MN CSW Permit Section 5 Stormwater Pollution Prevention Plan (SWPPP) Content MN CSW Permit Section 5 Stormwater Pollution Prevention Plan (SWPPP) Content

SECTION 5 STORMWATER POLLUTION PREVENTION PLAN (SWPPP) CONTENT

5.1

Stormwater Pollution Prevention Plan (SWPPP) Content.

5.2

The owner must develop and implement a SWPPP. The SWPPP must include items 5.3 through 5.26.

5.3

The SWPPP must incorporate specific Best Management Practices (BMP) used to comply with the requirements of this permit.

5.4

The SWPPP must include a narrative describing the timing for installation of all erosion prevention and sediment control BMPs and a description of the permanent stormwater treatment systems.

5.5

The SWPPP must include the location and type of all temporary and permanent erosion prevention and sediment control BMPs along with procedures used to establish additional temporary BMPs as necessary for the site conditions during construction. Standard details and/or specifications for BMPs must be included in the final plans and specifications for the project.

5.6

The SWPPP must include the calculations and other information used for the design of temporary sediment basins and any of the permanent stormwater treatment systems required in Section 15.

5.7

The SWPPP must include estimated quantities anticipated at the start of the project for the life of the project for all erosion prevention and sediment control BMPs (e.g., linear feet of silt fence or square feet of erosion control blanket).

5.8

The SWPPP must include the number of acres of impervious surface for both pre- and post-construction.

5.9

The SWPPP must include a site map with existing and final grades, including drainage area boundaries, directions of flow and all discharge points where stormwater is leaving the site or entering a surface water. The site map must indicate the areas of steep slopes. The site map must also include impervious surfaces, soil types and locations of potential pollutant-generating activities as identified in Section 12.

5.10

The SWPPP must include a map of all surface waters, existing wetlands, and stormwater ponds or basins that can be identified on maps such as United States Geological Survey 7.5 minute quadrangle maps, the National Wetland Inventory map or equivalent maps and are within one mile (aerial radius measurement) from the project boundaries that will receive stormwater from the construction site, during or after construction. The SWPPP must identify if the surface waters are special or impaired waters.

5.11

The SWPPP must include a site map showing construction activity areas that are adjacent to and drain to Public Waters for which the DNR has promulgated "work in water restrictions" during specified fish spawning time frames.

5.12

Permittees must identify locations of 50' buffer zones as required in item 9.17 and 100' permanent buffer zones as required in item 23.11, on plan sheets in the SWPPP.

5.13

If permittees determine compliance with the following requirements is infeasible, they must document the determination in the SWPPP:

a. temporary sediment basins as described in Section 14; and

b. for linear projects, if the permanent stormwater treatment system cannot be constructed within the right-of-way, a reasonable attempt must be made to obtain additional right-of-way (item 15.9); and

c. buffer zones as described in item 9.17 and item 23.11.

5.14

If permittees determine that a temporary sediment basin is infeasible as described in item 14.10, the SWPPP must describe the alternative BMPs used.

5.15

Where systems cannot meet the full volume reduction requirement on site, (e.g., the site has infiltration prohibitions, see item 16.14 through item 16.21) the permittee must document the reasons in the SWPPP.

5.16

The SWPPP must include any stormwater mitigation measures proposed to be part of the final project in any environmental review document, endangered species review, archeological or other required local, state or federal review conducted for the project. For purposes of this permit, mitigation measures means actions necessary to avoid, minimize, or mitigate for impacts related to erosion prevention, sediment control, the permanent stormwater treatment system, pollution prevention management measures and discharges associated with the project's construction activity.

5.17

The SWPPP must describe the methods used for permanent cover of all exposed soil areas.

5.18

Permittees must identify the locations of areas where construction will be phased to minimize the duration of exposed soil areas in the SWPPP.

5.19

For projects with a discharge point on the project within one (1) mile (aerial radius measurement) of and which flows to an impaired water, permittees must identify the impaired water(s), and any United States Environmental Protection Agency (USEPA)-approved Total Maximum Daily Load (TMDL) for the pollutant(s) or stressor(s) described in item 23.7. Permittees' identification must include those TMDLs approved at any time prior to permit application submittal and are still in effect.

5.20

Permittees must document in the SWPPP, all trained individuals identified in item 21.2. Documentation must include:

a. names of personnel required to be trained; and

b. dates of training and name of instructor(s) and entity providing training; and

c. content of training course.

If permittees do not know the names of the individuals at the time of application, the permittees must ensure they document training before construction activity commences.

5.21

The SWPPP must identify a person knowledgeable and experienced in the application of erosion prevention and sediment control BMPs who will coordinate with all contractors, subcontractors, and operators on-site to oversee the implementation of the SWPPP.

5.22

The SWPPP must describe any specific chemicals and chemical treatment systems used for enhancing the sedimentation process and how it achieves compliance with item 9.18.

5.23

The SWPPP must identify the person(s), organizations, or entities responsible for long-term operation and maintenance of permanent stormwater treatment systems.

5.24

The SWPPP must describe methods to minimize soil compaction and preserve topsoil. Minimizing soil compaction is not required where the function of a specific area dictates compaction.

5.25

The SWPPP must include any site assessments for groundwater or soil contamination required in item 16.15.

5.26

The SWPPP must account for the following factors in designing temporary erosion prevention and sediment control BMPs:

a. the expected amount, frequency, intensity, and duration of precipitation; and

b. the nature of stormwater runoff and run-on at the site, including factors such as expected flow from impervious surfaces, slopes, and site drainage features; and

c. the stormwater volume, velocity, and peak flowrates to minimize discharge of pollutants in stormwater and to minimize channel and streambank erosion and scour in the immediate vicinity of discharge points; and

d. the range of soil particle sizes expected to be present.