HomeMy WebLinkAbout1.00 General Application Materials_Part23Stockpile Management (SP)MM-2
November 2010 Urban Drainage and Flood Control District SP-3
Urban Storm Drainage Criteria Manual Volume 3
MM-2 Stockpile Management (SM)
SP-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Stockpile Management (SP)MM-2
November 2010 Urban Drainage and Flood Control District SP-5
Urban Storm Drainage Criteria Manual Volume 3
MM-2 Stockpile Management (SM)
SP-6 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Good Housekeeping Practices (GH) MM-3
November 2010 Urban Drainage and Flood Control District GH-1
Urban Storm Drainage Criteria Manual Volume 3
Photographs GH-1 and GH-2. Proper materials
storage and secondary containment for fuel tanks
are important good housekeeping practices. Photos
courtesy of CDOT and City of Aurora.
Description
Implement construction site good housekeeping practices to
prevent pollution associated with solid, liquid and hazardous
construction-related materials and wastes. Stormwater
Management Plans (SWMPs) should clearly specify control
measures including these good housekeeping practices:
Provide for waste management.
Establish proper building material staging areas.
Designate paint and concrete washout areas.
Establish proper equipment/vehicle fueling and
maintenance practices.
Control equipment/vehicle washing and allowable non-
stormwater discharges.
Develop a spill prevention and response plan.
Acknowledgement: This Fact Sheet is based directly on
EPA guidance provided in Developing Your Stormwater
Pollution Prevent Plan (EPA 2007).
Appropriate Uses
Good housekeeping practices are necessary at all construction sites.
Design and Installation
The following principles and actions should be addressed in SWMPs:
Provide for Waste Management. Implement management procedures and practices to prevent or
reduce the exposure and transport of pollutants in stormwater from solid, liquid and sanitary wastes
that will be generated at the site. Practices such as trash disposal, recycling, proper material handling,
and cleanup measures can reduce the potential for stormwater runoff to pick up construction site
wastes and discharge them to surface waters. Implement a comprehensive set of waste-management
practices for hazardous or toxic materials, such as paints, solvents, petroleum products, pesticides,
wood preservatives, acids, roofing tar, and other materials. Practices should include storage,
handling, inventory, and cleanup procedures, in case of spills. Specific practices that should be
considered include:
Solid or Construction Waste
o Designate trash and bulk waste-collection areas on-
site.
Good Housekeeping
Functions
Erosion Control No
Sediment Control No
Site/Material Management Yes
MM-3 Good Housekeeping Practices (GH)
GH-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Photograph GH-3. Locate portable toilet facilities on level
surfaces away from waterways and storm drains. Photo
courtesy of WWE.
o Recycle materials whenever possible (e.g., paper, wood, concrete, oil).
o Segregate and provide proper disposal options for hazardous material wastes.
o Clean up litter and debris from the construction site daily.
o Locate waste-collection areas away from streets, gutters, watercourses, and storm drains. Waste-
collection areas (dumpsters, and such) are often best located near construction site entrances to
minimize traffic on disturbed soils. Consider secondary containment around waste collection
areas to minimize the likelihood of contaminated discharges.
o Empty waste containers before they are full and overflowing.
Sanitary and Septic Waste
o Provide convenient, well-maintained, and properly located toilet facilities on-site.
o Locate toilet facilities away from storm drain inlets and waterways to prevent accidental spills
and contamination of stormwater.
o Maintain clean restroom facilities and empty portable toilets regularly.
o Where possible, provide secondary containment pans under portable toilets.
o Provide tie-downs or stake-downs for portable toilets.
o Educate employees, subcontractors, and suppliers on locations of facilities.
o Treat or dispose of sanitary and septic waste in accordance with state or local regulations. Do not
discharge or bury wastewater at the construction site.
o Inspect facilities for leaks. If found, repair or replace immediately.
o Special care is necessary during maintenance (pump out) to ensure that waste and/or biocide are
not spilled on the ground.
Hazardous Materials and Wastes
o Develop and implement employee and
subcontractor education, as needed, on
hazardous and toxic waste handling,
storage, disposal, and cleanup.
o Designate hazardous waste-collection
areas on-site.
o Place all hazardous and toxic material
wastes in secondary containment.
Good Housekeeping Practices (GH) MM-3
November 2010 Urban Drainage and Flood Control District GH-3
Urban Storm Drainage Criteria Manual Volume 3
o Hazardous waste containers should be inspected to ensure that all containers are labeled properly
and that no leaks are present.
Establish Proper Building Material Handling and Staging Areas. The SWMP should include
comprehensive handling and management procedures for building materials, especially those that are
hazardous or toxic. Paints, solvents, pesticides, fuels and oils, other hazardous materials or building
materials that have the potential to contaminate stormwater should be stored indoors or under cover
whenever possible or in areas with secondary containment. Secondary containment measures prevent
a spill from spreading across the site and may include dikes, berms, curbing, or other containment
methods. Secondary containment techniques should also ensure the protection of groundwater.
