17.48.010 Authority

The provisions contained in this chapter are adopted to comply with the requirements contained in the General Permit for Storm Water Discharge Associated with Small Municipal Separate Storm Sewer System (MS4) issued by the Montana Department of Environmental Quality to the City of Great Falls, most recent edition, and the City of Great Falls Storm Drainage Design Manual, June 1990, as amended.

17.48.020 Legislative findings

The City Commission makes the following findings:

1. During the construction process, soil is highly vulnerable to erosion by wind and water.
2. Sediment can clog drainage systems, increasing maintenance problems and costs.
3. Eroded soil endangers water resources by reducing water quality and causing the siltation of aquatic habitat for fish and other desirable species.
4. Air-borne soil particles diminish air quality and cause related health problems.

17.48.030 Purpose

This chapter is established to promote the public health, safety, and welfare and is intended to accomplish the following purposes:

1. minimize erosion during land development activities
2. minimize water pollution resulting from sediment and associated constituents
3. protect functional values of natural waterbodies and wetlands
4. minimize air pollution from air-borne soil particles
5. safeguard persons, protect property, and prevent damage to the environment in the City

17.48.040 General requirement

Land clearing, except that which is necessary to establish sediment control devices, shall not begin until all sediment control devices, as may be required to comply with this chapter, have been installed and stabilized.

17.48.050 Applicability

1. Generally. The provisions of this chapter apply in the following circumstances:
   1. when one acre or more is disturbed; or
   2. when soils on slopes of 12 percent or more are disturbed, regardless of surface area; or
   3. when 400 cubic yards or more of soil material are placed or moved on or within a site, regardless of surface area.
2. Exemptions. The following activities are exempt:
   1. any emergency activity that is immediately necessary for the protection of life, property, or natural resources
   2. nursery and agricultural operations
3. Director of Public Works. In this Chapter, the term “Director of Public Works” shall refer to the Director of Public Works of the City of Great Falls or his/her designee.

17.48.060 Technical standards and specifications

At the discretion of the Director of Public Works, best management practices (BMPs) shall be based on the design criteria contained in the EPA's Menu of BMPs, which is posted on the EPA’s website. This web-site includes a list of acceptable erosion control practices, including the specific design criteria and operation and maintenance requirements for each. The website may be updated and expanded in the future based on improvements in engineering, science, monitoring, and local maintenance experience. Erosion control practices that are designed and constructed in accordance with these design and sizing criteria will be presumed to meet minimum performance standards.

17.48.070 Design standards

1. Cut and fill slopes. Cut and fill slopes shall be no greater than 2:1, except as approved by the Director of Public Works to meet other community or environmental objectives.
2. Forests and wetlands. Land clearing and grading of natural resources, such as forests and wetlands, shall not be permitted, except as approved by the Director of Public Works, provided such removal is necessary and otherwise consistent with this Title and State and federal regulatory requirements. Land clearing techniques that retain natural vegetation and drainage patterns, as described in EPA’s Menu of BMPs, shall be used to the satisfaction of the Director of Public Works.
3. Erosion control. Erosion control requirements may include the following:
   1. Soil stabilization shall be completed within 15 working days of land clearing or inactivity in construction.
   2. If seeding or another vegetative erosion control method is used, it shall become established within 3 weeks or the Director of Public Works may require the site to be reseeded or a nonvegetative option employed.
   3. Special techniques that meet the design criteria outlined in EPA’s Menu of BMPs on steep slopes or in drainage ways shall be used to ensure stabilization.
   4. Soil stockpiles shall be stabilized or covered at the end of each workday.
   5. At the close of the construction season, the entire site must be stabilized with a heavy mulch layer or another method that does not require germination to control erosion.
   6. Techniques shall be employed to prevent the blowing of dust or sediment from the site.
   7. Techniques that divert upland runoff past disturbed slopes shall be employed.
4. Sediment control. Sediment control requirements may include:
   1. Settling basins, sediment traps, or tanks and perimeter controls.
   2. Settling basins that are designed in a manner that allow adaptation to provide long term stormwater management, if required by the Director of Public Works.
   3. Protection for adjacent properties by the use of a vegetated buffer strip in combination with perimeter controls.
5. Protection of waterbodies. Waterbody protection requirements may include:
   1. A temporary stream crossing shall be installed and approved by the Director of Public Works if a wet watercourse will be crossed regularly during construction.
   2. Stabilization of water channels before, during, and after any in-channel work.
   3. All on-site stormwater conveyance channels designed according to the criteria outlined in the EPA’s Menu of BMPs.
   4. Stabilization adequate to prevent erosion located at the outlets of all pipes and paved channels.
6. Construction site access. Construction site access requirements shall include:
   1. A temporary access road provided at all sites.
   2. Other measures required by the Director of Public Works in order to ensure that sediment is not tracked onto public streets by construction vehicles or washed into storm drains.

17.48.080 Inspection

1. City inspections. The Public Works Department shall make inspections as appropriate to ensure the terms of the approved erosion control plan have been or are being implemented. Plans for grading, stripping, excavating, and filling work bearing the stamp of approval of the City shall be maintained at the site during the progress of the work. To obtain inspections, the permittee shall notify the Public Works Department at least 2 working days before each of the following:
   1. start of construction
   2. installation of sediment and erosion measures
   3. completion of final grading
   4. close of the construction season, in the event of winter shutdown
2. Permitee inspections. The permittee or his/her agent shall make regular inspections of all control measures in accordance with the inspection schedule outlined in the approved erosion control plan. The purpose of such inspections will be to determine the overall effectiveness of the control plan and the need for additional control measures or modification to existing control measures. All inspections shall be documented in writing and submitted to the Public Works Department at the time interval specified in the approved permit.