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HomeMy WebLinkAbout1996 10 28 Regular Item B ('. C.OMMISSION AGENDA ITEM B REGULAR X CONSENT INFORMATIONAL October 28. 1996 Meeting MG~if /DEFT jL V uthorization REQUEST: Utility Department Requesting Authorization to Increase the Contract Amount for Well #6 and to Execute Supplement #2 to Amendment 32 for Consulting Engineering Services PURPOSE: The purpose ofthis Board item is to request additional construction funds for the Potable Water Supply Well #6 Contract with American Drilling, Inc. and to also authorize the execution of Supplement #2 to Amendment 32 - Construction Administration Services for Well #6 with Conklin, Porter & Holmes Engineers, Inc. CONSIDERATIONS: Approval of the additional construction fund monies and additional engineering services is needed to complete the construction of Potable Water Supply Well #6. The construction contract for Well #6 was awarded to American Drilling, Inc. in the amount of $130,000 as authorized by Consent Agenda Item B ofthe February 12, 1996 City Commission meeting agenda. The approval included a 10% contingency for a total authorized expenditure of$143,000. There have been many modifications to the bid quantities based on difficulties encountered during construction with the geology in the area. To date we have authorized two change orders totaling $9,269.10 which we thought would be sufficient to complete the well. However, during the final pump test, a subsidence occurred adjacent to the well which indicates an unacceptable connection between the surface sand layer and October 28, 1996 Regular Agenda Item B Page .1 well production zone. A detailed report from the hydrogeologist is attached which summarizes the project to date and lists our options. A proposed change order #3 is attached for modification to the well (Option #3 ofthe report) so the well can be completed and put in service. The total estimated cost including previous authorized change orders and proposed change order #3 is $161,882.10. Supplement #2 to Amendment 32 for Conklin, Porter and Holmes - Engineers, Inc authorizes an additional $8,855.00 which is for the increased cost of full time inspection during the completion of the well and for costs incurred that exceeded the original scope of work. Amendment 32 was for the design ofthe well at a cost of$15,000. Supplement #1 to Amendment 32 was for Construction Administration and Inspection Services at a cost of$11,840. Original Contract Change Order #1 Change Order #2 Proposed Change Order #3 Total $130,000.00 $7,805.70 $1,463.40 $22.553.00 $161,822.10 ALTERNATIVES: The City has three options to choose from for Well #6. 1. Well Abandonment and New Well Construction. This option is the most expensive because we have already close to $100,000 invested in this well. 2. Well Cavving. This option is the least expensive because we would be stopping where were at and incurring only minor additional expenses. However, we would not have gained our objective which is to provide a backup potable water supply well for WTP#2. 3. Well Modifications. This option entails temporarily backfilling, pressure grouting, and telescoping a 10" casing inside the existing 16" casing. The additional costs are estimated at $31,882.10 over the bid costs. While there is a slight chance that this option could fail the need for a second well makes this the most cost effective option. October 28, 1996 Regular Agenda Item B Page3. FUNDING: The cost for change order #3 to the construction contract with American Drilling,Inc. is $22,553.00 for a total estimated construction cost of$161,822.10. The cost for Supplement #2 to Amendment 32 for consulting engineering services with Conklin, Porter and Holmes - Engineers, Inc. is $8,885.00 all of which is for the hydrogeologist subconsultant. Funds are available from the Utility Enterprise Account fund balance. Funds for the contract change order and engineering supplement will be expended