Cost/Benefit Analysis for Geosynthetic Drainage Media vs. Natural Drainage Media

I. Basic Data VI. QA/QC Inspector Field Costs *
Area of Drainage Layers acres Cost/day $
Depth of Drainage Layers inches Days Needed Natural days
II. Sand or Stone Drainage Layer Cost Days Needed Geocomposite days
Cost of Material $/ton (delivered & installed) VII. Soil Required to Cover Geocomposite *
Unit Weight lb/cu.ft. Area of Drainage Layer acres
III. Geocomposite Cost * Depth of Drainage Layer inches
Cost of Geocomposite $/sq.ft. Cost of Cover Material for Geocomposite $/ton
IV. Geotextile Cushion * Unit Weight lb/cu.ft.
Cost of Geotextile $/sq.ft. IX. Landfill Airspace Savings 
V. Field QA/QC Testing * Unit Weight lb/cu.ft.
Natural Material Testing Costs Income Dollars Income $/waste/ton
Test Cost $
Geotextile Testing Costs
Test Cost $
Test Frequency
Geocomposite Testing Costs
Test Cost $
Test Frequency
 

* Additional Notes:
III.  Cost = Area * sq.ft. installed
IV. This section applies to utilizing natural materials as the drainage medium with a protective geotextile cushion above the geomembrane.  The geotextile cushioning is placed between the natural material and the geomembrane, and price is reflective of both supply and installation cost.  Geotextiles in this category range in unit weight from 12 - 16 ounces per sq.yd.
V.   In Natural Material the typical frequency is 1 series of tests per 500 tons used.  Test includes gradation and permeability.  Typical combined cost is about $200.  Total Tons = Volume * Density.
       In Geotextile Testing Costs, the typical testing is 1 per 100,000 sq.ft. at $1,000.
       In Geocomposite Testing Costs, the typical frequency is 1 series of tests per 100,000 sq.ft. of material.  Typical tests include transmissivity, short term compression, and physical properties ($245-$350) series.
VI.  Typically, installation of the geosynthetic is 50% faster than the natural material.  Assume 1 QC inspector on site (cost range from $270-$500)
VII. Cost of cover material is calculated delivered and installed.  The typical density of this is 130 PCF.