feet above
the SHWT. However, the separation may be reduced to no less than one foot if
the applicant provides a hydrogeologic evaluation that demonstrates that the
water table will subside to its pre -storm elevation within five days or less.
There are two primary reasons for the two -foot separation requirement; the first is
the inherent uncertainty in pinpointing the exact location of the SHWT in the field,
and the second is the potential for mounding of the groundwater table in the vicinity
of the infiltration system. If the mounding becomes severe enough, the infiltration
will not function as designed. See Part A-2 for guidance on what should be
provided in a hydrogeologic evaluation.
INFITRATION MDC 3: SOIL SUBGRADE SURFACE.
The surface of the soil subgrade shall have a slope of less than or equal to two
percent. Terraces and baffles may be installed to achieve a level subgrade.
A nearly level soil subgrade slope is necessary to ensure that stormwater will be
evenly infiltrated into the soil subgrade.
INFILTRATION MDC 4: PRETREATMENT.
Pretreatment devices shall be provided to prevent clogging. Pretreatment devices
may include measures such as sumps in catch basins, gravel verges, screens on
roof and patio drains, filters, filter strips, grassed swales, and forebays. Rooftop
runoff that is discharged to the surface of an infiltration system shall not require
pretreatment.
In selecting a pretreatment device, the designer should consider the slope, land
cover, and size of the drainage area. Drainage areas with high slopes, a
significant amount of pervious surfaces, or that are larger than an acre should have
a more robust pretreatment device like a forebay or sump. Smaller drainage areas
with a high percentage of built -upon area can typically have simpler pretreatment
systems like filter strips, swales or gravel verges.
INFILTRATION MDC 5: DRAWDOWN TIME.
Infiltration systems shall be designed to dewater the design volume to the bottom
of the infiltration device within 72 hours or less. In -situ soils may be removed and
replaced with infiltration media or infiltration media may be placed on top of in -situ
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soils if the applicant provides a soils report that demonstrates that the modified
soil profile allows for infiltration of the design volume within 72 hours or less.
The drawdown time requirement, in combination with the field -determined soil
infiltration rate, determines the minimum surface area for an infiltration system.
See Equation 1 below.
rion z: minimum surrace Area ror an inrnrrarion s
SA = FS * DV *12
K * T
where: SA = required minimum surface area of infiltration system (ft2)
FS = factor of safety (minimum of 2 is recommended)
DV = design volume (ft3)
K = hydraulic conductivity of soil (in/hr)
T = maximum dewatering time (72 hours)
Although some infiltration will likely occur from the sides of an infiltration system,
the DEQ recommends sizing the infiltration system's bottom surface area per this
equation and considering infiltration from the sides as a factor of safety.
A factor of safety is crucial in infiltration system design due to the following:
• The inherent uncertainty in soil testing;
• The likelihood that the soil will be compacted during construction, which can
reduce soil infiltration rates by more than an order of magnitude; and
• The likelihood that sediment will enter the infiltration system after it is
constructed and diminish the infiltration rate. If the system does not drain
within 72 hours throughout its operational life, then it will be out of
compliance with this MDC.
INFILTRATION MDC 6: OBSERVATION PORT.
For infiltration devices located under the ground surface, a minimum of one
inspection port shall be provided.
In order to monitor performance of the infiltration device, observations should be
conducted to determine how long it takes retained water to infiltrate into the soil
after a storm event
Recommendations
INFILTRATION RECOMMENDATION 1: TRENCH MEDIA.
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For infiltration trenches, medium or coarse sand, or crushed stone (i.e., uniformity
coefficient of 2 or smaller) is preferable as a drainage medium. Trench media
should be hard, durable, inert particles, free from slate, shale, clay, silt, and
organic matter.
Uniform materials have higher porosity (which provides a larger storage capacity),
which can reduce the amount of space and materials required to construct an
infiltration trench. The porosity of the material should be determined by laboratory
tests and certified by the supplier.
The trench media should be washed, or preferably, double -washed.