by January 15, 1997. RECOMMENDA TION: It is recommended that additional funds be authorized for the Well #6 construction contract with American Drilling, Inc. for a total estimated contract cost of$161,822.10 plus a 5% contingency. It is also recommended that authorization be given to execute Supplement 2 to Amendment 32 for consulting engineering services with Conklin, Porter and Holmes Engineers, Inc. for a cost of$8,885. The source of funds for both items will be the Utility Enterprise Fund. IMPLEMENTATION SCHEDULE: The contractor is tentatively scheduled for remobilization on November 18, 1996. All work should be completed by January 15, 1997. ATTACHMENTS: 1. Supplement #2 to Amendment 32 2. Hydrogeologist Report 3. Change Order #3 to Well #6 Contract with American Drilling, Inc. COMMISSION ACTION: Attachment No. 1 AMENDMENT No. 32 SUPPLEMENT No.2 CONSULTING ENGINEERING SERVICES This supplement is made and entered into this day of 1996, by and between the City of Winter Springs and Conklin, Porter and Holmes - Engineers, Inc. WHEREAS, the CITY and ENGINEER have previously entered into an Agreement for the ENGINEER's professional services (Amendment No. 32); and WHEREAS, the CITY and the ENGINEER shall refer to Amendment No. 32 herein, and desire to have it incorporated by reference; and WHEREAS, the CITY and the ENGINEER now wish to modify and add specific items to Amendment 32. NOW THEREFORE, in consideration of the mutual promises and covenants contained herein and given one to the other, the sufficiency of which is hereby acknowledged, the parties agree as follows: I. SCOPE OF WORK The scope of work has been agreed to by the parties, and is attached hereto and incorporated herein, by reference, as Exhibit 1. Terry M. Zaudtke, P .E., Senior Vice President, has been designated as Project Manager for this project, by the ENGINEER. II. EEE The fee has been agreed to by the parties, and as attached hereto and incorporated herein, by reference, as EXHIBIT II. . ID. TERM The term of this. Supplement shall be for four (4) months from the date of final execution by the City. fJ IV. ENTIRE AGREEMENT This supplement supersedes all previous authorizations, agreements, or representations, either verbal or written, heretofore in effect between the CITY and the ENGINEER that may have concerned the matters covered herein, except that this Supplement shall in no way supersede or amend Amendment 32 or other authorizations except as specifically provided herein. No additions, alterations, or variations to the terms of this Supplement shall be valid, nor can the provisions of this supplement be waived by either party, unless such additions, alterations, or waivers are expressly set forth in writing in a document of import equal to Amendment 32 or the Supplement, and duly executed. IN WITNESS WHEREOF, the parties hereto have executed this Supplement No.2 on the day and year first written above. CITY OF WINTER SPRINGS, FLORIDA BY: DATE: ATTEST AND SEAL: City Clerk !trOtKJAS,c ~/YI MlI~/I'tf, ~~I /o/f1l~"'-t '~l/f~ &'~/d4rdhJ..~~ CONKLIN, PORTER AND HOLMES ENGINEERS, INC. BY: 7J:;~ $" V,P- DATE: j. f(; . A~~_ ---..... .. .~. ...,........... .- .-.~....~,....:...~........l~'.JJ~... ..I..:",,,,~\L.'" ExmBIT I SUPPLEMENT No.2 ENGINEERING SCOPE OF SERVICES 1) Retain the services of a Geologist to provide the inspection services required for the modification of the well. These services are described in the attached letter from L J. Nodarse and Associates, ,... .. ".., ..~, .... , ~,u..~ ,j r... .;'.'.~ ,.~. .. ;,:, ~.. ~'_,' , '..,~..:.',' '~,..., l.. ..,:\: ..::,: L'~t..~.: G-:':~j',';,~" RECEIVED If Nodarse &.. Associates} Inc. s j:" 0 '1 n I,I".~.... ..... ....... \,; c::130 (OMUII!I ',"",~,., . . ~, ..