Eugene Planning Commission <br />August 22, 2016 <br />Page 5 <br />shall be selected from the Stormwater Management Manual and shall be based on <br />the following priority order: infiltration, filtration, off-site stormwater quality <br />management. <br />Ill. If selecting a filtration treatment facility, the applicant shall submit a report <br />that demonstrates at least one of the following development site conditions <br />exist: <br />a. Infiltration rates are less than 2 inches per hour; <br />b. Bedrock is less than 5 feet below the ground surface; <br />C. Groundwater elevations are less than 6 feet; or, <br />d. Ground surface slopes are greater than 10%. <br />112. If selecting off-site stormwater quality management by contributing to <br />the public off-site Stormwater quality facilities, through payment of a <br />higher stormwater system development charge adopted as part of the City's <br />system development charge methodology, the applicant shall submit a <br />report that demonstrates there is insufficient land area to construct an <br />approved infiltration or filtration facility by setting forth the required size <br />of the smallest infiltration or filtration facility needed for the <br />development's impervious surface area and a site plan demonstrating that <br />an approved infiltration or filtration facility cannot be located on the <br />development site without reducing the size of the proposed development <br />which is otherwise consistent with all other applicable lot and development <br />standards." (Emphasis supplied). <br />In summary, EC 9.6792(d) subsection (1) applies to on-site management of storm water quality. <br />Subsection (2) expressly applies to off-site storm water quality management. <br />Pages 30 to 32 of the April 4, 2016 revised narrative address storm water quality and EC <br />9.6792. Pages 30-32 of the revised narrative are attached hereto as Exhibit 6. In response to <br />EC 9.6792(3)(d), at page 32, the application states: <br />"The proposed water quality treatment will be accomplished using a <br />combination of infiltration planter boxes and filtration planter boxes. All of <br />the impervious surfaces will be treated prior to discharge to the public system. <br />Filtration planter boxes will be used to treat runoff from the roof. Regardless of <br />the soil infiltration capacity, the planter boxes around the building are required to <br />have an impervious liner due to the fact they are located less than 10 feet from the <br />building. Infiltration planter boxes will be located around the perimeter of the <br />parking area. Storm drainage will enter the planter boxes via curb cuts. These <br />planter boxes will be two feet wide so that a minimum five foot setback is <br />maintained from the property line. <br />"As noted previously, there is not sufficient area available to size these infiltration <br />planters to accommodate the flood control volume required by the Stormwater <br />Management Manual based on the assumed infiltration rate allowed by the <br />Manual. As such, these infiltration planters will still require the developer to <br />