HomeMy WebLinkAboutReportCity of College Station
Lick Creek Wastewater Treatment Plant
U. S. Environmental Protection Agency
National Pollutant Discharge Elimination System
Construction Stormwater Pollution Prevention Plan
April 2001
City of College Station
Lick Creek Wastewater Treatment Plant
U. S. Environmental Protection Agency
National Pollutant Discharge Elimination System
Construction Stormwater Pollution Prevention Plan
April 2001
Prepared for:
CITY OF COLLEGE STATION
Public Utilities Department
1601 Graham Road
College Station, TX 77842
uckCrk.cv2 COM Camp Dresser & McKee
REVIEWED FO R
CO~APLIANCE
MAY 1 1 2001
COLLEGE STATION
ENGINEERING
Prepared by:
CAMP DRESSER & McKEE INC.
9111 Jollyville Road
Suite 105
Austin, TX 78759
Stormwater Pollution Prevention Plan (SWPPP)
City of College Station
Certification
111 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
infoqnation 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. I am aware that there are significant
penalties for submitting false information, including the possibility of fine and
imprisonment for knowing violations.11
Attest: ~ ~-~
Title: ---~'-"'-o""'~ ... · '--=-...:c....'-\,._ _ _:~___._0\.-"-"-'f\._CI."=~+~""'-'-(-------------
· CDM Camp Dresser & McKee
Table of Contents
Introduction .......................................................................................................... 1
Site Description .................................................................................................... 1
Nature of Construction Activity ............................................................................. 2
Sequence of Construction .................................................................................... 2
Area of Site/Area of Soil Disturbance ................................................................... 2
Runoff Coefficient Estimates ................................................................................ 3
Receiving Waters and Wetlands .......................................................................... 3
Pollution Prevention Controls .............................................................................. .4
Erosion and Sedimentation Controls .................................................................... 5
Stormwater Management Controls ....................................................................... 6
Other BMP Controls ............................................................................................. 7
Maintenance of Controls ...................................................................................... 8
Inspection of Controls .......................................................................................... 8
Non-Stormwater Discharges ................................................................................ 9
Contractor Certification ...................................................................................... 10
Appendix A Project Best Management Practices (BMPs)
Appendix B SWPPP Inspection Forms
CDM Camp Dresser & McKee
City of College Station
Lick Creek WWTP Improvements
Stormwater Pollution Prevention Plan
Introduction
The City of College Station, Texas is planning to construct improvements and
expand the capacity of its Lick Creek Wastewater Treatment Plant (WWTP)
property located southeast of College Station in southern Brazos County. The
. project will provide the City the ability to treat the greater volumes of wastewater
flows that are being generated by the southern service collection area of College
Station. A site map that identifies the existing layout and the location of the Lick
Creek WWTP is presented as Figure 1.
The City of College Station is required to develop a Stormwater Pollution
Prevention Plan (SWPPP) to mitigate stormwater runoff impacts such as erosion
and sedimentation that may be related with this project's proposed construction
activities. The construction SWPPP is required by the U.S. Environmental
Protection Agency (EPA) through its National Pollutant Discharge Elimination
System (NPDES) program, which applies to all construction projects that disturb
more than 5 acres or on designated Federal lands. This project's construction
SWPPP will concentrate on appropriate erosion and sedimentation control
measures that are specified for implementation during and following the
intrusive construction activities. The SWPPP also identifies measures to prevent
non-stormwater discharges plus maintenance and inspection procedures that are
designed to assess whether the prescribed SWPPP controls are effective and
properly maintained. The proposed project is expected to disturb about a
maximum of 2.91 acres out of the 23.0-acre site and will require the filing of a
Notice of Intent (NOI) application with EPA Stormwater headquarters.
Site Description
The Lick Creek WWTP facility is located immediately south of Rock Prairie Road
in southeastern Brazos County. The Lick Creek WWTP site is situated about 3
miles east-northeast of the intersection of Texas State Highway 6 and Greens
Prairie Road and about 1.7 miles north-northeast of the Texas World Speedway.
The site is accessed from College Station via Rock Prairie Road and the site's
physical address is 14802 Rock Prairie Road. See Figure 1 for the site's location.
Maps that indicate the drainage patterns, existing topography, proposed grading,
soil disturbance areas, pollution prevention controls, soil stabilization measures,
the location of the local receiving water(s), and the identified stormwater
discharge points from the project site are presented as Figures 2, 3, and 4. Figure
2 is the Site Clearing and Erosion/Sedimentation Control Plan, Figure 3 is the
CDM Camp Dresser & McKee Inc. 1
Lick Creek Wastewater Treatment Plant Improvements
Construction Stormwater Pollution Prevention Plan
Proposed Site Plan, and Figure 4 is the Site Grading Plan (Sheets C-2, C-3, and C-
4 of the Lick Creek WWTP construction drawings).
Nature of Construction Activity
The total area of new impervious cover added to construct the project's proposed
improvements is estimated at approximately 0.47 acres (20, 310 square feet). This
0.47 acres will add to the site's existing impervious cover, which is about 0.72
acres, and will represent a new impervious cover amount of 1.19 acres for the
Lick Creek WWTP site.
