1 Scope
NOTE This standard covers the materials, installation, maintenance, and removal of temporary erosion prevention and sediment control measures used during the construction period to keep soil on the site and to keep sediment out of receiving waters and the storm drainage system. (1.1)
NOTE Erosion control is the first scope to be installed and among the last to be removed: perimeter controls and the stabilized entrance go in before grading begins, and temporary measures stay in service until the areas they protect reach permanent stabilization. (1.2)
NOTE The cost of a complete, well-maintained set of best management practices is trivial compared with the cost of a sediment discharge to a stream, a stop-work order from the permitting authority, civil penalties under the Clean Water Act, and the cleanup of sediment tracked onto public roads. (1.3)
NOTE This standard distinguishes between erosion prevention — keeping soil particles in place so they never become suspended (stabilization, blankets, seeding, mulch) — and sediment control — capturing soil particles that have already been mobilized before the runoff leaves the site (silt fence, inlet protection, traps, basins). (1.4)
NOTE Both are required: erosion prevention is always the first line of defense because it is cheaper and more effective than trying to settle out sediment after it is moving, and sediment control is the backstop that catches what erosion prevention misses. (1.5)
1.6All work shall comply with the project's coverage under the EPA Construction General Permit (CGP) or the applicable state NPDES stormwater permit, with the project Stormwater Pollution Prevention Plan (SWPPP), and with all conditions imposed by the permitting authority.
1.7In cases of conflict between this standard, the SWPPP, the civil erosion control plan, the governing permit, and local ordinance, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
NOTE The Contractor shall recognize that the SWPPP is a living document and that field conditions, weather, and the sequence of work will require the SWPPP to be revised and best management practices to be added, relocated, or upgraded during construction. (1.8)
1.9The Contractor shall coordinate work under this standard with Earthwork for grading sequence, soil stockpile protection, and construction dewatering; with Storm Drainage for inlet protection and protection of the installed storm system from construction sediment; with Asphalt Paving for removal of temporary controls before final paving; and with Landscape Irrigation for the transition from temporary stabilization to permanent vegetation. 2 Referenced Standards
2.1Materials, installation, testing, and execution shall comply with the latest adopted edition of the following standards and regulations.
2.2Where contract documents, adopted codes, the governing permit, and referenced standards conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
| Standard |
Title |
| Clean Water Act Section 402 |
National Pollutant Discharge Elimination System (NPDES) — the statutory basis for construction stormwater permitting |
| EPA NPDES CGP |
Construction General Permit (current edition) — federal construction stormwater permit and SWPPP requirements |
| ASTM D6461/D6461M |
Standard Specification for Silt Fence Materials |
| ASTM D7101 |
Standard Index Test Method for Determination of Unvegetated Rolled Erosion Control Product (RECP) Ability to Protect Soil from Rain Splash and Associated Runoff (sediment retention / RECP index) |
| ASTM D6459 |
Standard Test Method for Determination of Rolled Erosion Control Product (RECP) Performance in Protecting Hillslopes from Rainfall-Induced Erosion |
| ASTM D6460 |
Standard Test Method for Determination of Rolled Erosion Control Product (RECP) Performance in Protecting Earthen Channels from Stormwater-Induced Erosion |
| ASTM D4632 |
Standard Test Method for Grab Breaking Load and Elongation of Geotextiles (silt fence fabric strength) |
| ASTM D4751 |
Standard Test Methods for Determining Apparent Opening Size of a Geotextile (silt fence fabric AOS) |
| ASTM D4491 |
Standard Test Methods for Water Permeability of Geotextiles by Permittivity (silt fence fabric flow rate) |
| AASHTO M288 |
Standard Specification for Geosynthetic Specification for Highway Applications (temporary silt fence geotextile class) |
| EPA NPDES CGP Concrete Washout |
Construction General Permit prohibition on discharge of concrete washout water and requirement for containment |
NOTE State Department of Transportation erosion control standard specifications and standard drawings (e.g., the state DOT erosion and sediment control manual) and the local municipal separate storm sewer system (MS4) program requirements are referenced as concept where the project connects to or discharges to public infrastructure. (2.2.1)
2.2.2The specific governing permit edition and the applicable state or local erosion and sediment control manual shall be confirmed with the permitting authority before land disturbance begins.
