Loading...
HomeMy WebLinkAbout2004 11 22 Consent 204 COMMISSION AGENDA ITEM 204 CONSENT X INFORMATIONAL PUBLIC HEARING REGULAR November 22,2004 Meeting MGR r IDEPT Jff , Authorization REQUEST: Utility Department Requesting additional ftmding for the construction of Well #4 PURPOSE: The purpose of this Board item is to request additional funding for the construction of Well #4 in the amount of$86, 174.00. cONSIDERA nONS: This project is needed to complete the construction of the raw water well at WTP #1 on Northern Way. It was originally approved by the City Commission on November 24, 2003, in the amount of $271,956.00. The additional request is to redrill the well with a modified casing design that reduces the depth of the original casing design to take advantage of upper level production zones that are needed for the well to be viable. The final well will produce an estimated 1,200 gpm (gallons per minute) instead of the 1,500 gpm originally sought. This will still be sufficient to meet our long term potable water supply needs. The amount of the contract is currently $287,418.50 which includes $5,517.00 for Change Order #1 (Test Well #1) and $9,945.00 for Change Order #2 (Test Well #2). Funds expended to date are $117,024.55 less 10% retainage. The primary balance of the work still to be performed under the original contract is the installation of the 12" raw water line to the plant. The original well (1) was drilled to a depth of 300 feet where testing indicated the capacity was not as good as was expected. Due to conditions of the well, it was decided to drill a 5" test well (2) near the first well (1) to determine ifthere was better capacity and quality at a shallower depth. Indications of the test well (2) showed evidence of Consent Agenda Item 204 November 22,2004 Page 2 sufficient capacity at approximately 190 feet but the hydrogen sulfide levels were slightly higher than what was hoped for. It was believed that drilling another test well (3) farther away from the lake (by the tennis courts) could result in a better quality of water. The second test well (3) did not in fact produce the results that were any better than the first test well (2). Based on the information from all three wells, it is the engineer's recommendation that a new raw water well be drilled in the proximity of the original well (1) at a depth near 190 feet. The engineers' recommendation is attached. Staff concurs with the engineers' recommendation. FUNDING: Funding for the project is from the Utility Enterprise Fund 2004 Construction Fund. The amount originally budgeted for the project was $300,000.00. This additional request will bring the total authorization to $373,592.50 plus 10% contingency. The additional funding needed for this project will be transferred from the 434 Water Line Project (3640-65000- 30038) in the 2000 Utility Construction Fund. RECOMMENDATION: It is recommended that authorization be given to increase the contract for the construction of Well #4 to $373,592.50 plus 10% contingency payable from the 2000 Utility Construction Fund with the additional funds needed to come from the 434 Water Line Project (3640-65000-30038). IMPLEMENTATION SCHEDULE: The scope of work will be completed within 90 days of approval. ATTACHMENTS: 1. 2. Engineer Recommendation Cost Proposal from Sunshine Building and Development Corp COMMISSION ACTION: Attachment No. 1 Memo CPR Engineers, Inc. 1117 East Robinson Street Suite C Orlando, Florida 32801 Phone: 407-425-0452 Date: November 3,2004 To: Kip Lockcuff, P.E., City of Winter Springs Cc: Doug Taylor, City of Winter Springs Cc: Greg Bishop, City of Winter Springs Cc: Steve Baggs, e.O., City of Winter Springs Cc: John Bush, Sunshine Building and Developing Corporation Cc: Roy Silberstein, P.E., Groundwater Engineering, Inc. From: Scott A. Breitenstein, P.E., CPR Engineers, Inc. Re: WTP 1 - Well No.4 and Raw Water Main - Progress Report NO.8 CPR Job No.: W04104.3 On August 11th the City approved the installation of Test Well No.2 located by the tennis courts in Trotwood Park. The contract driller installed the test well, and Roy Silberstein, P.E., conducted the first set of field sampling on September 21 st. Mr. Silberstein prepared a summary of work, and provided a recommendation of discontinuance of Test Well NO.2 via his e-mail dated September 22nd, which is reprinted as follows: The 5-inch diameter Test Well 2 was cased into first limestone at 135 feet and drilled to a total depth of 205 feet. A cavity was encountered below 200 feet where loss of drill mud oCClI"ed Sand and clay above soft limestone with the cavity consisting of dark muddy cemented silts and lime. Water discharge was dark brown during air development. Field testing was conducted at Test Well 2 on Tuesday Sept 21. Pumping rate was 120 gpm for 3 hours with 4.0 feet of drawdown resulting in a marginal capacity of 30 gpm/ft. Test Weill