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Home My WebLink AboutHRDC 10 Sewer Engineers_report.pdf c K D WEST BABCOCK, (HRDC) SUBDIVISION SEWER AND WATER MAIN PAYBACKS May 5, 1994 Compiled for the HRDC and City of Bozeman by The City of Bozeman Engineering Department Page 1 Introduction In the spring of 1994, the West Babcock Subdivision was constructed through the coordinated efforts of the Human Resource Development Council and the City of Bozeman, for the purpose of providing a low income housing subdivision. Offsite sewer and water infrastructure was needed to serve the subdivision and as decided by the City Commission, the cost of these additional utilities would be "paid back" to the "owner" by future connecters to the lines, through a payback arrangement. HRDC Sewer Payback Area Two areas are delineated for the 10" sewer main constructed from the north edge of the HRDC subdivision to the intersection of N. 25th and Durston Rd. . One is the 118" Equivalent Payback Area" and the other, the 1110" Oversize Payback Area" . The 8" equivalent area represents the most likely lots to directly connect to the main, therefore responsible for the majority of the payback amount. The 10" oversize area represents the area benefiting by the extension of the 10" main, though not directly connecting to it . The areas exclude present and projected Rights of Ways, present and projected openspace and parks, leaving only present and projected lot area. Table 1 describes the properties in the payback areas and the methods used to calculate the areas . HRDC Water Payback Area Two payback areas were developed for the water mains required to service the HRDC Subdivision. A 10" main was constructed in Durston Rd. , from the west edge of West Park Manor Phase 4 Subdivision to the intersection of N. 25th and Durston. An 8" main was constructed from the north boundary of the HRDC subdivision to the intersection of N. 25th and Durston. The boundaries depicted on Exhibit 2, are the areas most likely to seek connection to these water mains in the future. The 8" water main payback area contains approximately 6 . 9 acres and the 10" water main payback area contains approximately 30 acres . These areas exclude present and projected Rights of Ways, parks and openspaces . Table 2 describes the properties in the payback areas and the methods of calculating the area. Page 2 Cost of the HRDC Water and Sewer Mains The infrastructure for the HRDC subdivision was designed and construction services provided by Morrison-Maierle/CSSA. The project contractor was Johnston Excavating. Table 3 illustrates the quantities and costs of the bid items to be "paid back" , as well as the proportional costs of engineering and inspection. Total sewer payback amount is estimated at $29, 532 . Total water payback amounts are estimated at; $41, 761 for the 8" main and $27, 035 for the 10" main. Final amounts will be determined following completion of construction of the HRDC Subdivision. Method of Assessment The areas calculated as the payback areas are approximate only. Actual assessments will vary depending on final platted lot sizes . Payback amounts will be collected in addition to regular costs of sewer and/or water hookup for those properties within the described payback boundaries . The amount will be collected at the time the customer applies for sewer or water service. All other costs of construction of sewer and water services will be borne by the applicant . The sewer payback amounts are $0 . 