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Home My WebLink AboutLetter of Request for Over-Praticipation (from DP Folder 1)ASH lit BROWJ'YE El'YGIJ'YEERIJ'YG, IJ'YC. October 20, 2003 Spencer Thompson, E. I. T. Graduate Civil Engineer Engineers and Consultants P.O. Box 10838, College Station, Texas 77842 979-846-6914 877-245-4839 Fax: 979-846-8914 Development Services, City of College Station College Station, TX 77840 Re.: Letter of Request for Over-Participation (OP) Estates at Spring Creek Development (ESCO) Sanitary Sewer Trunk Line Dear Mr. Thompson: My client is requesting Over-Participation support for the construction costs incurred for the excess sanitary sewer trunk line that the city has requested. The Estates at Spring Creek Development (-153.35 acres) necessitates a sanitary sewer trunk line with pipe sizes varying from 8110 through 12"0 with two creek borings. The City of College Station has requested that the trunk line be over-sized to service the rest of the Spring Creek Watershed Basin (-531 .20 acres) not already being served. (See Attachment #1) The over-sizing would require that the pipe sizes increase to 21 "0. Please reference Attachments #2 and #3 for area sewage productions and pipe capacities. It must be noted that this OP request is for only trunk lines 1 through 5 of the Estates at Spring Creek Sanitary Sewer Trunk Line. (Please see Attachment #1) Lines 6 through 8 will be developed at a later date. Spring Creek Watershed Basin (OP) Estates at Spring Creek Development, Section1 Sub-Total= Less Line Item 1.01 from Attach. #4 (8"0 Sewer Line) Total Over Participation = $380,806 -$183.266 $197,540 -$ 3,450 $194,090 Attachments to this letter include: 1) ESCO Sanitary Sewer Trunk Line layout, 2) proposed sewage productions for ESCO, 3) proposed sewage productions for the Spring Creek Watershed Basin and remaining Crowley Development, 4) Engineer's Cost Estimate for Estates at Spring Creek Development, 5) Engineer's Cost Estimate for Spring Creek Watershed Basin. Thank you for all your time and help on this project. Please contact me if you have any questions. ~,,,~. _r~E OF r~;'\\ Cb~t······~\$1··, .. * · ..•. *. . *'' •.. : .................. ~ 2 JOE I. GATIIS I Z··~··············:·· fj :\:•. ( 90964 Q ··$ 'tr,~··:.~f !\ \1-··~~ '\\:'ONA\. E~ F:\Projects\1045 -Munsey Developments\005 -Reatta Meadows Subdivision, Section 1 of 4\letters\COCS -SThompson04 -Letter.wpd /J/) ~ ? JUl-ZI!)-~~ A TI ACHMENT #1 Estates at Spring Creek Development Sanitary Sewer Trunk Line & Spring Creek Watershed Basin ATTACHMENT #2 Sanitary Sewer Production for the Estates at Spring Creek Development ATTACHMENT #2 COMPUTATION OF SEWAGE PRODUCTION -ESTATES AT SPRING CREEK DEVELOPMENT ADDED AREA AREA AVG TOTAL DESIGN DESIGN MIN. PIPE LENGTH ADDED TOTAL DENSITY FLOW FLOW PEAK FLOW FLOW DIA. LINE (FT) CAC) (AC) ADDED (GPO) (GPO) FACTOR CGPM) (CFS) REQUIRED 6 686 16.551 16.551 COMM 33,102 33 ,102 4.0 92 0.20 6" 160 SFD, 5 339 39.459 56.01 COMM 66,546 99 ,648 4.0 277 0.62 8" 4 607 10.988 66.998 43 SFD 15,910 115,558 4.0 321 0.71 10" 42 SFD, 3 971 12.7 79.698 PARK 19, 176 134,734 4.0 374 0.83 10" 2 417 14.926 94.624 59 SFD 21 ,830 156,564 4.0 435 0.97 10" 77 SFD, 858 25.859 120.483 COMM 41 ,308 197,872 4.0 550 1.22 12" MAXIMUM PIPE CAPACITIES AT MINIMUM VELOCITY & GRADE MANNING VELOCITY SLOPE AREA DIAMETER 00 mm 00 m~1 Q Cgpm) DESIGN CRITERIA 6" 0.013 2 0.5 0.196 176 370 GPO per Single Family Dwelling Unit (SFD) 2000 GPO per Commercial acre 8" 0.013 2 0.33 0.349 31 3 1,212 GPO per acre of Park 10" 0.013 2 0.25 0.545 489 12" 0.013 2 0.2 0.785 705 15" 0.013 2 0.15 1.227 1101 18" 0.013 2 0.11 1.767 1586 21 " 0.013 2 0.09 2.404 2158 ATTACHMENT #3 Sanitary Sewer Production for the Spring Creek Watershed Basin and Remaining Crowley Development ATTACHMENT #3 COMPUTATION OF SEWAGE PRODUCTION -SPRING CREEK WATERSHED ADDED MIN. PIPE PIPE LENGTH AREA AREA AVG TOTAL DESIGN DESIGN DIA. CAPACITIES (FT) & ADDED TOTAL DENSITY FLOW FLOW PEAK FLOW FLOW REQUIRED @GRADE LINE GRADE (AC) (AC) ADDED (GPO) (GPO) FACTOR (GPMl (CFS) @GRADE (GPO) 1640@ 1,380 8 0.8% 207.679 207.679 SFD 384,060 384 ,060 4.0 1,067 2.38 10" 1395 1358@ 507 SFD 7 0.6% 105.184 312.863 COMM 194,930 578,990 4.0 1,608 3.58 12" 1966 686@ COMM 6 0.25% 74.643 387.506 SCHOOL 73,102 652,092 4.0 1,811 4.03 21 " 2159 339@ 160 SFD, 5 0.25% 39.459 426.965 COMM 66,546 718,638 4.0 1,996 4.45 21" 2159 607@ 4 0.25% 10.988 437.953 43 SFD, 15,910 734,548 4.0 2,040 4.54 21 " 2159 971@ 42 SFD, 3 0.25% 12.7 450.653 PARK 19,176 753,724 4.0 2,094 4.66 21" 2159 417@ 2 0.25% 14.926 465.579 59 SFD 21 ,830 775,554 4.0 2,154 4.80 21" 2159 858@ 126 SFD, 1 0.25% 35 .829 501.408 COMM 59,438 834,992 4.0 2,319 5.17 21 " 2159 ATTACHMENT #4 Engineer's Cost Estimate for the Estates at Spring Creek Development 12110 Sanitary Sewer Trunk Line ESTATES AT SPRING CREEK DEVELOPMENT Engineer's Preliminary Opinion of Probable Construction Cost for 12,. 