Sequence of Construction
A prioritized work sequence for the construction of the Lick Creek WWTP project .
will be developed by the Contractor to ensure that the project will be completed
in accordance with the City's contractual time of completion schedule. The
Contractor will present the schedule of work to the City and the Engineer for
review prior to the beginning of construction. The general sequence of
construction planned for this project is detailed and specified by the Construction
Plans and Specifications that were designed for the City's Lick Creek WWTP
Improvements project.
• Refer to Project Specifications (Section 01010, Section 1.06), for further detail.
This project will require the filing of a Notification of Intent (NOi) application
with EPA Stormwater headquarters. The proposed project is expected to disturb
a maximum of about 2.91 acres out of the 23.0-acre. The NOi will require filing
with both the Contractor (site operator) and the City (owner) serving as co-
applicants of the SWPPP. The ultimate responsibility for SWPPP permit
compliance is assigned to the Contractor.
Area of Site/ Area of Soil Disturbance
The property that contains the Lick Creek WWTP site contains about 23.0 total
acres. The actual WWTP site lies within a fenced, 6-acre tract that is located on
the southern end of the 23-acre property. The total amount of soil disturbance
that is expected at the WWTP site during construction of the proposed
improvements is about 126,650 square feet (sf) or about 2.91 acres. The areas
where soil disturbance is anticipated during construction is shown in Figure 2
• Refer to Project Specifications (Section 01110, Part 3), for further detail.
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Lick Creek Wastewater Treatment Plant Improvements
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Runoff Coefficient Estimates
Estimates of runoff coefficient from within the project1s limits of construction
have been prepared for pre-construction and post-construction scenarios. The
runoff coefficient for a given land area is defined as the percentage of total
rainfall during a storm event that will discharge as runoff. In this project's case,
the pre-and post-construction runoff coefficients for the Citis proposed Lick
Creek WWTP improvements are shown to be only slightly change stormwater
runoff impacts.
SITE RUNOFF COEFFICIENTS:
Pre-Development Runoff Coefficient (Rv Pre):
Rv = runoff coefficient= 0.546(IC)2 + 0.328(IC)+ 0.030
Rv Pre= 0.546 (0.031)(0.031) + 0.328(0.031) + 0.030 = 0.040
Post-Development Runoff Coefficient (Rv Post):
Rv = runoff coefficient = 0.546(IC)2 + 0.328(IC)+ 0.030
Rv Post= 0.546 (0.052)(0.052) + 0.328(0.052) + 0.030 = 0.048
Based on the TNRCC runoff coefficient/impervious cover relationship (Edwards
Aquifer Protection Program Technical Guidance Manual, June 1999), the pre-
construction runoff coefficient is computed as about 0.040 (3.1 % site impervious
cover (IC)), while the post-construction runoff coefficient value is about 0.048
(5.2 % site IC). Because both of these values are well below the value of 20% IC
(the value where stormwater runoff is considered to generate significant flows
with a runoff coefficient of about 0.12), this project1s proposed changes are
considered to have a negligible environmental impact from the standpoint of
nonpoint source pollution. Because of the minimal amount of stormwater
expected to be generated by the proposed project, only temporary BMPs are
planned for use as pollution prevention controls ·as detailed and specified by the
construction documents.
Receiving Waters and Wetlands
The City of College Station's proposed Lick Creek WWTP improvements is
contained within a 23-acre, city-owned property located southeast of College
Station. Drainage from the construction activities during storm events will flow
entirely into the Lick Creek watershed, the project site's local receiving water.
No surface water drainageways were identified within the proposed project site
and stormwater runoff will be characterized by overland flows.
• Refer to Environmental Evaluation prepared by CSC Engineering and
Environmental Consultants, Inc. Report (December 2000), for further detail.
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Lick Creek Wastewater Treatment Plant Improvements
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The National Wetlands Inventory Map that identifies the project site (Ferguson
Crossing, TX USGS 7.5' quadrangle) indicates that none of its land is designated
as a wetland area. Adjacent land located immediately south of the Lick Creek
WWTP site within the Lick Creek watershed is mapped as a wetland area. The
fenced 6-acre area that contains the Lick Creek WWTP is free of wetland areas.
Threatened and Endangered Species
No threatened or endangered species were identified on the 6-acre construction
site. However, the Navasota Ladies' -Tresses (spiranthes parksii), an endangered
vasciular plant species listed by the U.S. Fish and Wildlife Service and the Texas
Parks and Wildlife Department, has been mapped in the general vicinity of the
Lick Creek WWTP site. A field survey was performed by CSC Engineering and
Environmental Consultants in November 2000 and determined that two potential
habitat areas exist to the west and northwest of the 6-acre construction site.
These potential Navasota Ladies' -Tresses habitat areas are not located within the
proposed area of soil disturbance. Appropriate erosion and sedimentation
controls will be practiced to minimize any potential adverse runoff impacts.
• Refer to Environmental Evaluation prepared by CSC Engineering and
Environmental Consultants, Inc. Report (December 2000), for further detail.
Historical Preservation Concerns
No historical preservation, cultural or archaeological concerns were noted on the
6-acre construction site. The Texas Historical Commission has identified seven
archeological sites (three prehistoric and four historic sites) in adjacent areas near
the Lick Creek WWTP. None of these sites are considered significant and
archeological fieldwork is not warranted in these adjacent, identified sites.
