Community Assessment Report - Onsite Sewage Treatment ...

analysis over a 25-year period showing the average present worth costs for the entire CAR Areabased on the different cluster and ISTS scenarios proposed in the report.Table 9: Present Worth Analysis (25-year) Average Costs CAR Area-Wide by AlternativeAlternative 1Managed ISTSProgram*Alternative 2LISTS Cluster + Alternative 3 MSTSISTS*ClusterAlternative 3MSTS Clusterwith NitrogenRemovalTotal System Costs $ 251,300 $ 420,300 $ 612,400 $ 909,610Annual Operation & Maintenance Costs(25 year present worth value) $ 22,000 $ 49,000 $ 91,000 $ 355,000Estimated Total Present Worth $ 273,300 $ 469,300 $ 703,400 $ 1,264,610Estimated Total Equivalent Annual Cost(annualized over a 25-year period, 2%interest) $ 13,999 $ 24,038 $ 36,028 $ 64,774Estimated Average Equivalent AnnualCost per Property $ 1,000 $ 1,720 $ 2,580 $ 4,630Estimated Average Equivalent MonthlyCost per Property $ 83.33 $ 143.33 $ 215.00 $ 385.83* Assumes no properties on holding tanks.The estimated Total Present Worth amounts (of the alternatives cost over a 25-year period) aretallied in Table 9 in the middle row. The estimated Total Equivalent Annual Cost represents theannual cost to pay the Total Present Worth Cost over a 25-year period assuming a 2% subsidizedloan rate. The estimated Average Equivalent Annual Cost per Property is simply the total annualcost divided by the number of participating units.The Estimated Average Equivalent Annual Cost per Property shown in Table 9 is not the actualcost experienced by the property owner each year. The timing and magnitude of actual costs willvary including upfront capital costs (i.e., assessments, individual system repairs, etc.) andperiodic operation and maintenance (fees, utility bills, pump replacements, etc.). The PresentWorth Analysis serves as a method of comparison and does not reflect the timing of actualpayment. Table 9 assumes that for Alternative 1 ISTS, the future ISTS type as shown inAppendix B is the ISTS in use at the residences during the present worth analysis period. InT:\2797-01 Chisago County\CAR\ROLLINGS SHORES CAR 090712.docx4-7