208 - Soil Erosion and Sedimentation Control (NPDES)
GENERAL DESCRIPTION
Definitions and Terms
Best Management Practices (BMPs): BMPs are structural, vegetative, and procedural practices designed to prevent or reduce soil erosion and sedimentation.
CFR: Code of Federal Regulations
Dense-Graded Aggregate: Dense-graded aggregate is a mixture of aggregates with an even distribution of different size aggregates.
EGLE: Michigan Department of Environment, Great Lakes, and Energy
Erosion Control: Erosion control is the practice of preventing or minimizing soil loss using structural and non-structural measures or timely stabilization.
FHWA: (U.S. Department of Transportation) Federal Highway Administration Fine-Graded Aggregate: Fine-graded aggregate is a mixture of aggregates with an even distribution of small size aggregate particles.
Gully Erosion: Gully erosion is the severe erosion that creates large, deep channels in the land, often caused by uncontrolled runoff.
Hydroseeding: Hydroseeding is a method of applying seed, mulch, and fertilizer as a slurry to promote vegetation growth for erosion control.
NPDES: National Pollutant Discharge Elimination System
Open-Graded Aggregate: Open-graded aggregate is a type of aggregate material characterized by a high porosity and void content, allowing water to drain through freely. It is commonly used in drainage applications to prevent water accumulation on road surfaces.
Rill Erosion: Rill erosion is the formation of small, narrow channels (rills) due to concentrated surface water runoff. If left unattended, they eventually erode more becoming gullies.
Runoff: Runoff is water (rainfall, snowmelt, or irrigation) that flows over land instead of being absorbed.
Salvaged Aggregate: Salvaged aggregate refers to granular material salvaged from the project site. The material is tested to meet specific gradation requirements prior to re-use on the project.
Sediment Control: Sediment control involves implementing techniques to capture or slow down sediment transport to prevent it from leaving a site.
Sedimentation: Sedimentation is the deposition of eroded soil particles in water bodies, drainage systems, or land surfaces, often leading to water pollution and habitat degradation.
SESC: Soil Erosion and Sedimentation Control
Sheet Erosion: Sheet erosion occurs when a thin, uniform layer of soil is removed by rainfall or runoff.
Soil Erosion: Soil erosion is the process by which soil particles are detached and transported by wind, water, or other natural forces.
Stabilization: Stabilization is the establishment of vegetation or the proper placement, grading, or covering of soil to ensure its resistance to soil erosion, sliding, or other earth movement.
Storm Water Pollution Prevention Plan (SWPPP): An SWPPP is a site-specific plan that includes erosion and sediment control measures for construction activities.
Turbidity: Turbidity is the cloudiness or haziness of water due to suspended sediments, which can harm aquatic life.
General Overview
Soil erosion is a natural or human-induced process wherein soil particles are detached, transported, and redeposited by factors such as water, wind, or human activities like construction and deforestation. This phenomenon poses significant environmental concerns, leading to the loss of fertile topsoil, diminished agricultural productivity, and alterations in landscapes. In both terrestrial and aquatic ecosystems, soil erosion can have adverse impacts, making it a critical aspect of environmental management.
In response to the challenges posed by soil erosion, sedimentation control is imperative. This involves the implementation of measures to prevent or mitigate the deposition of eroded soil particles in water bodies, storm water systems, or other ecologically sensitive areas. Various techniques are employed for sedimentation control, including the use of sediment basins, silt fences, erosion control blankets, and storm water management practices. The goal is to trap, filter, or slow down the movement of sediment-laden water, thereby protecting water quality and aquatic habitats.
Sedimentation control is particularly crucial in construction and land development projects, where soil disturbance is inevitable. By incorporating best management practices (BMPs) into project plans, such as careful site grading, vegetation preservation, and erosion control measures, the negative environmental impacts of soil erosion can be minimized. This not only ensures compliance with environmental regulations but also promotes sustainable land use practices that safeguard ecosystems and maintain the integrity of water bodies.
MDOT is responsible for enacting various environmental control measures throughout the life of state transportation projects and activities to ensure issues related to environmental protection are appropriately considered and to provide transportation services that comply with the following rules and regulations.