2.2.3Where the state operates its own NPDES program, the state construction stormwater general permit governs in place of the EPA CGP, and its inspection frequencies, stabilization deadlines, and BMP design criteria shall be followed where they differ from this standard.
3 Submittals
3.1 Action Submittals
3.1.1The Contractor shall submit the following for the Engineer of Record's review prior to any land disturbance:
- Stormwater Pollution Prevention Plan (SWPPP) prepared in accordance with the governing permit, including the site map showing the location and type of every best management practice, the receiving waters and their impairment or tier status, the soil types and existing drainage patterns, and the basis for permit termination at final stabilization
- Erosion and sediment control installation sequence and phasing narrative, showing which controls are installed before grading begins, how controls are added and relocated as the work progresses through each phase, and how disturbed area is limited at any one time
- Product data for silt fence fabric (ASTM D6461 / AASHTO M288 temporary class), fiber rolls and wattles, compost socks, inlet protection devices, rolled erosion control products and turf reinforcement mats (with the ASTM D6459 / D6460 performance class), and seed, mulch, and soil binder materials
- Seeding plan for temporary and permanent stabilization, including the temporary seed mix and rate, the permanent seed mix and rate, soil amendments, and the mulch or tackifier
- Sediment basin and sediment trap design where required, with calculations and details prepared and stamped by a licensed professional engineer
- Concrete washout containment detail and the dewatering discharge / sediment filtration plan
☑ Stormwater Pollution Prevention Plan (SWPPP) with BMP site map
☐ Erosion and sediment control installation sequence and phasing narrative
☐ Product data for perimeter controls, inlet protection, RECPs, and stabilization materials
☐ Temporary and permanent seeding plan with mixes and rates
☐ Sediment basin / sediment trap design (PE-stamped, where required)
☐ Concrete washout and dewatering discharge / filtration plan
3.1.2Land-disturbing activity shall not begin on any portion of the site until the perimeter controls and other initial best management practices for that portion are installed and the relevant submittals are reviewed and returned.
3.1.3Submittal review does not relieve the Contractor of responsibility for compliance with the governing permit and the Clean Water Act.
3.2.1Throughout construction the Contractor shall maintain and make available the following:
- SWPPP inspection reports for every required inspection, signed by the qualified person who performed the inspection, recording the condition of each best management practice, deficiencies found, corrective actions taken, and the dates of those actions
- Rain gauge records or a record of the precipitation source used to identify qualifying rain events that trigger a post-storm inspection
- The identity and qualifications of the designated person responsible for SWPPP inspections
- A log of all SWPPP revisions, including the date, the reason for the change, and the best management practices added, relocated, or upgraded
☑ Signed SWPPP inspection reports (routine and post-storm)
☑ Rain gauge / precipitation records identifying qualifying events
☑ Qualified inspector identity and qualifications
☑ SWPPP revision log
3.2.2Inspection reports and the SWPPP shall be kept on site (or otherwise readily available to the permitting authority) for the full duration of permit coverage.
3.3 Closeout Submittals
3.3.1Prior to substantial completion and before permit termination the Contractor shall provide:
- Final stabilization documentation confirming that all disturbed areas have achieved permanent stabilization as defined by the governing permit (uniform perennial vegetative cover of the required density, or permanent non-vegetative cover such as pavement or riprap)
- Confirmation that all temporary best management practices have been removed and the areas they occupied have been stabilized
- The Notice of Termination (NOT) submitted to the permitting authority, or evidence that it is ready for submittal once final stabilization is verified
- Photographic record of stabilized areas and the complete inspection report file
☑ Final stabilization documentation (permanent cover achieved)
☑ Confirmation of temporary BMP removal and area stabilization
☑ Notice of Termination (NOT) to permitting authority
☑ Photographic record and complete inspection report file
4 Quality Assurance
4.1 Qualified Inspector
4.1.1The Contractor shall designate a qualified person, knowledgeable in the principles and practice of erosion and sediment control, to perform the SWPPP inspections required by the governing permit.
4.1.2The qualified person shall have the authority to direct corrective action, to order additional best management practices, and to halt land-disturbing activity that threatens an unpermitted discharge.
4.1.3The Contractor shall not substitute the designated qualified person without ensuring the replacement meets the same qualification.
