Timeline of Key Milestones and Dates DateKey Milestone February 2007Washtenaw County Drain Commissioner’s Office authorizes a project to identify opportunities to reduce flooding and improve water quality in Allen Creek Summer 2007After evaluating potential projects - and 5 public hearings - Pioneer High School identified as the #1 opportunity in the watershed for storm water improvements October 10, 2007Presented project concept to the Board of Education, obtained support to pursue grant and loan funding July 1, 2008DEQ loan application submitted to Michigan Department of Environmental Quality requesting 4.4 million dollars for Pioneer High School storm water project August 20, 2008Project update presented at Board of Education meeting. The Board passed a resolution supporting the project as developed with AAPS and authorizing the superintendent to provide the necessary easements

DateKey Milestone October 2008Notification from the Michigan Department of Environmental Quality that the storm water project is funded for 4.4 million dollars October 2008Design project authorized by Washtenaw County Drain Commissioner’s Office November 2008Pioneer High School storm water project options developed for Ann Arbor Public Schools’ consideration December 3, 2008 Presentation to Ann Arbor Public Schools board members of storm water project options January 20, 2009Prepare draft plans and specifications in partnership with AAPS for MDEQ review March 27, 2009Working with AAPS continue to revise plans for final approval by MDEQ by June-August 2009 and 2010 Construction June 22, 2009Loan closing

OPTION 1

OPTION 2

COMPARISON OF SITE LAYOUT OPTIONS DESIGN ASPECTSOPTION 1OPTION 2 Basin LocationsTwo basins in grass areaGrass and parking lot Infiltration Capabilities Yes for westerly basin / * unknown for easterly basin Yes in the grass area / No under the parking lot Water Quality/Stormwater Benefit E. coli Phosphorous Volume Rate Credit acres 93 lbs $3,836 per lb 321,000 $13.70 cf Min 12% $1, acres maximum 63 lbs; $5,702 per lb 225,000 $19.60 cf Min 6% $720 Volume -For basin off 42” sewer -For basin off 54” sewer 125,000 cft 196,000 cft 125,000 cft 100,000 cft Approximate Basin Dimensions -For basin off 42” sewer -For basin off 54” sewer 156’ x 100’ x 8’ 220’ x 150’ x 6’ 156’ x 100’ x 8’ 155’ x 110’ x 6’

Hydraulic Grades -For basin off 42” sewer -For basin off 54” sewer 9” increase in water surface at str. # 16 6” increase in water surface at str. # 15 9” increase in water surface at str. # 16 33” increase in water surface at str. #15 (may impact pool discharge) Facets of Construction > No impact to soccer field > Some possible impacts to parking lots; contractor may have to use a portion of lot for staging > Northerly entrance drive off of would need to be shared with school traffic or closed to school traffic if basins built consecutively > Native materials can be used for backfill > Schedule would be more flexible starting after football season and continuing into the school year > More soil to level out playfield area/football parking area > No impact to soccer field > Most of parking lot must be removed and replaced; therefore, work would have to be done in a summer season > Some fill would need to be imported to backfill area under parking lot > Parking lot lighting must be removed and replaced > Both entrance drives off of Main St. would need to be utilized for construction traffic > Less soil to level out playfield area/football parking area