280TEMPORARY EROSION AND SEDIMENT CONTROL

Temporary Erosion and Sediment Control Art. 280.03 127 EROSION CONTROL

280.01Description. This work shall consist of constructing, maintaining,

removing, and disposing of temporary erosion control systems.

280.02Materials. Materials shall be according to the following

Item Article/Section

CONSTRUCTION REQUIREMENTS

280.03General. The Contractor shall name a person at the preconstruction

meeting who shall be on the jobsite during construction and who shall be responsible for ensuring the erosion control work is completed in a timely manner.

The Contractor and the Department shall schedule and conduct a jobsite inspection to review and designate the locations and types of erosion control systems to be placed. This inspection shall be conducted prior to beginning any work which will disturb existing drainage or require erosion control.

Erosion control systems shall be installed prior to beginning any activities which will potentially create erodible conditions. Erosion control systems for areas outside the limits of construction such as storage sites, plant sites, waste sites, haul roads, and Contractor furnished borrow sites shall be installed prior to beginning soil disturbing activities at each area. These offsite systems shall be designed by the Contractor and be subject to the approval of the Engineer.

The temporary erosion and sediment control systems shown on the plans represent the minimum systems anticipated for the project. Conditions created by the Contractor’s operations, or for the Contractor’s convenience, which are not covered by the plans, shall be protected as directed by the Engineer at no additional cost to the Department. Revisions or modifications of the erosion and sediment control systems shall have the Engineer’s written approval.

Art. 280.03 Temporary Erosion and Sediment Control 128 Work shall be coordinated such that no more than a total of 10 acres (4 hectares) are disturbed at a time. Completed slopes shall be seeded and mulched as the excavation proceeds to the extent considered desirable and practical. Permanent seeding shall be used whenever possible. Under no circumstances shall the Contractor prolong final grading and shaping so that the entire project can be permanently seeded at one time.

Temporary erosion control systems shall be coordinated with the permanent erosion control features to ensure economical, effective, and continuous erosion control. Work shall also be coordinated such that permanent erosion control features and seeding are not damaged; and repeated disturbances of temporary erosion control systems are kept to a minimum.

280.04Temporary Erosion Control Systems. Temporary erosion control

systems shall be constructed as shown on the plans and, where appropriate, according to the manufacturer’s specifications. Specific requirements for the various types of systems shall be as follows.

temporary ditch checks to prevent siltation, erosion, or scour of ditches and drainage ways. Temporary ditch checks shall be constructed with products from the Department’s qualified product list, rolled excelsior, or with aggregate placed on filter fabric when specified. Filter fabric shall be installed according to the requirements of Section 282. Riprap shall be placed according to Article 281.04. Manufactured ditch checks shall be installed according to the manufacturer’s specifications. Spacing of ditch checks shall be such that the low point in the center of one ditch check is at the same elevation as the base of the ditch check immediately upstream. Temporary ditch checks shall be sufficiently long enough that the top of the device in the middle of the ditch is 6 in. (150 mm) lower than the bottom of the terminating ends of the ditch side slopes.

When rolled excelsior is used, each ditch check shall be installed and maintained such that the device is no less than 10 in. (250 mm) high at the point of overflow. Units installed at a spacing requiring a height greater than 10 in. (250 mm) shall be maintained at the height for the spacing at which they were originally installed.

placed adjacent to an area of construction to intercept a sheet flow of water borne silt and sediment and prevent it from leaving the construction area. The barrier shall be constructed with rolled excelsior, silt filter fence, or urethane foam/geotextiles.

inlets or outfalls, and other similar locations as required to intercept waterborne silt and sediment and prevent it from entering the drainage system or exiting the construction area. The protection shall be constructed with hay or straw bales, silt filter fence, above grade inlet filters (fitted and non-fitted), or inlet filters.

Temporary Erosion and Sediment Control Art. 280.05 129 When above grade inlet filters (fitted and non-fitted) are specified, they shall be of sufficient size to completely span and enclose the inlet structure. Prior to ordering materials, the Contractor shall determine the size of the various drainage structures being protected.

