Stabilization Guidelines – NEW for 2012!
NPDES Stormwater Discharge Permit for Construction Activities (NCGO1)
NCDENR/Division of Water Quality
| SITE AREA DESCRIPTION |
STABILIZATION |
TIMEFRAME EXCEPTIONS |
| Perimeter dikes, swales, ditches, slopes |
7 days |
None |
| High Quality Water (HQW) Zones |
7 days |
None |
| Slopes steeper than 3:1 |
7 days |
If slopes are 10’ or less in length and are not steeper than 2:1, 14 days are allowed. |
| Slopes 3:1 or flatter |
14 days |
7 days for slopes greater than 50’ in length. |
| All other areas with slopes flatter than 4:1 |
14 days |
None, except for perimeters and HQW Zones. |
Seedbed Preparation:
- Chisel compacted areas and spread topsoil three inches deep over adverse soil conditions, if available.
- Rip the entire area to six inches deep.
- Remove all loose rock, roots and other obstructions, leaving surface reasonably smooth and uniform.
- Apply agricultural lime, fertilizer and superphosphate uniformly and mix with soil (see mixture below).
- Continue tillage until a well-pulverized, firm, reasonably uniform seedbed is prepared four to six inches deep.
- Seed on a freshly prepared seedbed and cover seed lightly with seeding equipment or cultipack after seeding.
- Mulch immediately after seeding and anchor mulch.
- Inspect all seeded areas and make necessary repairs or reseedings within the planting season, if possible. If stand should be more than 60% damaged, re-establish following the original lime, fertilizer and seeding rates.
- Consult S&EC Environmental Engineers on maintenance treatment and fertilization after permanent cover is established.
Mixture
| Agricultural Limestone |
2 tons/acre (3 tons/acre in clay soils) |
| Fertilizer |
1,000 lbs/acre – 10-10-10 |
| Superphosphate |
500 lbs/acre – 20% analysis |
| Mulch |
2 tons/acre – small grain straw |
| Anchor |
Asphalt emulsion at 300 gals/acre |
Seding Schedule
For Shoulders, Side Ditches, Slopes (Max 3:1):
| Date |
Type |
Planting Rate |
Aug 15–Nov 1 |
Tall Fescue |
300 lbs/acre |
Nov 1–Mar 1 |
Tall Fescue & Abruzzi Rye |
300 lbs/acre |
Mar 1–Apr 15 |
Tall Fescue |
300 lbs/acre |
Apr 15–Jun 30
|
Hulled Common Bermudagrass |
25 lbs/acre
|
Jul 1–Aug 15
|
Tall Fescue AND Browntop Millet or Sorghum-Sudan Hybrids*** |
125 lbs/acre (Tall Fescue); 35 lbs/acre (Browntop Millet); 30 lbs/acre (Sorghum-Sudan Hybrids) |
For Shoulders, Side Ditches, Slopes (3:1 to 2:1):
| Date |
Type |
Planting Rate |
Mar 1–Jun 1 |
Sericea Lespedeza (scarified) and use the following combinations: |
50 lbs/acre (Sericea Lespedeza); |
Mar 1–Apr 15 |
Add Tall Fescue |
120 lbs/acre |
Mar 1–Jun 30 |
Or add Weeping Love grass |
10 lbs/acre |
Mar 1–Jun 30 |
Or add Hulled Common Bermudagrass |
25 lbs/acre |
Jun 1–Sept 1 |
Tall Fescue AND Browntop Mullet or Sorghum-Sudan Hybrids*** |
120 lbs/acre (Tall Fescue); 35 lbs/acre (Browntop Mullet); 30 lbs/acre (Sorghum-Sudan Hybrids) |
Sept 1–Mar 1 |
Sericea Lespedeza (unhulled – unscarified) AND Tall Fescue |
70 lbs/acre (Sericea Lespedeza); 120 lbs/acre (Tall Fescue) |
Nov 1–Mar 1 |
AND Abruzzi Rye |
25 lbs/acre |
Consult S&EC Environmental Engineers for additional information concerning other alternatives for vegetation of denuded areas. The above vegetation rates are those that do well under local conditions; other seeding rate combinations are possible.
*** TEMPORARY: Reseed according to optimum season for desired permanent vegetation. Do not allow temporary cover to grow more than 12" in height before mowing; otherwise, fescue may be shaded out.