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HomeMy WebLinkAbout1997-08-20 WSB AGENDA1. 2. 3. 4. 5. AGENDA ENGLEWOOD WATER AND SEWER BOARD WEDNESDAY, AUGUST 20, 1997 5:00 p.m. ** CONFERENCE ROOM A ** MINUTES OF THE JULY 8, 1997 WATER & SEWER BOARD. (ATT. 1) GUEST: GREG DYE OF CAMP DRESSER & McKEE RE: THIRD AMENDMENT TO AGREEMENT AND ALLEN PLANT PROJECT UPDATE. (ATT. 2) "NO COMMENT" POLICY ON McLELLAN RESERVOIR PROPERTY. VALLEY SANITATION DISTRICT -BOARD AND ATTORNEY WILL APPEAR AT NEXT MEETING. OTHER. WATER & SEWER BOARD MINUTES July 8, 1997 The meeting was called to order at 5 :06 p.m. Chairperson Neumann declared that a quorum was present . Members present: Members absent : Also present : Clark, Habenicht , Guy, Neumann, Otis, Wiggins Burns, Higday, Vobejda Stewart Fonda, Director of Utilities 1. MINUTES OF THE JUNE 10 , 1997 MEETING. The Englewood Water and Sewer Board Minutes from the June 10 , 1997 meeting were approved as written . Ms . Habenicht moved : Mr. Guy seconded : Ayes : Nays : Members Absent : Motion carried. To approve the June 10 , 1997 Englewood Water and Sewer Board Minutes as written. Clark, Neumann, Otis, Wiggins None Burns, Higday, Vobejda 2 . LETTER FROM VALLEY SANITATION DISTRICT REGARDING DISSOLUTION DATED JUNE 16 , 1997 . The Board received a letter from Valley Sanitation District regarding the dissolution of Valley Water District and Valley Sanitation District . The Water and Sewer Broad invites the Valley Sanitation District 's representative(s) to the next meeting to further discuss this issue . 3. LETTER TO LYNN HALL AT 3385 S. MARION ST. Mr. Fonda informed the Water and Sewer Board members that Ms . Hall had a special medical problem that required the use of distilled water. Due to Ms . Hall's needs, distilled water was being made available to her at the Allen Filter Plant or at the Bi-City Wastewater Plant. Mr. Fonda indicated that special requests should continue to be considered on an individual basis . 4. PROPOSED ORDINANCE: PROBHIBITED DISCHARGES . The board received a copy of a memorandum regarding an addition to the Municipal Code concerning Storm Water at the June 10th, meeting . Ms. Neumann noted that the correction needed in paragraph ( a ) had been corrected in both the Memorandum and the attached City Ordinance . Mr. Guy moved : Mr. Otis seconded : Ayes : Nays : Members Absent : Motion carried . To recommend Council approval of the addition to the Storm Water ordinance : Section 12-15-9 PROHIBITED DISCHARGES . Clark, Habenicht, Neumann , Wiggins None Bums, Higday , Vobejda 4. LETTER TO MR . RICK CABLES, FOREST SUPERVISOR REGARDING SUPPORT FOR THE ALTERNATIVE A2. The Board approved to support the Wild and Scenic River Study Report and Draft Legislative Environmental Impact Statement for the North Fork of the South Platte and the South Platte Rivers as outlined in the Draft LEIS . Ms . Neumann moved : Mr. Wiggins seconded : To support Alternative A2 . Ayes : Clark, Guy , Habenicht , Otis , Wiggins Nays : None Members Absent: Burns, Higday, Vobejda Motion carried. 5. A SPECIAL REQUEST WAS MADE BY MS . HABENICHT. The Water and Sewer Board Members, Mr. Fonda, and Ms. Miller wish to state: we are thinking about Ms. Cathy Burrage and that we wish her a speedy recovery. The next Water and Sewer Board meeting will be August 20 , 1997, at 5:00 p .m. in Conference Room A. Respectfully submitted, Cathy Miller Acting Recording Secretary AUG 08 '97 08:53AM CAMP DRESSER & MC KEE TIIIRD AMENDMENT TO AGREEMENT This THIRD AMENDMENT made this ____ day of ____ , 1997 between the City of Englewood, Colorado ("OWNER") and Camp Dresser & McKee Inc. ("ENGINEER") modifies the AGREEMENT between the OWNER and the ENGINEER dated May 6, 1996. The AGREEMENT is modified by this TillRD AMENDMENT to (1) provide modifications to the final design of improvements to the Allen WTP; (2) Bidding Phase Services ; and (3) Construction Phase Services. Specifically, the following modifications to Exhibit A to the AGREEMENT are agreed to: 1. Add the following paragraphs to Exhibit A: "1 .5 Additional Design Investigations and Final Design: 1) Investigate and report on filter pipe gallery flooding during backwash 2) Design additional raw water piping, metering, overflow and discharge structures for the North and South Reservoirs and redesign of City Ditch turnout