5.4.1 You must include in your SWPPP, and update when necessary, the dates when
major grading activities occur, when construction activities temporarily or
permanently cease on a portion of the site, and when stabilization measures are
initiated.
5.4.2 You must achieve Final Stabilization prior to filing a Notice of Termination in
accordance with Part 7.1
or the expiration of coverage under this, or a
subsequent, generic permit.
5.5 Do I have to use Structural Practices?
You must use controls to accomplish the following:
5.5.1 As necessary to prevent violations of water quality or offsite sedimentation, you
must divert flows from exposed soils, store flows, retain sediment on site, or
otherwise limit runoff and the discharge of pollutants from exposed areas of the
site.
5.5.2 Structural practices to prevent violations of water quality or offsite sedimentation,
which may include the following: silt fences, earth dikes, diversions, swales,
sediment traps, check dams, subsurface drains, pipe slope drains, level
spreaders, storm drain inlet protection, rock outlet protection, reinforced soil
retaining systems, gabions, coagulating agents, and temporary or permanent
sediment basins.
5.5.3 Silt fences or equivalent structural controls are required for all side slope and
down slope boundaries of the construction area.
5.5.4 Structural best management practices must be placed on upland soils unless a
State of Florida environmental resource permit
issued pursuant to Chapter 373,
F.S., or applicable regulations of the DEP or WMD otherwise authorize.
5.6 What requirements apply to sediment basins?
If you have 10 or more disturbed acres on your site, the following design requirements
shall be met:
• For drainage basins with 10 or more disturbed acres at one time, a
temporary (or permanent) sediment or wet detention basin providing
3,600 cubic feet of storage per acre drained must be provided until final
stabilization of the site. The 3,600 cubic feet of storage area per acre
drained does not apply to flows from off-site areas and flows from on-
site areas that are either undisturbed or have undergone final
stabilization where such flows are diverted around both the disturbed
area and the sediment basin.
• For drainage basins with 10 or more disturbed acres at one time and
where a temporary sediment basin providing 3,600 cubic feet of storage
per acre drained is not attainable, a combination of smaller sediment
basins, sediment traps, wet detention systems, or other best
management practices must be used.
5.6.1 For drainage basins of less than 10 disturbed acres, sediment basins and
sediment traps are recommended but not required.
5.6.2 Areas that will be used for permanent stormwater infiltration treatment (e.g.,
stormwater retention basins) should not be used for temporary sediment basins
unless appropriate measures are taken to assure removal of accumulated fine
sediments, to avoid excessive compaction of soils by construction machinery or
equipment, and to assure that the design infiltration capacity is met.