(\i., t.. J', '" ~ .1'( :- 1:, A....S . ~.,' ,,\ t.'; L;;&""il~ ORLMiDJ, FWf@:\ September 27, 1996 Project No. 95-E-0384 TO: CPR Engineers 1104 East Robinson Street Orlando, Florida 32801 Attn: Mr. Terry Zaudtke RE: Additional Consulting Services Winter Springs Well #6 Winter Springs, Seminole County, Florida Dear Mr. Zaudtke: In accordance with your request, L.J. Nodarse & Associates, Inc. (UN) is pleased to present for your review our scope of services and estimated costs to complete monitoring of the installation of the City of Winter Springs Water Supply Well #6. . Based on our understanding of the required scope, the following is our recommended scope of services: 1. Oversee drilling of new 15 inch hole to a depth of 250 feet. 2. Oversee installation of 10 inch liner including installation and grouting. 3. Oversee drilling of 9 7/8 inch open hole from 250 to 400 feet. 4. Oversee well development. 5. Review pump test procedures prior to initiation of pwnp test and pump test final data. Attachment A is a breakdown of our estimated cost to complete these tasks. In addition, we have also included a breakdown of costs incurred in Attachment A that were over and above our initial scope of services contained in our originaL proposal. CLOSURE UN appreciates the opportunity to submit this proposal and we look forward to working with you on this project. If you have any questions or if we can provide any additional information, please feel free to call us at your convenience. Sincerely, al Nodarse, P.E. L.J. NODARSE & ASSOCIATES, INC. V ( ~ -rT~,ty ~vid B. Twedell Principal Scientist DBT/UN:cah 5-384.dd.sv. Geotechnical, Environmental. &. Materials Engineers 807 South Orlando Avenue + Suite A + Winter Park. Florida 32789 + Telephone 407.740.6110 + Facsimile 407.740.6112 7. ATTACH~rENT A ESTLvlATED COSTS CITY OF WINTER SPRINGS WELL #6 f 1. Oversight of 15 inch hole to 250 feet Senior Geologist ]2 hrs @ S95.00/hr $1,140.00 2. Oversee 10 inch liner lnstllilation and grouting Senior Geologist 12 hrs @ $95.00/hr 1,140.00 3. Oversee drilling of 9 7/8 inch hole to 400 feet Senior Geologist 24 hrs @ $95.00/hr 2,280.00 4. \Vell. development oversight Senior Geologist 8 hrs @ $95.00/hr 760.00 5. Pump test proce.dures a'1d data revic,\'/ Senior Geologist 4 hrs @ $95.00ihr 380.00 6. Oversight of 3 inch monitoring weU pump test including data logger, four hour pump test and data review Senior E:1Vironmcntal Technician 7 hrs @ $45.00/hr Senior Geologist. 2 hrs @ $95.00/hr Data Logger Rental 190.00 275.00 315.00 MeeUngs, additional ol~-site well construction monitoring Senior Ge(llogist 25 hrs @ $95.ODihr -L.3.liOO TOTAL ESTL\lA TED PROJECT COSTS $8,855.00 .. ....' H'......' "." I." .."'.. ..u~1 .\. ,,,."" ...... ',W'" ',." ..;.-,;,,,..;;.""';.......~..:j.:.....,n.;~:.:~.t EXHIBIT II SUPPLEMENT NO.2 COST ANALYSIS Inspection Services - L. J. Nodarse SUBTOTAL (Supplement No.2) $ 8,855.00 $8,855.00 Original Authorization Amendment 32 (Design and Permitting) $15,000.00 Supplement No. 1 - Construction Administration 11,840.00 Supplement No.2 - Inspection Services 8,855.00 TOTAL AUTHORIZATION $35,695.00 h. __...._.......,._.'.... ...~.._",......~u......L...,;,.. ......,..,......~ .,.... . ....:.....'....."..J Attachment No. 2 MEMORANDUM TO: Mr. Kipton D. Lockcuff, P.E., City Of Winter Springs, Director Of Utilities THROUGH: Terry Zaudtke, P.E. - Conklin Porter and Holmes, Engineers FROM: David B. Twedell, L.J. Nodarse & Associates, Inc. David H. Kincaid, P.G. - Kincaid Environmental Services, Inc. DATE: October 8, 1996 SUBJECT: Winter Springs Potable Water Supply Well No.6 This memo will serve as an update with regard to the project statUs of municipal supply well No. 6, for the City of Winter Springs. In accordance with your request, this memo will summarize the well completion status, problems encountered during well installation and proposed options which may eliminate the problems. As you are aware, two wells exist at the site located at the eastern end of Clearn Court. The first well is a 3-inch diameter test well and the other is a 16-inch diameter production well. The wells are approximately 50 feet from each other. During the installation of the wells, unstable