structure 3) Potassium Permanganate feed modifications -relocate plant feed room and modify existing pump station for second feed facility 4) Relocate blower facility to a separate building 5) Prepare an Environmental Assessment for CW &PA Loan Application 6) Prepare predesign and design of site flood proofing and drainage 7) Perform an inspection of the filtered water channel: prepare a report, and design repairs 8) Incorporate the ClearweU Modification Project into the Project, and provide assistance with GAC Filter Media Service Contract and in obtaining NPDES Discharge Permits 9) Evaluate a new round of proposals from lamella plate pack suppliers 10) Revise design of Pretreatment Facility to accommodate Waterlink Supersettler plate system 11) Perform a design investigation and prepare specifications for (a) repairs to the holes and nicks in the Exterior Insulation Finish System (EJFS), (b) re-coating of the entire EIFS , and (c) refinishing of doors and windows 1.6 The Bidding Phase Services described in paragraph 2.3. of the AGREEMENT are hereby authorized. The net cost for printing of the contract documents issued during the Bidding Phase will be paid for by the OWNER. Net cost is defined as the actuai cost of printing as arranged for by the ENGINEER Jess the net value of the document deposit AUG 08 '97 08:54AM CAMP DRESSER & MCK EE received and held by the ENGlNEER from prospective bidders after all refunds have been issued. 1. 7 The Construction Phase Services described in paragraph 2.4 of the AGREEMENT are hereby authorized." 2. The schedule for performance ofENGINEER's services in the TIIlRD AMENDMENT is as follows: 1.5 Additional Design Investigations and Final Design Commence Work Complete Work Work underway October 31, 1997 October l, 1997 December 31, 1997 1.6 1.7 Bidding Phase Services Construction Phase Services November 1, 1997 May 1, 1999 (substantial completion) August 31, 1999 (final completion) 3. Payment of Services rendered by ENGINEER. The following are budget costs for services authorized by this TIIlRD AMENDMENT: 1.5 l.6 1.7 Additional Design Investigations and Final Design I) Filter pipe gallery flooding 2) 3) 4) 5) 6) 7) 8) 9) IO) Additional raw water facilities Additional Potassium Pennanganate facilities Separate Blower Building Environmental Assessment Site Floodproofing, drainage -preliminary design -design Filtered Water Channel -inspection and report -design Clearwell Modifications -design GAC Filter Service Contracts and NPDES Discharge Pennits -assistance Lamella plate pack supplier negotiations Revised design to accommodate Waterlink 11) Design, specifications for repair/refinish of Exterior Insulation Finish System Subtotal, Additional Design Bidding Phase Services Construction Phase Services Total 07ll1\l0!141147DNMGT\AMENDJ 8fti'!'I JW $ 10,880 18,000 0 59,000 5,300 18 ,460 57,500 8,300 9,200 3,400 6,500 8,500 7,000 4.300 216,340 30,000 623.000 $869 340 2 AUG 08 '97 08:54AM CAMP DRESSER & MC KEE Accordini:Iy, the following modificatiom; are made to paragraph 4.1 of Exhibit A to the AGREEMENT: . "4.1 For the Basic Services performed, the OWNER agrees to pay the ENGINEER fees not to exceed SZ.200,258, based upon the following elements: 4.1. l Tl1e portion of the total fees attributable to each component of the project is as follows: Preliminary Design Residuals Assistance and Study First Amendment -Floc/Sed Equipment Investigation Second Amendment -Final Design Third Amendment -Additional Design • Bidding Services -Construction Services Total $251,127 67,927 19,864 992,000 216,340 30,000 623.000 $2 200 258 4 .1.2 For work done by the ENGINEER except for Resident Project Representative services, services will be billed based on an amount equal to ENGINEER's Direct Labor Costs times a factor of 3. l for services rendered by principals and employees engaged directly on the Project, plus out-of-pocket expenses incurred in connection with these services, plus payment for work done by subconsultants (outside professionals) at cost to ENGINEER. For work done by the ENGINEER in providing full-time Resident Project Representative services, these services will be billed based on an amount equal to ENGINEER's Direct Labor Costs times a factor of 2.3." 