§ 11-5. Design requirements.

(a)

Grading, erosion control practices, sediment control practices, and water course crossings shall be adequate to prevent transportation of sediment from the site to the satisfaction of the city engineer.

(b)

Cut and fill slopes shall be no greater than 3:1, except as approved by the city engineer to meet other community or environmental objectives.

(c)

Clearing and grading of natural resources, such as forests and wetlands, shall not be permitted, except when in compliance with all other chapters of this Code.

(d)

Clearing techniques that retain existing vegetation to the maximum extent practicable shall be used and the time period for disturbed areas to be without vegetative cover shall be minimized to the extent practical, to the satisfaction of the city engineer.

(e)

Clearing, except that necessary to establish sediment control devices, shall not begin until all sediment control devices have been installed and have been stabilized.

(f)

Phasing shall be required on all sites disturbing greater than ten acres, with the size of each phase to be established at plan review and as approved by the city engineer.

(g)

Erosion control requirements shall include the following:

(1)

Soil stabilization shall be completed within five days of clearing or inactivity in construction.

(2)

If seeding or another vegetative erosion control method is used, it shall become established within two weeks or the department of public works may require the site to be reseeded or a non-vegetative option employed.

(3)

Techniques shall be employed to ensure stabilization on steep slopes and in drainage ways.

(4)

Soil stockpiles must be stabilized or covered at the end of each workday, or perimeter controls must be in place to prevent silt from the stockpile from leaving the site.

(5)

The entire site must be stabilized, using a heavy mulch layer or another method that does not require germination to control erosion, at the close of the construction season.

(6)

Techniques shall be employed to prevent the blowing of dust or sediment from the site.

(7)

Techniques shall be employed to divert upland runoff past disturbed slopes.

(h)

Sediment control requirements shall include:

(1)

Settling basins, sediment traps, or tanks and perimeter controls.

(2)

Settling basins shall be provided for each drainage area with ten or more acres disturbed at one time and shall be sized to contain 0.5 inch of sediment from the drainage area and be able to contain a two-year, 24-hour storm. If the provision of a basin of this size is impractical, other similarly effective BMPs, as evaluated and specified in the SWPPP, shall be provided.

(3)

Settling basins shall be designed in a manner that allows adaptation to provide long-term storm water management, as required by the department of public works.

(4)

Settling basins shall have stabilized spillways to minimize the potential for erosion of the spillway or basin embankment.

(5)

Protection for adjacent properties by the use of a vegetated buffer strip in combination with perimeter controls.

(i)

Water course protection requirements shall include:

(1)

Encroachment into or crossings of active water courses/riparian areas and wetlands shall be avoided to the maximum extent practicable. Where applicable, all local, state and federal permits and approvals shall be provided to the department of public works prior to the issuance of a site disturbance permit.

(2)

Stabilization of any watercourse channels before, during, and after any in-channel work.

(3)

If a defined watercourse is to be re-aligned or reconfigured, clearing and grubbing activities within 50 feet of the watercourse shall not begin until all materials and equipment necessary to protect the watercourse and complete the work are on site. Once started, work shall be completed as soon as possible. Areas within 50 feet of the watercourse shall be recontoured and revegetated, seeded or otherwise protected within five working days after grading has ceased.

(4)

All storm water conveyances shall be designed according to the criteria of the Metropolitan St. Louis Sewer District (MSD) and the necessary MSD permits obtained. However, the 25-year storm frequency shall be used in computing post development runoff.

(5)

Stabilization adequate to prevent erosion shall be provided at the outlets of all pipes and paved channels.

(j)

Construction site access requirements shall include:

(1)

A temporary access road provided at all sites including a wash-down area with an identified water sources supporting all active sites,

(2)

Other measures required by department of public works in order to ensure that sediment is not tracked onto public streets by construction vehicles or washed with wash effluent channeled directly into storm drains.

(k)

Control requirements for construction materials, construction wastes and other wastes generated on site shall include provisions, satisfactory to the department of public works, for:

(1)

Spill prevention and control facilities for materials such as paint, solvents, petroleum products, chemicals, toxic or hazardous substances, substances regulated under the Resource Conservation and Recovery Act (RCRA) or the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), and any wastes generated from the use of such materials and substances, including their containers. Any containment systems employed to meet this requirement shall be constructed of materials compatible with the substances contained and shall be adequate to protect both surface and ground water.

(2)

Collection and disposal of discarded building materials and other construction site wastes, including those listed in subsection (1) above.

(3)

Litter control.

(4)

Control of concrete truck washouts.

(5)

Assurance that on-site fueling facilities will adhere to applicable federal and state regulations concerning storage and dispensers.

(6)

Provision of sufficient temporary toilet facilities to serve the number of workers on site.

(Ord. No. 04-07, § 2, Exh. 1, 1-26-04)