- 682 - SECTION 810 -- EROSION CONTROL
810.01 Description
1.This work consists of the pr eparation of slopes and waterways and the furnishing and application of soil retention blankets at the locations shown in the contract or the temporar y erosion control plan, or as directed by the Engineer. Seed and fertilizer ar e not required with Erosion Control “Class 1A” (Slope Protection Netting).
810.02 Material Requirements
1.The soil retention blanket shall be of the type specified in the contract and shall be on the Depa rtment’s Approved Products List.
2.Soil retention blankets used in a temporary capacity shall be any product designated on the Department’s Approved Products list as Erosion Control “Class 1”.
3.Wire staples used for anchoring the soil retention blanket shall be from products designated on the Depart ment’s Approved Products List.
4.The seed shall comply with and be applied in accordance with the applicable portion of Section 801. The s eed mixture shall be of the types and applied at the rate shown in the contract.
5.The fertilizer shall comply with the applicable portion of Section 804.
810.03 Construction Methods
1.This work shall be performed as soon as practicable after finish grading operations have been completed or as directed by the Engineer.
2.No restrictive seeding time periods will apply to this work.
3.Site Preparation:
a.The Contractor shall fill, tamp and shape earth to the finish grade as needed to repair erosion to the grades and conditions shown in the contract.
b.If additional fill dirt is r equired, it must be provided and placed at no additional cost to the Department.
c.The Contractor shall perfor m all work in the areas to be protected so that the land surface is graded smooth and free of all debris, including roots and stones larger than 1 inch (25 mm) in their largest dimension.
d.Vegetation shall be removed from these areas except for the desirable native vegetation that has been designated by the Engineer to remain undisturbed.
e.The soil in the areas to be protected by the soil retention blanket shall be loosened to a depth of not less than 1 inch (25 mm) by discing, harrowing, raking, or other approved methods.
f.The site shall be drill seeded and fertilized prior to the installation of the soil retention blanket. In the event that it is impractical to install seed or fertilizer by mechanical means due to safety concerns, size or accessibility of the location, the seed and/or fertilizer may be installed by manually broadcasting and lightly incorporating the seed into the soil in a uniform manner. Erosion Control 810.03 - 683 - 5. Covercrop Seed may be used in conjunction with soil retention blankets used in a temporary capacity. Seeding rates shall be as shown in Section 802 of the St andard Specifications.
6.The fertilizer shall be applied prior to seeding and incorporated into the soil in accordance with Section 804.
a.The fertilizer shall be of the types and applied at the rate shown in the special provisions.
b.Fertilizer is not required for soil retention blankets being used in a temporary capacity.
c.No fertilizer shall be used wi th 50 feet from a wetland, lakes or streams.
7.The Contractor shall obtain t he Engineer's approval of all soil preparation work, fertilizer, and seed prior to the installation of the soil retention blanket.
8.Placement: a. Upon obtaining the Engineer’s approval of the soil preparation, the Contractor shall place the soil re tention blankets immediately following fertilizing and seeding operations.
b.The blanket shall be laid out flat, parallel to the surface runoff flow direction, and secured as shown in t he contract for each specific type of erosion control. Wire staples shall be used for anchoring the soil retention blanket.
c.The Contractor shall place Erosion Control “Class 1A” (Slope Protection Netting) immediately after the mulch or slope protection has been applied and anchored as per the specif ication for the mulching or slope protection operations.
d.The Erosion Control “Class 1A” (Slope Protection Netting) shall be installed as shown in the Standard Plans for Erosion Control.
e.Care shall be exercised in placing the blanket so as not to disturb previously seeded areas.
9.Erosion Control “Class 2C” a. The area designated to be covered with Erosion Control “Class 2C” shall be shaped and graded as per the contract.
b.Place the Erosion Control “Class 2C” soil retention blanket over the area and trench edges into t he soil as specified in the contract.
c.When placement is at a culvert location, cut a hole in the blanket for the culvert opening.
d.Seed and fertilize the area and soil fill with approximately 1/2 inch (12 mm) of soil, raki ng it into the material.
e.When items a. through d. above are completed to the satisfaction of the Engineer, the area shall be overlain with a soil retention blanket from the Department’s Approved Products List under the item, Erosion Control “Class 1F”. The Erosion Control “Class 1F” shall be pinned in place.
810.03 Erosion Control
- 684 - f. The installation of Erosion Control “Class 1F” as a component of the Class 2C System is considered subsidiary to the Erosion Control “Class 2C”.
810.04 Method of Measurement
1.Erosion control areas are measured by the square yard (square meter).
2.The areas are computed by multiplying the length times the nominal width at each location shown in the contract.
810.05 Basis of Payment
1.P a y I t e m P a y U n i t Erosion Control, Class_____ Square Yard (SY) [Square Meter (m2)] Temporary Erosion Control Blanket Square Yard (SY) [Square Meter (m2)]
2.Payment is full compensation for all work described in this Section. - 685 - SECTION 811 -- TRANSITION MAT
811.01 Description
1.This work consists of the fu rnishing and installation of transition mats as shown in the contract or as directed by the Engineer. A transition mat is a semi-rigid plastic, rubber mat or concrete blocks imbedded into a high strength geogrid that protects t he soil from scour and erosion. It is placed in ditches or at the culvert outlets and is generally used in conjunction with a soil retention blanket.
811.02 Material Requirements
1.The Transition Mat shall be lis ted on the Department’s Approved Products List.
2.Erosion Control Class 2A is required under all installations.
811.03 Construction Methods
1.This work shall be performed as soon as possible after the finish grading operations have been completed.
2.The Contractor shall install the soil retention blanket as detailed in
3.The transition mat shall be placed as per the manufacturers recommended installation instructions at the locations as shown in the contract.
811.04 Method of Measurement
1.The quantity of transition mat fo r which payment will be made will be the number of square yards placed.
2.Sod placed will be paid for according to Section 809 – Sodding. 3. Soil retention blankets placed will be paid for according to
811.05 Basis of Payment
1.P a y I t e m P a y U n i t Transition Mat Square Yard
2.All anchoring devices shall be s ubsidiary to the item “Transition Mat”.
3.Payment is full compensation for all work described in this Section.
Source: Nebraska Standard Specifications for Highway Construction, 2017 Edition. Pages 716–718 of 1,048.