4 . Reason for TIIlRD AMENDMENT 1.5 Additional Design Investigations and Final Design 1) Filter pipe gallery flooding. Under certain operational procedures , the filter gallery between Fiher No. 3 and No. 4 floods during backwash. Extensive field and hydraulic investigation revealed a partial blockage in the drain piping, pipe sagging, and serious air entrainment during backwash which restricts hydraulic flow. To repair/correct these deficiencies would probably cost $100,000 to $200,000. Fortunately, a reasonable alternate was developed near the end of the design phase -the problem does not occur at lower backwash rates (less than 16 gpm/ft2). Granular activated carbon (GAC) as a filter medium requires a lower backwash rate than does anthracite, and it was the OWNER's desire to retrofit three filters with GAC rather than just two (Filters No. :Z and No . 3 ). Therefore, by retrofitting Filter No. 4 also with GAC and backwashing at a lower rate, the filter gallery will not flood (based on an actual test at 16 gpm/ft2 rate), and three filters will be equipped with GAC. 2) Additional raw water facilities. By designing overflow and discharge structures for both the North and South ReseIYoirs, it will be possible to completely avoid (except under emergency water supply conditions) the return and reuse of waste backwash and filter-to-waste water. This change in procedure is being strongly U710\IOS74114T11""'!G1'4M~O.J ¥111'17 Jw 3 AUG 08 '97 08:54AM CAMP DRESSER & MCKEE endorsed by EPA, the State Health Department, and A WW A as a way to minimize exposure to microbial risk (Giardia and Crypto). It also should reduce the potential for taste and odors and manganese problems. By redesigning the City ditch turnout structure and associated yard piping, operational flexibility is provided to select individually or mix raw water sources from the Union Avenue Pump Station, City ditch, or the North Reservoir. 3) Potassium Permanganate Feed Modifications. The original design contemplated a complete feed facility. The modifications to provide two facilities can be accomplished as a no-cost design change. 4) Separate Blower Building. The initial design contemplated locating the blower for air/water backwash in the existing filter building. Two separate locations were attempted io the filter building, and for various reasons, would have not worked well. It was finally decided by the ENGINEER and plant staff jointly to relocate the blower to a separate small building adjacent to the filter building. 5) Environmental Assessment. The loan the OWNER contemplated receiving from the Colorado Water and Power Authority is based on the recent SOW A authorization by the federal government. Because federal funds were involved, the NEPA requirement to prepare an Environmental Assessment must be complied with. 6) Site Floodproofing, Drainage. After final design of the improvements to the Project were initiated, the OWNER learned that flood studies perfonned by the Urban Drainage and Flood Control District indicated the Allen plant was not adequately protected from flooding by Big Dry Creek. This work item is to prepare preliminary and final design for a berm and floodwall along the creek to protect the plant. 7) Filtered Water Channel. Older parts of the Allen plant were constructed with only a single concrete wall separating the filtered water channel from the backwash water and filter-to-waste channel. Ifthere were any cracks in this wall, it could be a serious cross connection. This issue was discussed with the State Heaith Department. To construct a new set of channels would be very expens.ive . The Health Department agreed that if a physical inspection revealed channel wall integrity and/or minor repairs necessary for channel wall integrity, and if those repairs were made, the design would be acceptable. This work item accomplished that inspection and minor repair design. 8) Clean Well Modifications. a) b) Structural repairs were investigated in 1995 and no repair work was performed then because of high bids. The work has now been folded into the current project and should be able to be lLccomplished at a reasonable cost. GAC filter services contract assistance. Rather than purchase GAC filter material (which has a limited life and must be replaced in approximately three years), the OWNER has opted to receive proposals for a service 4 AUG 08 '97 08:55AM CAMP DRESSER & MCKEE contract from two activated carbon suppliers, providing for initial furnishing of the media, six-month testing of its continued usefulness, and ultimately, removal, disposition, and replacement. The ENGINEER has assisted the OWNER in the review of these proposals. c) NPDES Permit Assistance. See item 2 above. The OWNER already bas a NPDES pennit for the South Reservoir. The ENGINEER assisted in obtaining a pennit for the North Reservoir to provide complete operational flexibility. 