Designate staging areas for activities such as fueling vehicles, mixing paints, plaster, mortar, and
other potential pollutants. Designated staging areas enable easier monitoring of the use of materials
and clean up of spills. Training employees and subcontractors is essential to the success of this
pollution prevention principle. Consider the following specific materials handling and staging
practices:
o Train employees and subcontractors in proper handling and storage practices.
o Clearly designate site areas for staging and storage with signs and on construction drawings.
Staging areas should be located in areas central to the construction site. Segment the staging area
into sub-areas designated for vehicles, equipment, or stockpiles. Construction entrances and exits
should be clearly marked so that delivery vehicles enter/exit through stabilized areas with vehicle
tracking controls (See Vehicle Tracking Control Fact Sheet).
o Provide storage in accordance with Spill Protection, Control and Countermeasures (SPCC)
requirements and plans and provide cover and impermeable perimeter control, as necessary, for
hazardous materials and contaminated soils that must be stored on site.
o Ensure that storage containers are regularly inspected for leaks, corrosion, support or foundation
failure, or other signs of deterioration and tested for soundness.
o Reuse and recycle construction materials when possible.
Designate Concrete Washout Areas. Concrete contractors should be encouraged to use the washout
facilities at their own plants or dispatch facilities when feasible; however, concrete washout
commonly occurs on construction sites. If it is necessary to provide for concrete washout areas on-
site, designate specific washout areas and design facilities to handle anticipated washout water.
Washout areas should also be provided for paint and stucco operations. Because washout areas can
be a source of pollutants from leaks or spills, care must be taken with regard to their placement and
proper use. See the Concrete Washout Area Fact Sheet for detailed guidance.
Both self-constructed and prefabricated washout containers can fill up quickly when concrete, paint,
and stucco work are occurring on large portions of the site. Be sure to check for evidence that
contractors are using the washout areas and not dumping materials onto the ground or into drainage
facilities. If the washout areas are not being used regularly, consider posting additional signage,
relocating the facilities to more convenient locations, or providing training to workers and
contractors.
When concrete, paint, or stucco is part of the construction process, consider these practices which will
help prevent contamination of stormwater. Include the locations of these areas and the maintenance
and inspection procedures in the SWMP.
MM-3 Good Housekeeping Practices (GH)
GH-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
o Do not washout concrete trucks or equipment into storm drains, streets, gutters, uncontained
areas, or streams. Only use designated washout areas.
o Establish washout areas and advertise their locations with signs. Ensure that signage remains in
good repair.
o Provide adequate containment for the amount of wash water that will be used.
o Inspect washout structures daily to detect leaks or tears and to identify when materials need to be
removed.
o Dispose of materials properly. The preferred method is to allow the water to evaporate and to
recycle the hardened concrete. Full service companies may provide dewatering services and
should dispose of wastewater properly. Concrete wash water can be highly polluted. It should
not be discharged to any surface water, storm sewer system, or allowed to infiltrate into the
ground in the vicinity of waterbodies. Washwater should not be discharged to a sanitary sewer
system without first receiving written permission from the system operator.
Establish Proper Equipment/Vehicle Fueling and Maintenance Practices. Create a clearly
designated on-site fueling and maintenance area that is clean and dry. The on-site fueling area should
have a spill kit, and staff should know how to use it. If possible, conduct vehicle fueling and
maintenance activities in a covered area. Consider the following practices to help prevent the
discharge of pollutants to stormwater from equipment/vehicle fueling and maintenance. Include the
locations of designated fueling and maintenance areas and inspection and maintenance procedures in
the SWMP.
o Train employees and subcontractors in proper fueling procedures (stay with vehicles during
fueling, proper use of pumps, emergency shutoff valves, etc.).
o Inspect on-site vehicles and equipment regularly for leaks, equipment damage, and other service
problems.
o Clearly designate vehicle/equipment service areas away from drainage facilities and watercourses
to prevent stormwater run-on and runoff.
o Use drip pans, drip cloths, or absorbent pads when replacing spent fluids.
o Collect all spent fluids, store in appropriate labeled containers in the proper storage areas, and
recycle fluids whenever possible.
Control Equipment/Vehicle Washing and Allowable Non-Stormwater Discharges. Implement
practices to prevent contamination of surface and groundwater from equipment and vehicle wash
water. Representative practices include:
o Educate employees and subcontractors on proper washing procedures.
o Use off-site washing facilities, when available.
o Clearly mark the washing areas and inform workers that all washing must occur in this area.
o Contain wash water and treat it using control measures. Infiltrate wash water when possible, but
maintain separation from drainage paths and water bodies.
Good Housekeeping Practices (GH) MM-3
November 2010 Urban Drainage and Flood Control District GH-5
Urban Storm Drainage Criteria Manual Volume 3
o Use high-pressure water spray at vehicle washing facilities without detergents. Water alone can
remove most dirt adequately.
o Do not conduct other activities, such as vehicle repairs, in the wash area.
o Include the location of the washing facilities and the inspection and maintenance procedures in
the SWMP.