| Table 1 – Natural Resources and Environmental Protection Act 1994 PA 451, as amended ! | |
|---|---|
| Part 91 | Regulates SESC measures. |
| Part 31 | Regulates floodplains and floodways through the NPDES. Any work within a floodplain requires a Floodplain Permit and compliance with the State Flood Hazard Management Plan. |
| Part 301 | Regulates inland lakes and streams. Any work below the ordinary high-water elevation of an inland lake or stream requires an Inland Lakes and Streams Permit. |
| Part 303 | Regulates wetland protection. Any work within a wetland requires a State Wetland Permit. Any unavoidable wetland impacts resulting from construction activities in a regulated wetland must be properly mitigated on a no-net-loss basis. |
| Part 315 | Regulates dam safety. Any construction, enlargement, repair, reconstruction, alteration, removal, or abandonment of any dam requires a Dam Safety Permit. |
| Part 323 | Regulates shorelands protection and management. Any vegetation removal, drainage alteration, land alteration, or construction within flood risk, high risk erosion, or environmental areas requires a Shorelands Protection and Management Permit. |
| Part 325 | Regulates submerged lands on the Great Lakes. Any dredging, filling, or related construction activities in, over, or adjacent to any of the Great Lakes requires a Great Lakes Submerged Lands Permit. |
| Part 353 | Regulates sand dune protection and management. Any vegetation removal, construction, or earth change within a critical dune area requires a Sand Dune Protection and Management Permit. |
EGLE has designated MDOT as an Authorized Public Agency (APA). The APA designation allows MDOT to accomplish earth change activities without attaining an SESC permit from a County Enforcing Agency (CEA) or Municipal Enforcing Agency (MEA). The APA designation requires all earth disturbance activities to follow the EGLE approved MDOT SESC Procedures, which are outlined in the MDOT SESC Manual. Road and bridge construction contract plans include SESC measures to be used during construction. The Engineer and Contractor are responsible for installing and maintaining the measures shown on the plans. If needed, the SESC plans may be modified to accommodate any unforeseen earth disturbance activities that could result in violation of Part 91.
The Contractor is responsible for installing and maintaining temporary and permanent SESC measures until the site is stabilized, the project has been determined to be stabilized, and a Notice of Termination has been submitted (if applicable).
CFR/FHWA Regulations
Michigan Act 451 requires various environmental protection measures be implemented during a construction project. Table 1 specifies some parts of Act 451 which are commonly referenced for construction projects.
For projects with federal aid, 23 CFR 650 Subpart B, Erosion and Sediment Control on Highway Construction Projects applies. FHWA policy requires all highways funded in whole or in part under Title 23, United States Code, be located, designed, constructed, and operated according to standards that will minimize erosion and sediment damage to the highway and adjacent properties and abate pollution of surface and ground water resources. Guidance for the development of standards used to minimize erosion and sediment damage is referenced in §650.211 of Title 23.
MDOT requires the Special Provision for Non-Compliance with Soil Erosion and Sedimentation Control Requirements be included in all project proposals. It details the mandatory correction timelines and actions which can be taken against the Contractor if they do not comply with making necessary corrections. Refer to Subsection 6.3 of this section for more details detailing a Contractor’s non-compliance with installing and maintaining SESC devices.
MATERIALS
All materials must meet acceptance requirements in the Materials Source Guide and be listed on the Contractor-provided Material Source Lists in the project files.
Description of Materials
Silt Fence
Silt fence is a permeable barrier erected adjacent to disturbed areas to capture sediment from sheet flow. Generally, silt fence is constructed of porous woven geotextile fabric attached to wooden posts. The purpose of silt fence is to protect downslope surface waters and properties by removing suspended solids from runoff prior to leaving the site. Silt fence is not to be installed in areas of concentrated flow, such as ditches or across streams.
Inlet Protection
Inlet protection fabric drops are typically made from non-woven geotextile blanket materials and come in various sizes to accommodate different inlet sizes and design. They play a crucial role in sediment control on construction sites, effectively preventing soil and debris from entering storm water inlets and drainage systems.
Filter Bags
Filter bags are fabricated from geotextile material. They must be non-woven and meet the physical requirements for geotextile blanket. Filter bags allow for settlement and filtering of sediment from the water being pumped from the construction site.
Turbidity Curtain
Turbidity curtains are used to isolate construction activities from a watercourse and to provide an area of slack water to allow for the settlement of sediment suspended in the water. Turbidity curtains can be fabricated from geosynthetic material in accordance with the requirements of Subsection 916.07 of the Standard Specifications for Construction. They may also be fabricated from polymer-impregnated geosynthetics. When polymer curtains are used the permittivity and apparent opening sizes of the material are waived.
Mulching
Mulch requirements vary from shredded bark to straw to synthetic netting depending on slope and water runoff. Mulching provides protection from erosion and promotes growth of vegetation. Materials are either on the approved products list or have a special provision which states approved products. Refer to Subsection 917.14 of the Standard Specifications for Construction for additional material requirements.
- Mulch:
- Shredded hardwood mulch consists of tree bark stripped and shredded from sawn logs with a debarking machine. The shredded hardwood mulch must be capable of passing through a conventional mulch blower. Do not use wood chips or recycled construction materials.
- Straw must be clean, undamaged, root free, and in an air-dry state. It must be free of weed seed and other deleterious materials.
- Mulch Blanket:
- Standard mulch blanket consists of a layer of mulch overlaid by a layer of netting.
- High velocity mulch blanket has a layer of straw sandwiched between two layers of netting.
- Modified mulch blanket is similar to standard or high velocity mulch blankets but has a biodegradable netting. The netting must be made of non-plastic materials such as jute, sisal, or coir fiber. Any type of plastic netting, despite degradability level, is not allowed.
- Turf reinforcement mats are synthetic netting products used on steep slopes or slopes with high velocity water. They consist of a layer of ultraviolet (UV) stabilized polyolefin fibers between 2 layers of black UV-stabilized polypropylene netting with polyolefin thread.