NOTE The qualified inspector is the single most important quality measure in erosion control: best management practices fail silently between storms, and only a trained eye walking the site catches an undermined silt fence, a clogged inlet protection device, or a stockpile shedding sediment before the next rain turns it into a discharge. (4.1.4)
4.2 Inspection Frequency
4.2.1The qualified person shall inspect the site at the frequency required by the governing permit.
● Every 7 calendar days, plus within 24 hours of a qualifying rain event
○ Every 14 calendar days, plus within 24 hours of a qualifying rain event
○ Every 7 calendar days (no rain-triggered inspection; continuous-coverage option)
○ Per governing permit conditions
0.251
Default: 0.5 in of rainfall in 24 hours
4.2.2Routine inspections shall be performed on the schedule selected, and a post-storm inspection shall be performed within 24 hours after the end of any qualifying rain event.
4.2.3Sites that discharge to a sediment- or nutrient-impaired water, or to a water designated as Tier 2, Tier 2.5, or Tier 3, shall be inspected at the more frequent 7-calendar-day interval where the governing permit so requires.
NOTE The 14-day-plus-storm inspection option is available only where the permit allows it and where disturbed area is limited; when disturbance is not limited or the receiving water is sensitive, the 7-day frequency applies, and the Contractor shall confirm the applicable frequency against the specific permit before relying on the less frequent option. (4.2.4)
4.2.5Each inspection shall be documented on a signed report retained with the SWPPP.
4.3 Pre-Construction Conference
4.3.1Prior to land disturbance the Contractor shall participate in a pre-construction conference attended by the Contractor's superintendent, the designated qualified inspector, the civil engineer of record, and the Engineer of Record.
4.3.2The conference shall review the SWPPP, the best management practice locations and installation sequence, the inspection and maintenance protocol, the stabilization deadlines, the procedures for revising the SWPPP, and the chain of responsibility for corrective action.
5 Site and Environmental Conditions
5.1 Receiving Waters and Discharge Points
5.1.1The Contractor shall identify every point at which stormwater leaves the site and the receiving water to which each discharge point drains.
Standard receiving water (no special impairment or tier designation)
Sediment- or nutrient-impaired water (303(d) listed)
Tier 2 / Tier 2.5 / Tier 3 high-quality water
Direct discharge to a sensitive water requiring enhanced controls
Per drawings — SWPPP site map (deferred by default)
5.1.2The sensitivity of the receiving water shall be confirmed against the permit and the state's impaired-waters list, because it drives the inspection frequency, the stabilization deadline, and whether enhanced or additional best management practices are required.
5.1.3Where any discharge point drains to a sensitive or impaired water, the Contractor shall provide the enhanced controls and the more frequent inspections the permit requires for that condition.
5.2 Disturbed Area and Soil Conditions
5.2.1The total area of land disturbance and the area disturbed at any one time shall be tracked, because both govern the permit obligations and the stabilization deadline.
● 1 acre or greater of disturbance — permit and SWPPP required
○ Less than 1 acre but part of a common plan of development totaling 1 acre or greater — permit required
○ Less than 1 acre and not part of a larger common plan — verify local requirements with authority
NOTE Construction activities that disturb one acre or more of land, or less if part of a common plan of development or sale that totals one acre or more, require NPDES permit coverage and a SWPPP before land disturbance begins. (5.2.2)
NOTE Where the project limits the area disturbed at any one time, the limitation shall be enforced in the field and reflected in the phasing narrative, because limiting open disturbed area both reduces erosion and may qualify the project for a less frequent inspection schedule and a longer stabilization deadline. (5.2.3)
6 Erosion Control Measures
6.1 Stabilization Principle
6.1.1Disturbed soil shall be stabilized as soon as practicable, and never later than the stabilization deadline of the governing permit, on any portion of the site where earth-disturbing activity has permanently or temporarily ceased.
● Within 14 calendar days (disturbance limited to 5 acres or less at one time)
○ Within 7 calendar days (disturbance not limited, or discharge to sensitive water)
○ Per governing permit conditions
6.1.2Stabilization shall be initiated immediately whenever earth-disturbing activity has permanently or temporarily ceased on a portion of the site and will not resume within the period the permit allows.
NOTE Late or missing stabilization is the single most common erosion control violation and the one most likely to produce a sediment discharge, because bare graded soil erodes rapidly in the first significant rain after disturbance. (6.1.3)
6.1.4Stabilization is required regardless of season; where seeding cannot establish vegetation in the current season, the Contractor shall provide a non-vegetative cover (mulch, blanket, or other approved cover) to hold the soil until seeding is possible.