To increase the runoff capture storage volume of trenches, plastic, aluminum or
concrete gallery frames can be inserted. The gallery frames introduce open space
inside the trench and help distribute flow. Adequate maintenance access must be
provided to the gallery frames.
INFILTRATION RECOMMENDATION 2: TRENCH GEOTEXTILES.
For infiltration trenches, drainage media should be enclosed on all sides by a
geotextile filter.
Proper specification of the geotextile prevents two problems: accumulation of soil
into the device and clogging at the soil interface. The top surface of the geotextile
should be 6-12 inches below the upper surface of the drainage media. The other
surfaces of the geotextile should be in contact with the in -situ soil. The fabric,
together with the overlying material, can be removed and disposed of when
excessive sediments accumulate on the filter and begin to retard flow into the
device.
INFILTRATION RECOMMENDATION 3: PUMPED INFILTRATION.
If a project has soils with high infiltration rates, but there is not adequate
separation from the
SHWT at the discharge point, the designer has the option of using "pumped
infiltration."
Pumped infiltration can be a good option for some projects, particularly where SA
waters requirements apply. It is typically accomplished by providing a storage
pond at the low point of the drainage area and a pump to convey the stormwater to
a higher elevation.
DEQ recommends that the following information be considered in the design and
provided in the submittal:
1. Pump elevation: Set the pump inlet piping at or above sediment cleanout
level of the storage pond to avoid clogging the pump. The cleanout
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elevation typically corresponds to 0.75 times the design depth of the
storage pond.
2. Routing calculations: Provide routing calculations that demonstrate that
the design volume can be adequately conveyed from the storage pond to
the infiltration system during the storm event. The pump should be sized
such that the operating point is less than the drawdown rate for the basin.
3. Gate valve and discharge line size: Insure that these are provided to
adjust and convey flow at system operation point.
4. Pump system details: Pump system details should be provided on the
plans, calculations, and specifications and should include:
a. Sealed TDH calculations with piping and fitting count, operating point,
entry and exit losses.
b. Pump specification sheet with model number and impeller size.
c. Pump curve with operating point.
d. The pump "on" elevation at a minimum of four inches above pump "off'
elevation identified on the plans (six inches recommended).
e. Check valve provided on pump discharge line to prevent backflow
when pump is
"off."
Construction
Care should be used during installation to minimize compaction of soil on the
bottom and walls of infiltration devices since this will reduce the permeability at the
soil interface. To avoid compacting the drainage media, light equipment and
construction techniques that minimize compaction should be used.
Runoff shall not be directed into an infiltration device until the drainage area is
stabilized. A construction sequence must be followed that reflects the need to
protect the functioning of the infiltration device. The longevity of infiltration devices
is strongly influenced by the care taken during construction.
Infiltration trenches should not be covered by an impermeable surface unless there
is suitable maintenance access, the design specifies a H-20 loading capacity, and
the permit application includes a cross-section of the H-20 design. Direct access
must be provided to all infiltration devices for maintenance and rehabilitation.
OSHA safety standards should be consulted for trench excavation.
A minimum of one observation well shall be included in the design of an infiltration
system to periodically verify that the drainage media is fully draining. The
monitoring well shall consist of a 4- to 6-inch-diameter, perforated polyvinyl
chloride (PVC) pipe with a locking cap. The well should be placed near the center
of the facility or in the general location of the lowest point within the facility, with the
invert at the excavated bottom of the facility.
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Maintenance
For the first year of operation, installations should be inspected monthly and after
each major storm. After the first year, quarterly inspections, preferably conducted
after a storm, are recommended.
In order to monitor performance of the infiltration device, observations should be
conducted to determine how long it takes retained water to infiltrate into the soil
after a storm event. The determination can be made in two ways. The most
informative way is to read the water level several times over a period of days after
a large storm. The alternative is a "one -stop" method, where a single reading is
taken and compared with the local rainfall record. Although less accurate than the
multiple reading method, the one -stop method will still allow significant
deterioration in performance to be recognized.
Maintenance is very important for infiltration devices. Property owners should be
educated in the function and maintenance requirements of infiltration devices.