• Refer to Environmental Evaluation prepared by CSC Engineering and
Environmental Consultants, Inc. Report (December 2000), for further detail.
Pollution Prevention Controls
The City's proposed Lick Creek WWTP project SWPPP will implement
appropriate best management practices (BMPs) during the project's construction
that will help prevent pollution caused by stormwater runoff from the site to
protect the local receiving waters. The pollution prevention BMP measures
presented by the project's SWPPP may be classified as follows:
• erosion and sedimentation controls;
• stormwater management controls; and
• Other BMP controls.
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In addition to these practices, this construction SWPPP outlines the BMP
maintenance and inspection schedules and procedures specified for this project.
Fact sheets describing the various BMP controls used for this project are
presented in Appendix A.
Erosion and Sedimentation Controls
Erosion and sedimentation controls are used to contain soils and associated
pollutant transport generated by construction sites from entering onsite or
adjacent stormwater drainageways that could eventually impact local receiving
waters. These controls address erosion and sedimentation concerns during active
and post-construction work phases. Erosion and sedimentation BMP controls are
generally divided into two broad categories: structural practices and stabilization
practices, which are detailed below.
Structural BMPs include those controls that are intended to divert flows from
disturbed soils, detain or retain runoff, or minimize runoff and pollutant
discharge from exposed soils through temporary and/ or permanent BMP
measures. Temporary structural controls are employed through the active and
post-construction phases, while permanent structural controls are applied to
control site runoff for stormwater runoff treatment on a long-term basis.
Because of the small size of impacted land areas that are proposed by this project,
temporary structural BMPs have been recommended to minimize on-site erosion
and sedimentation processes. Silt fences are structural source control BMPs that
will be used to protect drainageways from soil erosion and sediment transport
caused by sheet flow during storm events. Silt fences are constructed of a filter
fabric which is entrenched on the upgradient side and is attached to 12-gauge
steel welded wire fabric that is anchored by steel supporting poles on the
downgradient side. Silt fences detain stormwater flows and capture sediment
and are typically used to protect streams, drainage channels, and site perimeters
from overland flow.
Silt fencing will be placed at the locations indicated by this SWPPP (refer to
Figure 2). The silt fencing will be maintained throughout the active construction
phase and will remain until soil stabilization has been achieved. The inspection
and maintenance schedule to ensure that the silt fencing functions properly
during the construction project is presented in a later section.
Stabilization BMPs include those controls that provide cover and stability to
soils through the use of vegetation, mulches, geotextiles, rip rap or gabions. The
City's SWPPP for this project calls for the use of both temporary and permanent
stabilization practices. Hydroseeding of grass will establish permanent stabilized
cover in all disturbed areas within the limits of construction. Tree protection will
also be practiced as a stabilization control, through the placement of temporary
COM Camp Dresser & McKee Inc. 5
Lick Creek Wastewater Treatment Plant Improvements
Construction Stormwater Pollution Prevention Plan
fencing to protect trunks and driplines. No trees may be removed by the
Contractor without approval from the Engineer and the City.
Hydroseeding provides permanent soil stabilization by diminishing the erosion
potential from the direct impact of rainfall and will, furthermore, restore this
project site to its pre-construction state. As a permanent BMP control, hydraulic
seeding of grass provides quickly established soil protection along with effective
filtration of sediment from overland flows during storm events. Hydroseeding
and the establishment of permanent grasses are also credited with the filtering of
nutrients and removal of some toxic materials.
Hydroseeding, for this project will apply a natural area seed mix that includes a
mixture of buffalo grass, sideoats gramma, indiangrass, switchgrass, little
bluestem, and green spangletop. Winter fescue will be used during the cold
weather periods. To prevent unnecessary erosion of newly topsoiled and graded
slopes and the unnecessary siltation of drainageways, the Contractor will
conduct seeding and fiber mulching upon satisfactory completion of every 10,000
square feet and must perform seeding within ten (10) days of final soil
preparation. The use of hydroseeding will be applied at all areas of soil
disturbance that lie within the project1s limits of construction and will occur as an
ongoing soil stabilization procedure until satisfactory completion is accepted by
the City.
Stormwater Management Controls
Stormwater management controls include BMPs that are installed during the
construction process to control pollutants discharged in stormwater after all
construction activities have been completed. Examples of stormwater manage-
ment controls include detention structures, retention structures, wet ponds,
vegetated swales for flow attenuation, infiltration basins, and sequential
treatment train systems. Pollution prevention plans are required to provide
explanation of the technical rationale used to select appropriate stormwater
BMPs to control pollutants where flows exceed predevelopment levels.
Stormwater management control structures should also provide velocity dissi-
pation devices at all discharge locations to receiving waters and throughout the
length of the outfall channel downgradient of the control structure. Velocity
dissipation devices are intended to prevent undesired changes in the
hydrological characteristics of the receiving water as a result of the installation of
the stormwater management control structure.