Develop a Spill Prevention and Response Plan. Spill prevention and response procedures must be
identified in the SWMP. Representative procedures include identifying ways to reduce the chance of
spills, stop the source of spills, contain and clean up spills, dispose of materials contaminated by
spills, and train personnel responsible for spill prevention and response. The plan should also specify
material handling procedures and storage requirements and ensure that clear and concise spill cleanup
procedures are provided and posted for areas in which spills may potentially occur. When developing
a spill prevention plan, include the following:
o Note the locations of chemical storage areas, storm drains, tributary drainage areas, surface
waterbodies on or near the site, and measures to stop spills from leaving the site.
o Provide proper handling and safety procedures for each type of waste. Keep Material Safety Data
Sheets (MSDSs) for chemical used on site with the SWMP.
o Establish an education program for employees and subcontractors on the potential hazards to
humans and the environment from spills and leaks.
o Specify how to notify appropriate authorities, such as police and fire departments, hospitals, or
municipal sewage treatment facilities to request assistance. Emergency procedures and contact
numbers should be provided in the SWMP and posted at storage locations.
o Describe the procedures, equipment and materials for immediate cleanup of spills and proper
disposal.
o Identify personnel responsible for implementing the plan in the event of a spill. Update the spill
prevention plan and clean up materials as changes occur to the types of chemicals stored and used
at the facility.
MM-3 Good Housekeeping Practices (GH)
GH-6 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Spill Prevention, Control, and Countermeasure (SPCC) Plan
Construction sites may be subject to 40 CFR Part 112 regulations that require the preparation and
implementation of a SPCC Plan to prevent oil spills from aboveground and underground storage tanks.
The facility is subject to this rule if it is a non-transportation-related facility that:
Has a total storage capacity greater than 1,320 gallons or a completely buried storage capacity
greater than 42,000 gallons.
Could reasonably be expected to discharge oil in quantities that may be harmful to navigable waters
of the United States and adjoining shorelines.
Furthermore, if the facility is subject to 40 CFR Part 112, the SWMP should reference the SPCC Plan.
To find out more about SPCC Plans, see EPA's website on SPPC at www.epa.gov/oilspill/spcc.htm.
Reporting Oil Spills
In the event of an oil spill, contact the National Response Center toll free at 1-800-424- 8802 for
assistance, or for more details, visit their website: www.nrc.uscg.mil.
Maintenance and Removal
Effective implementation of good housekeeping practices is dependent on clear designation of personnel
responsible for supervising and implementing good housekeeping programs, such as site cleanup and
disposal of trash and debris, hazardous material management and disposal, vehicle and equipment
maintenance, and other practices. Emergency response "drills" may aid in emergency preparedness.
Checklists may be helpful in good housekeeping efforts.
Staging and storage areas require permanent stabilization when the areas are no longer being used for
construction-related activities.
Construction-related materials, debris and waste must be removed from the construction site once
construction is complete.
Design Details
See the following Fact Sheets for related Design Details:
MM-1 Concrete Washout Area
MM-2 Stockpile Management
SM-4 Vehicle Tracking Control
Design details are not necessary for other good housekeeping practices; however, be sure to designate
where specific practices will occur on the appropriate construction drawings.
Silt Fence (SF)SC-1
November 2010 Urban Drainage and Flood Control District SF-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph SF-1. Silt fence creates a sediment barrier, forcing
sheet flow runoff to evaporate or infiltrate.
Description
A silt fence is a woven geotextile fabric
attached to wooden posts and trenched
into the ground. It is designed as a
sediment barrier to intercept sheet flow
runoff from disturbed areas.
Appropriate Uses
A silt fence can be used where runoff is
conveyed from a disturbed area as sheet
flow. Silt fence is not designed to
receive concentrated flow or to be used
as a filter fabric. Typical uses include:
Down slope of a disturbed area to
accept sheet flow.
Along the perimeter of a receiving
water such as a stream, pond or
wetland.
At the perimeter of a construction site.
Design and Installation
Silt fence should be installed along the contour of slopes so that it intercepts sheet flow. The maximum
recommended tributary drainage area per 100 lineal feet of silt fence, installed along the contour, is
approximately 0.25 acres with a disturbed slope length of up to 150 feet and a tributary slope gradient no
steeper than 3:1. Longer and steeper slopes require additional measures. This recommendation only
applies to silt fence installed along the contour. Silt fence installed for other uses, such as perimeter
control, should be installed in a way that will not produce concentrated flows. For example, a "J-hook"
installation may be appropriate to force runoff to pond and evaporate or infiltrate in multiple areas rather
than concentrate and cause erosive conditions parallel to the silt fence.
See Detail SF-1 for proper silt fence installation, which involves proper trenching, staking, securing the
fabric to the stakes, and backfilling the silt fence. Properly installed silt fence should not be easily pulled
out by hand and there should be no gaps between the ground and the fabric.