Especially important is the maintenance of vegetated areas that drain to the
infiltration system. Areas that are allowed to become bare and unvegetated will
contribute excess sediment to the infiltration system and hasten its failure. Any
sediment deposits in pretreatment devices should be removed at least annually.
The surface of infiltration systems must be kept in good condition. In many
instances, it is convenient to cover infiltration trenches with concrete grid pavers or
similar permeable paving systems that can be removed easily and replaced as
necessary to service the trench.
The top several inches of drainage media and the filter cloth along the top of the
drainage media should be replaced annually or at least when the dewatering time
is longer than 5 days. If after replacing the top media the infiltration rate is still not
in the acceptable range, the entire facility must be dismantled and reconstructed.
Proper disposal of the materials removed is necessary; the aggregate and cloth
should be appropriately packaged and delivered to the local landfill, provided the
operating authority approves the disposal.
Since infiltration trenches and infiltration basins have different configurations and
maintenance needs, an appropriate sample operation and maintenance table is
offered for each one.
Sample Operation and Maintenance Provisions for Infiltration
Trenches
Important operation and maintenance procedures:
The drainage area of the infiltration trench will be carefully managed to reduce
the sediment load to the sand filter.
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2. The water level in the monitoring wells will be recorded once a month and after
every storm event greater than 1.0 inches (or 1.5 inches if in a Coastal
County).
The infiltration trench will be inspected quarterly and within 24 hours after every
storm event greater than 1.0 inches (or 1.5 inches if in a Coastal County).
Records of operation and maintenance will be kept in a known set location and will
be available upon request.
Inspection activities shall be performed as follows. Any problems that are found
shall be repaired immediately.
Table 1: Sample Operation and Maintenance Provisions for Infiltration Trenches
The entire infiltration
Trash/debris is present.
Remove the trash/debris.
trench
Regrade the soil if necessary to remove
Areas of bare soil and/or
the gully, plant ground cover and water
erosive gullies have formed.
until established. Provide lime and a
one-time fertilizer application
The grass filter strip or
other pretreatment area
Search for the source of the sediment
Sediment has accumulated to
and remedy the problem if possible.
a depth greater than three
Remove the sediment and dispose of it
inches.
in a location where it will not cause
impacts to streams or the SCM.
Unclog the conveyance and dispose of
The structure is clogged.
any sediment in a location where it will
The flow diversion
not cause impacts to streams or the
structure (if applicable)
SCM.
The structure is damaged.
Make any necessary repairs or replace if
damage is too much for repair.
Water is pond ing on the
Remove the accumulated sediment from
surface for more than 24
the top of the infiltration trench and
hours after a storm.
dispose of it in a location that will not
impact a stream or the SCM.
Do not pull the weeds (may pull out
The trench
Grass or other plants are
media as well). Wipe them with a
growing on the surface of the
systemic herbicide such as glyphosate
trench.
and then return within the week to
remove them by hand. (Another option
is to pour boiling water on them or
steam them.)
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Observation well
The emergency overflow
berm
The receiving water
Water present more than Clean out any clogged underdrain pipes.
three days after a storm event Consult an appropriate professional for
clogged soil subgrade.
Erosion or other signs of
damage have occurred at the
outlet.
Erosion or other signs of
damage have occurred at the
outlet.
Discharges from the
infiltration trench are causing
erosion or sedimentation in
the receiving water.
Repair or replace the berm.
Repair the damage and improve the flow
dissipation structure.
Contact the local NCDEQ Regional
Office.
Sample Operation and Maintenance Provisions for Infiltration Basins
Important operation and maintenance procedures:
The drainage area will be carefully managed to reduce the sediment load to the infiltration
basin.
2. No portion of the infiltration basin will be fertilized after the initial fertilization that is required
to establish the vegetation. Lime may be allowed if vegetation is planted on the surface of
the infiltration system and a soil test shows that it is needed.
3. The vegetation in and around the basin will be maintained at a height of four to six inches.
After the infiltration basin is established, it will be inspected quarterly and within 24 hours
after every storm event greater than 1.0 inches (or 1.5 inches if in a Coastal County).