- Bonded fiber matrix consists of long strand, virgin wood fibers bound together by a pre-blended, high strength polymer adhesive. 90% of the mixture by weight is wood fibers where the other 10% by weight is the adhesive. All virgin wood fibers should be thermal refined from clean whole wood chips. The organic binders must be high viscus colloidal polysaccharide tackifier with activating agents to render the resulting matrix insoluble upon drying. This is commonly applied in hydroseeding operations.
- Mulch Anchoring:
- Wood stakes or other biodegradable anchors are used to hold down mulch blankets. Steel wire staples or pins are not allowed to anchor the netting.
- Various tackifiers are used to anchor mulch in place. Common tackifier types include latex-based, recycled newsprint, wood fiber, and guar gum, among others. Refer to Subsection 917.14.C of the Standard Specifications for Construction for additional material requirements.
Aggregates
Depending on the intended use of the soil erosion device, various aggregate types can be used. All aggregates must meet the MDOT gradation requirements. All aggregates should be natural unless otherwise stated.
- Riprap comes in 2 sizes: Standard (8 x 16 inches) or heavy (>16 inches). Refer to Subsection 916.01.C of the Standard Specifications for Construction for more riprap requirements.
- Cobblestone varies from 3 to 10 inches in size and may be round or semi-rounded.
- Coarse grade aggregates include 6A or 3x1.
- Dense-graded aggregates include 21AA or 22A.
- Open-graded aggregates include 34R or 46G.
Pictures of Materials
EQUIPMENT
The following equipment can be used:
- Trencher
- Backhoe
- Excavator
- Skid steer
- Front end loader
- Dump truck
- Crane
- Barge
- Stone/rock tub
- Boat
- Pump
- Hydroseeder/mulcher
- Straw blower
Description of Equipment
Silt Fence
There are two primary methods for installing silt fence. The amount of silt fence to be installed is typically the deciding factor.
- Manual installation of silt fence includes using a shovel to dig/backfill the trench and a hammer to drive the silt fence stakes into the ground. This is typically used only for short runs.
- Mechanical installation of silt fence includes the use of equipment, like a trencher, to dig a trench along the line where the silt fence is to be installed. The silt fence stakes are then driven into the ground with a hammer before the bottom of the silt fence is backfilled with a shovel.
There is also a third, but uncommon, silt fence installation method, which involves a silt fence machine. Silt fence installation machines may be used to install silt fence. They are advantageous for long stretches of fence. They work by trenching and installing the fabric into the ground and simultaneously installing the posts. Posts must be installed attached to the fabric during installation. Separate installation of silt fence fabric and posts is not allowed. If silt fence is damaged during installation with a machine, then replacement of the silt fence must be completed at the Contractor’s expense.
Inlet Protection
Fabric drops are installed in drainage structures by hand. For heavy covers, a lifting device is used. When moving the drainage structure cover is not required, geotextile is placed over the cover by hand before shoveling stone on top of the geotextile.
Sediment Traps and Basins
To install sediment traps and basins, an excavator or backhoe is typically used to dig a hole to the required specifications, typically in a roadside ditch. Excess material is loaded onto a truck and removed from the area.
Filter Bag
The hose of the discharge pump is placed into the filter bag access by hand and secured. The bag and hose are typically laid on the ground for support during pumping operations. The ground should be level, upland of the natural flow, and have sufficient vegetation.
Gravel Access Approach
An excavator is used to dig out the area denoted for the gravel access approach. Geotextile fabric is hand-placed over the footprint of the approach and stone is dumped at the location by a truck, loader, skid steer, or other means. If the access approach is larger, a bulldozer will spread out the gravel. If the area is smaller, an excavator will spread out the gravel.
Turbidity Curtain
The length and depth of the turbidity curtain determines the installation method. Shallow turbidity curtains are placed in the water by hand using a boat or barge, or by floating it to the desired location. Deep turbidity curtains are typically installed using a crane or excavator to lift them over the waterway and lower them into position. Laborers help guide the placement of the turbidity curtain as it is being lowered into the water course.
Check Dams
Check dams are installed by a machine placing the stone where it needs to go. Hand work may be required for final shaping of check dams. They are typically installed in roadside ditches. Common equipment includes:
- Excavators
- Front end loaders
- Backhoes
- Skid steer
Sand and Stone Bags
Sand and stone bags are placed in the proposed location by hand. Transportation of the sand or stone bag to the proposed location could include boats, barges, stone/rock tub, trucks, front end loaders, etc.
Pictures of Equipment
PRECONSTRUCTION
Any special project considerations regarding soil erosion and sedimentation control or sensitive environmental areas should be discussed at the preconstruction meeting as detailed in the boilerplate preconstruction meeting minutes located in Division 1, Supplemental Information, of this manual. If the project contains the Special Provision for Non-Compliance with Soil Erosion and Sedimentation Control Requirements (20SP-208A-01), it should be reviewed and discussed.