When inlet filters are specified, they shall be installed either directly on the drainage structure or under the grate of the drainage structure resting on the lip of the frame. The fabric bag shall hang down into the drainage structure. Prior to ordering materials, the Contractor shall determine the size and shape of the various drainage structures being protected.

temporary basins at pipe inlets or outfalls, in ditches, and in drainageways to capture water borne silt and prevent it from exiting the construction area. The outfall of these basins is usually protected by perimeter erosion barrier to capture remaining silt.

to intercept water borne silt and runoff.

erodible/bare areas to minimize the amount of exposed surface area. Seed bed preparation will not be required if the surface of the soil is uniformly smooth and in a loose condition. Light disking shall be done if the soil is hard packed or caked. Erosion rills greater than 1 in. (25 mm) in depth shall be filled and area blended with the surrounding soil. Fertilizer nutrients will not be required.

The original seed bags shall be opened in the presence of the Engineer. The seed shall be applied by hand broadcasting to achieve a reasonably uniform coverage at a rate of 100 lb/acre (110 kg/ha). Seed shall be applied to all bare areas every seven days, regardless of weather conditions or progress of the work. The Engineer may require that critical locations be seeded immediately, and the Contractor shall seed these areas within 48 hours of such a directive.

over designated areas to prevent sheet erosion of areas that are to be altered during a later construction phase. The temporary mulch cover shall be installed according to Article 251.03, except for any reference to seeding.

installing erosion control blanket or heavy duty erosion control blanket over areas that are to be reworked during a later construction phase. Work shall be according to Article 251.04, except references to seeding and fertilizer shall not apply. When an area is to be reworked more than once, the blanket shall be carefully removed, properly stored, and then reinstalled over the same area.

280.05Maintenance. The temporary erosion control systems shall be

properly maintained as directed by the Engineer to control siltation. This work shall include repair of the various systems, removal of trapped sediment, and cleaning of

Art. 280.06 Temporary Erosion and Sediment Control 130 any silt filter fabric. Accumulated silt in sediment basins shall be removed when the basin becomes 75 percent filled. Trapped sediment and accumulated silt shall be disposed of according to Article 202.03.

280.06Disposal. All temporary erosion control systems shall be removed at

the direction of the Engineer and be disposed of according to Article 202.03.

280.07Method of Measurement. This work will be measured for payment

according to the following.

sediment basins and temporary ditches will be measured for payment in place and the volume computed in cubic yards (cubic meters).

The aggregate used for sediment basins will be measured for payment in tons (metric tons).

long axis of the device in place in feet (meters), except for aggregate ditch checks which will be measured for payment in tons (metric tons). Payment will not be made for aggregate in excess of 108 percent of the amount specified by the Engineer.

in feet (meters).

individual items and the unit of measurement will be each.

payment in pounds (kilograms) of seed applied.

Article 251.06(b).

payment in place in square yards (square meters) of actual surface covered.

Temporary erosion control measures and work ordered by the Engineer due to the Contractor’s carelessness or failure to install permanent controls will not be measured for payment.

Temporary or permanent erosion control systems required for areas outside the limits of construction will not be measured for payment.

280.08Basis of Payment. . This work will be paid for according to the

following.

sediment basins and temporary ditches will be paid for at the contract unit price per cubic yard (cubic meter) for EARTH EXCAVATION FOR EROSION CONTROL.

Riprap Art. 281.02 131

The aggregate used for sediment basins will be paid for at the contract unit price per ton (metric ton) for AGGREGATE (EROSION CONTROL).

per foot (meter) for TEMPORARY DITCH CHECKS, except for aggregate ditch checks which will be paid for at the contract unit price per ton (metric ton) for AGGREGATE DITCH CHECKS.

price per foot (meter) for PERIMETER EROSION BARRIER.

per each for INLET AND PIPE PROTECTION.

Protection of drainage structures with inlet filters will be paid for at the contract unit price per each for INLET FILTERS.

contract unit price per pound (kilogram) for TEMPORARY EROSION CONTROL SEEDING.

Article 251.07.

be paid for at the contract unit price per square yard (square meter) for TEMPORARY EROSION CONTROL BLANKET or TEMPORARY HEAVY DUTY EROSION CONTROL BLANKET.

The work of removing, storing, and reinstalling the blanket over areas to be reworked more than once will not be paid for separately but shall be included in the cost of the temporary erosion control blanket or temporary heavy duty erosion control blanket.

SECTION 281. RIPRAP

281.01Description. This work shall consist of furnishing and placing bedding

material, a protective course of stone or broken concrete laid as riprap for erosion protection or sediment control.

281.02Materials. Materials shall be according to the following

Item Article/Section

CONSTRUCTION REQUIREMENTS