Records of operation and maintenance will be kept in a known set location and will be available
upon request.
Inspection activities shall be performed as follows. Any problems that are found shall be
repaired immediately.
Table 2: Sample Operation and Maintenance Provisions for Infiltration Basins
The entire infiltration Trash/debris is present. Remove the trash/debris.
basin
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Regrade the soil if necessary to remove
Areas of bare soil and/or
the gully, plant ground cover and water
erosive gullies have formed.
until established. Provide lime and a
one-time fertilizer application
The grass filter strip or
other pretreatment area
Search for the source of the sediment
Sediment has accumulated to
and remedy the problem if possible.
a depth greater than three
Remove the sediment and dispose of it
inches.
in a location where it will not cause
impacts to streams or the SCM.
Unclog the conveyance and dispose of
The structure is clogged.
any sediment in a location where it will
The flow diversion
not cause impacts to streams or the
structure (if applicable)
SCM.
The structure is damaged.
Make any necessary repairs or replace if
damage is too much for repair.
The inlet pipe is clogged (if
Unclog the pipe and dispose of any
applicable)
sediment in a location where it will not
cause impacts to streams or the SCM.
The inlet pipe is cracked or
otherwise damaged (if
Repair or replace the pipe.
applicable).
The inlet device
Regrade the swale if necessary and
Erosion is occurring in the
provide erosion control devices such as
swale (if applicable).
reinforced turf matting or riprap to avoid
future erosion problems.
Stone verge is clogged or
Remove sediment and clogged stone
covered in sediment (if
and replace with clean stone.
applicable).
Search for the source of the sediment
More than four inches of
and remedy the problem if possible.
sediment has accumulated.
Remove the sediment and dispose of it
in a location where it will not cause
impacts to streams or the SCM.
Erosion of the basin surface
Provide additional erosion protection
The basin
has occurred or riprap is
such as reinforced turf matting or riprap
displaced.
if needed to prevent future erosion
problems.
Water is standing more than
Replace the top few inches of soil to see
three days after a storm
if this corrects the standing water
event.
problem. If not, consult an appropriate
professional for a more extensive repair.
The embankment
Shrubs or trees are growing
Remove trees and shrubs immediately.
on the embankment.
C-1. Infiltration System
13
Revised: 11-20-2020

NCDEQ Stormwater BMP Manual
Environmental
Quality
The outlet device
The receiving water
An annual inspection by an
appropriate professional
shows that the embankment
needs repair.
Clogging has occurred
Make needed repairs immediately.
Clean out the outlet device and dispose
of sediment in a location where it will not
cause impacts to streams or the SCM.
The outlet device is damaged. Repair or replace the outlet device.
Erosion or other signs of
damage have occurred at the
outlet.
Discharges from the
infiltration trench are causing
erosion or sedimentation in
the receiving water.
Old Versus New Design Standards
Repair the damage and improve the flow
dissipation structure.
Contact the local NCDEQ Regional
Office.
The following is a summary of some of the changes in infiltration system design
standards between the archived version of the BMP Manual and the current MDC for
infiltration systems. It is intended to capture the highlights only; any infiltration system
MDC that are not captured in this table are still required per 15A NCAC 02H .1051.
Soil permeability Infiltration systems only allowed Infiltration systems shall be designed
requirements if the in -situ soil has an to dewater in 72 hours or less based
infiltration rate of at least 0.52 on the soil infiltration rate. (Lower
inch/hour. infiltration rate soils will require a
larger surface area.)
Flow splitting device Required; only the runoff from Not required. Infiltration systems can
the design storm is allowed to be designed with an outlet device
be directed to the infiltration that attenuates peak flow above the
system. ponding depth for the design storm.
Level spreader for the Required Not required; outlet must be
overflow designed so that erosion does not
occur.
Maximum depth of media Specified. Not specified; however, the invert of
for infiltration trenches the infiltration system must meet the
SHWT requirements in the MDC.
C-1. Infiltration System 14 Revised: 11-20-2020

Appendix F
Erosion and Sedimentation Control Permit