The proposal for projects subject to NPDES regulations or earth disturbances of five acres or greater will contain a National Pollutant Discharge Elimination System permit. Refer to the MDOT SESC Manual for comprehensive procedures.
Prior to the start of construction, the Inspector should perform the following:
- Review the plans to verify the location where SESC measures are to be installed.
- Review the plans and specifications for specific details that may include sensitive areas associated with protected habitat or species.
- Special provisions may note the use of a geotextile fabric under aggregate for check dams.
- Verify all materials are approved for use and meet specifications, and verify stockpiled materials are protected from weather and sunlight as required by the specifications and manufacturer recommendations.
- Obtain photographs of material tickets, storage method, and their location.
- Hold an onsite meeting with the Contractor to discuss:
- The construction methods that will be used to complete the work.
- Required traffic control measures, proximity of traffic to the work area, and maintaining driveways during construction.
- Communication required if impacting residents or businesses during installation.
- Residents and businesses should be contacted if there will be disruptions to services. Coordination by the Contractor with impacted users may be required if disruption is necessary.
- Review of local ordinances.
- Communicate with state specialists who are required due to project specific requirements.
- Disposal of excavated material and material stockpile locations. The Contractor should provide authorization letters to the Engineer noting material stockpile and disposal locations.
- Soil erosion and sedimentation control measures that will be utilized to minimize soil erosion and subsequent sedimentation.
- Methods for securing the site during work operations and at the end of each workday.
- Timeline expectations for installing SESC measures and completing corrective work in accordance with the specifications. Timely maintenance of SESC devices is key for an effective project.
- The construction methods that will be used to complete the work.
Submittals and Shop Drawings
It is good practice to have the Contractor supply a shop drawing for turbidity curtain prior to installation. Pay special attention to the depth of the required turbidity curtain.
Permits
NPDES and other permits required under the Natural Resources and Environmental Protection Act, 1994 PA 451, as amended are obtained during the preliminary engineering phase of a project. The permits are included in the contract documents. The Engineer is responsible for enforcing the permit requirements while the Contractor is responsible for construction activities described in the permit.
Notice of Coverage
For projects subject to NPDES regulations, EGLE must receive a Notice of Coverage prior to the start of the project describing the project details. Development staff will prepare the Notice of Coverage and submit it to the Construction Field Services (CFS) Division. CFS staff will sign and submit the Notice of Coverage. EGLE provides a letter of authorization. Upon stabilization of the site, the MDOT Construction Engineer should contact their Region representative (Superior Region – Region Construction Engineer; Metro & North Regions – Region Soils Engineer; All other regions – Region Resource Specialist) for completing the Notice of Termination and submitting it to MiWaters.
For projects which have an earth disturbance five acres or greater, a Notice of Coverage is required prior to the start of earth disturbance. Once SESC measures are on the design plans and meet the requirements of Part 91 Rule 323.1703, the CFS-designated Certified Agreement Administrator completes and signs the application and submits the application to EGLE.
Notification to CEA, MEA, and County Drain Commissioner
As an APA, MDOT is not required to obtain individual SESC permits from the CEA, MEA, nor the County Drain Commissioner. The Engineer is required to notify the appropriate enforcing agency that an earth disturbance project will be starting. This notification is done by sending a copy of the preconstruction meeting minutes to the appropriate enforcing agency. A contact list for the various permitting agencies can be found on EGLE’s website under Part 91 Agencies.
Qualified Products List
The Qualified Products List (QPL) in the Materials Source Guide lists specific products that can be used for silt fence, turf mulch blankets, and mulch binders (tackifiers). If a product that is not on the list is brought to the jobsite, it must be sampled and tested prior to use on the project.
Contractor-Submitted Plans/Procedures
Should there be any reported non-emergency deficiencies, the Contractor has the option to submit a corrective action plan for review by the Engineer to address the deficiencies if it is not practical to complete the repairs within the required 5 days.
CONSTRUCTION
Prior to commencing any construction operation that constitutes an earth change activity, including clearing, appropriate temporary and permanent SESC must be installed as shown on the plans.
Silt Fence
Silt fence should be installed at the downslope edge of areas of earth disturbance along the same elevation.
Proper silt fence installation:
- Dig an anchor trench at least 6 inches deep by 6 inches wide where the silt fence is to be placed. It is not acceptable to install silt fence without trenching it in.
- Unroll and place the silt fence in the trench with the silt fence posts on the downslope side. The silt fence fabric should be pushing into the posts when the fence is retaining runoff.
- Where two sections of silt fence are to be connected, wrap the two end posts together so fabric is surrounding the posts creating a barrier to eliminate sediment passage.
- Starting with the end post, pound the posts into the ground until the top of the bury flap is at ground level. As consecutive posts are driven, ensure the fabric spans between posts are taut.
- Backfill and compact the trench over the top of the bury flap.
- Remove and dispose of collected sediment when it reaches 50% of the fence height.
Inlet Protection Fabric Drop and Geotextile with Aggregate
Fabric Drop
Installing inlet protection fabric drops requires careful attention to detail to ensure optimal performance.