Silt fence must meet the minimum allowable strength requirements, depth of installation requirement, and
other specifications in the design details. Improper installation
of silt fence is a common reason for silt fence failure; however,
when properly installed and used for the appropriate purposes, it
can be highly effective.
Silt Fence
Functions
Erosion Control No
Sediment Control Yes
Site/Material Management No
SC-1 Silt Fence (SF)
SF-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Photograph SF-2. When silt fence is not installed along
the contour, a "J-hook" installation may be appropriate
to ensure that the control measure does not create
concentrated flow parallel to the silt fence. Photo
courtesy of Tom Gore.
Maintenance and Removal
Inspection of silt fence includes observing the
material for tears or holes and checking for slumping
fence and undercut areas bypassing flows. Repair of
silt fence typically involves replacing the damaged
section with a new section. Sediment accumulated
behind silt fence should be removed, as needed to
maintain control measure effectiveness, typically
before it reaches a depth of 6 inches.
Silt fence may be removed when the upstream area
has reached final stabilization.
Silt Fence (SF)SC-1
November 2010 Urban Drainage and Flood Control District SF-3
Urban Storm Drainage Criteria Manual Volume 3
SC-1 Silt Fence (SF)
SF-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Sediment Control Log (SCL)SC-2
November 2010 Urban Drainage and Flood Control District SCL-1
Urban Storm Drainage Criteria Manual Volume 3
Photographs SCL-1 and SCL-2. Sediment control logs used as 1) a
perimeter control around a soil stockpile; and, 2) as a "J-hook"
perimeter control at the corner of a construction site.
Description
A sediment control log is a linear roll
made of natural materials such as
straw, coconut fiber, or other fibrous
material trenched into the ground and
held with a wooden stake. Sediment
control logs are also often referred to
as "straw wattles." They are used as a
sediment barrier to intercept sheet flow
runoff from disturbed areas.
Appropriate Uses
Sediment control logs can be used in
the following applications to trap
sediment:
As perimeter control for stockpiles
and the site.
As part of inlet protection designs.
As check dams in small drainage
ditches. (Sediment control logs
are not intended for use in
channels with high flow
velocities.)
On disturbed slopes to shorten flow
lengths (as an erosion control).
As part of multi-layered perimeter control along a receiving water such as a stream, pond or wetland.
Sediment control logs work well in combination with other layers of erosion and sediment controls.
Design and Installation
Sediment control logs should be installed along the contour to avoid concentrating flows. The maximum
allowable tributary drainage area per 100 lineal feet of sediment control log, installed along the contour, is
approximately 0.25 acres with a disturbed slope length of up to 150 feet and a tributary slope gradient no
steeper than 3:1. Longer and steeper slopes require additional measures. This recommendation only
applies to sediment control logs installed along the contour. When installed for other uses, such as
perimeter control, it should be installed in a way that will not
produce concentrated flows. For example, a "J-hook" Sediment Control Log installation may be appropriate to force runoff to pond and Functionsevaporate or infiltrate in multiple areas rather than
concentrate Erosion Control and cause erosive conditions parallel to the control measure.Yes
N
SC-2 Sediment Control Log (SCL)
SCL-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Although sediment control logs initially allow runoff to flow through the control measure, they can
quickly become a barrier and should be installed is if they are impermeable.
Design details and notes for sediment control logs are provided in Detail SCL-1. Sediment logs must be
properly trenched and staked into the ground to prevent undercutting, bypassing and displacement. When
installed on slopes, sediment control logs should be installed along the contours (i.e., perpendicular to
flow).
Improper installation can lead to poor performance. Be sure that sediment control logs are properly
trenched, anchored and tightly jointed.
Maintenance and Removal
Be aware that sediment control logs will eventually degrade. Remove accumulated sediment before the
depth is one-half the height of the sediment log and repair damage to the sediment log, typically by
replacing the damaged section.
Once the upstream area is stabilized, remove and properly dispose of the logs. Areas disturbed beneath
the logs may need to be seeded and mulched. Sediment control logs that are biodegradable may
occasionally be left in place (e.g., when logs are used in conjunction with erosion control blankets as
permanent slope breaks). However, removal of sediment control logs after final stabilization is typically
recommended when used in perimeter control, inlet protection and check dam applications.
Sediment Control Log (SCL)SC-2
November 2010 Urban Drainage and Flood Control District SCL-3
Urban Storm Drainage Criteria Manual Volume 3
SC-2 Sediment Control Log (SCL)
SCL-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Sediment Control Log (SCL)SC-2
November 2010 Urban Drainage and Flood Control District SCL-5
Urban Storm Drainage Criteria Manual Volume 3
Straw Bale Barrier (SBB)SC-3
November 2010 Urban Drainage and Flood Control District SBB-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph SBB-1. Straw bale barrier used for perimeter control.
Photo courtesy of Tom Gore.
