29.060 Performance Standards.

(1) Responsible Party. The responsible party shall implement an erosion and sediment control plan, developed in accordance with MMC 29.080, that incorporates the requirements of this section.

(2) Plan. A written erosion and sediment control plan shall be developed in accordance with MMC 29.080 and implemented for each construction site.

(3) Requirements. The erosion and sediment control plan shall meet the following minimum requirements to the maximum extent practicable:

(a) BMPs shall be designed, installed and maintained to control total suspended solids carried in runoff from the construction site as follows.

1. For construction sites with one acre or greater of land disturbing construction activity, reduce the total suspended solids load by 80 percent, on an average annual basis, as compared with no sediment or erosion controls until the construction site has undergone final stabilization. No person shall be required to exceed an 80 percent sediment reduction to meet the requirements of this paragraph. Erosion and sediment control BMPs may be used alone or in combination to meet the requirements of this subsection. Credit toward meeting the sediment reduction shall be given for limiting the duration or area, or both, of land disturbing construction activity, or other appropriate mechanism.

2. For construction sites with less than one acre of land disturbing construction activity, reduce the total suspended solids load using BMPs from the Wisconsin Department of Natural Resources Technical Standards. These sites are not required to satisfy a numeric performance standard.

3. Soil loss prediction tools that estimate the sediment load leaving the construction site under varying land and management conditions, or methodology identified in subchapter V of Wis. Admin. Code NR 151, may be used to calculate sediment reduction.

(b) Notwithstanding subsection (3)(a) of this section, if BMPs cannot be designed and implemented to reduce the sediment load by 80 percent, on an average annual basis, the plan shall include a written and site-specific explanation as to why the 80 percent reduction goal is not attainable and the sediment load shall be reduced to the maximum extent practicable.

(c) Where appropriate, the plan shall include sediment controls to do all of the following to the maximum extent practicable:

1. Prevent tracking of sediment from the construction site onto roads and other paved surfaces. Each site shall have a tracking pad installed in accordance with the City’s standard specifications. Any sediment reaching a public or private road shall be removed before the end of each workday. Flushing may not be used unless approved by the Director of Public Works.

2. Prevent the discharge of sediment as part of site dewatering. Water pumped from the site shall be treated by temporary sedimentation basins or other appropriate controls for the highest dewatering pumping rate. Dewatering must also comply with WDNR rules. Water may not be discharged in a manner that causes erosion of the site or receiving channels.

3. Protect the separate storm drain inlet structure from receiving sediment.

(d) The use, storage and disposal of building materials, debris, garbage, chemicals, cement, concrete truck washout, litter, sanitary waste, toxic materials, hazardous materials, cleaning wastes, and other compounds and materials used on the construction site shall be managed during the construction period, to prevent their entrance into storm sewers and waters of the State. However, projects that require the placement of these materials in waters of the State, such as constructing bridge footings or BMP installations, are not prohibited by this subsection provided they have appropriate permits.

(e) Site Erosion Control. The following criteria apply only to land development or land disturbing construction activities that result in runoff leaving the site:

1. Channelized runoff from adjacent areas passing through the site shall be diverted around disturbed areas, if practical. Otherwise, the channel shall be protected as described below in subsection (3)(e)(3)(C) of this section. Sheetflow runoff from adjacent areas greater than 10,000 square feet in area shall also be diverted around disturbed areas, unless shown to have resultant runoff velocities of less than one-half foot per second across the disturbed area for the set of one-year design storms. Diverted runoff shall be conveyed in a manner that will not erode the conveyance and receiving channels.

2. All activities on the site shall be conducted in a logical sequence to minimize the area of bare soil exposed at any one time. Existing vegetation shall be maintained as long as possible.

3. Runoff from the entire disturbed area on the site shall be controlled by meeting either subsections (3)(e)(3)(A) and (B) or (A) and (C) of this section and WDNR Technical Standards, whichever is more restrictive.

A. All disturbed ground left inactive for 14 or more days shall be stabilized by mulching, temporary or permanent seeding, sodding, covering with tarps, or equivalent BMPs. Seeding and sodding may only be used from April 1st to October 15th of any year. If temporary seeding is used, a permanent cover shall also be required as part of the final site stabilization.

B. For sites with 10 or more acres disturbed at one time, or if a channel originates in the disturbed area, one or more sedimentation basins shall be constructed. Sedimentation basins shall be designed, constructed and maintained per WDNR Technical Standards. At a minimum each sedimentation basin shall have a surface area of at least one percent of the area draining to the basin and at least three feet of depth. Sediment shall be removed to maintain a depth of three feet. The basin shall be designed to trap sediment greater than 15 microns in size, based on the set of one-year design storms having duration from one-half to 24 hours. The basin discharge rate shall also be sufficiently low as to not cause erosion along the discharge channel or the receiving water.

C. For sites with less than 10 acres disturbed at one time, filter fences, straw bales, or equivalent BMPs shall be placed along all sideslope and downslope sides of the site. If a channel or area of concentrated runoff passes through the site, filter fences shall be placed along the channel edges to reduce sediment reaching the channel.

D. Runoff from sites or slopes of 12 percent or more may require additional or different control methods which are not listed in this subsection (3)(e)(3).

(f) Any soil or dirt storage piles containing more than 10 cubic yards of material should not be located with a downslope drainage length of less than 25 feet to a roadway or drainage channel. If remaining for 15 days or more, the piles shall be stabilized by mulching, vegetative cover, tarps, or other means. Erosion from piles which will be in existence for less than 14 days shall be controlled by placing straw bales or filter fence barriers around the pile. In-street utility repair or construction, soil or dirt storage piles located closer than 25 feet of a roadway or drainage channel must be covered with tarps or suitable alternative control. The storm drain inlets must be protected with straw bale or other appropriate filtering barriers.

(4) Location. The BMPs used to comply with this section shall be located prior to runoff entering waters of the State or regional stormwater treatment facilities.

(5) Alternate Requirements. The administering authority may establish requirements more stringent than those set forth in this section if the administering authority determines that an added level of protection is needed for sensitive resources.

[Ord. 08-523 § 7, 2008. Prior code § 29.06]