T.F. Green Airport Improvement Program - FEIS Chapters - PVD

T.F. Green Airport Improvement ProgramEnvironmental Impact Statement and Final Section 4(f) EvaluationTable 6-15Potential Stormwater Control Measures Operations and Maintenance ProceduresStormwaterControl Measures Inspection Frequency Minimum Maintenance and Key Items to CheckDetention SystemsInfiltration SystemsVegetated SwalesAnnually and after stormevents greater than or equalto a 1-year storm eventAnnually and after stormevents greater than or equalto a 1-year storm eventAnnually and after stormevents greater than or equalto a 1-year storm eventBioretention During the si x monthsimmediately followi ngconstruction the facility shal l bei nspected at l east twi ce and afterany storm events great than orequal to a 1-year storm event.Thereafter, the facili ty shall bei nspected annually and afterstorm events greater than orequal to a 1-year storm event• Sl• Reinforce existing riprap i n areas that have been compromised.•• Sediment should be removed from the forebay when the desi• All• Mow the grass at l east grass at least four times annually.• Remove any dead or dyi ng vegetati• Replace any vegetati on that has died off.opes of the basin should be inspected for erosion and gullying. Stabili ze and reseed as needed.All structural components should be inspected and repaired if necessary.gn depth has been reduced by 50%.trash and debris shall be removed and disposed of in accordance with all federal and local regulati ons.on and any vegetation that has a negati ve impact on stormwater fl ow.• Inspect facility to ensure desi gn rates are being met.• Repair and stabilize any eroded areas.• If sediment or organic debris build-up has limited the infiltration capabilities to below the design rate,the top 6 inches should be removed and the surface roto-till ed to a depth of 12 i nches. Restore basinth original design specifications.on pads and dispose of in accordance with all federal andbottom in accordance wi• Remove any oil or grease with oil absorptilocal regulations.•regulations.• Mow the grass at l• Inspect for si• Remove any dead or dying vegetation.• Replace any vegetati on that has died off.All trash and debris should be removed and disposed of in accordance with al l federal and localeast grass at least four times annually.gns of wetness or damage to structures.• Mow the grass to maintain grass height of 4-6 i nches, wi th mandatory mowi• Remove litter and debri s.• All structural components should be inspected and repaired if necessary.• Sl opes of the basin should be inspected for erosion and gullyi ng. Stabili• Nutrient and pesticide use management annuall y.• Dethatch swal e bottom and remove thatch annuall y.• Disc or aerate swale bottom annually.• Sediment shall be removed from the swale when sediment accumulates to a depth of approxi3 inches.ng when height exceeds 10 i nches.ze and reseed as needed.mately• Vegetati on along maintenance roads shall be mowed annually.• Scrape the channel bottom every five years to restore the original cross section and infiltration rate.• Soil erosion shal l be repaired.•• Reinforcement planting shall be performed if at least 50 percent of the vegetatiachieved within two years.• Herbaceous vegetation shall be separated when overcrowded is observed (approxi• The mulch layer shal l be replenished to its original depth every two years, or as di• Vegetati on along maintenance roads shall be mowed annually.• If the facility hol ds water 48 hours after precipitation events, the surface shall be roto-tillPruning or replacement of woody vegetation shall occur when dead or dying vegetation is observed.on coverage is notmately every three years).rected based on inspecti ons.ed and re-vegetated.Chapter 6 – Mitigation 6-36 July 2011\\Mawatr\ev\09228.00\reports\FEIS_Final_July_2011\PVD_CH06_Mitigation_JUL_2011.doc