Description
A straw bale barrier is a linear wall of
straw bales designed to intercept sheet
flow and trap sediment before runoff exits
a disturbed area.
Appropriate Uses
Appropriate uses of properly installed
straw bale barriers may include:
As a perimeter control for a site or soil
stockpile.
As a sediment control at the toe of an
erodible slope.
Along the edge of a stream or drainage
pathway to reduce sediment laden runoff from entering the waterway.
As part of an inlet protection design in sump conditions (See Inlet Protection Control Measure).
Do not use straw bale barriers in areas of concentrated flow or in areas where ponding is not desirable.
Straw bales tend to degrade quickly, so they should generally not be used in areas where longer term
disturbance is expected.
Due to a history of inappropriate placement, poor installation, and short effective lifespan, the use of
straw bales is discouraged or prohibited by some communities.
Design and Installation
The maximum recommended tributary drainage area per 100 lineal feet of straw bale barrier is 0.25 acres
with a disturbed slope length of up to 150 feet and a tributary slope gradient no steeper than 3:1; longer
and steeper slopes require additional measures. Design details with notes are provided in Detail SBB-1.
To be effective, bales must be installed in accordance with the design details with proper trenching,
staking, and binding. Jute and cotton string must not be used to bind the straw bale. The bales should be
certified weed-free prior to use.
Maintenance and Removal
Check bales for rotting and replace as necessary. Straw bales degrade, and rotting bales require
replacement on a regular basis (as often as every three months) depending on environmental conditions.
Check for undercutting, bypassed flows, and displacement.
Repair by properly re-installing the straw bale barrier and
repairing washouts around the bales. Remove sediment
accumulated behind the bale when it reaches one-quarter of
the bale height. Remove and properly dispose of the straw
bale once the upstream area has been stabilized. Areas of
disturbance beneath the bale should be seeded and mulched
when the bale is removed.
Straw Bale Barrier
Functions
Erosion Control No
Sediment Control Moderate
Site/Material Management No
SC-3 Straw Bale Barrier (SBB)
SBB-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Straw Bale Barrier (SBB)SC-3
November 2010 Urban Drainage and Flood Control District SBB-3
Urban Storm Drainage Criteria Manual Volume 3
Brush Barrier (BB)SC-4
November 2010 Urban Drainage and Flood Control District BB-1
Urban Storm Drainage Criteria Manual Volume 3
Description
A brush barrier is a perimeter sediment
control constructed with stacked shrubs,
tree limbs, and bushy vegetation that has
been cleared from a construction area.
Brush barriers reduce sediment loads by
intercepting and slowing sheet flow
from disturbed areas.
Appropriate Uses
Brush Barrier
Functions
Erosion Control Moderate
Sediment Control Moderate
Site/Material No
A brush barrier is an appropriate control
measure at sites where there is adequate
brush from the clearing and grubbing of
the construction site to construct an
effective brush barrier. Brush barriers
are typically used at the toe of slopes and Photograph BB-1. Br
us
h barrier constructed with chipped wood.
Photo courtesy of EPA.should be implemented in combination
with other control measures such as surface roughening and reseeding. Brush barriers should be considered short-term, supplemental control measures because they are constructed of materials that naturally decompose. Brush barriers are not
acceptable as a sole means of perimeter control, but they may be used internally within a site to reduce slope length or at the site perimeter in combination with other perimeter controls for multi-layered protection.
Brush barriers are not appropriate for high-velocity flow areas. A large amount of material is needed to
construct a useful brush barrier; therefore, alternative perimeter controls such as a fabric silt fence may be
more appropriate for sites with little material from clearing.
Design and Installation
The drainage area for brush barriers should be no greater than 0.25 acre per 100 feet of barrier length.
Additionally, the drainage slope leading down to a brush barrier must be no greater than 3:1 and no
longer than 150 feet.
To construct an effective brush barrier, use only small shrubs and limbs with diameters of 6 inches or
less. Larger materials (such as a tree stump) can create void spaces in the barrier, making it ineffective.
The brush barrier mound should be at least 3 feet high and 5 feet wide at its base.
In order to avoid significant movement of the brush and improve effectiveness, a filter fabric can be
placed over the top of the brush pile, keyed in on the upstream side, and anchored on the downstream
side. On the upgradient side, the filter fabric cover should be
buried in a trench 4 inches deep and 6 inches wide.
SC-4 Brush Barrier (BB)
BB-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Maintenance and Removal
Inspect the brush barrier for voids where concentrated flow or erosion is occurring. Voids in the brush
barrier should be filled with additional brush. Accumulated sediment should be removed from the uphill
side of the barrier when sediment height reaches one-third of the height of the barrier.
If filter fabric is used, inspect the filter fabric for damage; replace and properly secure it, as needed.
Once the upstream area has been vegetated or stabilized, the brush barrier should be removed and the
underlying area revegetated.
Rock Sock (RS)SC-5
November 2010 Urban Drainage and Flood Control District RS-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph RS-1. Rock socks placed at regular intervals in a curb
line can help reduce sediment loading to storm sewer inlets. Rock
socks can also be used as perimeter controls.