9) Lamella Plate Supplier Negotiations. Because patent and licensing agreements expired, new suppliers of lame Ila plate packs were recognized as being in the market in June 1997. This provided an opportunity for the OWNER to test whether the negotiated price it had received from Parkson Corporation ($719,400) was inflated. In the end, the supplier Waterlink was selected-at a lower price, and the City will be receiving an all stainless steel system instead of a system with polystyrene plates . 10) Revised Design to Accommodate Waterlink . The Waterlink system requires three beams to support the plate packs versus four beams as required for the Parkson system . The smaU cost for redesign is worth the savings and improved material received ~ see item 9) above . 1 l) Design, Specifications for Repair/Refinish of Exterior Insulation Finish System. The existing system for the filter plant involves a polystyrene insulation overlain with Y.-incb stucco. At comers of the building where "dings" have occurred, and at locations where woodpeckers have drilled a hole through the stucco finish (about 50 holes), plant personnel have attempted to patch the dings and holes. The color of the original stucco finish has bleached, and the newer repairs show a blotched pattern on the walls. This design effort is to put an additional protective coating over the stucco to make it "woodpecker-proof" and to restore the exterior trim finish for the windows and doors . 1.6 Bidding Phase services. Advertisement for bids is scheduled for October I, 1997. Authorization of this services is now timely. l . 7 Constroction Phase Services Bids are scheduled to be taken October 31, 1997 . Because there are many bid alternatives and some negotiations with the apparent low bidder may be necessary, it is anticipated that bids will be left open for 60 days, and the construction contract may not be awarded until December 31 , 1997 . Th is authorization for construction phase services must be given in any case in the next three months, so it has been included heroin to reduce paperwork . All other terms and conditions of the AGREEMENT of May 6, 1996, as amended remain in full force and effect. IN WITNESS WHEREOF, the parties hereto have executed this AGREEMENT to be effective as of the date first above written . 0710\IOS74\1~1DNMGlVIMl!ND.J &11197 jw s AUG 08 '97 08=55AM CAMP DRESSER & MCKEE P.7/7 OWNER: ENGINEER: Cicy ofEn;lewood Camp Presser & McKee Inc By: Thomas J. Bums .By: Carl P. Houck Title: Mayor Title: Vice Prcsisient Address for giving notices: Address for giving notices: City of Englewood 13 31 1 Zth Street. Suite 1200 3400 South Elati.Street Denyer. Colorado 80202 Englewood. Colorado 801 JO 0710\10'"741l47DNMG1'.i\Ml!ND .J llN9'I' jw 6 -RU G 2 0 '97 11=44RM CRMP DRE SS ER & MCK ll City of Englewood Water Board Pruentation August 20, 1997 Allen WTP Improvements Presentation Outline l. Overview of Project a) Project Facilities -Tent talk diagram -Alternate Bid Items 1) Raw Water Delivery System Improvements Allow swapping of water rights to yield obtaining a greater quantity of high quality water and avoid recycling potentially contmtinatcd water through the plant. 2) Sludge Dewatering Building and Drying Arca 3) For the south filters, air :K:our and OAC 4) Improvements to the filter· to-waste faoilities for the south fibr:n. b) Water Quality -How will new treatment help solve the dirty water problems • Improved chemical feed facility for river water •New chemical feed facility for City Ditch water • Nonh Reservoir taken out of service and cleaned • How will the new treatment facilities help solve the taste and odor problems • Improved chemical feed facilities -pre-oxidants • Granular Activated Carbon Facilities II. Changes to Project a) FaciJitic:& • Major Changes • Cost Reduction Items • Keep the same size piping for the north filter