6.2 Temporary Seeding
6.2.1Disturbed areas that will remain inactive longer than the stabilization deadline but are not at final grade shall be temporarily seeded with a fast-germinating cover.
Annual ryegrass (fast germination, cool season)
Cereal grain (oats, rye, or wheat) for cool-season cover
Browntop millet or other warm-season annual
Regional temporary mix per state erosion control manual
Per drawings — erosion control plan
6.2.2Temporary seeding shall use a fast-germinating annual species appropriate to the season and the region.
6.2.3Temporary seed shall be applied at the rate specified in the seeding plan and protected with mulch or a tackifier until germination.
NOTE Temporary seeding alone does not provide immediate protection, because the soil is exposed until the cover germinates and establishes; on slopes and in the interval before establishment, mulch or a rolled erosion control product shall provide the immediate cover. (6.2.4)
6.3 Permanent Seeding and Hydroseeding
6.3.1Areas brought to final grade shall receive permanent stabilization by seeding, sodding, or other permanent vegetative cover as shown on the landscape and erosion control plans.
Drill or broadcast seeding with mulch
Hydroseeding (seed, fertilizer, and hydraulic mulch in slurry)
Sod
Permanent seeding under a rolled erosion control product on slopes
Per drawings — erosion control plan
6.3.2Permanent seeding shall use the permanent seed mix, soil amendments, and application rate specified in the seeding plan and coordinated with Landscape Irrigation where permanent landscape establishment follows. 6.3.3Hydroseeding may be used to apply seed, fertilizer, and hydraulic mulch in a single slurry pass, and is well suited to slopes and large areas where drill seeding is impractical.
NOTE Permanent stabilization is not achieved until a uniform perennial vegetative cover of the density required by the permit (commonly 70 percent of the native background cover) is established over the disturbed area. (6.3.4)
6.4 Mulch and Soil Binders
6.4.1Seeded areas shall be mulched to retain moisture, moderate soil temperature, and protect against rainfall impact until vegetation establishes.
Straw or hay mulch, crimped or tackified
Hydraulic mulch (wood fiber) with tackifier
Bonded fiber matrix (BFM) for steeper or sensitive slopes
Soil binder / polymer tackifier on areas awaiting seeding
13
Default: 2 tons per acre
6.4.2Straw or hay mulch shall be anchored by crimping, tackifier, or netting so that it is not displaced by wind or runoff.
NOTE Loose mulch applied without anchoring blows off the slope and provides no protection in the first wind or rain event. (6.4.3)
6.4.4Hydraulic mulch and bonded fiber matrix may be used where straw is impractical or where a more erosion-resistant cover is required on slopes.
6.5 Rolled Erosion Control Products and Turf Reinforcement Mats
6.5.1Slopes too steep for mulch alone, and channels subject to concentrated flow, shall be protected with a rolled erosion control product (RECP) or turf reinforcement mat (TRM) selected for the slope or channel velocity.
Single-net straw blanket (temporary) — slopes 3:1 or flatter
Double-net straw or straw-coconut blanket (temporary) — slopes up to 2:1
Coconut (coir) blanket (extended-term) — slopes up to 1:1 and low-flow channels
Turf reinforcement mat (permanent, non-degradable) — steep slopes and high-velocity channels
Per drawings — erosion control plan
NOTE Erosion control blankets are degradable products composed of straw, wood, or coconut fiber bound in netting, and provide temporary or extended-term protection while vegetation establishes; turf reinforcement mats are permanent, non-degradable synthetic matrices that reinforce vegetation for long-term protection of steep slopes and high-velocity channels. (6.5.2)
6.5.3The product class shall be selected for the slope steepness or channel design velocity, with the manufacturer's published performance (ASTM D6459 for slopes, ASTM D6460 for channels) meeting or exceeding the project condition.
6.5.4Blankets and mats shall be installed in intimate contact with the prepared soil surface, anchored with staples or stakes at the manufacturer's spacing, with upslope ends keyed into an anchor trench and overlaps shingled in the direction of flow.
NOTE A blanket that bridges over rills, is loosely stapled, or is not keyed in at the top will allow water to run beneath it and erode the soil it was meant to protect. (6.5.5)
6.5.6Seed shall be applied beneath the blanket or mat before installation so that vegetation establishes through the product.