Description
A rock sock is constructed of gravel
that has been wrapped by wire mesh or
a geotextile to form an elongated
cylindrical filter. Rock socks are
typically used either as a perimeter
control or as part of inlet protection.
When placed at angles in the curb line,
rock socks are typically referred to as
curb socks. Rock socks are intended to
trap sediment from stormwater runoff
that flows onto roadways as a result of
construction activities.
Appropriate Uses
Rock socks can be used at the perimeter
of a disturbed area to control localized
height.
Once upstream stabilization is complete, rock socks and
accumulated sediment should be removed and properly disposed.
sediment loading. A benefit of rock
socks as opposed to other perimeter controls is that they do not have to be trenched or staked into the
ground; therefore, they are often used on roadway construction projects where paved surfaces are present.
Use rock socks in inlet protection applications when the construction of a roadway is substantially
complete and the roadway has been directly connected to a receiving storm system.
Design and Installation
When rock socks are used as perimeter controls, the maximum recommended tributary drainage area per
100 lineal feet of rock socks is approximately 0.25 acres with disturbed slope length of up to 150 feet and
a tributary slope gradient no steeper than 3:1. A rock sock design detail and notes are provided in Detail
RS-1. Also see the Inlet Protection Fact Sheet for design and installation guidance when rock socks are
used for inlet protection and in the curb line.
When placed in the gutter adjacent to a curb, rock socks should protrude no more than two feet from the
curb in order for traffic to pass safely. If located in a high traffic area, place construction markers to alert
drivers and street maintenance workers of their presence.
Maintenance and Removal
Rock socks are susceptible to displacement and breaking due to vehicle traffic. Inspect rock socks for
damage and repair or replace as necessary. Remove sediment by sweeping or vacuuming as needed to
maintain the functionality of the control measure, typically when sediment
has accumulated behind the rock sock to one-half of the sock's Rock Sock
Functions
Erosion Control No
Sediment Control Yes
Site/Material Management No
SC-5 Rock Sock (RS)
RS-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Rock Sock (RS)SC-5
November 2010 Urban Drainage and Flood Control District RS-3
Urban Storm Drainage Criteria Manual Volume 3
Sediment Basin (SB) SC-7
August 2013 Urban Drainage and Flood Control District SB-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph SB-1. Sediment basin at the toe of a slope. Photo
courtesy of WWE.
Description
A sediment basin is a temporary pond
built on a construction site to capture
eroded or disturbed soil transported in
storm runoff prior to discharge from the
site. Sediment basins are designed to
capture site runoff and slowly release it to
allow time for settling of sediment prior
to discharge. Sediment basins are often
constructed in locations that will later be
modified to serve as post-construction
stormwater basins.
Appropriate Uses
Most large construction sites (typically
greater than 2 acres) will require one or
more sediment basins for effective
management of construction site runoff. On linear construction projects, sediment basins may be
impractical; instead, sediment traps or other combinations of control measures may be more
appropriate.
Sediment basins should not be used as stand-alone sediment controls. Erosion and other sediment
controls should also be implemented upstream.
When feasible, the sediment basin should be installed in the same location where a permanent
post-construction detention pond will be located.
Design and Installation
The design procedure for a sediment basin includes these steps:
Basin Storage Volume: Provide a storage volume of at least 3,600 cubic feet per acre of drainage
area. To the extent practical, undisturbed and/or off-site areas should be diverted around sediment
basins to prevent “clean” runoff from mixing with runoff from disturbed areas. For undisturbed areas
(both on-site and off-site) that cannot be diverted around the sediment basin, provide a minimum of
500 ft3/acre of storage for undeveloped (but stable) off-site areas in addition to the 3,600 ft3/acre for
disturbed areas. For stable, developed areas that cannot be diverted around the sediment basin,
storage volume requirements are summarized in Table SB-1.
Basin Geometry: Design basin with a minimum length-to-width ratio of 2:1 (L:W). If this cannot be
achieved because of site space constraints, baffling may
be required to extend the effective distance between the
inflow point(s) and the outlet to minimize short-circuiting.
Dam Embankment: It is recommended that
embankment slopes be 4:1 (H:V) or flatter and no steeper
than 3:1 (H:V) in any location.
Sediment Basins
Functions
Erosion Control No
Sediment Control Yes
Site/Material Management No
SC-7 Sediment Basin (SB)
SB-2 Urban Drainage and Flood Control District August 2013
Urban Storm Drainage Criteria Manual Volume 3
Inflow Structure: For concentrated flow entering the basin, provide energy dissipation at the point
of inflow.