inlet and outlet -very expensive to enlarge, due to significant structural modifications. The plant will still have adequate filtration capacity . • Eliminating the additional office space and building modifications - plant staff havo said that they can utilize the existing building • Deleted sludge thickener from project. All solids will be taken to the washwater reservoir for processing. • Deleted third pretreatment train . Negotiations with the Health Department have allowed the elimination of a third process unil HU~ c~ -~r i 1:44Hf'1 CRMP DRE SS ER & MCK EE -Cost Increase Item& • Enclosed walkway between the existing filter building and the new pretreatment building. • Sole-sourced equipment to match cxistin& equipment and meet operations staff preferences. • Disinfection baftle in clear well to improve disinfection capabilitie1 . that was somewhat lost with the incorporation of Granular Activated Carbon . * Flood proofing the site • unanticipated. Site was flood proofed in the 1980 improYement&. A recent flood analysis yields a higher flood plain which puts the Allen WTP in the flood plain. Removing the plant from the flood plain is necessary to obtain approval of the health department and to obtain loan . The City is being proactive in designing facilities to remove the plant from the flood plain . •Modifying one of the south filten to include Granular Activated Carbon and Air Scour . An original altcmate bid item, now necesaitated to eliminate the ongoing problem oftbe flooding filter pipe gallery. • Repairs to wood pecker holes in the exterior of the existing building. b) Project Construction Com -Predesign Base Project Construction Cost Estimate"" $10.38M ·Current estimated Bue Project Construction Cost = $1 lM Altemste Bid Jtmt I 2 3 (for 2 filters) 4 E;rtimm GmJ:StwctiQP ~ $470,000 $670,000 $240,000 $170,000 Total Estimated Construction Costs, including all Alt. Bid Items ,,. $12 .SSM COUNCIL COMMUNICATION Date Agenda Item Subject September 2, 1997 COM Contract Amend. #3 Initiated By Staff Source Utilities Department Stewart Fonda , Director of Utilities COUNCIL GOAL AND PREVIOUS COUNCIL ACTION Council approved the Second Amendment to Agreement with Camp Dresser & McKee (COM) in February 3, 1997 for the Final Design Proposal for the Allen Filter Plant Improvements .. RECOMMENDED ACTION Council approval , by motion , of Contract Amendment No . 3 for design modifications for the Allen Filter Plant improvements . BACKGROUND, ANALYSIS, AND ALTERNATIVES IDENTIFIED COM studied the existing water treatment facilities of the City and prepared a Preliminary Design for the Allen Filter Plant Improvements . Public concern over water quality issues such as taste and odor, cryptosporidium and giardia, together with the requirement to meet increasingly stringent regulations resulting from the 1986 Safe Drinking Water Amendment have prompted upgrading of the current water treatment facilities . Public meetings were held and a rate increase to fund the improvements was adopted. Preliminary design by COM was approved by Council on May 6, 1996. The Final Design Proposal was approved February 3, 1997 . The proposed Third Amendment to Agreement is for additional design investigations that will address the following; retrofitting Filter No . 4 to prevent filter pipe gallery flooding, designing overflow and discharge structures for both the North and South Reservoirs, potassium permanganate feed modifications , blower relocate to a separate building adjacent to the filter building, environmental assessment to comply with NEPA loan requirements , berm and floodwall design at Big Dry Creek to provide drainage and floodproof the Plant, and an inspection of channel wall integrity and/or minor repairs . This channel separates the filtered water from the backwash water and the filter-to-waste channel. The Third Amendment would also address clear well modifications for repair work, GAC filter services contract facilitation and NPOES Permit assistance for the North Reservoir. Other items covered by this Amendment would include Lamella Plate supplier negotiations , design revision to accommodate a Waterlink system and design specifications to repair and refinish the existing filter plant exterior. FINANCIAL IMPACT The Third Amendment to the Agreement between the City of Englewood and COM