<br />Ordinance -- Page 3 of 10 <br /> <br />2. For interior alterations of an existing structure Replacement of impervious surface <br />area that does not expose more than 1,000 square feet of soil (for purposes of this <br />subsection, “soil” means: the unconsolidated mineral or organic material on the <br />immediate surface of the Earth that serves as a natural medium for the growth of <br />land plants); <br /> <br />3. For the construction of more than 1,000 square feet of impervious surface that <br />replaces existing impervious surface for purposes of maintenance or repair for the <br />continuance of the current function, providing that as part of such m Maintenance and/or <br />repair the applicant is replacing less than 50% of the length of the stormwater drainage <br />system (including pipes, drainageway catch basins and drywells) on the development <br />site activities on an existing structures, or facilitiesy or other impervious surface <br />to prevent its decline, lapse or cessation in the use of the existing structures, <br />facilities, or impervious surface, as long as no additional hydrologic impacts <br />result from the repair or maintenance activity; or <br /> <br />4. For the construction of new or replaced impervious surface where all of the <br />stormwater runoff from the impervious surface will discharge into an on-site, privately <br />maintained underground injection control system that is registered and approved by the <br />Oregon Department of Environmental Quality; <br /> <br />5. For the construction of a single-unit dwelling or duplex on a lot or parcel that was <br />created by a land division application submitted and approved by the City prior to March <br />1, 2014, that is consistent with the approved land use application and the City’s <br />stormwater quality (pollution reduction) standards in place at the time of the land division <br />application; or <br /> <br />6. For the construction of a single-unit dwelling or duplex on a lot or parcel that was <br />created by a land division application that included the construction of a public or private <br />street or shared driveway submitted and approved by the City after March 1, 2014, if the <br />lot or parcel adjoins the public or private street or shared driveway and the facility within <br />the public or private street or shared driveway is an infiltration or filtration facility <br />designed and sized to accommodate stormwater runoff from the adjoining lots or parcels <br />at full buildout of the lots or parcels. <br /> <br />4. Construction of new or replaced impervious surface that will be served by <br />an existing City approved stormwater quality facility that was designed and sized <br />to treat the stormwater runoff from the proposed impervious surface. <br /> <br />(fc) The standards in EC 9.6792(3) do not apply to land use applications or development <br />permit applications within the S-DR Downtown Riverfront Special Area Zone. Instead, the <br />standards at EC 9.3155(17) apply. <br /> <br />(3) Standards. <br /> <br />Commented [DS2]: Testimony raised questions about <br />the meaning of this text. StaƯ response: A definition of <br />“soil” is added here, taken from the National Resources <br />Conservation Service, to make this section more clear. <br />Replacement of impervious surface could be for <br />buildings, driveways, sidewalks and pavements. Typical <br />driveway, sidewalk and pavement structures have <br />aggregate base rock over the soil. StaƯ plan to provide <br />clarification and graphics to the Stormwater <br />Management Manual showing the structural layers <br />including the soil layer. <br />Commented [DS3]: Testimony raised concerns about <br />the use of the term “hydrologic impacts.” StaƯ have <br />addressed this concern by removing that text, as it is not <br />needed for this subsection. <br />Commented [DS4]: Testimony raised concerns that the <br />removal of this language might remove the ability for the <br />use of a private UIC. StaƯ response: This language is not <br />needed in code. This subsection sets out the exemptions <br />to the requirement to infiltrate runoƯ. UICs do infiltrate <br />runoƯ, so they do not need this exemption. <br />Commented [DS5]: Testimony raised concerns that <br />removing these two exemptions will require existing lots <br />that are served by water quality treatment systems that <br />were previously approved by the City to construct <br />additional facilities to meet the new standards. StaƯ have <br />addressed this concern by proposing more explicit <br />language to exempt such existing systems so long as they <br />were designed and sized to treat the runoƯ from the <br />proposed construction.