Because the construction of the City1s Lick Creek WWTP improvements are not
expected to generate a significant increase in post-development stormwater
runoff when compared to pre-development levels, this construction SWPPP is not
specifying the need for post-construction stormwater controls. Only a minor
CDM Camp Dresser & McKee Inc. 6
Lick Creek Wastewater Treatment Plant Improvements
Construction Stormwater Pollution Prevention Plan
increase (0.46 acres effective area) of impervious cover is anticipated from the
scope of this construction project and the overall land use of the proposed site
will remain unchanged, so the need to provide post-construction stormwater
management controls is not considered necessary.
Other BMP Controls
Other BMP controls that are suggested to be contained within a construction
SWPPP include a solid waste disposal plan and a plan to minimize the off-site
tracking of disturbed soils through the use of stabilized construction roads/ areas.
Both of these controls, plus supplemental control measures (described in the
project's Technical Specifications) designed to prevent pollutants from entering
the local receiving waters, are presented below. Additionally, the City's SWPPP
and related construction drawings and specifications developed for this project
are compliant with applicable state and local waste disposal, sanitary, or septic
system regulations.
Waste management and disposal of trash, debris, vegetation, or excess excavated
material will be disposed of at an off-site location that has been approved by the
City. Unacceptable disposal sites include, but are not limited to, sites located
within a wetland or critical habitat, designated 100-year floodplains, and sites
where disposal will have a detrimental effect on surface water or groundwater
quality or restrict the flows of such waters. Appropriate temporary storage and
disposal practices will keep solid waste materials in enclosed trash containers to
limit contact with rain and stormwater runoff.
Minimization of off-site tracking of disturbed soils will be addressed in areas
where temporary storage yards and temporary access roads/parking areas are
established. The storage yards will be used for the storage of materials that are
not subject to damage by weather conditions. Temporary gravel surfacing of the
storage yards will serve to minimize off-site impacts due to construction area
activities. The site's existing roadway will serve as a form of a stabilized
construction entrance to provide a transition between disturbed soil and non-
disturbed areas. Both the temporary storage yards and access roads/parking
areas will be properly removed and the landscape stabilized to a condition that is
satisfactory to the Engineer.
A hazardous waste pollution control contingency plan specifies that the
Contractor will provide the appropriate methods, means, and facilities required
to prevent the contamination of soil, water, or air through the discharge of
noxious substances from construction operations. The City's SWPPP requires the
provision of proper equipment and personnel to perform emergency measures
necessary to contain any spills, and to remove contaminated soils or liquids.
A surface water control plan to divert stormwater and/ or surface water flows
from impacting the construction area's disturbed soils or from discharging to
CDM Camp Dresser & McKee Inc. 7
Lick Creek Wastewater Treatment Plant Improvements
Construction Stormwater Pollution Prevention Plan
adjoining properties is specified by this SWPPP, as detailed in the project manual.
The plan prescribes that the Contractor will control fill, backfilling, grading and
ditching to direct surface drainage away from excavations, pits, tunnels, and
other construction areas. Surface waters are to be directed to drain to the proper
runoff courses.
Maintenance of Controls
All erosion/ sedimentation and stabilization controls that are recommended by
this SWPPP will be regularly inspected for functionality and adequately main-
tained throughout the course of this construction project to prevent pollutants
from being discharged to the local receiving waters. BMP control inspection
schedules are presented in the following section. Procedures to be followed by
the Contractor to properly maintain the previously ~dentified structural and
stabilization controls for optimal efficiency are discussed below.
Maintenance of silt fencing will be performed whenever site inspections find that
deposited sediment has accumulated to one half the height of the filter fabric or if
the fabric or fencing is damaged such to cause malfunction. All excess sediment
will be removed from the silt fencing and either beneficially reused or properly
stored and disposed. Damaged filter fabric will either be replaced or patched
with a minimum 2-foot overlap from the tom fabric areas. The Contractor will be
prepared to make any other repairs necessary to ensure that the silt fencing is
adequately filtering all runoff that is being received.
Hydroseeded areas will be maintained by proper watering and fertilization
practices. Lawn areas that have become stabilized will be mowed and
maintained in good condition and will be re-seeded as necessary until a good,
healthy, uniform growth is established. Once stabilized, the engineer for
provisional acceptance (according to the project manual) will mspect the seeded
lawn areas. All seeded areas will be guaranteed by the Contractor for not less
than one year from the time of provisional acceptance. A final inspection will be
performed by the engineer, at which time any deficient lawn areas must be
renovated, re-seeded, and maintained. After all necessary corrective work is
completed, the engineer will certify in writing the final acceptance of the seeded,
stabilized area.
Inspection of Controls
NPDES stormwater requirements state that qualified personnel must inspect the
disturbed areas of construction projects, storage areas exposed to precipitation,
and structural/ stabilization BMPs on a regular basis during dry periods and after
significant storm events. The City of College Station's SWPPP specifies that the
Contractor will make visual inspections of all silt fencing and hydroseeded areas
at least once per week and promptly after every significant (> 0.5-inch) rainstorm.
CDM Camp Dresser & McKee Inc. 8
Rr_rawh2o.swppp
Raw Water Pump Station Expansion
Construction Stormwater Pollution Prevention Plan
All temporary storage yards, temporary construction parking areas, and
stormwater discharge points must also be inspected according to this schedule, to
examine the effectiveness of the BMP controls specified by this SWPPP, and their
ability to protect the local receiving waters.