includes design modifications as well as the next proj ect phase work for bidding and construction phase services . (COM letter dated August 8 , 1997 .) This Amendment raises the engineering fees for this project to $2 ,220 ,258. The water rate increase to fund this project was passed by Council on March 18 , 1996. This is a budgeted item . LIST OF ATTACHMENTS Letter dated Aug. 8 , 1997 from COM Third Amendment to Agreement THIRD AMENDMENT TO AGREEMENT This THIRD AMENDMENT made this ____ day of _____ 1997 between the City of Englewood, Colorado ("OWNER") and Camp Dresser & McKee Inc. ("ENGINEER") modifies the AGREEMENT between the OWNER and the ENGINEER dated May 6, 1996. The AGREEMENT is modified by this THIRD AMENDMENT to (1) provide modifications to the final design of improvements to the Allen WTP; (2) Bidding Phase Services; and (3) Construction Phase Services. Specifically, the following modifications to Exhibit A to the AGREEMENT are agreed to: 1. Add the following paragraphs to Exhibit A: "1.5 Additional Design Investigations and Final Design: 1) Investigate and report on filter pipe gallery flooding during backwash 2) Design additional raw water piping, metering, overflow and discharge structures for the North and South Reservoirs and redesign of City Ditch turnout structure 3) Potassium Pennanganate feed modifications -relocate plant feed room and modify existing pump station for second feed facility 4) Relocate blower facility to a separate building 5) Prepare an Environmental Assessment for CW&PA Loan Application 6) Prepare predesign and design of site flood proofing and drainage 7) Perfonn an inspection of the filtered water channel; prepare a report, and design repairs 8) Incorporate the Clearwell Modification Project into the Project, and provide assistance with GAC Filter Media Service Contract and in obtaining NPDES Discharge Pennits 9) Evaluate a new round of proposals from lamella plate pack suppliers 10) Revise design of Pretreatment Facility to accommodate Water link Supersettler plate system 11) Perfonn a design investigation and prepare specifications for (a) repairs to the holes and nicks in the Exterior Insulation Finish System (EIFS), (b) re-coating of the entire EIFS, and ( c) refinishing of doors and windows 1.6 The Bidding Phase Services described in paragraph 2.3. of the AGREEMENT are hereby authorized. The net cost for printing of the contract documents issued during the Bidding Phase will be paid for by the OWNER. Net cost is defined as the actual cost of printing as arranged for by the ENGINEER less the net value of the document deposit 0710\IOS74\1470NMG'l\AMEND.3 811197 jw ,. . ved and held by the ENGINEER from prospective bidders after all refunds have ;n issued. The Construction Phase Services described in paragraph 2.4 of the AGREEMENT are hereby authorized." .ne schedule for performance ofENGINEER's services in the THIRD AMENDMENT is as follows: 1.5 1.6 1.7 Additional Design Investigations and Final Design Bidding Phase Services Construction Phase Services Commence Work Complete Work Work underway October 31, 1997 October I, 1997 December 31, 1997 November I, 1997 May 1, 1999 (substantial completion) August 31 , 1999 (final completion) 3. Payment of Services rendered by ENGINEER. The following are budget costs for services authorized by this THIRD AMENDMENT: 1.5 Additional Design Investigations and Final Design 1) Filter pipe gallery flooding $ 10,880 2) Additional raw water facilities 18,000 3) Additional Potassium Permanganate facilities 0 4) Separate Blower Building 59,000 5) Environmental Assessment 5,300 6) Site Floodproofing, drainage -preliminary design 18,460 -design 57,500 7) Filtered Water Channel -inspection and report 8,300 -design 9,200 8) Clearwell Modifications -design 3,400 GAC Filter Service Contracts and NPDES Discharge 6,500 Permits -assistance 9) Lamella plate pack supplier negotiations 8,500 10) Revised design to accommodate Waterlink 7,000 11) Design, specifications for repair/refinish of Exterior 4.300 Insulation Finish System Subtotal, Additional Design 216,340 1.6 Bidding Phase Services 30,000 1.7 Construction Phase Services 62J,OQO Total $862,J40 0710\IOS74\147DNMGl\AMEND.J 818197 jw 2 Accordingly, the following modifications are made to paragraph 4.1 of Exhibit A to the AGREEMENT: "4.1 For the Basic