To install an inlet protection fabric drop, start by clearing the area around the storm water inlet of any debris or loose soil. Lay the fabric drop over the inlet opening, ensuring it fully covers and extends beyond the edges of the inlet. Secure the fabric in place using stakes, sandbags, or other appropriate anchoring methods. Additionally, inspect the fabric to ensure there are no gaps or wrinkles that could compromise its effectiveness.
Fabric drops should be checked regularly to monitor the condition of the fabric and promptly address any signs of wear or damage. If left unchecked, fabric drops can get too full to allow water to drain properly, potentially leading to flooding of the surrounding area.
To remove inlet protection fabric drops, carefully disengage the securing mechanisms and lift the fabric away from the inlet. It is critical that the fabric is not punctured or damaged during removal to prevent the retained sediment from entering the structure. Inspect the fabric for damage or wear, and if reusable, clean and store it properly for future use. Do not remove fabric drops from the structures until all permanent restoration is complete and there is no risk of sediment runoff.
Geotextile with Aggregate
Similar to fabric drops, geotextile fabric and aggregate work to alleviate sediment from entering the storm water system. These are primarily installed at inlets where there is not a cover and rim to support a fabric drop. The geotextile fabric is laid over the inlet. If within a curb, the geotextile fabric should be secured behind the back of the curb. Placing a sand or stone bag is sufficient, but trenching in the fabric is another option. If a large opening is below the geotextile fabric, a wire mesh should be placed under the geotextile fabric. Enough fabric should be used to completely cover the opening and have a 1-foot overlap on all sides. Open-graded aggregate, like 34R or 46G, or coarse-graded aggregate, like 6A, should be used to cover the fabric. The aggregate should extend 1 foot beyond the edge of the fabric in all dimensions and have a minimum thickness of 2 inches.
Caution must be used during removal of aggregate and geotextile fabric. Sediment or stone can easily be lost into the inlet if caution is not used. The Contractor is responsible for removing any material lost into the inlet during removal of the device at no cost to the contract.
Sediment Traps and Sediment Basins
Sediment traps and sediment basins are strategically designed to intercept and detain storm water runoff, allowing sediment particles to settle out before the water is discharged into nearby water bodies. Sediment traps and sediment basins are typically placed in ditches or other areas of concentrated flow. A sediment trap consists of 5 cubic yards or less of excavation with a check dam on the downstream edge, while a sediment basin is deep enough to double the cross-sectional area of the ditch and is at least four times the width of the ditch in length. Depending on the amount of flow, multiple sediment traps may be required. Both sediment traps and sediment basins require ongoing maintenance and should be cleaned when approximately 50% of the capacity is full of sediment.
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Dewatering with Filter Bag
Filter bags should be used to collect sediment during dewatering operations. Each dewatering pump should have its own filter bag, and the bag should be large enough to handle the flow. If sediment is making its way out of the bag, the bag may not be big enough to allow the sediment time to settle.
Filter bags should be placed on a flat area as far away from a water body as practical. Ideally, the bags should be placed in an area with a vegetative buffer between the bag and a water body to allow the discharged water more time to filter out. The bags should be replaced when they are too full of sediment to allow them to work properly. Care must be taken when disposing of filter bags to prevent the accumulated sediment from entering nearby waterways. Gravel filter berms must be used in conjunction with filter bags for added filtration.
Gravel Access Approach
Gravel access approaches are used to minimize tracking of material from the project site onto public roadways from construction vehicles and equipment. The area should be cleared of all vegetation and debris prior to installation. A geotextile separator must be placed underneath the aggregate. 3x1 aggregate or other approved material should be placed to a depth of at least 6 inches. The approach should be at least 50 feet in length and wide enough to accommodate all construction traffic entering the public roadway. The approaches should be inspected periodically to determine if they need to be cleaned out.
Turbidity Curtain
Turbidity curtains are used within water bodies to contain sediment laden water from leaving the project site. They work by isolating a section of water and allowing the sediment to settle to the bottom. For river applications, the curtain should be installed parallel to the direction of flow.
Turbidity curtains can be shallow or deep. A shallow curtain is typically used in water less than 2 feet in depth and can be staked in. There is also floating version of the shallow curtain that can be used provided it is anchored to the channel bottom.
A deep curtain is defined as 2 feet or greater and up to 10 feet in depth. If the water in the channel is 10 feet or less, the ballast chain must extend to the bottom. If the water is deeper than 10 feet, a 10-foot curtain is required and must be anchored to the bottom.
Check Dams
Checks dams are typically constructed in ditches or areas of concentrated flow. The purpose of a check dam is to reduce water velocity and capture sediment, though a check dam is not a filtering device. The amount and spacing is based on the steepness of the ditch. A general guideline is to have the crest of the downstream check dam to be at the same elevation of the toe of the upstream check dam. Check dams can be made of cobblestone, coarse aggregate 3x1, and riprap. Regardless of material used, the aggregate is placed in the ditch line to create a berm 18 inches high, with a flat top, and 1-on-6 slopes along the centerline of the ditch. A notch should be placed in the center of the berm to direct flow through the center of the check dam and prevent erosion to the ditch banks. The notch should be the width of the ditch bottom. Sediment traps are typically installed in conjunction with check dams to catch sediment eroded into the ditch. In cases where a sediment trap is installed with the check dam, the sediment trap is installed upstream of the check dam.