Table SB-1. Additional Volume Requirements for Undisturbed and Developed Tributary Areas
Draining through Sediment Basins
Imperviousness (%)
Additional Storage Volume (ft3)
Per Acre of Tributary Area
Undeveloped 500
10 800
20 1230
30 1600
40 2030
50 2470
60 2980
70 3560
80 4360
90 5300
100 6460
Outlet Works: The outlet pipe shall extend through the embankment at a minimum slope of 0.5
percent. Outlet works can be designed using one of the following approaches:
o Riser Pipe (Simplified Detail): Detail SB-1 provides a simplified design for basins treating no
more than 15 acres.
o Orifice Plate or Riser Pipe: Follow the design criteria for Full Spectrum Detention outlets in the
EDB Fact Sheet provided in Chapter 4 of this manual for sizing of outlet perforations with an
emptying time of approximately 72 hours. In lieu of the trash rack, pack uniformly sized 1½ - to
2-inch gravel in front of the plate or surrounding the riser pipe. This gravel will need to be
cleaned out frequently during the construction period as sediment accumulates within it. The
gravel pack will need to be removed and disposed of following construction to reclaim the basin
for use as a permanent detention facility. If the basin will be used as a permanent extended
detention basin for the site, a trash rack will need to be installed once contributing drainage areas
have been stabilized and the gravel pack and accumulated sediment have been removed.
o Floating Skimmer: If a floating skimmer is used, install it using manufacturer’s
recommendations. Illustration SB-1 provides an illustration of a Faircloth Skimmer Floating
Outlet™, one of the more commonly used floating skimmer outlets. A skimmer should be
designed to release the design volume in no less than 48 hours. The use of a floating skimmer
outlet can increase the sediment capture efficiency of a basin significantly. A floating outlet
continually decants cleanest water off the surface of the pond and releases cleaner water than
would discharge from a perforated riser pipe or plate.
Sediment Basin (SB) SC-7
August 2013 Urban Drainage and Flood Control District SB-3
Urban Storm Drainage Criteria Manual Volume 3
Illustration SB-1. Outlet structure for a temporary sediment basin - Faircloth Skimmer Floating Outlet. Illustration courtesy
of J. W. Faircloth & Sons, Inc., FairclothSkimmer.com.
Outlet Protection and Spillway: Consider all flow paths for runoff leaving the basin, including
protection at the typical point of discharge as well as overtopping.
o Outlet Protection: Outlet protection should be provided where the velocity of flow will exceed
the maximum permissible velocity of the material of the waterway into which discharge occurs.
This may require the use of a riprap apron at the outlet location and/or other measures to keep the
waterway from eroding.
o Emergency Spillway: Provide a stabilized emergency overflow spillway for rainstorms that
exceed the capacity of the sediment basin volume and its outlet. Protect basin embankments from
erosion and overtopping. If the sediment basin will be converted to a permanent detention basin,
design and construct the emergency spillway(s) as required for the permanent facility. If the
sediment basin will not become a permanent detention basin, it may be possible to substitute a
heavy polyvinyl membrane or properly bedded rock cover to line the spillway and downstream
embankment, depending on the height, slope, and width of the embankments.
SC-7 Sediment Basin (SB)
SB-4 Urban Drainage and Flood Control District August 2013
Urban Storm Drainage Criteria Manual Volume 3
Maintenance and Removal
Maintenance activities include the following:
•Dredge sediment from the basin, as needed to maintain control measure effectiveness, typically when
the design storage volume is no more than one-third filled with sediment.
•Inspect the sediment basin embankments for stability and seepage.
•Inspect the inlet and outlet of the basin, repair damage, and remove debris. Remove, clean and
replace the gravel around the outlet on a regular basis to remove the accumulated sediment within it
and keep the outlet functioning.
•Be aware that removal of a sediment basin may require dewatering and associated permit
requirements.
•Do not remove a sediment basin until the upstream area has been stabilized with vegetation.
Final disposition of the sediment basin depends on whether the basin will be converted to a permanent
post-construction stormwater basin or whether the basin area will be returned to grade. For basins being
converted to permanent detention basins, remove accumulated sediment and reconfigure the basin and
outlet to meet the requirements of the final design for the detention facility. If the sediment basin is not to
be used as a permanent detention facility, fill the excavated area with soil and stabilize with vegetation.
Sediment Basin (SB) SC-7
August 2013 Urban Drainage and Flood Control District SB-5
Urban Storm Drainage Criteria Manual Volume 3
SC-7 Sediment Basin (SB)
SB-6 Urban Drainage and Flood Control District August 2013
Urban Storm Drainage Criteria Manual Volume 3
Sediment Basin (SB) SC-7
August 2013 Urban Drainage and Flood Control District SB-7
Urban Storm Drainage Criteria Manual Volume 3
Sediment Trap (ST)SC-8
November 2010 Urban Drainage and Flood Control District ST-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph ST-1. Sediment traps are used to collect sediment-laden
runoff from disturbed area. Photo courtesy of EPA Menu of BMPs.
Description
Sediment traps are formed by excavating
an area or by placing an earthen
embankment across a low area or
drainage swale. Sediment traps are
designed to capture drainage from
disturbed areas less than one acre and
allow settling of sediment.
