- 686 - SECTION 812 -- SILT CHECKS
812.01 Description
1.This work consists of furnishi ng and placing silt check devices at the locations shown in the contract or as directed by the Engineer.
2.There are two separate and di stinct types of silt checks.
a.Silt Checks are placed as show n in the contract or as directed by the Engineer after final grading is complete in conjunction with the final stabilization.
b.Temporary Silt Checks are placed as shown in the Temporary Erosion Control plans or as directed by the Engineer throughout the construction process.
812.02 Material Requirements
1.Approved silt check devices are listed in and shall be selected from the Department’s Approved Products List.
a.Silt Checks used for final stabilization shall be the type shown in the contract and selected from the Department’s Approved Products List.
b.Temporary Silt Checks ma y be any product listed on the Department’s Approved Products List. T he following chart shall be used to determine the appropriate application of Temporary Silt Checks during construction. Type Material Ditch Grade Uses/Locations 1 – Low 9 “ Diameter Straw Wattle < 2% Medians, Slopes and Urban Ditches 1 – High 12” Diameter Straw Wattle < 2% Wetlands, Stream Banks, Slopes and Rural Ditches 2 – Low 9” Diameter Wood Fiber Wattle All Medians and Urban/Rural Ditches 2 - High 12” Diameter Wood Fiber Wattle All Wetlands, Stream Banks, and Rural Ditches 3 – Low 9” Diameter Coir Wattle All Slopes, and Rural Ditches 3 – High 12” Diameter Coir Wattle All Wetlands, Stream Banks, Slopes and Rural Ditches 4 Synthetic All Urban Ditches
2.All silt check devices have uniq ue staking or pinning requirements based upon the Best Management Practices (BMPs) and its use. The hold down stakes and pins shall be as show n on the Silt Check All Types Special Plan.
812.03 Construction Methods
1.The silt checks shall be placed and secured as shown in the contract or as directed by the Engineer.
2.The limits of the completed silt check shall extend up the foreslope and backslope of the ditch to effectiv ely contain the run-off and prevent Silt Checks 812.05 - 687 - erosion and washout at the edges of the installation as shown on the Silt Check All Types Special Plan.
3.Temporary Silt Checks a. The “Temporary Silt Checks” shall be installed at the locations shown in the contract, Temporary Erosion Control Plan or as directed by the Engineer.
b.The “Temporary Silt Checks” shall be installed immediately after the rough grading is completed in an area.
c.Temporary Silt Checks used as perimeter control shall be installed prior to grading operations.
d.The “Temporary Silt Check” shal l be left in place until the finish grading begins. Reinstall the “Temporary Silt Checks” as soon as finish grading is done unless the permanent er osion control is in itiated immediately after finish grading. “Temporary Silt Checks” shall be in place at all times after finish grading until permanent “Silt Check,” are in place.
e.The Temporary Silt Check shall be removed and remain the property of the Contractor when it is no longer functional or needed.
812.04 Method of Measurement
1.All work involved in constructi ng silt checks as described above will be included and paid for per linear feet of devices used in the erosion checks.
2.“Temporary Silt Checks” will be measured by the linear foot (meter) for the initial installation. The removi ng or replacing of the temporary silt checks will not be measured for paymen t, but will be considered subsidiary to the initial installation.
3.Removal of sediment will be measured based on equipment rental. All incidentals associated with the cleanout will be subsidiary to the equipment rental items.
812.05 Basis of Payment
1.P a y I t e m P a y U n i t Silt Check, Type _____ Linear Foot Temporary Silt Check Linear Foot Rental of Skid Loader, Fully Operated Hour Rental of Loader, Fully Operated Hour Rental of Crawler Mounted Hour Hydraulic Excavator, Fully Operated Rental of Dump Truck, Fully Operated Hour Rental of Backhoe, Fully Operated Hour 2. Payment is full compensation for all work described in this Section. - 688 - SECTION 813 -- MULCH PERIMETER CONTROL
813.01 Description
1.This work consists of grinding and placing slash mulch at locations as shown in the contract or as directed by the Engineer.
813.02 Material Requirements
1.All tree and shrub debris, generated during the clearing and grubbing operations, shall be ground by a mechanical chipper, hammermill, tub grinder, or other approved method.
2.Maximum length of individual pieces shall not exceed 20 inches. Maximum width shall not exceed 2 inches. Material shall be accepted based upon a visual inspection.
3.The Contractor shall be responsible for all labor, materials, equipment and services as may be nece ssary for the generation of the slash mulch.
813.03 Construction Methods
1.Slash mulch berms shall be constr ucted prior to grading activities occurring in the locations noted in t he contract or as directed by the Engineer.
2.Mulch may be placed where mulch perimeter control or low porosity silt fence is indicated in the contra ct. The maximum height of the berm shall not exceed 36 inches.
3.Mulch may be placed where silt checks are indicated in the contract. The maximum height of t he berm shall not exceed 24 inches.
4.In the event that the quantity of mulc h generated exceeds the amount necessary to construct the berms shown in the contract, additional berms shall be constructed as an alte rnative to low porosity silt fence or erosion checks at locations approved by the Engineer.
5.In the event that the quantity of mulch gen erated under runs plan quantity, the Contractor shall place what is produced at locations approved by the Engineer. No off project mulch will be required to be furnished by the Contractor.
6.Upon completion of the project, all slash mulch berms shall be left in place or spread out around the area of their original placement.
813.04 Method of Measurement
1.Slash Mulch-Grinding will be measured by the amount produced after grinding in cubic yards.
2.Slash Mulch-Placement will be me asured by the amount placed in cubic yards.
813.05 Basis of Payment
1.P a y I t e m P a y U n i t Slash Mulch-Grinding Cubic Yard (CY) Slash Mulch-Placement Cubic Yard (CY) 2. Stockpiling and rehandling of material is subsidiary to the Slash Mulch-Grinding item.
Source: Nebraska Standard Specifications for Highway Construction, 2017 Edition. Pages 720–721 of 1,048.