207 Temporary Sediment and Erosion Controls
SS 832 Temporary Sediment and Erosion Controls
Description (832.01)
SS 832 replaces
C&MS 207 or SS 877. At the time of
this publication revisions to SS 832 were under committee review and not yet
finalized. The information contained in
this MOP section is an interpretation of the proposed revisions. SS 832 as
discussed, includes the NPDES permit and BMP pricing structure as appendices
(formerly SS 833 and PN 205)
Projects which involve one (1) acre or more of earth disturbing activity are required to have an NPDES Permit. This permit pertains to the work within the project work limits.
1. The Contractor is required to furnish a fully executed Co-permittee form.
2. The Contractor is required to furnish site specific Storm Water Pollution Prevention Plan (SWPPP) that is compliant with the NPDES Permit see SS832 Appendix E.
3. The Contractor is required to locate, furnish, and maintain all TSEC BMP as identified in the Contractors SWPPP.
4. Project personnel are required to read the permit, SS832 Appendix E, and should inform the Contractor of any non-compliant permit conditions known on the construction site.
5. If stream or river crossing (causeway) provisions is not part of the project permit(s), the Contractor must obtain the proper permit to construct a stream or river crossing. Fording streams, rivers or waterways is not permitted.
Definitions (832.02)
Co-permittee Both ODOT and the Contractor are identified as “Operators” in the NPDES Permit. As a result both ODOT and the Contractor are required to keep the construction activity in compliance with the NPDES Permit. ODOT contractually holds the Contractor responsible for compliance and provides compensation for the Contractor’s efforts. ODOT cannot knowingly allow a permit violation to exist. If a permit violation or deficiency is identified the Contractor should be notified and reminded of his contractual responsibility to maintain permit compliance.
Standard Construction Drawing Reference (832.03)
The Standard Construction Drawings (SCD) provides detailed information for the materials, construction and installation of most of the TSEC BMP. This should be brought to the Contractor’s attention as early in the project as possible and preferably at or before the preconstruction meeting. Project staff should use the SCD when inspecting or measuring TSEC BMP for payment.
Requirements (832.04)
Post construction NPDES Storm Water Management Requirements are not included in this specification. Post construction controls are not considered “Temporary” and therefore are addressed in the project plans.
Provisions (832.05)
The “Provisions” portion of the specification identifies how the ODOT contract handles storm water enforcement actions resulting from non-compliance. The NPDES permit holds the “operator” responsible for compliance. BOTH ODOT and the Contractor are identified as Operators. If a non-compliant condition results in an enforcement action the Contractor agrees to:
· Make all necessary corrections resulting from an incomplete or inadequate SWPPP
· Reimburse ODOT for any fine penalty assessment damage judgment or expense resulting from non-compliance regulatory action.
· Indemnify and hold the Department harmless for any fine penalty assessment damage judgment or expense resulting from non-compliance regulatory action
· If a stop work order is issued resulting from an incomplete or inadequate SWPPP and or TSEC BMPs the Department will find the Contractor in default.
· Failure to correct non-compliant site conditions may result in suspension of the work and/or removal of the project superintendent.
When notifying the Contractor of non-compliance matters, the provisions portion of the spec should be referenced.
EDA Requirements (832.06)
ODOT Maintenance projects involving less that 5 acres of maintenance work activity are exempt from the NPDES permitting requirements. For a project to be eligible for this exemption it is required that ALL work activity included in the project falls under the OEPA approved list of “Maintenance Activities”. The approved list can be found at:
http://www.epa.state.oh.us/dsw/storm/routine_maint.html
If the Contractor elects to work outside of the project limits (typically areas for borrow, waste, staging or storage) and the EDA is greater than 1 acre, then the Contractor is required to obtain the NPDES General Construction permit.
Work outside the project work limits
1. If the project has identified any EDA within the project limits (even less than one acre Project EDA), ODOT will compensate the Contractor for the installation of appropriate TSEC BMP. For projects with more than one (1) acre of EDA, the Contractor is required to include all work areas located outside of the project work limits in his SWPPP. The cost for expanding the SWPPP coverage outside of the project work limits is included in the lump sum price bid for SWPPP. See 107.19 for general environmental protection requirements. It is important to note that some areas may be on ODOT RW but outside of the project work limits, or within the limits, but the Contractor has made a change to the work (i.e. filling an infield). ODOT provides compensation for appropriate TSEC BMP on all construction projects that have a project EDA > 0. The only exception is for projects identified as “maintenance” on the plan title sheet (see 832.06 A)
2. Placement of fill in water areas (i.e. streams, ponds, lakes, waterways etc.) without a permit is illegal. The Contractor is required to furnish the proper permit for any area affected by his operation that is outside of the project work limits. In particular this includes temporary work pads, stream crossings, causeways or placement of any fill in water areas (See107.19).