10 per square foot of platted lot within the 8" equivalent payback area and $0 . 002 per square foot of platted lot within the 10" oversize area. The water payback amounts are $0 . 138 per square foot of platted lot within the 8" main payback area and $0 .021 per square foot of any platted lot within the 10" main payback area. 4r Il i t TABLE 1 HRDC, (WEST BABCOCK) SUBDIVISION SEWER PAYBACK CALCULATION * Acreages used in calculations represent platted and future platted lots, (no R.O.W., open space, or parks included). See Exhibit for boundaries of payback area SUBDIVISION SOURCE ACREAGE OF ACREAGE OF OR OF LOTS IN 8' EQUIV. LOTS IN OVERSIZE PLAT INFORMATION P.B. AREA P.B. AREA Kable Subdivision Plat 3.93 Simpkins Subdivision Plat + County Appraiser 2.42 Egbert Subdivision Plat + County Appraiser 1.36 HRDC, (West Babcock) Subdivision Proposed Final Plat 4.85 Fellows Property, Unplatted COS 1817 + Scaling 2.47 0.52 Lessley Property, Unplatted Scaling + Tax Roll 7.77 Neibauer Property, Unplatted Surrounding Plats 3.56 TOTAL LOTS 6.401 20.48 I8" Equivalent Sewer Payback for platted or projected lot: $27,754.05/6.4 ac = $0.10/sf 10" Oversize Sewer Payback for platted or projected lot: $1,778.40/20.48 ac = $0.002/sf 'f TABLE 2 HRDC, (WEST BABCOCK) SUBDIVISION WATER PAYBACK CALCULATIONS * Acreages used in calculations represent platted and future platted lots, (no R.O.W., open space, or parks included). See Exhibit for boundaries of payback areas SUBDIVISION SOURCE ACREAGE OF ACREAGE OF OR OF LOTS FOR LOTS FOR PLAT INFORMATION 8' MAIN P.B. 10' MAIN P.B. Kable Subdivision Plat 3.93 3.93 Fellows Property, Unplatted COS 1817 + Scaling 2.47 13.58 Lessley Property, Unplatted Scaling + Tax Roll 1.70 Smith Property, Unplatted Proposed Annie Sub. Ph. II 9.78 TOTAL LOTS 6.40 28.99 8" Water Payback for Platted or Projected Lot: $41,761.31/6.40 =$6525.20/ac = $0.15/sf 10" Water Pavback for Platted or Projected Lot: $27.034.50/28.99=$932.55/ac = $0.021/sf ABLE 3 HRDC. (WEST BABC_OCn SUBDIVISION SEWER AND WATER_PAYBACK COST ESTIMATE Unit Costs from Johnston Excavating's Low Bid * Engineering and Inspection proportionaly based on Morrison-Maierle/CSSA Professional Services Contract/Cost Estimate San. Sewer Sta 0+00 - 15+46 ITEM UNIT EST. UNIT PRICE EST. ACT. ACT QTY TOTAL QTY TOTAL loll PVC If 1546 $12.30 $19,015.80 $0.00 T-2 Bedding cy 81 $0.15 $12.15 $0.00 Pipe Insulation ea 1 $75.00 $75.00 $0.00 Std. 5'-0" Manhole ea 4 $1,475.00 $5,900.00 $0.00 Manhole additional vert.feet of 6.95 $90.00 $625.50 $0.00 Connection at Durston ea 1 $500.00 $500.00 $0.00 Engineering &Inspection* - - $3,404.00 $3,404.00 $0.00 TOTAL SEWER** $29,532.45 $0.00 8" PVC If $11.15 **Total for 8"equivalent system = $27,754.05 **Oversizing cost for the 10" main = $1.778.40 8' Water Sta 8+18 - 23+60 8" D.I.P. If 1572 $18.00 $28,296.00 $0.00 6"D.I.P. If 31.5 $16.74 $527.31 $0.00 Hydrant Assembly ea 3 $1,600.00 $4,800.00 $0.00 8"G.V. ea 5 $650.00 $3,250.00 $0.00 Pipe Insulation ea 1 $75.00 $75.00 $0.00 ,Engineering &Ins ection* - - $4,813.00 1 $4,813.00 $0.00 TOTAL W ATE R $41,761.31 $0.00 10' Water Sta 1+42 - 8+18 10" D.I.P. If 696 $20.50 $14,2 88.00 $0.00 6" D.I.P. If 10.5 $16.74 $175.77 $0.00 Hydrant Assembly ea 1 $1,600.00 $1,600.00 $0.00 10" G.V. ea 3 $850.00 $2,550.00 $0.00 Pipe Insulation ea 1 $75.00 $75.00 $0.00 Connection at Durston ea 1 $1,400.00 $1,400.00 $0.00 Pavement R&R If 700 $5.50 $3,850.00 $0.00 Engineering &Inspection* - - $3,115.731 $3.115.731 $0.00 TOTAL WATER 1$27,034.50 $0.00