To provide further definition of this inspection schedule, as required by the
NPDES stormwater regulations, once per week will mean once every seven (7)
calendar days and promptly after every rainstorm will mean within 24 hours of
the end of a storm event that is 0.5-inch or greater. Hydroseeded areas that have
become stabilized and have been granted provisional acceptance by the engineer
will be required for inspection at least once per month.
A reporting form to note the results of each inspection will be maintained by the
Contractor. The inspection reporting form will identify the name of the
inspector, the date of the inspection, the identity of the (Sub)Contractor, the
condition of the BMP, and whether or not the BMP is observed to be functioning
properly or if corrective action is necessary. An example of a SWPPP inspection
form is presented (with other SWPPP forms) in Appendix B. The inspector, or
Contractor, should also note any off-site pollutant sources that are observed
discharging onto the construction site. Any of the BMP control measures that are
determined to need corrective action will be restored to satisfactory conditions as
soon as practicable.
N on-Stormwater Discharges
The general permit states that all discharges covered under the NPDES storm-
water rules must be composed entirely of stormwater, with the exception of fire
fighting activities, fire hydrant flushing, water line flushing, irrigation drainage,
lawn watering, routine building washdown, air conditioning condensate,
springs, and uncontaminated groundwater. If non-stormwater discharges to the
storm drain system or receiving waters are present, they must be covered by a
separate (process water) NPDES permit. Non-stormwater discharges are not
anticipated from any of the construction activities planned for this project.
CDM Camp Dresser & McKee Inc. 9
Contractor Certification
The Contractor for the City's Lick Creek WWTP project is identified below. The
Contractor will perform most of the tasks identified .in the Sequence of
Construction section acccrding Lo the estimated. 9Chedule. However,
subcontractors may handle portions ol the project.
The Contractor SWPPP Certification Statement and authorization signature page
to honor its terms and conditions are presented on the following page. The
Contractor's business name, address and phone number, as well as any
subcontractors will be identified after determination through the project's bid
process.
'1 certify under penalty of law that I understand the terms and
conditions of the general National Pollutant Discharge Elimiruition
System (NPDFS) permit that authorizes the stormwater discharges
associated with industrial activities from the construction site
identified as part o.f this certification ...
Ridgway
Name of Contractor. BRYAN CONSTRUCTION COMPANY
Address of Contractor: P. 0. Box 408 7
Bryan, TX 77805
Site J .. o~on:
City of College Station Lick Creek WWTP Sire
14802 Rack Prairie Road
College Station. TX 7784S
Date: April 4, 2001
CDM ~p ~&.MdCea Inc.
Rr_rawh2o.swppp
Appendix A
Project Best Management Practices
CDM Camp Dresser & McKee Inc.
Section 4 -Construction BMPs
Silt Fence Applications
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~I Perime~rControl J - -----c Drainage area 1 ,, / Disturbed • ~.;;~ _ limits ~ " Area CO\~:#;;::;-· <t;\O -
DESCRIPTION
A silt fence consists of geotextile fabric supported by poultry netting or other
backing stretched between either wooden or metal posts with the lower edge
of the fabric securely embedded in the soil. The fence is typically located
downstream of disturbed areas to intercept runoff in the form of sheet flow.
Silt fence provides both filtration and time for sedimentation to reduce
sediment and it reduces the velocity of the runoff. Properly designed silt fence
is economical since it can be re-located during construction and re-used on
other projects.
PRIMARY USE
Silt fence is normally used as perimeter control located downstream of
dism:bed areas. It is only feasible for non-concentrated, sheet flow conditions.
APPLICATIONS
Silt fence is an economical means to treat overland, non-concentrated flows for
all types of projects. Silt fences are used as perimeter control devices for both
site developments and linear (roadway) type projects. They are most effective
with coarse to silty soil types. Due to the potential of clogging, silt fence should
not be used with clay soil types.
In order to reduce the length of silt fence, it should be placed adjacent to the
down slope side of the construction activities.
DESIGN CRITERIA
0 Fences are to be constructed along a line of constant elevation (along a
contour line) where possible.
0 Maximum slope adjacent to the fence is 1:1.
0 Maximum distance of flow to silt fence should be 200 feet or less.
0 Maximum concentrated flow to silt fence shall be 1 CFS per 20 feet of
fence.
0 If 50% OT less of soil, by weight, passes the U.S. Standard sieve No.
200, select the equivalent opening size (E.0.5.) to retain 85% of tlie soil.
0 Maximum equivalent opening size shall be 70 (#70 sieve).
0 Minimum equivalent opening size shall be 100 (#100 sieve) .
. o If 85% OT more of soil, by weight, passes the U.S. Standard sieve No.
200, silt fences shall not be used due to potential clogging.