6.6 Dust Control
6.6.1The Contractor shall control wind erosion and fugitive dust from disturbed areas, stockpiles, and haul routes.
☑ Water application by truck or sprinkler on active areas and haul roads
☐ Temporary stabilization (mulch, seeding, or tackifier) on inactive areas
☐ Soil binder / polymer on exposed surfaces
☐ Wind barriers or reduced disturbed area
6.6.2Active disturbed areas and unpaved haul roads shall be watered or otherwise treated as needed to prevent visible dust from leaving the site.
6.6.3Water for dust control shall be applied at a rate that suppresses dust without generating runoff that mobilizes sediment.
7 Sediment Control Measures
7.1 Perimeter Sediment Control
7.1.1The down-gradient perimeter of disturbed areas shall be protected with sediment controls installed before up-gradient land disturbance begins, to intercept sediment-laden sheet flow before it leaves the site.
Silt fence (sheet flow; drainage area not exceeding 0.25 acre per 100 ft; slope length and steepness limited)
Fiber roll / wattle (sheet flow; slope interruption)
Compost filter sock
Reinforced (wire-backed) silt fence for higher flow or longer service
Per drawings — erosion control plan
7.1.2Silt fence shall be installed only where flow is shallow sheet flow, not in concentrated channels, and not across drainage areas exceeding the limit the device can handle (commonly 0.25 acre per 100 feet of fence on limited slopes).
NOTE Silt fence is a sediment control, not an erosion control, and is not a substitute for stabilizing the soil up-gradient; it captures sediment that erosion prevention failed to keep in place. (7.1.3)
NOTE Concentrating flow against a long, unbroken run of silt fence overtops or undermines it; the fence shall be installed in shorter segments following the contour with the ends turned up-gradient (J-hooks) so that captured water ponds and infiltrates rather than running along the fence to a low point. (7.1.4)
7.2 Silt Fence Installation
7.2.1Silt fence fabric shall conform to ASTM D6461 / AASHTO M288 temporary silt fence requirements for grab strength, apparent opening size, and permittivity.
● Standard geotextile silt fence fabric on posts (ASTM D6461 / AASHTO M288 temporary)
○ Wire-backed (reinforced) silt fence for longer runs or higher sediment load
7.2.2Silt fence shall be installed by slicing the fabric into the soil with a mechanical static-slicing device, or by digging a trench, inserting the toe of the fabric, and backfilling and compacting over it, so that the bottom of the fabric is keyed into undisturbed soil.
NOTE Fabric stapled to the surface without toe-in embedment will be undercut and will fail in the first runoff event. (7.2.3)
7.2.4Posts shall be installed on the down-gradient side of the fabric and the fabric fastened to the up-gradient face so that the soil load holds the fabric against the posts.
7.3 Storm Inlet Protection
7.3.1All storm drain inlets that receive runoff from the disturbed area, and inlets immediately down-gradient of the site, shall be protected to keep construction sediment out of the storm drainage system.
Prefabricated inlet insert / sediment bag
Filter fabric and frame around the inlet
Gravel-and-wire (rock filter) inlet protection
Block-and-gravel inlet protection (curb inlets)
Per drawings — erosion control plan
7.3.2Inlet protection shall be installed before land disturbance begins in the contributing drainage area and shall be coordinated with Storm Drainage so that the device matches the inlet type. 7.3.3Inlet protection shall be inspected after every qualifying rain event and the captured sediment removed when it reaches half the device capacity.
NOTE Clogged inlet protection that dams flow and causes ponding is both a flooding hazard and a sign the device needs cleaning; it shall not be left in a condition that backs water onto the road or into the work area. (7.3.4)
7.4 Sediment Traps and Sediment Basins
7.4.1Where the disturbed drainage area to a common discharge point exceeds the threshold of the governing permit, a sediment trap or sediment basin shall be provided to settle out sediment before runoff leaves the site.
Sediment trap (smaller drainage areas, typically up to ~5 acres)
Sediment basin (larger drainage areas, typically 5 acres and above)
Sediment basin with skimmer (surface-withdrawal dewatering)
Not required — drainage area below threshold; perimeter controls only
Per drawings — erosion control plan (deferred by default)
18003600
18003600
Default: 3600 cubic feet per acre of drainage area
NOTE A temporary sediment basin shall be provided where ten or more acres of disturbed land drain to a common location, unless the permit or the civil engineer establishes a different threshold. (7.4.2)
7.4.3Sediment basin and sediment trap sizing, embankment design, side slopes (2:1 or flatter for excavated basins), and outlet and emergency spillway design shall be prepared and stamped by a licensed professional engineer and included in the SWPPP.