Services performed, the OWNER agrees to pay the ENGINEER fees not to exceed $2,200,258, based upon the following elements: 4.1.l The portion of the total fees attributable to each component of the project is as follows: Preliminary Design Residuals Assistance and Study First Amendment -Floc/Sed Equipment Investigation Second Amendment -Final Design Third Amendment -Additional Design -Bidding Services -Construction Services Total $251, 127 67,927 19,864 992,000 216,340 30,000 623.000 $2.200.258 4.1.2 For work done by the ENGINEER except for Resident Project Representative services, services will be billed based on an amount equal to ENGINEER's Direct Labor Costs times a factor of 3. I for services rendered by principals and employees engaged directly on the Project, plus out-of-pocket expenses incurred in connection with these services, plus payment for work done by subconsultants (outside professionals) at cost to ENGINEER. For work done by the ENGINEER in providing full-time Resident Project Representative services, these services will be billed based on an amount equal to ENGINEER's Direct Labor Costs times a factor of 2.3." 4. Reason for THIRD AMENDMENT 1.5 Additional Design Investigations and Final Design 1) Filter pipe gallery flooding. Under certain operational procedures, the filter gallery between Filter No. 3 and No. 4 floods during backwash. Extensive field and hydraulic investigation revealed a partial blockage in the drain piping, pipe sagging, and serious air entrainment during backwash which restricts hydraulic flow. To repair/correct these deficiencies would probably cost $100,000 to $200,000. Fortunately, a reasonable alternate was developed near the end of the design phase -the problem does not occur at lower backwash rates (less than 16 gpm/ft2). Granular activated carbon (GAC) as a filter medium requires a lower backwash rate than does anthracite, and it was the OWNER's desire to retrofit three filters with GAC rather than just two (Filters No . 2 and No. 3). Therefore, by retrofitting Filter No. 4 also with GAC and backwashing at a lower rate, the filter gallery will not flood (based on an actual test at 16 gpm/ft2 rate), and three filters will be equipped with GAC. 2) Additional raw water facilities. By designing overflow and discharge structures for both the North and South Reservoirs, it will be possible to completely avoid (except under emergency water supply conditions) the return and reuse of waste backwash and filter-to-waste water. This change in procedure is being strongly 0710\IOS741147DNMGTIAMEND.3 811197 jw 3 endorsed by EPA, the State Health Department, and A WW A as a way to minimize exposure to microbial risk (Giardia and Crypto). It also should reduce the potential for taste and odors and manganese problems. By redesigning the City ditch turnout structure and associated yard piping, operational flexibility is provided to select individually or mix raw water sources from the Union Avenue Pump Station, City ditch, or the North Reservoir. 3) Potassium Permanganate Feed Modifications. The original design contemplated a complete feed facility. The modifications to provide two facilities can be accomplished as a no-cost design change. 4) Separate Blower Building. The initial design contemplated locating the blower for air/water backwash in the existing filter building. Two separate locations were attempted in the filter building, and for various reasons, would have not worked well. It was finally decided by the ENGINEER and plant staff jointly to relocate the blower to a separate small building adjacent to the filter building. 5) Environmental Assessment. The loan the OWNER contemplated receiving from the Colorado Water and Power Authority is based on the recent SDWA authorization by the federal government. Because federal funds were involved, the NEPA requirement to prepare an Environmental Assessment must be complied with. 6) Site Floodproofing, Drainage. After final design of the improvements to the Project were initiated, the OWNER learned that flood studies performed by the Urban Drainage and Flood Control District indicated the Allen plant was not adequately protected from flooding by Big Dry Creek. This work item is to prepare preliminary and final design for a benn and floodwall along the creek to protect the plant. 