NCTCOG Construction BMP Manual 4-21
I Slope Protection J
I Sediment Trapping ]
Channel Protection
Temporary Stabilization
Permanent Stabilization
Waste Management
Housekeeping Practices
Targeted Constituents
• Sediment
0 Nutrients
Toxic Materials
0 Oil & Grease
0 Floatable Materials
0 Other Construction
Wastes
Implementation
Requirements
0 Capital Costs
• Maintenance
0 Training
0 Suitability for
Slopes >5%
Legend
• Significant Impact
0 Medium Impact
0 Low Impact
? Unknown or
Questionable Impact
Fe= 0.75
S-1
North Central Texas
Council of Governments
February 1993
Section 4 -Construction BMPs
Silt Fence
0 Sufficient room for the operation of sediment removal equipment shall be provided between the
silt fence and other obstructions in order to properly maintain the fence.
0 The ends of the fence shall be turned upstream to prevent bypass of stonnwater.
LIMITATIONS
Minor ponding will likely occur at the upstream side of the silt fence resulting in minor localized flooding.
Fences which are constructed in swales or low areas subject to concentrated flow may be overtopped
· resulting in failure of the filter fence. Silt fences subject to areas of concentrated flow (waterways with
flows > 1 ds) are not acceptable.
Silt fence can interfere with construction operations, therefore planning of access routes onto the site is
critical.
Silt fence can fail structurally under heavy storm flows, creating maintenance problems and reducing the
effectiveness of the system.
MAINTENANCE REQUIREMENTS
Inspections should be made on a weekly basis, especially after large storm events. If the fabric becomes
clogged, it should be cleaned or if necessary, replaced.
Sediment should be removed when it reaches approximately one-half the height of the fence.
Specification Section
8
Detail ID 2020
~I
NCTCOG Construction Manual 4-21 February 1993
Vegetation
.,
7
FJow
DESCRIPTION
Vegetation, as a Best Management Practice, is the sowing of annual grasses,
small grains or legumes to provide interim and permanent vegetative
stabilization for disturbed areas.
PRIMARY USE
Vegetation is used as a temporary or permanent stabilization teclmique for
areas disturbed by construction but not protected by pavement, building or
other structures. As a temporary control, vegetation is used to stabilize
stockpiles and barren areas which are inactive for long periods of time. As a
permanent control, grasses and other vegetation provide good protection for
the soil along with some filtering for overland runoff. Subjected to acceptable
runoff velocities, vegetation can provide a good method of permanent storm
water management as well as a visual amenity to the site.
Other BMPs may be required to assist in the establishment of vegetation. These
other techniques include erosion control matting, swales and dikes to direct
flow around newly seeded areas and proper grading to limit runoff velocities
during construction.
APPLICATIONS
Vegetative techniques can and should apply to every construction project with
few exceptions. Vegetation effectively reduces erosion in swales, stock piles,
berms, mild to medium slopes and along roadways. Vegetative strips can
provide some protection when used as a perimeter control for utility and site
development construction.
In many cases, the initial cost of temporary seeding may be high compared to
tarps or covers for stockpiles or other barren areas subject to erosion yet
inactive. This initial cost should be weighed with the amount of time the area is
to remain inactive, since maintenance cost for vegetated areas is much less than
most structural controls.
DESIGN CRITERIA
Surfa~ Prqxzratum
0 Interim or final grading must be completed prior to seeding,
minimizing all steep slopes.
0 Install all necessary erosion structures such as dikes, swales,
diversions, etc., prior to seeding.
NCTCOG Construction BMP Manual 4-11
Section 4 -Construction BMPs
Applications
Perimeter Control
Slope Protection ]
Sediment Trapping
I Channel Protection J
I Temporary Stabilization)
I Permanent Stabilization)
Waste Management
Housekeeping Practices
Targeted Constituents
• Sediment
Q Nutrients
Toxic Materials
0 Oil & Grease
0 Floatable Materials
0 Other Construction
Wastes
Implementation
Requirements
Q Capital Costs
Q Maintenance
· 0 Training
• Suitability for
Slopes >5%
Legend
e Significant Impact
Q Medium Impact
0 Low Impact
? Unknown or
Questionable Impact
Fe= 0.90
E-4
North Central Texas
Council of Governments
February 1993
Section 4 -Construction BMPs
VeQetation
O Groove or furrow slopes steeper than 3:1 on the contour line before seeding.
0 Provide 4-6 inches of topsoil over rock, gravel or otherwise unsuitable soils.
0 Seed-bed should be well pulverized, loose and uniform.
Plant Selection, Fertilization and Seeding
0 Use only high quality, USDA certified seed.
0 Use an appropriate species or species mixture adapted to local climate, soil conditions and season
according to the table on the following page. Consult with the local office of the U.S. Soil
Conservation Service (SCS) or Engineering Extension service as necessary for selection of proper
species and application technique in this area.
0 Seeding rate should be in accordance with the table on the following page or as recommended by
the SCS or engineering extension service.
0 Fertilizer shall be applied according to the manufacturer's recommendation with proper spreader
equipment. Typical application rate for 10-10-10 grade fertilizer is 700-1000 lb/acre. DO NOT
OVER APPLY FERfilIZER.
0 If hydro-seeding is used, do not mix seed and fertilizer more than 30 minutes before application.
0 Evenly apply seed using cyclone seeder, seed drill, cultipacker or hydroseeder.
0 Provide adequate water to aid in establishment of vegetation.
0 Use appropriate mulching techniques where necessary.
LIMITATIONS
Vegetation is not appropriate for areas subjected to heavy pedestrian or vehicular traffi c. As a temporary
technique, vegetation may be costly when compared to other techniques.