Check Dam Details
Mulch Treatments
Straw Mulch
Straw mulch is placed over bare topsoil with an appropriate tackifier to prevent erosion while seeds germinate and grow. Straw should be evenly distributed over the bare topsoil in a loose or open enough way to allow some sunlight and air to penetrate, but thick enough to shade the ground. As the material is spread out, the Inspector should check if it is clean, undamaged, rot free, free of foreign matter, and substantially free of weed seed. If any of these conditions occur, correction must be made by the Contractor at no cost to the contract. Ensure all clumps are distributed during placement of the straw. Immediately after placement of the straw, a tackifier should be sprayed over the straw to hold it in place.
Mulch Blanket and Turf Reinforcement Mat
The type of mulch blanket used is determined based on the slope of the area or environmental restrictions. The contract documents will specify where the different mulch blanket types are required. Regardless of type, the mulch blanket should be laid flat on the grade and adjacent mulch blankets should be shingle lapped. Within 8 feet of the road edge, the mulch blanket should be placed parallel to the roadway. Further than 8 feet from the road edge, the mulch blanket can be placed either perpendicular or parallel to the roadway. The mulch blanket must be installed in an anchor trench, in accordance with the manufacturer’s recommendations, and adjacent to a roadway. Wood or biodegradable stakes, at least 6 inches in length, should be used to anchor mulch blankets. Steel staples or pins are not allowed. Stakes should be placed approximately every 3 feet along the slope. All mulch blankets should be overlapped a minimum of 6 inches during installation. Attention must be made to not stretch the mulch blanket during installation.
Turf reinforcement mats follow the same requirements as mulch blankets during installation. A turf reinforcement mat is typically installed in the bottom of the ditch where there is a higher concentration of runoff and greater potential for erosion.
Bonded Fiber Matrix
Only certain types of bonded fiber matrix are permitted for use; check the project-specific special provision for approved materials. Before application begins, ensure the proper mixture of seed, fertilizer, fibrous material, and water is combined and thoroughly mixed within the holding tank. Once thoroughly mixed, the bonded fiber matrix is sprayed uniformly over the proposed areas. The tackifier within the bonded fiber matrix mixture holds the material in place and becomes impermeable upon drying. The application rate at which the bonded fiber matrix is applied must be verified to meet the manufacturer’s recommendations based on field conditions.
INSPECTION & TESTING
Inspection Procedures
The Inspector should utilize, at a minimum, the following tools to perform the required inspection: 100-foot tape measure or longer
- 25-foot tape measure
- Measuring wheel
- Chaining pin
- 6-foot stick ruler
- 4-foot level
- Working plans
- Survey equipment
- Camera
- Rain gauge
Training
Personnel who have SESC decision making authority or inspection responsibilities are required to complete, at a minimum, the EGLE Construction Storm Water Operator (CSWO) exam. Personnel who have SESC decision making authority must have the Comprehensive SESC Certification. Contact EGLE for exam schedule. When submitting an SESC renewal or examination, the application must note on the bottom to invoice MDOT, for MDOT employees only. For training requirements see Section 1.2 of the MDOT SESC Manual.
Contractor Obligation
The Contractor is responsible for constructing and maintaining both the temporary and permanent SESC measures shown on the construction plans in accordance with the MDOT SESC Manual. Site specific earth disturbances may result in the need to modify the existing plan or add additional SESC measures to comply with Part 91. The Engineer is responsible for ensuring Part 91 compliance.
If the Contractor is working outside the MDOT right-of-way for borrow operations, waste or disposal areas, or any other earth disturbance activity affecting 1 or more acres of land or located within 500 feet of a lake or stream, the property owner must obtain an SESC permit from the applicable MEA or CEA and EGLE. A copy of all permits and restoration agreements with the landowner must be provided to the Engineer.
If the Contractor obtains MDOT permission to disturb an area outside the limits of earth disturbance but within the project limits, a separate earth change plan using Form 1568, Project Staging or Excess Material Location on MDOT ROW, must be completed and submitted to the Engineer for review and approval. Earth change plan requirements can be found in the MDOT SESC Manual. After all approvals have been obtained, provide a copy to the CFS Division Resource Specialist for submittal in the MiEnviro permit system. All slopes and ditches within 150 feet of a stream, lake, or wetland must be permanently restored within 24 hours of final grading or final earth change.
If the Special Provision for Environmentally Sensitive Areas is included in the proposal, no earthwork, grading, or other disturbance is allowed within the limits of the environmentally sensitive areas as stated in the special provision and plans. Permanent SESC for slopes, channels, and ditches and other disturbed areas must be completed within five calendar days after final grading or final earth change.