0 Estates at Spring Creek Sanitary Sewer Trunk Line ABEi No. 1045005 October 20, 2003 The following construction estimate is based on the engineer's preliminary opinion of probable construction costs. This estimate constitutes our best judgement at this time. Please note that the engineer does not have any control over contractor or supplier workloads and the degree to which inflation may affect project costs between now and the bid date. During design and construction, additional features may become apparent as the work progresses, which will result in an increase in cost. Item Description Estimated Estimated ESTIMATED No. Quantity Unit Cost TOTAL COSTS 1.00 12" SANITARY SEWER TRUNK LINE 1.01 8"0 ASTM 03034 SOR 26 PVC Sewer 345LF $10.00 $3,450 Line (includes installation, testing, and cleanup.) 1.02 . 10"0 ASTM 03034 SOR 26 PVC Sewer 1,995 LF $14.00 $27,930 Line (includes installation, testing, and cleanup.) · 1.03 12110 ASTM 03034 SOR 26 PVC Sewer 858LF $16.00 $13,728 Line (includes installation, testing, and cleanup.) 1.04 8' -10' Trenching & Backfill -Non-158 LF $12.00 $1 ,896 Structural (includes backfill and cleanup) 1.05 10' -12' Trenching & Backfill -Non-304 LF $16.00 $4,864 Structural (includes backfill and cleanup) 1.06 12' -15' Trenching & Backfill -Non-2,426 LF $20.00 $48,520 Structural (includes backfill and cleanup) 1.07 16" Bore (Includes mobilization, 3/8" thk. 310 LF $225.00 $69,750 steel casing, spacers, capping, cleanup) 1.08 Trench Safety 3,198 LF $1 .50 $4,797 1.09 4' Standard Manhole (0 -6' Deep) 9EA $1,750.00 $15,750 (includes installation, testing, and cleanup.) 1.10 Additional Depth for 4' Dia. Standard Manhole 73VF $100.00 $7,300 Subtotal Item 1.00 -12" Sewer Trunk Line: $166,605 Contingency(10%): $16,661 ------ Preliminary Total Construction Costs: . $183,266 ------ ~~'"'''.,.., JI"' ~E OF ri:i:'\\ ~c:,~~······~.s>'''• 1'1.:· * ···.*.'~ , .................... ~ 2 JOEi.GATTiS J I··~··············:·· fj ~·· ( 90964 Q .·$. .. ,O~/ CE NS t..•~~.ii • \,<:-;s ........ .!..~ '\~~IONAl f:.JF' .,,,,,~ I ({)-U> -2e::0 s ATTACHMENT #5 Engineer's Cost Estimate for the Spring Creek Watershed Basin 21"0 Sanitary Sewer Trunk Line ESTATES AT SPRING CREEK DEVELOPMENT Engineer's Preliminary Opinion of Probable Construction Cost for 21··0 Estates at Spring Creek Sanitary Sewer Trunk Line ABEi No. 1045005 October 20, 2003 The following construction estimate is based on the engineer's preliminary opinion of probable construction costs. This estimate constitutes our best judgement at this time. Please note that the engineer does not have any control over contractor or supplier workloads and the degree to which inflation may affect project costs between now and the bid date. During design and construction, additional features may become apparent as the work progresses, which will result in an increase in cost. Item No. Description 1.00 21" SANITARY SEWER TRUNK LINE 1.01 21110 ASTM 02241SOR26 PVC Sewer Line (includes installation, testing, and cleanup.) 1.02 8' - 1 O' Trenching & Backfill -Non- structural (includes backfill and cleanup) 1.03 10' -12' Trenching & Backfill -Non- structural (includes backfill and cleanup) 1.04 12' -15' Trenching & Backfill -Non· Structural (includes backfill and cleanup) 1.05 30" Bore (Includes mobilization, 3/8" thk. steel casing, spacers, capping, cleanup) 1.06 Trench Safety 1.07 5' Standard Manhole (0 - 6' Deep) (includes installation, testing, and cleanup.) 1. 08 Additional Depth for 4' Dia. Standard Manhole Estimated Quantity 3,198 LF 158 LF 304 LF 2,426 LF 310 LF 3,198 LF 9EA 73VF Estimated Unit Cost $45.00 $12.00 $16.00 $20.00 $380.00 $1 .50 $1 ,900.00 $100.00 ESTIMATED TOTAL COSTS $143,910 $1 ,896 $4,864 $48,520 $117,800 $4,797 $17, 100 $7,300 Subtotal Item 1.00 -21" Sewer Trunk Line: $346,187 ------ Contingency(10%): $34,619 ------