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Findings and Analysis (from the full report) <br />The above graph demonstrates that the MnDOT Specified topsoil in both 4" and 6" depths <br />'out- performed' the Borrow Topsoils overall - with the 4" Spec'd soil almost doubly effective <br />in soil moisture retention than the 4" Borrow Topsoil, (and at the same time growing <br />demonstrably better turf). <br />The total gallons used for each test plot is generally as predicted. <br />Total Gallons Used Each Plot <br />• 4,114 •A 2" Borrow <br />• 2,107 -B 4" Spec'd Soil <br />• 3,131 — 6" Spec'd Soil <br />• 3,959 <br />�D 4" Borrow <br />• The 4" Spec'd soil is generally doubly effective as both depths of Borrow soil. <br />• The 4" Spec'd soil was approximately 33% more efficient than the 6" Spec'd soil over <br />the course of the August - October season. <br />• Perhaps the most illustrative example of the Spec'd soils relative efficacy occurs in later <br />October as the evaporation and transpiration wane due to environmental conditions of <br />cooler temps and shorter days (see values at top of the graph). The Spec'd soils <br />maintained adequate soil moisture (between 30 and 32 %) - but the Borrow soils still <br />required some irrigation. <br />Municipal Utility Cost/ Benefit Summary <br />Within the full report analysis, the Spec'd topsoil was evaluated for both those who would <br />incur the real costs of the topsoil, as well as the utility at large, and found that the proverbial <br />'rising tide floats all boats'. Thus, if the homeowner's annual savings on irrigation of $74.30 is <br />adjusted to 26 years ($1,932) and coupled with his /her savings in operating cost (electricity, <br />chemicals) to the utility ($105), as well as reduced capital costs (new water wells) for using <br />Spec'd soils to the utility ($65); the homeowner is fully paid back the 26th year if there would be <br />[only] a 13% aggregrate increase of either or both, water rates and inflation. <br />3 <br />