geologic strata were encountered at both locations. The drilling contractor has taken appropriate steps to minimize the difficulities associated with the unstable zones. However, the 16-inch diameter production well is unfinished at this time due to the difficulties encountered and this well requires additional work for completion. Construction at both wells includes outer steel surface casings. Surface casings are typically installed to stabilize unconsolidated (uncemented), unstable geologic strata such as sand, silt, clayey sand, etc. Stabilization is necessary to prevent borehole collapse and the possible forma.tion of collapse features. The inner, 3-inch diameter casing of the first well was installed to a depth of 250 feet, with the lower-most 180 feet consisting of uncased open-hole section within limestone strata. The well was installed to provide stratigraphic information, water quality data and to monitor aquifer hydraulic characteristics during testing of the production well. However, due to unstable downhole geologic conditions, it became necessary to case the hole to stabilize it. Based on review of the driller's log, sandy clay was encountered down to a depth of 20 feet. Below this unit, a layer of clay (with a little sand) was encountered from 20 feet down to the top of the limestone which was encountered at a depth of 52 feet below land surface. Limestone continued from this depth down to a depth of 220 feet, where a 25-foot thick layer of silica sand was encountered down to a depth of 245 feet. Once through this sand zone, the 3-inch diameter steel casing was set and grouted into limestone at a depth of 250 feet to eliminate the sand and stabilize the hole. Following the casing set and grouting, the test hole was continued. Limestone was encountered from 245 feet and continued down to the termination depth of 430 feet. A cavity zone was encountered at a depth of 340 feet, as evidenced by the 100% loss of drilling fluid. Typically, cavity zones may provide much of the water production for a well. A water quality sample was collected after well installation. Based on water quality . 'I 2 results, water quality is good within the 250-430 foot zone. Prior to the installation of the production well, a 6-inch diameter test hole was completed to a depth of 298 feet to collect stratigraphic data. The surface casing had been previously installed prior to drilling activities at this location. The 6-inch diameter test hole was advanced through the unconsolidated sand, and clayey sediments down to limestone. Limestone was encountered at a depth of 58 feet. The test hole was continued down to the termination depth of 298 feet. At a depth of 100 feet, a loss of drilling fluid occured, indicating a cavity zone. Below this cavity zone, limestone was encountered down to 298 feet. Based on the occurrence of sand in the first test well within the 220-245 foot zone, drill cuttings were closely inspected to observe for the occurrence of silica sand. No silica sand was encountered below the top of limestone (52 feet) in the 6-inch diameter test hole. Following completion of the test hole, a 23-inch diameter drill bit was used to enlarge the hole in order to set the 16-inch diameter well casing into position. The 23-inch hole was advanced to a depth of approximately 147 feet, when a small area subsided approximately 6 feet southeast of the well. The area was approximately 6 feet in diameter and 5 feet deep. The following day, it was observed that the borehole had been filled with silica sand up to a depth of 123 feet. During drilling, sand from overlying zone(s) had apparently raveled downward and allowed overlying sediments to collapse. The subsided area was backfilled with sand and no further collapse at that location has occurred. To eliminate this unstable condition, a decision was made to set the 16-inch casing and pressure grout it into position, as deep as possible withinin this unstable zone. Casing sections were