7) Filtered Water Channel. Older parts of the Allen plant were constructed with only a single concrete wall separating the filtered water channel from the backwash water and filter-to-waste channel. If there were any cracks in this wall, it could be a serious cross connection. This issue was discussed with the State Health Department. To construct a new set of channels would be very expensive. The Health Department agreed that if a physical inspection revealed channel wall integrity and/or minor repairs necessary for channel wall integrity, and if those repairs were made, the design would be acceptable. This work item accomplished that inspection and minor repair design. 8) Clear Well Modifications. a) b) 0710\lOS74\147DNMG'l\AMEND.3 811197 jw Structural repairs were investigated in 1995 and no repair work was performed then because of high bids. The work has now been folded into the current project and should be able to be accomplished at a reasonable cost. GAC filter services contract assistance. Rather than purchase GAC filter material (which has a limited life and must be replaced in approximately three years), the OWNER has opted to receive proposals for a service contract from two activated carbon suppliers, providing for initial 4 furnishing of the media, six-month testing of its continued usefulness, and ultimately, removal, disposition, and replacement. The ENGINEER has assisted the OWNER in the review of these proposals. c) NPDES Pennit Assistance. See item 2 above. The OWNER already has a NPDES pennit for the South Reservoir. TI1e ENGINEER assisted in obtaining a permit for the North Reservoir to provide complete operational flexibility. 9) Larnella Plate Supplier Negotiations. Because patent and licensing agreements expired, new suppliers of larnella plate packs were recognized as being in the market in June 1997 . This provided an opportunity for the OWNER to test whether the negotiated price it had received from Parkson Corporation ($719,400) was inflated. In the end, the supplier Waterlink was selected -at a lower price, and the City will be receiving an all stainless steel system instead of a system with polystyrene plates . 10) Revised Design to Accommodate Waterlink. The Waterlink system requires three beams to support the plate packs versus four beams as required for the Parkson system . The small cost for redesign is worth the savings and improved material rece ived -see item 9) above. 11) Design, Specifications for Repair/Refinish of Exterior Insulation Finish System. The existing system for the filter plant involves a polystyrene insulation overlain with Y-i-inch stucco. At comers of the building where "dings " have occurred, and at locations where woodpeckers have drilled a hole through the stucco finish (about 50 holes), plant personnel have attempted to patch the dings and holes. The color of the original stucco finish has bleached , and the newer repairs show a blotched pattern on the walls . This design effort is to put an additional protective coating over the stucco to make it "woodpecker-proof'' and to restore the exterior trim finish for the windows and doors. 1.6 Bidding Phase services. Advertisement for bids is scheduled for October 1, 1997. Authorization of this services is now timely . 1.7 Construction Phase Services Bids are scheduled to be taken October 31 , 1997. Because there are many bid alternatives and some negotiations with the apparent low bidder may be necessary, it is anticipated that bids will be left open for 60 days, and the construction contract may not be awarded until December 31 , 1997 . This authorization for construction phase services must be given in any case·in the next three months, so it has been included herein to reduce paperwork. All other terms and conditions of the AGREEMENT of May 6, 1996 , as amended remain in full force and effect. 0710\IOS741147DNMGnAMEND.3 818197 jw 5 IN WI1NESS WHEREOF, the parties hereto have executed this AGREEMENT to be effective as of the date first above written. OWNER: ENGINEER: City of En~lewood Camp Dresser & McKee Inc. Thomas J. Bums Carl P. Houck Title: Mayor Title: Vice President Address for giving notices: Address for giving notices: City of Englewood 1331 17th Street. Suite 1200 3400 South Elatj Street Denver. Colorado 80202 Englewood. Colorado 80110 0710\IOS741147DN'MGTIAMEND.J 818197 jw 6