Site Map(s) (8.2.3)
Attach one (or more) map(s) that provide, at a minimum, the following information. The map(s) should be prepared so
that all of the required information is clearly displayed and it is clear what BMPs will be installed in each major stage of construction,
including the time between the cessation of active construction and final stabilization. Provide multiple maps as necessary to
clearly describe BMP timing and placement. The scale of the map(s) must be sufficient to identify the location of all the items
listed below:
1. Preconstruction topography and location of surface waters of the state
2. Construction site boundaries.
3. All areas of soil disturbance and areas that are to remain undisturbed.
4. The location of surface waters of the state including any unnamed drainages.
5. Areas used for storage of building materials, soils, wastes, fuel, and concrete washout areas.
6. Locations of all existing or planned temporary or permanent erosion and sedimentation controls.
7. Locations of all other structural and non-structural best management practices for pollutants other than sediment,
including but not limited to, fueling/maintenance areas and concrete washout disposal areas.
8. Site topography or storm water drainage patterns including lines showing boundaries between different
drainage areas in the project area(s).
9. Areas where dedicated support activities (e.g. operations producing earthen materials such as sand and gravel,
staging areas, portable asphalt or concrete batch plants) occur and are to be covered under the same
general permit authorization. Include all the same information requested in this section on these off site maps.
10. Storm water discharge locations. Include discharge locations for offsite operations covered under this permit.
11. North Arrow. Include a legend where needed for clarity.
Best Management Practices (8.2.4)
At a minimum, structural storm water best management practices (BMPs) are expected to withstand and function properly during
precipitation events up to, and including, a 2-year, 24-hour storm event. Visible and measurable erosion (see Part 7.4 of the LCGP)
that leaves the site from such storm events should be minimal. The 2-year, 24-hour event in Wyoming ranges from 0.8 to 2.6 inches.
An isopluvial map of the 2-year, 24-hour storm depth for the state of Wyoming is available on the WDEQ storm water website.
Permittees may substitute equivalent data published by the local municipality or regulatory agency.
The plan shall clearly describe the relationship between the stages of construction and the implementation and maintenance
of controls and measures. For example, which controls will be implemented during each stage of construction, such as,
clearing and grubbing necessary for perimeter controls, initiation of perimeter controls, remaining clearing and grading,
road grading, storm drain installation, final grading, stabilization and removal of control measures.
The description of controls shall address the following minimum components. If the space provided below is inadequate,
please attach additional sheets.
Erosion Prevention BMPs (8.2.4.1a). Clearly describe in detail the storm water erosion control BMPs that will be used at each major
stage of construction. Indicate the location of the described measures on the site map(s) as required above. Examples of erosion
control BMPs include, but are not limited to, preserving existing vegetation, scheduling (i.e., minimizing site disturbance at a
given time), surface roughening, temporary and permanent seeding or planting, soil binders or tackifiers, erosion control
blankets/mats, wind erosion control, storm water diversion practices upslope of a construction site, pipe slope drains and outlet
protection.