welded together and lowered downhole. A header plate with a pipe connector was welded on the top of the uppermost casing section. The intent was to pump grout under high pressure, down the center of the casing while slightly raising and lowering the casing, to wash the casing down to a deeper depth. However, when this was tried, the borehole collapsed again and the raveled sand could not be dislodged. Following this procedure, the bottom of the 16-inch diameter casing was at a depth of 89 feet below land surface. The casing was grouted into position at this depth. Following grouting, the open hole section of the well was extended to a depth of 218 feet below land surface. Drilling was stopped at that depth because the production capacity appeared to be appropriate and no other difficulties had been encountered to that depth. Following completion of the well, an aquifer pumping test was initiated on August 30, 1996. The piping from the well was connected to the discharge line which terminates at the water plant and the test was begun. Immediately after starting the pumping, the in-line flow meter became erratic and then inoperative. The flow meter transducer was removed and found to be clogged with limestone silt and sand. The transducer was cleaned and reinstalled in an effort to continue the test. However, the transducer became inoperative again within 2-5 minutes. At that time, a small discharge spigot located near the flow transducer was opened to inspect for sand, etc. The discharge was extremely milky in color and contained significant quantities of limestone sand and silt and small limestone fragments from the drilling operation. Because of this, an accurate test could not be performed so the test was aborted and the pump man was instructed to continue pumping to clean out the well. The initial pumping rate was estimated to be approximately 1,200 " 3 gpm. The pumping rate was increased to approximately 2,000 gpm to better clear the well. A short time afterward, the well began to pump silica sand and an additional small area subsided approximately 4 feet northeast of the well. This feature is approximately 8 feet in diameter and approximately 6-7 feet in depth. When the subsidence occurred, pumping was stopped. No additional drilling or pumping has been performed at the site since. Geophysical logging was recently performed on the well to provide additional borehole data and confirm borehole characteristics. Based on logging results, the bottom of the open hole is at a depth of 201 feet, indicating some additional ravelling and subsequent infilling of the well. Also,. an enlarged cavity zone occurs from approximately 92-100 feet in depth. Based on the small areas of subsidence and the problems associated with silica sand encountered during drilling and grouting procedures, it is apparent that the zone from the top of limestone (52 feet) down to a depth of at least 100 feet is unstable and continues to provide a connection to land surface. The well has an unstable zone therefore, from the bottom of the casing (89 feet) down to a depth of at least 100 feet. Based on this problematic condition, several options were discussed at a meeting with City personnel. Options discussed included: Option 1 - Well Abandonment And New Well Construction This option would propose the abandonment of the existing well and construct a new well, hopefully at a new location. However, the City has already incurred most of the cost of the well and a new location may have additional geologic difficulties. It should be noted that valuable data has been collected during all phases of drilling and well construction at this site. This data helps to build an understanding of subsurface geologic conditions, and how to overcome such conditions. Starting a new well yields the highest level of risk (unknowns). By starting a new well, the City would be starting the whole process over again. As such, well abandonment and new well construction is not