When the following standards are met, excavation and filling operations are allowed in all areas of the city with an approved grading plan issuance of a zoning permit unless the property is covered by shoreland, wetland or bluff overlay zones or similar environmental standards or regulations as specified in any city, state or federal regulations that require additional permits or approvals.
Subd. 1. Grading plans shall provide information indicating the following:
A. The surface shall be prepared to receive fill by removing vegetation, debris, topsoil and other unsuitable material and scarifying (creating irregularities in the surface of existing soil) to provide a bond between the existing soils and the fill material;
B. All fill shall be compacted to 90% of maximum density as determined by ASTM D 1557, Modified Proctor, in lifts not exceeding 12 inches in depth and shall be allowed to sit idle over a winter season. If the proposed fill will be supporting structural improvements (buildings, structures, pavements and the like), greater compaction may be necessary, and a geotechnical engineer's recommendation may be required;
C. No rock or similar irreducible material greater than four inches in any dimension shall be included in the fill;
D. The slope created by the fill shall be no steeper than is safe for the intended use and shall not be steeper than 4H to 1V (25% slope) or shall be justified by soils reports or engineering data;
E. Slopes steeper than 4H to 1V are permitted only if approved by the City Engineer;
F. Where existing grade is at a slope steeper that 5H to 1V (20% slope) and the depth of the fill exceeds five feet, benching shall be provided. A key shall be provided which is at least ten feet wide and two feet deep;
G. During excavation or filling operation the site shall be managed so that it shall not present a danger from caving in or sliding banks. The site may require fencing and erosion prevention measures which will be determined and required at the discretion of the city;
H. The site shall be properly drained with any drainage properly managed during the fill process to best management practices. No cross property sheet drainage shall be permitted;
I. Erosion of the ground in the area of discharge during filling shall be prevented by installation of non-erosive down drains or other devices. Grading shall not create drainage patterns or routes that will adversely affect down gradient properties;
J. At the completion of a landfill or excavation/grading operation, the premises shall be graded, leveled and all exposed soils shall be fully restored with vegetation, mulch and/or a permanent non-erodible surface;
K. Drainage across property lines shall not exceed that which existed prior to grading. Excess or concentrated drainage shall be contained on site or directed to an approved drainage facility;
L. The site shall be left so that storm water drainage runoff and storm water passage or flowage cannot become a source of, or an aggravation to, storm water drainage conditions in the area; and
M. The final elevation shall be determined and specified on the zoning permit. Final elevation required by the city shall be based on:
1. Existing elevation of adjacent streets and lots; and
2. Elevation required for proposed structures to meet floodplain requirements (679 feet) or hook up to city sewer.
Subd. 2. The filling operations shall not consist of garbage, animal or vegetable refuse, poisons, contaminants, chemicals, organic or tree waste, decayed material, filth, sewage or similar septic or biologically dangerous material deemed to be unsuitable by the city.
Subd. 3. The filling operations shall only be allowed to occur between the hours of 7:00 a.m. to 7:00 p.m. Monday through Friday, and 8:00 a.m. to 6:00 p.m. on Saturday.
Subd. 4. For projects with a land disturbance area of one acre or more, the state's Pollution Control Agency general permit authorization to discharge storm water associated with construction activity under the national pollutant discharge elimination permit is required (or as amended by MPCA). This permit requires the development of a storm water pollution prevention plan (SWPPP).
(Ord. 699, passed 1-18-22)