Vegetation is not appropriate for rock, gravel or coarse grained soils unless 4 to 6 inches of topsoil is
applied.
MAINTENANCE REQUIREMENTS
Protect newly seeded areas from excessive runoff and traffic until vegetation is established. A watering and
fertilizing schedule will be required as part of the SWPPP to assist in the establishment of the vegetation.
Specification Section
NIA
Detail ID N/A
NCTCOG Construction Manual 4-12 February 1993
Solid Waste Management
DESCRIPTION
Large volumes of solid waste are often generated at construction sites
including: packaging, pallets, wood waste, concrete waste, soil, electrical
wiring, cuttings, and a yariety of other materials. The solid waste management
practice lists techniques to minimize the potential of storm water
contamination from solid waste through appropriate storage and disposal
practices.
PRIMARY USE
These practices should be a part of all construction practices. By limiting the
trash and debris on site, storm water quality is improved along with reduced
clean up requirements at the completion of the project.
APPLICATIONS
The solid waste management practice for construction sites is based on proper
storage and disposal practices by construction workers and supervisors. Key
elements of the program are education and modification of improper disposal
habits. Cooperation and vigilance is required on the part of supervisors and
workers to ensure that the recommendations and procedures are followed.
Following are lists describing the targeted materials and recommended
procedures:
0 Targeted Solid Waste Materials
Paper and cardboard containers
Plastic packaging
Styrofoam packing and forms
Insulation materials (non-hazardous)
Wood pallets
Wood cuttings
Pipe and electrical cuttings
Concrete, brick, and mortar waste
Shingle cuttings and waste
Roofing tar
Steel (cuttings, nails, rust residue)
Gypsum board cuttings and waste
Sheathing cuttings and waste
Miscellaneous cutting and waste
Food waste
Demolition waste
Storage Procedures
0 Wherever possible, minimize production of solid waste materials.
0 Designate a foreman or supervisor to oversee and enforce proper solid
waste procedures.
0 Instruct construction workers in proper solid waste procedures ..
0 Segregate potentially hazardous waste from non-hazardous
construction site debris.
0 Keep solid waste materials under cover in either a closed dumpster or
other enclosed trash container that limits contact with rain and runoff.
CJ Store waste materials away from drainage ditches, swales and catch
basins.
NCTCOG Construction BMP Manual 4-43
Section 4 -Construction BMPs
Applications
Perimeter Control
Slope Protection
Sediment Trapping -Channel Protection
Temporary Stabilization
Permanent Stabilization
I Waste Management I
I Housekeeping Practices I
Targeted Constituents
0 Sediment
• Nutrients
Toxic Materials
0 Oil & Grease
• Floatable Materials
• Other Construction
Wastes
lmplementatl on
Requirements
Q Capital Costs
Q Maintenance
Q Training
0 Suitability for
Slopes >5%
Legend
• Significant Impact
Q Medium Impact
0 Low Impact
? Unknown or
Questionable Impact
W-1
North Central Texas
Council of Governments
February 1993
Section 4 -Construction BMPs
Solid Waste Manaqement
0 Do not allow trash containers to overflow.
0 Do not allow waste materials to accumulate on the ground.
0 Prohibit littering by workers and visitors.
0 Police site daily for litter and debris.
0 Enforce solid waste handling and storage procedures.
Disposal Procedures
0 · If feasible, segregate recyclable wastes from non-recyclable waste materials and dispose of
properly.
0 General construction debris may be hauled to a licensed construction debris landfill (typically less
expensive than a sanitary landfill).
0 Use waste facilities approved by local jurisdiction.
0 Runoff which comes into contact with unprotected waste shall be directed into structural treatment
such as silt fence to remove debris.
Education
0 Educate all workers on solid waste storage and disposal procedures.
0 Instruct workers in identification of solid waste and hazardous waste.
0 Have regular meetings to discuss and reinforce disposal procedures (incorporate in regular safety
seminars).
0 Oearly mark on all solid waste containers which materials are acceptable.
Quality Control
0 Foreman and/ or construction supervisor shall monitor on-site solid waste storage and disposal
procedures.
0 Discipline workers who repeatedly violate procedures.
Requirements
0 Job-site waste handling and disposal education and awareness program.
0 Commitment by management to implement and enforce Solid Waste Management Program.
0 Compliance by workers.
0 Sufficient and appropriate waste storage containers.
0 Timely removal of stored solid waste materials.
0 Possible modest cost impact for additional waste storage containers.
0 Small cost impact for training and monitoring
0 Minimal overall cost impact.
LIMITATIONS
Only addresses non-hazardous solid waste.
One part of a comprehensive construction site management program.
Specification Section NIA
Detail ID N/A
NCTCOG Construction Manual 4-44 February 1993
Appendix
B
Rr_rawh2o.swppp CDM Camp Dresser & McKee Inc.