7.4.4A basin shall provide storage of not less than 3,600 cubic feet per acre of drainage area where the permit specifies it, or the volume the engineer's design establishes, and shall dewater from the surface (skimmer or equivalent) so that the cleanest water is released and the settled sediment is retained.
NOTE Accumulated sediment shall be removed when it reaches the design cleanout level (commonly one-half the storage volume) so that the impoundment retains its settling capacity. (7.4.5)
7.5 Check Dams
7.5.1Temporary channels, swales, and ditches subject to concentrated flow shall be protected from scour by check dams where the channel gradient or velocity would otherwise erode the channel.
Rock / riprap check dam
Wattle or fiber-roll check dam (low-flow channels)
Sandbag check dam
Not required — channel lined or velocity within non-erosive limit
7.5.2Check dams shall be spaced so that the toe of the upstream dam is at the elevation of the crest of the next dam downstream, limiting the effective channel gradient between dams and reducing flow velocity.
7.5.3Check dams shall have a center crest lower than the side abutments so that flow passes over the center and not around the ends, and the channel below each dam shall be protected from the plunge of overtopping flow.
NOTE Check dams are grade-control and velocity-reduction devices, not perimeter sediment controls, and shall not be used as a substitute for silt fence on a slope. (7.5.4)
8 Stabilized Construction Entrance
8.1A stabilized construction entrance shall be provided at every point where construction vehicles enter or leave the site onto a public road, to remove mud and sediment from tires before vehicles reach the pavement.
● 1.5 in to 3 in crushed stone
○ 2 in to 4 in crushed stone
○ Recycled concrete aggregate of equivalent size
Per drawings — erosion control plan
8.2The stabilized entrance shall be constructed of coarse crushed stone over a geotextile separator, of the depth and length specified, and shall be wide enough to accommodate the largest vehicle entering the site.
NOTE The geotextile separator beneath the stone prevents the stone from being pushed into the subgrade, which would let the entrance turn to mud and stop functioning. (8.3)
8.4Where vehicles continue to track sediment onto the public road despite the stabilized entrance, the Contractor shall add a wheel wash or shall increase the entrance length, and shall sweep the public road at a frequency that prevents sediment accumulation.
8.5Sediment tracked onto a public road shall be removed by sweeping or shoveling and shall not be flushed into the storm drainage system.
9 Concrete Washout and Dewatering
9.1 Concrete Washout
NOTE A designated concrete washout facility shall be provided and used for all washout of concrete trucks, pumps, and tools, because concrete washout water is highly alkaline (pH commonly above 12) and is a prohibited discharge under the governing permit. (9.1.1)
Lined excavated pit with signage
Prefabricated above-ground washout container
Self-contained roll-off washout unit
Per drawings — erosion control plan
9.1.2The washout facility shall be lined and sized to contain all washout liquid and solids without overtopping or leaking to the ground, and shall be clearly signed so that all drivers and crews use it.
9.1.3Concrete washout water and slurry shall not be discharged to the ground, to the storm drainage system, or to any surface water.
9.1.4Hardened washout solids shall be removed and disposed of properly, and the facility shall be maintained with capacity available before it overtops.
9.2 Dewatering Sediment Control
9.2.1Water pumped from excavations, trenches, or impoundments shall be discharged through a sediment control so that the discharge does not carry sediment off the site or to a surface water.
Dewatering filter bag
Sediment trap or sediment basin before discharge
Vegetated buffer / level spreader on site
Portable sediment tank / dirt bag with rock outlet
9.2.2Dewatering discharge shall be filtered through a dewatering filter bag, routed to a sediment trap or basin, or discharged to a vegetated buffer such that the discharge is free of visible sediment and complies with the permit.
9.2.3Dewatering shall not discharge directly to a storm inlet, to a surface water, or off site without an effective sediment control between the pump and the discharge point.
9.2.4Dewatering means and methods, drawdown, and the management of groundwater are governed by Earthwork; this standard governs only the sediment control on the discharge. 10 Maintenance and Inspection
10.1All erosion and sediment control best management practices shall be maintained in effective operating condition for the full duration of permit coverage.