Appropriate Uses
Sediment traps can be used in
combination with other layers of erosion
and sediment controls to trap sediment
from small drainage areas (less than one
acre) or areas with localized high sediment loading. For example, sediment traps are often provided in
conjunction with vehicle tracking controls and wheel wash facilities.
Design and Installation
A sediment trap consists of a small excavated basin with an earthen berm and a riprap outlet. The berm
of the sediment trap may be constructed from the excavated material and must be compacted to
95 percent of the maximum density in accordance with ASTM D698. An overflow outlet must be
provided at an elevation at least 6 inches below the top of the berm. See Detail ST-1 for additional design
and installation information.
Maintenance and Removal
Inspect the sediment trap embankments for stability and seepage.
Remove accumulated sediment as needed to maintain the effectiveness of the sediment trap, typically
when the sediment depth is approximately one-half the height of the outflow embankment.
Inspect the outlet for debris and damage. Repair damage to the outlet, and remove all obstructions.
A sediment trap should not be removed until the upstream area is sufficiently stabilized. Upon removal of
the trap, the disturbed area should be covered with topsoil and stabilized.
Sediment Trap
Functions
Erosion Control No
Sediment Control Yes
Site/Material Management No
SC-8 Sediment Trap (ST)
ST-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Sediment Trap (ST)SC-8
November 2010 Urban Drainage and Flood Control District ST-3
Urban Storm Drainage Criteria Manual Volume 3
Vegetated Buffers (VB) SC-9
November 2010 Urban Drainage and Flood Control District VB-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph VB-1. A vegetated buffer is maintained between the
area of active construction and the drainage swale. Photo courtesy
of WWE.
Description
Buffer strips of preserved natural
vegetation or grass help protect
waterways and wetlands from land
disturbing activities. Vegetated buffers
improve stormwater runoff quality by
straining sediment, promoting
infiltration, and slowing runoff
velocities.
Appropriate Uses
Vegetated buffers can be used to
separate land disturbing activities and
natural surface waters or conveyances.
In many jurisdictions, local governments
require some type of setback from natural waterways. Concentrated flow should not be directed through
a buffer; instead, runoff should be in the form of sheet flow. Vegetated buffers are typically used in
combination with other perimeter control meas such as sediment control logs or silt fence for multi-
layered protection.
Design and Installation
Minimum buffer widths may vary based on local regulations. Clearly delineate the boundary of the
natural buffer area using construction fencing, silt fence, or a comparable technique. In areas that have
been cleared and graded, vegetated buffers such as sod can also be installed to create or restore a
vegetated buffer around the perimeter of the site.
Maintenance and Removal
Inspect buffer areas for signs of erosion such as gullies or rills. Stabilize eroding areas, as needed. If
erosion is due to concentrated flow conditions, it may be necessary to install a level spreader or other
technique to restore sheet flow conditions. Inspect perimeter controls delineating the vegetative buffer
and repair or replace as needed.
Vegetated Buffers
Functions
Erosion Control Moderate
Sediment Control Yes
Site/Material Management Yes
Chemical Treatment (CT) SC-10
November 2010 Urban Drainage and Flood Control District CT-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph CT-1. Proprietary chemical treatment system being
used on a construction site with sensitive receiving waters. Photo
courtesy of WWE.
Description
Chemical treatment for erosion and
sediment control can take several forms:
1. Applying chemicals to disturbed
surfaces to reduce erosion (these uses
are discussed in the Soil Binders Fact
Sheet).
2. Adding flocculants to sedimentation
ponds or tanks to enhance sediment
removal prior.
3. Using proprietary barriers or flow-
through devices containing flocculants
(e.g., "floc logs").
The use of flocculants as described in No. 2 and No. 3 above will likely require special permitting.
Check with the state permitting agency. See the Soil Binder Control Measure Fact Sheet for
information on surface application of chemical treatments, as described in No. 1.
Appropriate Uses
At sites with fine-grained materials such as clays, chemical addition to sedimentation ponds or tanks can
enhance settling of suspended materials through flocculation.
Prior to selecting and using chemical treatments, it is important to check state and local permit
requirements related to their use.
Design and Installation
Due to variations among proprietary chemical treatment methods, design details are not provided for this
control measure. Chemical feed systems for sedimentation ponds, settling tanks and dewatering bags
should be installed and operated in accordance with manufacturer's recommendations and applicable
regulations. Alum and chitosan are two common chemicals used as flocculants. Because the potential
long-term impact of these chemicals to natural drainageways is not yet fully understood, the state does
not currently allow chemical addition under the CDPS General Stormwater Construction Discharge
Permit. Additional permitting may be necessary, which may include sampling requirements and
numeric discharge limits.
Any devices or barriers containing chemicals should be installed following manufacturer's guidelines.
Check for state and local jurisdiction usage restrictions and requirements before including these practices
in the SWMP and implementing them onsite. Chemical Treatment
Functions
Erosion Control Moderate
Sediment Control Yes
Site/Material Management No