recommended at this time. Option 2 - Well Capping This option would propose the capping of the existing well and no additional work. The water management district would need to be contacted to determine if capping would be acceptable. This option does nothing to increase the City's water supply capacity. Additionally, the water management district will most likely require abandonment at some time in the future if the well is not put into service. Option 3 - Well Modifications This option would propose modifications to the eXIstmg production well in an attempt to eliminate the pumping of silica sand. With this option, the openhole section of the well would be backfilled with sand up to a depth of approximately 105 feet to temporarily plug off most of ! ,,, . 4 the open hole section. Following backfilling, the zone around the bottom of the casing (89 feet) down to 105 feet would be pressure grouted to force the grout out into the limestone to seal off the connection to land surface. The water management district will likely be in favor of this, if not actually requiring it. Following grouting, a borehole will be redrilled to a depth of 250 feet. A lO-inch diameter well casing will be set at this depth and grouted into position through the center of the existing 16-inch diameter casing. The lO-inch diameter casing will seal off the unstable, problematic zone(s) encountered which are producing the silica sand. It is believed that this option will provide the best solution for the problems encountered and be the most cost effective solution as well. Accordingly, this option is recommended. As discussed during the meeting with City personnel, the site is situated in the general vicinity of the 51. Johns River system. Within this system, geologic faults have been documented. These geologic faults can produce very complex and difficult conditions during the drilling of water wells. Accordingly, rehabilitative modifications to water supply wells within this area should be considered somewhat of a risk. It is possible that modifications to this well may not correct all possible problems. Additionally, assumming that modifications are successful in eliminating the silica sand, the well production flow capacity will remain unknown until well modifications have been completed and the well tested. However, much information has been obtained at this site. As each difficulty has been encountered, the situation has been evaluated by the engineer, the geologist and the drilling contractor. Although it is difficult to assign a statistical probability of success in this situation, the relative probability for the successful completion of this well is believed to be very high, based on data obtained at the site. Given this, it is believed that this well can be successfully modified to provide a seviceable well for the City. Attachment No. 3 TEST WELL 4 INCH DIAMETER 1 Mobilization! Demobilization LS 1 7,420.00 7,420.00 1 7,420.00 2 F&I - 4" Well Casing FT 100 15.00 1,500.00 100 1,500.00 3 Drilling Open Borehole FT 400 8.00 3,200.00 30 240.00 4 Water Quality and Analysis Each 8 250.00 2,000.00 2 500.00 5 Geo h ical Well Surve LS 1 2000.00 2 000.00 0 0.00 WATER SUPPLY WELL NO.6 6 Mobilization! Demobilization LS 1 12,000.00 12,000.00 1 12,000.00 7 F & I - 24" Well Casing FT 100 83.00 8,300.00 52 4,316.00 8 Drilling Open Borehole - 23" FT 110 23.00 2,530.00 95 2,185.00 9 F & I - 16" Well Casing FT 210 28.00 5,880.00 89 2,492.00 10 Grout 16" well Casing Sack 270 12.00 3,240.00 120 1,440.00 11 Drilling Open Borehole - 15" FT 220 16.00 3,520.00 103 1,648.00 12 F & I and Remove Test Pump LS 1 2,500.00 2,500.00 1 2,500.00 13 Well Development Hour 24 90.00 2,160.00 24 2,160.00 14 Aquifer Performance Test LS 1 7,500.00 7,500.00 1 7,500.00 15 Physical/Chemical Sampling and Testing LS 1 4,000.00 4,000.00 1 4,000.00 16 Disinfection LS 1 1,000.00 1,000.00 2 2,000.00 17 Bacteriological Testing LS 1 2,000.00 2,000.00 1 2,000.00 18 Priority Pollutant