Appendix B
SWPPP Inspection Forms
Storm Water Pollution Prevention Plan
Part A -Site Description
Attach NOi for general site Information
Type of Project
Schedule
Milestone
Part 8 -Existing Site Conditions
Existing Foliage
Type of Grass I Vegetation
Drainage Impacts
Scheduled Revised
Start Finish Start Finish
Approximate
Density%
Site
Coverage%
Pre-development Runoff Coefficient (C In Rational Formula)------
Post-development Runoff Coefficient
Onslte Systems
Pipe System Present D Yes DNo
If yes, brief description (size, location, number of onsite inlets)
Other Systems Present (Channel, creek, watercourse, etc.) · 0 Yes D No
If yes, brief description (name, location, floodplain/floodway considerations, etc.)
Otfsite Systems
Systems Impacting Site? D Yes 0No-
lf yes, brief description and potential site impacts.
Existing Areas of Erosion
Brief description of areas which show signs of existing erosion i.e. areas with gullies or
rills, sediment buildup .in -creeks, soil loss around structures, etc .. Note location,
approximate area arid probable cause (disturbed area,·steep slope, etc.)
..
Part C -Pollution Prevention Techniques
Erosion and Sediment Control
Technique
Used
D Project PhaslnQ
(Limits of phasing shall
be shown on SWPPP
Plan View) ·
D . Vegetative Techniques
Type of Vegetation
Phase Start Finish
Description of Use (application schedule, rate, maintenance schedule)
Install Date Remove Date Perm.?
D Mulch • Type:
D Interceptor Swale
Design Capacity D
Design Velocity
D Diversion Dike
Design Capacity D
Design Velocity
D Pipe Slope Drain
Design Capacity D
D Hay Bale Dike
Design Capacity • D Slit Fence
Design Capacity •
Technique
Used Install Date Remove Date Perm.?
D
D
D
Sediment Basin
Design Capacity {CF) __
Stabilized Construction Entrance
Sandbag Berm ·
D
• •
D Other Erosion Control Methods {Attach Information on design criteria and
maintenance requirements)
Type: D
Waste Management Practices
D Solid Waste Management
D Covered, Leakproof trash container on-site
D Covered dumpster on site
D Daily site clean up procedures Implemented
D Timely collection of waste from containers
D Hazardous Waste Management
D Controlled storage facilities for paint, thinner and solvents
D Dikes around site fueling areas and fuel storage areas
D Controlled storage facilities for fertilizer and other chemicals
D
D
D
D
D Procedures for handling spills Is established and posted on-site
Hazardous Materials Used or Found On-Site
D Paints D Olis Other
D Solvents D Grease
D Stains D Roofing Tar
D Wood Preservatives D Pesticides
D Fuels D Lead Based Paint
D Concrete Waste Management
.....
Part D -Contractor I Sub Contractor Certifications
Any contractor or subcontractor responsible for portions of the SWPPP or Impacts
the efforts of the SWPPP shall sign the the following certification prior to providing
services at the site.
I certify under penalty of law that I understand the terms and conditions of
the general National Pollutant Discharge Elimination System (NPDES)
permit that authorizes the storm water discharges associated with industrial
activity from the construction site identified as part of this certification.
Signed: ---------------
Name (Printed): -----------
Title: ----------------
Name of Firm: ------------
Date: ----------
Nature of Firm's Responsibility:
Address: _____________________ __
City, State Zip: --------------------Phone: ______________ _
Signed: ---------------
Name (Printed): ------------
Title: ----------------
Name of Firm:·------------
Date: ----------
Nature of Firm's Responsibility:
Address: _____________________ __
City, State Zip: -------------------Phone: ______________ _
Signed: ---------------
Name (Printed): ------------
Title: ----------------
Name of Firm: ------------
Date: ----------
Nature of Firm's Responsibility:
Address: _____________________ __
City, State Zip: --------------------Phone: ______________ _
Add additional certification sheets as necessary. ·
Plan view of site showing pollution prevention techniques Is required to complete SWPPP.
Operator Inspection Form
lnspeciton Date:_/ I_
Weekly: Q
Storm Event: [J Inches:
Project Name=-------------------------lnspector:. ________________________ _
Structural BMPs
Used?
Q Interceptor Swale
Q Diversion Dike
Q Pipe Slope Drain
Q Vegetation
Q Mulching
Q Erosion Control Mats
Q Other Controls
a Silt Fence
Q Straw Bale Dike
Q Tri-Sediment Filter
Q Inlet Protection
a Sediment Trap
a Sediment Basin
Q Check Dams
a Temp. Sed. Tank
a Stab. Const. Entry
a Sandbag Berms
0
0
Condition
(G, F, P)
Legend: G -Good, F-Fair, P-Poor
Actions Required
Are BMPs in place and maintained in according with SWPPP for site? 0 Yes [J No
If not provide short explanation on back of form.
Are there obvious signs of sediment loss or pollution from site? Q Yes Q No
If yes: Q SWPPP modifications required and/or O Controls are improperly installed or p6orly maintained
Are good housekeeping practices observed? QYes 0 No
If no, measures to implement: ---------------------
-I ~ertify that this is an accurate assessment of the pollution prevention controls in place on the
srte. ·
Inspector: ---------------Date:
"
Erosion and Sediment Control Calculations
4 5 6 7 8 9
1 2 3 Existing Conditions Disturbed Conditions 10 11
DA# Area (Ac} Avg. K LSu Cu ZAsu LSd Cd ZAsd Fe ZAret
Totals
Rating Factor