Category:802 Mulching

802.1 Design Guidance for Sec 802

Description (Sec 802.1)

Mulch is a vital component to stabilization efforts necessary to establish vegetative cover in disturbed areas. All exposed areas to be seeded shall be covered with mulch, erosion control blanket, in accordance with EPG 806.1.10 Erosion Control Blankets and Turf Reinforcement Mats, or other commercially available products used to facilitate vegetative growth and reduce erosion and sedimentation such as fiber reinforced matrix (FRM) (see EPG 806.1.9 Fiber Reinforced Matrix).

Planned Quantities (Sec 802.1.2)

Areas to be temporary seeded, in accordance with Sec 806, or initial applications of permanent seeding, in accordance with Sec 805, shall be calculated to receive mulch to the nearest 1/10th of an acre. Mulching will not be required for final seeded areas where temporary seeding is planned for temporary stabilization of areas to receive warm season grasses.

802.2 Construction Inspection Guidance for Sec 802

Description (Sec 802.2.1)

Mulch is a temporary ground cover treatment that provides multiple benefits to vegetation establishment. Mulching is applied to check erosion, preserve moisture, and moderate soil temperatures. Reducing the impact of rain is a significant factor in checking erosion. Mulch is the default type of ground cover protection and is used in all disturbed areas where sod, rock ditch liner, erosion control blankets, paving, or other permanent building materials are not used.

Material (Sec 802.2.2)

Vegetative Mulch (Sec 802.2.2.1)

The contractor shall provide a written certification that the mulch is in compliance with the specification.

Mulch Overspray (Sec 802.2.2.2)

The contractor shall provide a manufacturer’s certification that the overspray is in compliance with the specifications.

Mulch Overspray acceptance shall be by certification. The certification shall state that mulch overspray meets standard specifications and complies with contract requirements.

Construction Requirements (Sec 802.2.3)

All seeded areas are mulched in conjunction with the initial application of temporary and permanent seeding.

Proper application of mulch is critical keeping in mind that there is no constant relationship between weight and thickness. If the application is too light, the ground becomes susceptible to erosion and the lack of mulch would allow moisture necessary for plant growth to escape. If it is too heavy, the mulch will choke out any native plant species sowed. A lighter mulch application may be sufficient for moisture retention purposes on flat grades where erosion due to runoff is a minor threat. Slopes should have the specified applied rate. In areas more susceptible to runoff erosion, the contractor might elect to use a blanket to minimize erosion to control runoff damage while providing seed with a protective cover.

Acceptance

Areas where mulch has blown away usually identify a potential seeding failure. The contractor is responsible for the proper density of plants. Attention is warranted in the areas with thin mulch cover.

Method of Measurement (Sec 802.2.4)

Mulch is measured to the 1/10th of an acre. Areas with vegetative cover from temporary seeding in warm season grass areas will not require mulching unless excessive bare areas exist with no vegetative cover or areas where original mulch no longer exists.

Basis of Payment (Sec 802.2.5)

Mulch is paid at the contract unit price. The contractor is responsible to maintain mulch prior to acceptance, and for proper plant density. Areas that require mulch during overseeding operations due to lack of temporary vegetative growth or original mulch application shall be the responsibility of the contractor. If gully washouts are created by linear flow from outside the seeded areas, the contractor is not responsible for damage.