EGLE
EGLE may visit a project site in response to complaints, agency interest, or while performing audits of MDOT’s APA status. Continued disregard for EGLE concerns may result in a Notice of Violation being issued to MDOT. The MDOT SESC Manual describes procedures to ensure compliance. The Engineer must require the Contractor to complete any corrective actions within 5 days of the Notice of Violation. If it is not possible to make the corrective actions within that timeframe, the Engineer must submit a plan to EGLE describing the proposed actions. It is recommended the Engineer work with their Region Resource Specialist.
Inspection
MDOT will inspect construction sites for Part 91 and Part 31/NPDES compliance every 7 days or within 24 hours after a precipitation event that results in a discharge from the site into waters of the state or that leaves the MDOT right-of-way, including weekend days regardless of whether the Contractor is working. A discharge is defined as construction storm water runoff that does not infiltrate into the ground and leaves the construction site or enters waters of the state after a precipitation event. Engineering judgement must be used when determining whether a discharge has occurred. Inspectors must possess a current CSWO Certificate. Individuals who authorize changes to SESC measures shown on road or bridge construction plans must have a valid Comprehensive SESC Training Certificate.
Inspections are completed using Form 1126, National Pollutant Discharge Elimination System (NPDES) and Soil Erosion and Sedimentation Control (SESC).
Inspection reports must be maintained for three years and available for inspection by auditing agencies.
For a quick reference on proper installation processes for the different devices, reference the The MDOT Storm Water Management Construction Site Soil Erosion & Pollution Prevention Pocket Guide is available to field staff for reference.
The MDOT Construction Site Soil Erosion & Pollution Prevention Pocket Guide
The MDOT Construction Site Soil Erosion & Pollution Prevention Pocket Guide
Corrective Action Deadline
Corrective actions must be made within 24 hours if sediment has entered waters of the state, left MDOT right-of-way, and/or if public safety may be compromised. Otherwise, corrective actions must be made within 5 calendar days. Corrective actions, notification dates, and completion dates must be documented on Form 1126, National Pollutant Discharge Elimination System (NPDES) and Soil Erosion and Sedimentation Control (SESC).
Winter Construction Storm Water Inspection Reports
EGLE does not accept “frozen ground” as a weather condition for determining construction site inspection frequency. Onsite inspections must be resumed within 24 hours of any change in earth disturbance conditions that may allow construction storm water runoff to occur as a result of construction operations resuming, rainfall, or warming conditions that will cause snowmelt. Detailed weather conditions must be recorded on Form 1126, National Pollutant Discharge Elimination System (NPDES) and Soil Erosion and Sedimentation Control (SESC).
Construction activities with an earth disturbance of one or more acres of land or located within 500 feet of a lake or a stream must be inspected once every 7 days or within 24 hours after a precipitation event that results in a discharge from the site, including weekend days regardless of whether the Contractor is working. During inactive periods when a construction site has been temporarily stabilized and below freezing temperatures predominate, the certified CSWO, without performing an onsite inspection, may certify on Form 1126, National Pollutant Discharge Elimination System (NPDES) and Soil Erosion and Sedimentation Control (SESC), that weather and inactive conditions are such that runoff from the site will not occur.
Certified CSWO Procedures
- To cease onsite weekly inspections during periods of inactive earth change activity and/or during periods where discharges from the site are unlikely, the CSWO must confirm and document on Form 1126, National Pollutant Discharge Elimination System (NPDES) and Soil Erosion and Sedimentation Control (SESC), the following have occurred:
- Earth change activity has ceased.
- The site has temporary SESC measures implemented to minimize discharge of sediment from the site (must be confirmed by onsite inspection).
- Weather conditions are consistently below freezing and unlikely to result in runoff from the site.
Once conditions 1a, 1b, and 1c are met, subsequent weekly inspection documentation may be completed without a site visit by documenting weather conditions for the site location on Form 1126, National Pollutant Discharge Elimination System (NPDES) and Soil Erosion and Sedimentation Control (SESC). At a minimum, an inspection must be performed every 30 days, in accordance with Section 3.1.7 of the MDOT SESC Manual.
- Onsite inspections must resume if any of the following occurs:
- Earth change activity resumes.
- Weather conditions are such that snowmelt runoff or precipitation in the form of rain is likely to leave the right-of-way.
- Weather conditions are consistently above freezing for 3 days in a row and the possibility exists for surface runoff.
- The site becomes unstable and starts to cause erosion.
Once any of the conditions identified in 2a–2d occur, onsite inspections must resume within 24 hours. Onsite inspections must be performed weekly or within 24 hours of a precipitation event that results in runoff from the site.
Detailed Reporting of Weather Conditions Affecting a Construction Site
Warming conditions may result in runoff from the site. However, the ground may still be frozen. Typical weather condition documentation may be obtained from any reliable weather source. This documentation should include the reporting period and the high and average temperatures for the week.
Sediment Discharge into Waters of the State of Michigan
Part 31 of the Water Resources Protection of Public Act 1994 as amended regulates the discharge of storm water from construction activity under Section 323.2190. Part 31 utilizes a permit under the NPDES to regulate construction storm water. MDOT must take all reasonable steps to minimize any adverse impact to waters of the state.