3. The Contractor is required to furnish spill response equipment for all operations working next to a body of water. (See 107.19).
4. The Contractor is required to furnish a water handling control which will prevent sediment-laden water from entering “waters of the state”. This is an important consideration when working in and around water areas on (drilled shafts, cofferdams, dewatering operations etc. See 107.19.)
5. The Contractor is required to provide a location to properly wash out cement or concrete trucks. Concrete washdown water is toxic and can cause environmental damage including fish kills. Washdown sites must be located away from all bodies of water. The Contractor is required to locate the concrete washout BMP(s) on the SWPPP.
TSEC BMP Materials
(832.07)
Furnish the materials as outlined below:
1. Furnish commercial fertilizer, seed, and mulch material that meet 659.
2.
Furnish filter fabric material for ditch checks
that meets standard drawing DM-4.4. It is
important to note that this BMP includes the installation of an aggregate
component to prevent high flows and sediment accumulation from collapsing the
fabric fence.
3. Furnish rock material for ditch checks that meets standard drawing DM-4.4.
4. Furnish filter fabric material for inlet protection that meets standard drawing DM-4.4.
5. Furnish filter fabric material for perimeter controls that meets standard drawing DM-4.4.
6. Furnish filter fabric material or hay or straw bale material for bale filter dikes that meets standard drawing DM-4.3.
7. Furnish excavation and embankment material for sediment basins and dams that meets standard drawing DM-4.3.
8. Furnish pipe material for slope drains that meets standard drawing DM-4.3.
9. Furnish rock channel protection material that meets standard drawing DM-4.3.
Furnish
and Locate TSEC BMP (832.08)
The NPDES Permit requires that the SWPPP identify the type, location and size of all sediment and erosion controls installed or proposed on the project site. The Contractor is required to keep the SWPPP current with the controls installed and maintained on site SS832 Appendix E Part III.C.2.D.
Figure 832.A-
Figure 832.A1 - Construction Seed, with Dikes
Figure 832.A2 Perimeter Filter Fabric Fence
Perimeter Controls (SS 832.08 A)
Apply perimeter control practices to protect the disturbed area from offsite runoff and to prevent sediment from discharging off site to areas below the construction site. Sediment and runoff barriers surrounding the area disturbed by construction activity prevents runoff from moving offsite and impacting surface waters downstream
1. Perimeter controls must be placed and identified in the SWPPP before or concurrent with any clearing and grubbing operation.
2. The perimeter controls should be dated on the SWPPP along with the dates of the clearing and grubbing.
3. Perimeter controls BMP are detailed in standard drawing DM-4.4.
4. Perimeter controls can effectively divert water away from the project and, when designed properly, can separate watersheds into smaller drainage areas reducing the need for large sediment settling ponds.
5. Perimeter controls should be used to protect all water bodies (ponds, streams, wetlands, etc.) and any areas shown on the plan which may be adversely affected by construction surface drainage.
Figure 832.A3 Perimeter Control, Water Body Protection
Filter Fabric Fence
Filter Fabric Fence is used to control sheet flow (not concentrated flow). The application of Filter Fabric Fence is limited by the steepness of the slope and the size of the surface area draining toward the fence. The regulatory limitations for Filter Fabric Fence are outlined in the NPDES Permit see SS832 Appendix E, Part III.G.2.d.
It is critical that Filter Fabric Fence be installed in accordance with standard construction drawing DM 4.4. The fabric must be installed in a 6 inch X 6 inch trench and backfilled with compacted earth. Placement of the fence along the ground surface and shoveling fill on top of the lower edge of the fabric is NOT acceptable.
When Filter Fabric Fence fails in the field it is typically caused by one or more of the following:
1. Improper burial depth
2. Drainage area exceeds the capacity of the fence
3. Fence is not parallel to the surface contours
4. Poor maintenance
Dikes
Dikes can be used as a perimeter control. Dikes function best by collecting and concentrating sheet flow then directing it to an appropriate controlled outlet or other BMP which does not allow the discharge of sediment.
Inlet Protection (SS 832.08 B)
Place Inlet Protection as outlined below. The location and date of placement, maintenance or removal should be identified on the SWPPP. It is recommended that all inlet protection be numbered and dated both in the field and on the SWPPP.