Testing LS 1 3,000.00 3,000.00 1 3,000.00 19 Pump and Motor Each 1 6,000.00 6,000.00 1 6,000.00 20 Well Column LF 70 175.00 12,250.00 70 12,250.00 21 Concrete Pedestal, etc. LS 1 20,000.00 20,000.00 1 20,000.00 22 Electrical LS 1 18 000.00 18,000.00 1 18 000.00 Original Bid Amount $130,000.00 Revised Subtotal - Original Bid Items Only $113,151.00 CHANGE ORDER NUMBER 1 4" Test Well authorized 5/29/96 3 Delete 370 LF @ $8.00/LF LF -370 8.00 (2,960.00) 4 Delete 5 tests @ $250/test EA -5 250.00 (1,250.00) 5 Delete Geophysical well survey EA -1 2,000.00 (2,000.00) A Mobilization of small drill rig for 3" hole LS 1 1,500.00 1,500.00 B 3" steel casing LF 250 3.55 887.50 C Cement Grout Sack 13 12.00 156.00 D Drilling Mud Sack 32 8.35 267.20 E Drilling rig hourly rate Hr 43.5 150.00 6,525.00 F Open borehole LF 180 6.00 1,080.00 G Sand ocket dred in Hr 24 150.00 3 600.00 Subtotal C.O. 1 $7,805.70 CHANGE ORDER NUMBER 2 H Steel Casing pipe 814.38 I Re-stockin for unused 16" casin 649.02 Subtotal C.O. 2 $1,463.40 CHANGE ORDER NUMBER 3 4 Delete 1 @ $ 250/EA. -1 250.00 (250.00) 7 Delete 48 LF @ $83.00/LF -48 83.00 (3,984.00) 8 Delete 15 LF @ $23.00/LF -15 23.00 (345.00) 9 Delete 121 LF @ $28.00/LF -121 28.00 (3,388.00) 10 Delete 150 sacks @ $12.00/Sacks -150 12.00 (1,800.00) 11 Delete 117 LF @ $16.00/LF -117 16.00 (1,872.00) J Geophysical well log of 16" well 1 2,000.00 2,000.00 K R emobilization!demobilizatlon 1 9,000.00 9,000.00 L Mobilization of special Pressure Grout Equip. 1 5,000.00 5,000.00 M Backfill well for pressure grout 8 50.00 400.00 N Pressure grout 16" well per SJRWMD 120 12.00 1,440.00 0 Drill out sand backfill 129 10.00 1,290.00 P F & 110" casing 170 24.00 4,080.00 Q Cement 10" casing 286 12.00 3,432.00 R Drill 9-7/8 " open borehole 150 15.00 2,250.00 S Provide left hand coupling and nipple 1 1,500.00 1,500.00 T Geophysical well log of proposed 10" well 1 2,000.00 2,000.00 U F & I and Remove Test Pum 1 1,800.00 1,800.00 Subtotal C.O. 3 $22 553.00 REVISED PROJECT COST $161,822.10 Attachment No.4 CONTRACT CHANGE ORDER Change Order No. 3 Engineer Project No. W0446.01 Project Title: Water Supply Well No.6 Contractor: American Drilling, Inc. Reason for Change: Additional items are required due to unforeseen below surface conditions. Breakdown of Proposed Changes and Basis for Payment (Includes pertinent drawings, specifications, and documentation where necessary) Item No. and Description Change in Contract Cost + (-) Deletions: Item 4: Revise quantity to 2. Delete 1 @ $250.00 Item 7: Revise quantity to 52 ft. Delete 48 ft @ $83.00/ft. Item 8: Revise to 95 ft. Delete 15 feet @ $23.00/ft. Item 9: Revise quantity to 89 ft. Delete 121 ft @ $28.00/ft. Item 10: Revise quantity to 120 sacks. Delete 150 sacks at $12.00/sack Item 11: Revise quanity to 103 ft. Delete 117 ft @ $16.00/ft. TOTAL DELETIONS: ($250.00) (3,984.00) ($345.00) ($3,388.00) ($1,800.00) ($1,872.00) ($11,639.00) Additions: Item J. Geophysical Well Logging 16" Well Item K. Remobilization/demobilization of drill rig Item L. Mobilization of special grout equipment Item M. Backfill well for pressure grout, 8cy @ $50.00/cy Item N. Pressure grout well per SJRWMD. 120 sacks at $2.00/sack Item O. Drill out sand backfill - 129 ft @$lO.OO/ft. Item P. F & I 10" casing - 170 ft @ $24.00/ft. Item Q. Cement 10" casing, 286 sacks @ $12.00/sack Item R. Drill a 7/8" open bore hole - 150 ft @ $15.001ft. Item S. Provide left hand coupling and nipple Item T. Geophysical log of 10. well Item U. F & I and remove test pump. $ 1,000.00 2,000.00 9,000.00 5,000.00 400.00 1,440.00 1,290.00 4,080.00 3,432.00 2,250.00 1,500.00 2,000.00 1,800.00 TOTAL ADDITIONS: $34,192.00 (1) Total Proposed Change in Contract Cost +(-) $ $ 22.553.00 (2) Original Contract Price 130.000.00 (3) Total All Previous Change Orders (Change Order No.1 thro 2) $ 9.269.10 (4) New Contract Price (Total of Item 1 & Item 4) $ 161.882.10 Recommended By Engineer: Date: Accepted By Contractor: Date: Accepted By Owner: Date: