Challenges of Building Your Filter or Drain

Federal Energy Regulatory CommissionConstruction Submittals – Toe Drain Pipe• Design vs. ASTM vs. What’s available …• Design – largest allowable slot for coarse aggregate 0.25 in.• ASTM F949 pipe 24-36 inch - slot size 0.125 in. – design OK• Manufacturers – for larger pipe – 0.375 in holes• Problem – find manufacturer willing to do special order• Solution – 11,000 lf 24-36 in pipe gang drill 0.25 slotsLessons:• Manufacturer’s may not produce according to ASTM standard• Not all will do special order• Check prior to bidding