Stabilization, or establishing ground cover to protect disturbed soils from erosion, is not only a good practice, it is required by law. The Nebraska state Construction General Permit states that, with a few exceptions such as snow cover or frozen ground conditions, “stabilization measures must be initiated as soon as practicable in portions of the site where construction activities have temporarily or permanently ceased, but in no case more than 14 days after the construction activity in that portion of the site has temporarily or permanently ceased.” Since it is unlikely that suitable vegetation can be established within 14 days, other methods of stabilization must be considered. Covering exposed or disturbed areas protects the soil from raindrop impact, slows the flow of and infiltrates stormwater, and protects newly seeded areas. It also helps retain soil moisture, which will help your vegetation become established more quickly.
One of the simplest methods of erosion control is mulching. Straw or hay mulch should be applied at a rate of 2-3 tons per acre. To provide good ground cover, at least 50% of the mulch should be ten inches in length or longer. The mulch should be crimped using a weighted roller that anchors the mulch into the soil. If the area is seeded before the mulch is applied, this can be a very simple and effective method of preventing erosion while vegetation is established.
Another method of erosion control is a rolled erosion control blanket. These can be made from natural or synthetic materials and can be effective in protecting steeper slopes from erosion. They are designed to be rolled onto the area and stapled into place. Always follow installation specifications, as poor installation can cause these products to fail.
If the blanket is not properly anchored and stapled, it can either be washed away or stormwater can wash out soil underneath the blanket, causing small gullies that are difficult to seed. If the area is seeded and the erosion control blanket is installed correctly, grass will grow up through the blanket, and over time, the blanket will degrade.
If you have a stormwater permit (state or local) in your name, it is very important to close out that permit upon completion of a project. As long as that permit is open, you are the responsible party for any stormwater discharges coming from your site. A permit may be closed out under only two circumstances: either final stabilization must be achieved, or the permit must be transferred to another Operator or the Owner.
Under the first circumstance, coverage under a NPDES construction permit may be terminated 180 calendar days after all soil disturbing construction activity has been completed, final stabilization has been achieved, and all temporary BMPs (silt fence, inlet protection, etc.) have been removed. In order for a site to be considered stabilized, any areas that are not impervious (covered by buildings or pavement), must be vegetated with 70% perennial groundcover. Annual vegetation, such as cover crops, do not count as final stabilization. A simple test to see if you have 70% vegetation is to take a 100 foot long tape measure, lay it out over an area that is representative of the whole site, and count how many plants (in most cases blades of grass) coincide with the 1-foot marks. If there are plants at 70 or more of these marks, then you have the required stabilization. After final stabilization has been achieved for 180 calendar days, you may then file a Notice of Termination (NOT) which will terminate your permit coverage.
The alternative method of terminating permit coverage is to transfer the permit to another Operator or the Owner. In order to do this, you must file a Construction Storm Water Notice of Transfer (CSW-Transfer) that lists the current permit authorization number and the portion of the project that is to be transferred. It is possible to retain responsibility for only part of a project, but to transfer a portion of the project to the new owner. The person to whom you are transferring the permit is then required to submit a Notice of Intent (NOI) to the state, and the current permittee may now file an NOT.
There is often some confusion over who is eligible to take over responsibility for a Construction General Permit. The permittee must be either the owner or operator of the site. This means that the general contractor for a project is eligible to hold the permit. If for some reason the general contractor changes during the course of the project, the permit may be transferred to the new Operator. However, subcontractors, such as landscapers, are not allowed to take responsibility for the permit, because they do not meet the definition of “operator” for the project. If a contractor’s portion of a project is complete and they want to terminate their permit coverage before final stabilization is completed, then their only option is to transfer permit coverage to the owner. The new permittee will then be responsible for all inspections and best management practices required by the Construction General Permit.
If you ever have any questions about the permitting process, contact your local stormwater coordinator. Contact information for the ten communities in NebraskaH2O can be found under the Communities tab on this website.