Rating System

LEED BD+C: New Construction, LEED BD+C: New Construction, LEED BD+C: New Construction, LEED BD+C: Schools, LEED BD+C: Schools, LEED BD+C: Core and Shell, LEED BD+C: Core and Shell

Rating System Version

v2 - LEED 2.2, v2 - LEED 2.2, v3 - LEED 2009, v2 - Schools 2007, v3 - LEED 2009, v2 - LEED 2.0, v3 - LEED 2009

Inquiry

The project is located in central Allentown, Pennsylvania, and the site itself is located in a zone of sinkholes and unstable limestone substructure. Our geotechnical advisors have recommended that there be no water retention at all on the site, including the tanks that would be necessary to retain stormwater before releasing it through a sand filtration system. They have also advised that no water be allowed to enter the ground through permeable landscaping, as that will significantly increase the chances of sinkhole formation or movement.\n\nThis project is installing in all stormwater runoff lines a series of "Snouts" from Best Management Products, which are fixtures placed over stormwater inlet lines in sumps that force water settlement before it passes on into the outfall pipe. BMP will certify that these snouts, as implemented in our design, will achieve better than the target 80% removal of TSS from all site stormwater before it enters the city stormwater systems. However, BMP will not certify that these products will remove any particular amount of TP. Rather, they note that Phosphorus will both attach itself to suspended solids -- which would be removed with the TSS -- and some Phosphorus will remain in solution, which their system will not remove.\n\nTo achieve the intent of the credit, we propose to implement a series of control measures in building operations to reduce Phosphorus levels entering runoff stormwater. Because the project is on an urban site, most Phosphorus would be introduced to the site through either landscape fertilizers or through landscape, plaza, and building cleaning materials. The Phosphrus control plan we intend to implement will address these three areas as such:\n\n1) The landscape vegetation is selected that requires low to no regular fertilization. Trees are contained in underground boxes with solid paving to within 6 inches of the trunks, and they are injection fertilized.\n\n2) The plaza cleaning plan (as proscribed in the building specifications) will use low Phosphate or Phosphate-free citrus based cleaning agents.\n\n3) The building window-washing plan (as proscribed in the building specifications) will use low Phosphate or Phosphate-free citrus based cleaning agents.\n\nWill such a strategy of reducing phosphorus entering the stormwater streat rather than removing it after the fact satisfy the intent of the credit?\n