● Remove accumulated sediment when it reaches one-third the exposed fabric height
○ Remove accumulated sediment when it reaches one-half the exposed fabric height
10.2Each best management practice shall be inspected at the required frequency and after every qualifying rain event, and any damage, undermining, sediment accumulation, or loss of function shall be corrected.
10.3Accumulated sediment shall be removed from silt fence when it reaches one-third the exposed fabric height, from inlet protection at one-half device capacity, and from traps and basins at the design cleanout level.
10.4Corrective action for a deficiency that could result in a discharge shall be initiated immediately and completed within the time the governing permit allows (commonly within 7 calendar days, and before the next storm where practicable).
10.5Sediment removed from best management practices shall be placed in a stabilized area on site where it will not re-enter runoff, and shall not be deposited in a drainage way or below the high-water line of a water body.
NOTE Failure to maintain best management practices after a storm is a leading cause of sediment discharges; a control that worked at installation is worthless once it is full of sediment, undermined, or torn, and the post-storm inspection exists precisely to catch this. (10.6)
11 Sequencing and Phasing
11.1Erosion and sediment control shall be sequenced so that controls are functional before the disturbance they protect against occurs, and so that disturbed area is minimized at any one time.
Limited to 5 acres or less at any one time (enables 14-day stabilization option)
Phased per the erosion control plan, no fixed acreage limit
Per governing permit conditions
11.2Perimeter controls, the stabilized construction entrance, and storm inlet protection shall be installed first, before mass grading begins.
11.3Grading shall be phased so that areas are brought to grade and stabilized before new areas are opened, rather than disturbing the entire site at once.
11.4Temporary controls shall be relocated and added as the work moves across the site, and the SWPPP and its site map shall be revised to reflect the controls actually in place at each phase.
NOTE Disturbing the whole site at the outset to gain access maximizes exposed soil and erosion and is the opposite of good sequencing; phased disturbance keeps less soil exposed, reduces the size of required sediment impoundments, and may qualify the project for the less frequent inspection schedule. (11.5)
12 Final Stabilization
12.1Final stabilization shall be achieved on all disturbed areas before permit coverage is terminated.
Uniform perennial vegetative cover at 70 percent of native background density
Permanent non-vegetative cover (pavement, riprap, building footprint, or equivalent)
Combination of vegetative and non-vegetative cover per the governing permit
12.2Final stabilization is achieved when all land-disturbing activity is complete and the disturbed area is covered by a uniform perennial vegetative cover of the density required by the permit, or by an equivalent permanent non-vegetative cover.
12.3Temporary best management practices shall not be removed until the areas they protect have achieved final stabilization.
NOTE Removing silt fence, inlet protection, and other controls before the soil is stabilized exposes the site to a sediment discharge at the very end of the project, when the temptation to demobilize is greatest. (12.4)
12.5Once final stabilization is achieved and the temporary controls are removed and their footprints stabilized, the Contractor shall submit the Notice of Termination to the permitting authority to end permit coverage.
12.6Synthetic best management practice materials (silt fence fabric, netting, and similar) shall be collected and disposed of properly and shall not be buried in place.
13 Delivery, Storage, and Handling
NOTE Seed shall be delivered in labeled, sealed containers showing the species, purity, germination percentage, and test date, and shall be stored dry and cool so that germination is not degraded. (13.1)
13.2Geotextile silt fence fabric, rolled erosion control products, and turf reinforcement mats shall be protected from prolonged ultraviolet exposure before installation, because UV degrades the polymers and reduces strength and service life.
13.3Seed past its test date or showing reduced germination shall not be used without re-testing, and damaged or UV-degraded geosynthetics shall be rejected.
13.4Mulch, compost, and erosion control products shall be stored so they remain dry and free of contamination until placed.
14 Warranty
14.1Where the contract documents establish a stabilization warranty, the Contractor shall warrant that permanently stabilized areas remain stabilized and that vegetative cover establishes to the required density for the warranty period.
One full growing season
1 year from final stabilization
Not applicable — no establishment warranty on this project
14.2Areas that fail to establish the required vegetative cover within the warranty period shall be re-prepared, re-seeded, and re-mulched at the Contractor's expense until the required cover is achieved.
14.3The warranty does not relieve the Contractor of responsibility for any sediment discharge or permit violation occurring during the construction period and before permit termination.