Common use of Infiltration Clause in Contracts

Infiltration. BMPs shall be designed, installed, and maintained to infiltrate runoff to the maximum extent practicable in accordance with the following, except as provided in subsections (C)(3)(e) through (C)(3)(g) of this section. a. For residential developments, one of the following shall be met: i. Infiltrate sufficient runoff volume so that the post-development infiltration volume shall be at least of the pre- development infiltration volume, based on an average annual rainfall. However, when designing appropriate infiltration systems to meet this requirement, no more than one percent of the project site is required as an effective infiltration area. ii. Infiltrate twenty-five (25) percent of the post-development runoff from the two- year, twenty-four (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 one percent of the project site is required as an effective infiltration area. b. For nonresidential development, including commercial, industrial, and institutional development, one of the following shall be met: i. Infiltrate sufficient runoff volume so that the post-development infiltration volume shall be at least sixty (60) percent of the pre-development infiltration volume, based on an average annual rainfall. However, when designing appropriate infiltration systems to meet this requirement, no more than two percent of the project site is required as an effective infiltration area. ii. Infiltrate ten (10) percent of the runoff from the two-year, twenty-four (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-

Infiltration. BMPs shall be designed, installed, and maintained to infiltrate runoff to the maximum extent practicable in accordance with the following, except as provided in subsections (C)(3)(e) subds. 5. through (C)(3)(g) of this section8. a. 1. For residential developments, developments one of the following shall be met: i. a. Infiltrate sufficient runoff volume so that the post-development infiltration volume shall be at least of the pre- development infiltration volume, based on an average annual rainfall. However, when designing appropriate infiltration systems to meet this requirement, no more than one percent of the project site is required as an effective infiltration area. ii. Infiltrate twenty-five (25) percent of the post-development runoff from the two- year, twenty-four (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 one percent of the project site is required as an effective infiltration area. b. For nonresidential development, including commercial, industrial, and institutional development, one of the following shall be met: i. Infiltrate sufficient runoff volume so that the post-development infiltration volume shall be at least sixty (60) percent 90% of the pre-development infiltration volume, based on an average annual rainfall. However, when designing appropriate infiltration systems to meet this requirement, no more than two percent 1% of the project site is required as an effective infiltration area. iib. Infiltrate 25% of the post-development runoff from the 2 year -24 hour design storm with a type II distribution. Separate subcatchments for and not composite curve numbers as defined in TR-55 shall be used to model pervious and impervious surfaces within watershed areas located in the development site, when calculating runoff volumes. However, when designing appropriate infiltration systems to meet this requirement, no more than 1% of the project site is required as an effective infiltration area. 2. For non-residential development, including commercial, industrial and institutional development, one of the following shall be met: a. Infiltrate ten (sufficient runoff volume so that the post-development infiltration volume shall be at least 60% of the pre-development 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. b. Infiltrate 10) percent % of the runoff from the two2-year, twenty-four (24) year - 24 hour design storm with a Type 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-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. 3. Pre-development condition shall be the same as in par. (b). 4. Before infiltrating runoff, pretreatment shall be required for parking lot runoff and for runoff from new road construction in commercial, industrial and institutional areas that will enter an infiltration system. The pretreatment shall be designed to protect the infiltration system from clogging prior to scheduled maintenance and to protect groundwater quality in accordance with subd. 8. Pretreatment options may include, but are not limited to, oil/grease separation, sedimentation, biofiltration, filtration, xxxxxx or filter strips.

Infiltration. BMPs shall be designed, installed, and maintained to infiltrate runoff to the maximum extent practicable in accordance with the following, except as provided in subsections (C)(3)(e) through (C)(3)(g) of this section. a. For residential developments, one of the following shall be met: i. Infiltrate sufficient runoff volume so that the post-development infiltration volume shall be at least of the pre- pre-development infiltration volume, based on an average annual rainfall. However, when designing appropriate infiltration systems to meet this requirement, no more than one percent of the project site is required as an effective infiltration area. ii. Infiltrate twenty-five (25) percent of the post-development runoff from the two- two-year, twenty-four (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 one percent of the project site is required as an effective infiltration area. b. For nonresidential development, including commercial, industrial, and institutional development, one of the following shall be met: i. Infiltrate sufficient runoff volume so that the post-development infiltration volume shall be at least sixty (60) percent of the pre-development infiltration volume, based on an average annual rainfall. However, when designing appropriate infiltration systems to meet this requirement, no more than two percent of the project site is required as an effective infiltration area. ii. Infiltrate ten (10) percent of the runoff from the two-year, twenty-four (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-TR-55. However, when designing appropriate infiltration systems to meet this requirement, no more than two percent of the project site is required as an effective infiltration area. c. Pre-development condition shall be the same as in subsection (C)(3)(b)(ii) of this section. d. Before infiltrating runoff, pretreatment shall be required for parking lot runoff and for runoff from new road construction in commercial, industrial and institutional areas that will enter an infiltration system. The pretreatment shall be designed to protect the infiltration system from clogging prior to scheduled maintenance and to protect groundwater quality in accordance with subsection (C)(3)(g) of this section. Pretreatment options may include, but are not limited to, oil/grease separation, sedimentation, biofiltration, filtration, xxxxxx or filter strips.