Figure 832.B - Inlet Protection
1. If Inlet Protection is being used as a TSEC BMP it is required that they be located on the SWPPP
2. Inlet Protection should be dated on the SWPPP.
3. Inlet protection should be used around Catch Basin inlets and/or any structure that conveys storm water.
4. Inlet protection requirements are detailed on standard drawing DM-4.4.
5. When Inlet Protection fails in the field it is typically caused by one or more of the following:
a. Improper burial depth
b. Inadequate height of fence above inlet invert
c. Improper lap of fabric
d. Poor maintenance
Construction Seeding and Mulching (SS 832.08.C)
Seed and mulch all areas, or as required by the permit and before winter shut down.
Figure 832.C - Construction Seeding and Mulching
1. The rate furnished for straw mulch is 2 tons per acre. (0.5 metric ton/1000 m²)
2. The rate furnished for fertilizer is ½ the rate found in Item 659.
3. Do not place construction seed on frozen ground.
4. Install Construction Seed and Mulch on disturbed areas that work will be suspended during the winter. Standard Construction Seed and Mulch should not be installed between October 15 and March 15.
5. Winter Seed and Mulch is the standard erosion control practice for EDA occurring between October 15 and March 15. This BMP includes mulch crimped in place or a Bonded Fiber Matrix capable of providing sufficient protective cover to comply with the NPDES Permit. The cost for installing BFM mulch is typically greater than crimped mulch. The BFM mulch is better suited for limited area applications on steep slopes or areas where crimping implement access is limited. The use of other seed and/or mulch materials in this time period requires Department approval.
6. Construction seed areas that are required by the permit as the project construction progresses.
7. The date of construction seed placement should be recorded on the SWPPP and corresponding NPDES inspections.
Slope Protection (SS 832.08.E)
Fill Slopes that are greater than 8 feet (2.5M) and have had no filling activity for three weeks.
Figure 832 E - EC Items Required For Slope Protection
1. If dikes are being used as a TSEC BMP it is required that they be located on the SWPPP
2. Dikes should be dated on the SWPPP along with the date of the slope construction.
3. Dike and slope drain construction requirements are outlined on standard drawing DM-4.3.
Figure 832 E2 - Item 670 Recommended for Cut Slope construction
When constructing cut slopes a surface water control ditch shall be installed before the slope excavation begins.
1. The ditch should be constructed at the top of the cut slope.
2. If the ditch is being used as a TSEC BMP it is required that it be located on the SWPPP.
3. It is important that the ditch is constructed with sufficient grade to prevent water from saturating the underlying soils and causing slope instability problems.
Ditch Checks and Ditch Protection (SS 832.08.F)
Figure 832 F1- Filter Fabric Ditch Check
1.
Construct
Filter Fabric Ditch Checks as soon as ditch is cut.
2. Ditch checks shall be placed per the SWPPP or as required.
3. Ditch checks are TSEC BMP and are required to be recorded on the SWPPP along with the ditch construction.
4. Filter fabric ditch checks construction requirements are detailed on the standard drawing DM-4.4.
5. Filter Fabric Ditch Checks are limited to drainage areas of 2 acres (0.8 ha) or less.
6. Filter Fabric Ditch Checks include #1 thru #4 stone component (unless the Department specifically waives this requirement when installed in the “clear zone”).
7. It is important that ditch checks be in place by the end of the day if working on the ditch.
Figure 832 F2 - Rock Ditch Check
1. Rock Ditch Checks shall be placed per the SWPPP or as required.
2. If Rock Ditch Checks are used as TSEC BMP they should be recorded on the SWPPP.
3. Rock Ditch Checks should be installed as soon as the ditch is cut.
4. Rock Ditch Checks construction requirements are detailed on the standard drawing DM-4.4.
5. Rock Ditch Checks are limited to drainage areas between 2 and 5 acres (0.8 and 2.0 ha).
6. It is important that ditch checks be replaced by the end of the day if working on the ditch.
Bale Filter Dike (SS 832.08.G)
Figure 832 G - Bale Filter Dike
1. Bale Filter Dikes shall be placed per the SWPPP or as required.
2. Install near the toe with slope no greater then 2:1 and having a length less than 100 feet (30m).
3. Construct Bale Filter Dike within 7 days of completing grubbing operation and before grading begins.
4. Bale Filter Dike construction requirements are detailed on the standard drawing DM-4.3.
Sediment Basins and Dams (SS 832.08.H)
Figure 832 H -
1. Sediment basins and dams are required to be placed within 7 days after completion of grubbing and constructed before grading begins.
2. Sediment basins and dams should be installed as per the SWPPP or as required.
3. Sediment basins are a TSEC BMP and are required to be recorded on the SWPPP.
4. Typical field locations include: the bottom of a ravine, culvert inlets and outlets, at the end of a ditch, and any concentrated water exit point.
