Trans 401.105(2)(2) Upon receipt of an erosion control order form ordering changes or corrections to existing best management practices, the prime contractor shall implement, or cause to be implemented, the necessary corrective action within the time specified in the order or, if no time is specified, within 24 hours after receiving the order. The prime contractor shall deliver the erosion control order form to the project engineer upon completion of the corrective action and shall include on the form a description of the corrective action implemented and the date completed.

Trans 401.105(3)(3) The department may approve or reject any completed corrective action by inspecting the affected area within 16 hours after the prime contractor or utility person delivers the completed erosion control order form to the project engineer or, for utility facility projects, to the department’s authorized representative. The department shall consider all matters required in an erosion control order satisfactorily completed after that 16 hours has elapsed, or at 12 noon on the day the 16 hours expires, whichever is later, unless within the later of those 2 times the department has inspected and rejected the corrective action implemented. If a discharge occurs after the prime contractor or utility person delivers the erosion control order form under this section but before the later of those 2 times, the prime contractor or utility person shall have an opportunity to demonstrate that the corrective action was completed as required prior to the discharge. If the department does not reject any completed corrective action within the time specified in this subsection, the department may compel corrective action at the affected area only by issuing a new erosion control order.

Trans 401.105(4)(4) Notwithstanding any time period permitted under this section for completing corrective action, a prime contractor is considered not in compliance with the contract documents, as defined in s. Trans 401.12 (1) (a), for any area or matter described in the erosion control order form as requiring changes or corrections until such time as the change or correction is satisfactorily completed, as determined under sub. (3).

Trans 401.105(5)(5) Written notices are considered delivered to a prime contractor for purposes of this section when the written notice is presented to the head representative of the prime contractor then available on the project site or selected site, or when written notice is delivered to the prime contractor’s principal place of business, whichever occurs earlier. Written notices are considered delivered to a project engineer or to the department when the written notice or form is presented to the project engineer or to the authorized department representative then available on the project site, or when written notice is delivered to the project engineer’s principal place of business, whichever occurs earlier.

Trans 401.106(1)(1) Definitions. In this section:

Trans 401.106(1)(a)(a) “Average annual rainfall” means the rainfall determined by the following year and location for the location nearest the project site: Madison, 1981 (Mar. 12-Dec. 2); Green Bay, 1969 (Mar. 29-Nov. 25); Milwaukee, 1969 (Mar. 28-Dec. 6); Minneapolis, 1959 (Mar. 13-Nov. 4); Duluth, 1975 (Mar. 24-Nov. 19).

Trans 401.106(1)(b)(b) “TR-55” means the United States Department of Agriculture, Natural Resources Conservation Service (formerly Soil Conservation Service), Urban Hydrology for Small Watersheds, Second Edition, Technical Release 55, June 1986, or Technical Release 55 for Windows (Win TR-55), 2002.

Trans 401.106 NoteNote: TR-55 is on file with the offices of the Legislative Reference Bureau, the Secretary of State, and the Department of Transportation, Office of General Counsel. Copies may be obtained by writing to the U.S. Department of Agriculture, Natural Resources Conservation Service, Conservation Engineering Division, 14th and Independence Avenue, SW., Room 6136-S, Washington, DC 20250. The phone number for the division is: 202-720-2520, and the fax number is: 202-720-0428. TR-55 is available electronically at:

Trans 401.106(2)(2) Plan. The department shall develop and implement a written plan that includes the requirements of subs. (3) to (10) for each transportation facility. This plan may be part of the erosion control plan.

Trans 401.106(3)(3) Total suspended solids. Best management practices shall be designed, installed and maintained to control total suspended solids carried in runoff from the transportation facility as follows:

Trans 401.106(3)(a)(a) For transportation facilities first constructed on or after January 1, 2003 by design, reduce the suspended solids load to the maximum extent practicable, based on an average annual rainfall, as compared to no runoff management controls. A reduction in total suspended solids by at least 80% meets the requirements of this paragraph.

Trans 401.106(3)(b)(b) For highway reconstruction and non-highway redevelopment, by design, reduce to the maximum extent practicable the total suspended solids load by at least 40%, based on an average annual rainfall, as compared to no runoff management controls. A 40% or greater total suspended solids reduction shall meet the requirements of this paragraph. In this paragraph, “redevelopment” means the construction of residential, commercial, industrial or institutional land uses and associated roads as a substitute for existing residential, commercial, industrial or institutional land uses.

Trans 401.106(3)(c)(c) Notwithstanding pars. (a) and (b), if the design cannot achieve the applicable total suspended solids reduction specified, the design plan shall include a written and site-specific explanation why that level of reduction is not attained and the total suspended solids load shall be reduced to the maximum extent practicable.

Trans 401.106(4)(4) Peak discharge.

Trans 401.106(4)(a)(a) By design, BMPs shall be employed to maintain or reduce the peak runoff discharge rates, to the maximum extent practicable, as compared to pre-development site conditions for the 2-year 24-hour design storm or to the 2-year design storm with a duration equal to the time of concentration applicable to the transportation facility. Pre-development conditions shall assume “good hydrologic conditions” for appropriate land covers as identified in TR-55 or an equivalent methodology. The meaning of “hydrologic soil group” and “runoff curve number” are as determined in TR-55. However, when pre-development land cover is cropland, rather than using TR-55 values for cropland, the runoff curve numbers in Table 2 below shall be used.

Trans 401.106(4)(b)1.1. A transportation facility where the change in hydrology due to development does not increase the existing surface water elevation at any point within the downstream receiving surface water by more than 0.01 of a foot for the 2-year 24-hour storm or for a 2-year design storm with a duration equal to the time of concentration.

Trans 401.106(5)(5) Infiltration.

Trans 401.106(5)(a)1.1. Infiltrate sufficient runoff volume so that the post-construction infiltration volume shall be at least 60% of the pre-construction infiltration volume, based on an average annual rainfall. However, when designing appropriate infiltration systems to meet this requirement, no more than 2% of the project site is required as an effective infiltration area.

Trans 401.106(5)(a)2.2. Infiltrate 10% of the post-development runoff volume from the 2-year 24-hour design storm with a type II distribution. Separate curve numbers for pervious and impervious surfaces shall be used to calculate runoff volumes and not composite curve numbers as defined in TR-55. However, when designing appropriate infiltration systems to meet this requirement, no more than 2% of the project site is required as an effective infiltration area.