If MDOT has a discharge of sediment into waters of the state, the MDOT Construction Engineer must:
- Provide in writing, to EGLE, the following information within five days of becoming aware of a discharge of sediment:
- A description of the discharge and its cause.
- The period of non-compliance, including exact dates and times, or if the non-compliance is not corrected, the anticipated time the non-compliance is expected to continue and the steps taken to reduce, eliminate, and prevent recurrence of the non-compliance.
Refer to Subsection 4.2.1 of this section for the EGLE SESC/CSWO individual in the respective region.
Submission of Notice of Termination
For projects which have an earth disturbance of 5 acres or greater, a Notice of Coverage is obtained during the project development. When a Notice of Coverage is obtained, a Notice of Termination is required to be submitted to EGLE when the project is determined to be stabilized. A site is stabilized when all temporary SESC measures have been removed, permanent SESC measures installed, and vegetation well established with no rills or gullies. SESC inspections must continue until the site is stabilized and the Notice of Termination has been submitted to EGLE.
The Engineer will request either the Region Soils Engineer or Region Resource Specialist to evaluate and determine if a construction site is stabilized. If the project is determined to be stabilized, the Region Soils Engineer or Region Resource Specialist contacts CFS to submit a Notice of Termination. Once the Notice of Termination is submitted, SESC inspections are no longer required.
Testing
Some materials are required to be sampled and tested for acceptance including silt fence, geotextiles, and grass seed mixtures. Refer to the MDOT Materials Source Guide to check the testing requirements. Depending on the quantities used on the project, multiple samples may need to be taken.
Non-Compliance of SESC
Review the Special Provision for Non-Compliance with Soil Erosion and Sedimentation Control Requirements included in the proposal for deficiency timeframe and monetary penalties for failure to correct deficiencies in the required timeframe.
When the Contractor fails to respond or to correct SESC actions within the appropriate timeframes shown on Form 1126, National Pollutant Discharge Elimination System (NPDES) and Soil Erosion and Sedimentation Control (SESC), the Contractor must be determined to be in non-compliance of SESC. When the Contractor is in non-compliance of SESC, the Engineer will issue Form 1165, Notice of Non-Compliance with Contract Requirements. The Engineer must detail language describing a projected project shutdown date and/or curtailment of biweekly progress estimates if the needs still are not resolved within the appropriate timeframes.
Request direct or contract agency maintenance forces to perform the corrective actions. The Contractor is subject to back charges for the costs associated for work completed by others. Ensure the Contractor has been non-responsive or refuses to complete directed work.
In certain situations, it may be possible to contract with another contractor to perform corrective actions. The Prime Contractor may be subject to back charges for the costs associated for work performed by others.
MEASUREMENT AND PAYMENT
Measurement and Payment
Unless otherwise stated, the unit cost for the item of work includes the cost of installing, maintaining, and removal of the SESC device. Any repairs of replacement of temporary or permanent SESC devices damaged by the Contractor’s negligence will be at no cost to the contract. Measurements are based on in-place dimensions. Any overlap is not included.
- By each: The total number of sediment traps, filter bags, sandbags, stone bags, inlet protection fabric drops, inlet protection geotextile with stone, inlet protection sediment trap, or gravel access approaches, will be paid by each item installed.
- By linear foot: The installation of check dams, silt fence, gravel filter berm, sand fence, and turbidity curtain are paid for by the linear foot removed.
- By station: Ditch intercepting is measured along the in-place ditch centerline by station.
- By square yard: Temporary plastic sheeting, geotextile cover, and aggregate cover are paid for by the square yard based on field measurements.
- By cubic yard: Sediment basins and sediment removal are paid by the cubic yard based on field measurements.
Refer to Section 816 of the Standard Specifications for Construction for information on mulching requirements. If the Contractor elects to substitute high velocity mulch blanket for standard mulch blanket, it will be at no additional cost to the contract.
Documentation Requirements
The Daily Work Report (DWR) should show all measurements, computations, and supporting documentation needed to verify the quantity submitted for payment. The Inspector should note in the remarks section of the report the material verification and equipment used for the delivery and placement. Each load ticket for aggregate material must include the required information. Refer to Subsection 109.01.B.6 of the Standard Specifications for Construction for the information required on each ticket.
Basis of Payment
All SESC measures are posted by in-place quantities. Overlaps are excluded from the measured quantity. Maintenance of the device is included with some items, but others have repairs or replacement paid for by MDOT if damages are caused by forces other than the Contractor’s negligence. Refer to Subsection 208.04 of the Standard Specifications for Construction for what is included with each item posting.
LOCAL AGENCY PROJECTS
Local agencies typically have their own standards for SESC measures. These standards are typically included in the plans. Be sure to reference the detail section of the plans to verify SESC requirements. Both local and MDOT SESC measures must be followed on Local Agency Projects (LAPs). EGLE winter inspection requirements apply to all LAPs which are covered pursuant to the provisions of Michigan’s Permit-by-Rule (R323.2190) of Part 31.
RAIL PROJECTS
-Reserved-