5.
6.
7.
Construction requirements for
8. Install Construction fence as needed for safety considerations.
River, Stream, and Water Body Protection (SS 832.08.I)
All rivers, streams, and water bodies must be protected from all sediment-laden or turbid water. 832 items are provided to ensure the protection of all rivers, streams, and surface waters.
Figure 832 I - Stream Protection
Stream Relocation (SS 832.08.J)
Fully stabilize any temporary-relocated waterway before the water is diverted as outlined below. Examples are temporary run-arounds to constructed culverts, temporary ditches, or any temporary waterway constructed by the Contractor to build the project. General and/or specific permits may be attached part of the special provisions shown in the plan. Some individual or specific permits may include requirements in addition to what is required under the general NPDES Permit.
Figure 832 J - Temporary Channel
Temporary Channel
1. Temporary channels require stabilization with rock channel protection, Item 670 Erosion Protection or a stand of grass at least 70% established.
2. Temporary channels are required to be stabilized before any flow is diverted into the channel.
Causeways and Access Fills (Stream and River Crossings and Fills) (SS 832.09).
Equipment can cross a waterway only by means of a permitted crossing or causeway. Regulatory permits are required prior to any disturbance to the waterway. Place Stream or River Crossings (Causeways) as outlined below and date the placement on the SWPPP.
Figure 832 K - Stream Crossing
1. Ensure the causeway is a height of 1 foot (.3m) above the normal water elevation per standard construction drawing DM-5.1.
2. The causeway should be as narrow as practical to provide for passage of the equipment while preventing the movement of any fill into the water.
3. Furnish culvert pipes if filling more than one-third of the waterway per standard construction drawing DM-5.1.
4. The minimum culvert size is 18 inches (0.5 m) or 2 times the normal depth, whichever is greater.
5. The maximum spacing between culverts is 10 feet (3m).
6. Only clean dump rock (non-erodible fill) should be used in the waterway.
7. Furnish 50 feet (15m) approach drive of dump rock (non-erodible fill) on both sides of the causeway.
8. Furnish a flow diversion dike in the approach drive.
Causeways and Access Fills Construction and Payment (SS 832.10).
Typically Causeways and Access Fill environmental protection costs are incidental to the work contained within the 404/401permit boundary. In some cases, Causeways and Access Fills are paid as a separate item. It is important to note that all environmental controls within the 404/401 permit boundary are incidental to the work conducted within that boundary. The Sediment and Erosion Control Prices (832.17) should not be used as compensation when BMPs are installed within the 404/401 permit boundary.
Figure 832.11 L - Required Maintenance
Maintenance (SS 832.11).
1. The Contractor is required to maintain all TSEC BMP throughout its functional life on the project.
2. All TSEC BMP are required to be sized and designed to withstand a minimum ½ inch rainfall event.
3. The cost for maintaining TSEC BMP is included in the price paid per unit of BMP (See SS832.16). Compensation is provided for TSEC BMP replacement and or repair required as a result of a rainfall event greater than ½ inch. The Contractor is required to inspect, record and report all impacts to the TSEC BMPs that require maintenance and/or replacement. TSEC BMP must be inspected within 24 hours of a ½ inch rainfall event.
4. Sediment that accumulates at the TSEC BMP requires removal and proper disposal as part of the Contractor’s responsibility for maintenance. Safeguards must be in place to prevent the release of sediment into waters of the state during the BMP maintenance effort. Disposal of accumulated sediment must be compliant with C&MS 107.19.
5. Routine maintenance and repair of TSEC BMP is required to be conducted within 3 days of the inspection which identified the need. Sediment settling ponds must be repaired and or maintained within 10 days of the inspection. If deficiencies or violations have been identified on site, the Contractor is required to correct and mitigate the conditions within 48 hours of notification by the Department or regulatory agency SS832.05.G.
6. TSEC BMP should not be removed until the Earth Disturbing Activity has been completed and a “uniform perennial vegetative cover with a density of at least 70% has been established” on all unpaved areas. If silt fence is removed to accommodate the final grading and seeding operation it should be replaced after the work is (sequentially) completed, or other BMPs should be installed to provide appropriate control. OEPA recommends the installation of sediment basins down gradient as an appropriate control measure when perimeter controls are removed for final grading and seeding.
TSEC BMP Maintenance Requirements
Routine maintenance on TSEC BMP is required when repairs are needed and when:
1. Rock Ditch Checks have sediment covering ½ the height of the rock.
2. Perimeter Filter Fabric Fence, Filter Fabric Ditch Checks and/or Inlet Protection have sediment covering ½ the height of the fabric.
