From Engineering Policy Guide
Construction Inspection Guidance for Sec 802
Description (Sec 802.1)
Mulch is a temporary treatment, and is used to prevent erosion of the ditch until permanent vegetation is established. 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 ditch protection and is used in all ditches where sod, rock ditch liner, erosion control blankets or paving are not used.
Material (Sec 802.2)
The contractor shall provide a written certification that the mulch is in compliance with the specification.
Mulch Overspray (Sec 802.2.2)
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 802.3)
All seeded areas are mulched.
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.
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 802.4)
Mulch is incidental to the seeding contract bid item.
Basis of Payment (Sec 802.5)
The contractor is responsible for proper plant density. If a lack of a stand is due to sheet and rill damage, the repairs are 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.