produced 130 gpm with less than 1.0 ft drawdown cased to 85ft when drilled to a depth of 190ft. Water discharge was initially silty brown clearing after 45 minutes. Field conductivity was 400 umhoslcm with a chloride of 40 mg/l, H2S of 2.25 mg/l, and iron of 0.25 mg/l. Although conductivity was 700 umhos and chloride was 140 mg/l at Test Well 1, H2S and iron are not improved at Test Well 2. After 90 minutes of pumping at 120 gpm, the well produced a large amount of quartz sand for a few minutes with some reduction over time - but was still evident with high turbidity at the end of pumping 90 minutes later. Recommend discontinuing drilling at Test Well 2 and consider options for drilling supply well 4 at Test Weill site. Test Weill and 2 data will be summarized in the final report for supply well 4. Mr. Breitenstein discussed the results of Test Well NO.2 with Mr. Lockcuff, and indicated that he supported Mr. Silberstein's recommendation of drilling a second Well No.4, near Test Well No. I. Also, Mr. Breitenstein indicated that based on the data from Test Well No.1, the new Well NO.4 would need approximately 50-feet of 24-inch steel casing, 80-feet of 16-inch steel casing, and have a total depth between 190 feet and 400 feet. Mr. Breitenstein stated it appeared that the hydrogen sulfide concentration at these depths would be approximately 2.5 mgIL, and that additional aeration treatment would be necessary per the FDEP. Mr. Lockcuff requested that Mr. Breitenstein obtain an estimated cost form Sunshine Development to drill a new Well No.4. Mr. Breitenstein stated that although the pay items would be the same (i.e. District permit, 24" casing, 16" casing, grouting, etc.), the unit costs of the original pay items may have increased since the project began, because of material cost increases. Mr. Lockcuff acknowledged that this could be the case, but stated to go ahead and get the cost estimation. After several discussions with the driller, Mr. Silberstein, and Mr. Breitenstein, Sunshine Development provided CPR the attached itemized cost estimate to drill the new Well No.4. Based on the attachment, the estimated cost to drill the new Well 4 is estimated to be $86.174.00. The work and materials necessary to drill the new well will include SJR WMD permitting, drilling the 24-inch casing, drilling the 16-inch casing, grouting of the casings, drilling the IS-inch open hole, installation of a temporary pump, and well development. The driller stated that partial mobilization to the site would be necessary, for drilling rig set up and preparation, as shown in Pay Item I-b. In addition, all field and laboratory sampling required for the Aquifer Performance Test Report, as required by the City's CUP, and the approved sampling plan prepared by Mr. Silberstein, are covered in Pay Items 6-b, 6-c, 8, and 10. Please note that Pay Items 11 through 14 are reprinted and/or presented as a summary of the original pay items 13 through 25, and the unit costs have not changed. CPR has reviewed the attached cost estimation provided Sunshine Development, and recommends that the new Well NO.4 be installed, if City approved. Attachment No. 2 Proposal - 2nd Well Sunshine Building and Development Corp. 11/210 Job le06 Item Available No. Description Prapo,sa' Test Tota' Original Contract 1.a St. John's Permit $ 1,380.00 $ 1,380.00 1-b MObilizatJon . Well Rigging 10',925.00 10,925.00 2 F & I 24n Casing 50 LF @ $200 10,000.00 10,000.00 3 23" BorehOle 30 LF @ $100 3,000.00 3,000.00 4 F & 116" Casing 80 LF @ $138 11,040.00 11,040.00 5 Grout 16" Well Casing 250 Sacks @ $36 9,000,00 9,000.00 6-a 15" Borehole 320 LF @ $63.20 20,224.00 20,224.00 6-b 3 Days Waler Testing Spec. 4,02 FIeld Analysis 1,500.00 S 3,450.00 4,950.00 e.c 7 Samples lab Analysis 500.00 3,220.00 3,720,00 7 F,I, & Remove Test Pump 9.775.00 9,775.00 8 Well Development 24 Hrs. ~ $90 1,585.00 575.00 2.160.00 9 Aquifer Performance Test (Step Drawc:lown) 3,565.00 805.00 4,370.00 S 4,370.0Gl 10 PhyslCjiUChemlcal Sampling & Testing 1,725.00 4 Samples during Development 1,840.00 1 Sampfe End; Stop 460.00 4,025.00 4.025.00 11 Disinfection 862.00 862.00 862.00 12 BT Sampling & Test 575.00 20 Samples 2,300.00 2,875.00 2,875.00 13 FOEP 345.00 1 Sample 2.875.00 3,220.00 3.220.00 14 Pump & Molor 120.825.80 120.825.80 120,825.8CJ Through BulJdrng Permit Total $ 206,826.80 $115,525.00 $222,351.80 $ 136,177 .81) Less Stored Material (14,070.00) (14,070.00) $20',281.80 $ 122,107.80 New Cost to drill second well S 'S,17 ".00 Since many items are with the ortglnal contract prices, we reserve the option of revising prices due to material increases (such as those experienced lately in steel, fuel, concrete, grout. etc.) We will exhaust all avenues open to us in order to hold our prices. Ilem NO.2 - Well figging consists of lear down old rigs; era ne. welding, shoes. tumbuctdes, tooling and pit digging to set up rig.