3.
4. Bale Filter Dikes have sediment covering ½ the height of the bale.
5. Erosion Control Mats require replacement when they are torn and or displaced.
6. Construction Seeding and Mulching has been displaced and re-application is needed.
Permanent stabilization must be achieved before the project is accepted. Once the project is “permanently stabilized” see SS832 Appendix G, Part VII.H all TSEC BMP must be removed and resulting debris disposed of appropriately.
Storm Water Pollution Prevention Plan (SS 832.12).
1.
The Department requires that the SWPPP be designed by
an Engineer (P.E.) that has attended and completed the CPESC Exam Review
Course. The effective date of the CPESC
training requirement is
2. The SWPPP must show the location of the TSEC BMP for all areas with EDA related to the project. This includes borrow, waste, staging and storage areas that experience EDA.
3. It is important that the SWPPP identify the watersheds and the area disturbed by the construction in each watershed (SS 832.12 G). This provides the project and Contractor with the location of all drainage outlets from the project. This information is helpful in conducting appropriate inspections (see SS 832.14 below).
4. If the Contractor is proposing BMPs other than those identified on the standard BMP pricing schedule, the SWPPP needs to describe the proposed BMPs for the Engineers approval particularly if compensation is a consideration.
SWPPP Acceptance (SS 832.13).
The intent of “acceptance” is to determine if the SWPPP developed by the Contractor is a reasonable reflection of the site conditions and identifies reasonable controls that will uphold compliance with the NPDES permit. Acceptance is not regulatory approval. If the SWPPP is accepted, the department is recognizing that the Contractor has developed what appears to be an appropriate plan to comply with NPDES. Sections A through G of Part III in the NPDES permit is a checklist that identifies the minimum SWPPP elements that the Contractor must have on his plan. If the SWPPP is not accepted by the project and the Contractor is requesting assistance from the project to develop an acceptable SWPPP, guidelines are available in the form of a checklist from OEPA. The checklist is titled: SWPPP Checklist for Construction Activities and it can be found at: http://www.epa.state.oh.us/dsw/storm/construction_index.html. Project staff can and should make recommendations to the Contractor to facilitate permit compliance. It is important to note that the Contractor’s responsibility and liability related to NPDES compliance is reduced when he is directed to perform compliance work by the department. The Contractor is required to tailor his operation in such a way to comply with the NPDES permit. The underlying point is that the purpose of this submittal is to demonstrate compliance with the contract documents. If the contractor intends on using the submittal as a mechanism to alter the contract requirements, he is required to “prominently call attention to the proposed deviation from the contract in the submittal.
Inspections and Updates (SS 832.14).
Inspections are a requirement of the SWPPP. The NPDES permit requires that all controls (BMPs) on the site are inspected at least once every 7 calendar days and within 24 hours of any storm event greater than one-half inch as per SS832 Appendix E part III.G.2.i. It is important that the inspection specifically include all discharge locations. If erosion is occurring or sediment is accumulating at a discharge location along the boundary of the project, immediate action needs to be taken to document and correct the problem. For situations where off site sediment is mixing with surface water from the project, care should be taken to separate the flows and divert the off site water away from the site (when possible). In many instances the separation and diversion of off site surface water is not possible. In these cases the contractor should monitor the in-coming surface water and document the conditions as part of the routine inspection effort. In the event that OEPA or others identify an NPDES permit violation, the remedy and/or corrective action can be identified and implemented quickly and additional enforcement actions can often time be avoided.
OEPA refers to the SWPPP as a “living breathing document”. The intent of the SWPPP requirement of the permit is to plan the work in advance and incorporate the BMPs in such a way that prevents the discharge of pollutants to waters of the state. The permit requires that the SWPPP be kept current with the site conditions and document the addition removal and maintenance of the BMPs on the SWPPP see SS832 Appendix E, part III.D. The Department requires that the contractor perform the required inspections. The inspector must be CPESC Trained. When modifications to the SWPPP are needed the inspector is required to get approval of the SWPPP design Engineer. The SWPPP design Engineer approval is documented as part of the routine inspection report provided to the project at least monthly. The Contractor’s Erosion Control Inspector is required to provide the project with a weekly certification that the site is compliant with the permit. If the project is not receiving the weekly certifications SS 832.05 should be enforced and the Contractor should be notified in writing. The certification requirement provides the project with the ability to track compliance issues and stay current with the required documentation.
Documentation Requirements – SS 832 Temporary Sediment and Erosion Controls
Documentation requirements include the entries in the “Inspector’s Daily Reports” that reflect the inspectors observations relative to the sediment and erosion control compliance of the site.