Corpus sync: neutrality remakes, note hygiene, datasheet relocation, transformer-split cross-refs
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title: Erosion and Sediment Control
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## In 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.
−## 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. {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.
## The Contractor shall coordinate work under this standard with [[sync/earthwork]] for grading sequence, soil stockpile protection, and construction dewatering; with [[sync/storm-drainage]] for inlet protection and protection of the installed storm system from construction sediment; with [[sync/asphalt-paving]] for removal of temporary controls before final paving; and with [[sync/landscape-irrigation]] for the transition from temporary stabilization to permanent vegetation.
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### 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. {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. {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.
# Erosion Control Measures {toc}
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### Temporary seed shall be applied at the rate specified in the seeding plan and protected with mulch or a tackifier until germination.
−### 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. {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.
## Permanent Seeding and Hydroseeding {toc}
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### 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. {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. {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.
## Silt Fence Installation {toc}
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### Inlet protection shall be inspected after every qualifying rain event and the captured sediment removed when it reaches half the device capacity.
−### 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. {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.
## Sediment Traps and Sediment Basins {toc}
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```
−### 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. {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.
### Sediment 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.
### A 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.
−### 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. {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.
## Check Dams {toc}
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## Concrete Washout {toc}
−### 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. {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.
```datasheet
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## The warranty does not relieve the Contractor of responsibility for any sediment discharge or permit violation occurring during the construction period and before permit termination.