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1b. Lift Station 10: Approve Consultant Contract09 CITY OF CHANHASSEN 7700 Market Boulevard PO Box 147 Chanhassen, MN 55317 Administration Phone: 952.227.1100 Fax: 952.227.1110 Building Inspections Phone: 952.227.1180 Fax: 952.227.1190 Engineering Phone: 952.227.1160 Fax: 952.227.1170 Finance Phone: 952.227.1140 Fax: 952.227.1110 Park & Recreation Phone: 952.227.1120 Fax: 952.227.1110 Recreation Center 2310 Coulter Boulevard Phone: 952.227.1400 Fax: 952.227.1404 Planning & Natural Resources Phone: 952.227.1130 Fax: 952.227.1110 Public Works 7901 Park Place Phone: 952.227.1300 Fax: 952.227.1310 Senior Center Phone: 952.227.1125 Fax: 952.227.1110 Web Site www.ci.chanhassen.mn.us MEMORANDUM TO: Todd Gerhardt, City Manager Uf FROM: Paul Oehme, Director of Public Works /City Engineer . DATE: June 10, 2013 v ' SUBJ: Lift Station 10 Improvements, Project No. 13 -07: Approve Consultant Contract PROPOSED MOTION "The City Council approves a consultant contract with WSB & Associates for design and construction administration services for Lift Station 10 Improvements in the amount of $46,667." City Council approval requires a simple majority vote of those present. BACKGROUND Lift Station No. 10 is located at the end of Big Woods Drive next to Lotus Lake and services a large area of the City's Lotus Lake Sanitary Sewer District. This sewer district is nearly fully developed however the sanitary lift station storage capacity is undersized for the size of the district. The lift station was originally constructed in 1975. The Lift Station No. 10 service area extends from Pleasant View Road to south of Sierra Trail between Lucy Lake and Lotus Lake. Two additional lift stations (Nos. 9 & 11) pump to the collection system, which conveys flow to Lift Station No. 10. The service area A-L- � cnaaenas rye x•— -- , + I + ew d " LeWnd C3 LS No. 10 Service Area F R 0-0- r-orcemain TOY >. L J:�� l _1 ,EM �.1. J - Lift Station 10 r� "N at Loma Lake ZIP Ake Ann 41 z Y •- eMV(tyitYt j s jam_ Lr, Chanhassen is a Community for Life - Providing for Today and Planning for Tomorrow Mr. Todd Gerhardt June 10, 2013 Page 2 encompasses approximately 480 acres and includes approximately 989 service connections. The sanitary sewer flow to the lift station is 0.271 million gallons per day (MGD). An 8 -inch forcemain extends from the lift station southeast along Lotus Lake to Hwy 101 where it discharges into a 21 -inch trunk sewer. The forcemain is approximately 7,625 feet in length. The station was last worked on in 2002 when new controls and a standby generator were installed. The lift station is the second largest pumping station the City maintains. DISCUSSION LS 10 wet well capacity is inadequate to effectively handle the volume of wastewater going through the station. The existing wet well has only about 8ft. of normal storage. The recommended storage for the volume of flow going to this station is calculated at 21 ft. Since the station has significantly undersized wet well capacity, the pumps cycle continuously causing premature wear. These pumps are constantly being serviced. The significant amount of pump cycling per day is also electrically inefficient. Additionally, when problems occur, emergency responders have very little time to diagnose, correct the problem and get the station running again before it overflows because the station essentially does not have any emergency storage. Staff is proposing to drill a new wet well on the existing lift station easement to create the recommended normal and emergency storage. The station is in close proximity to residential lakeshore properties so construction is limited to the existing lift station easement. The new wet well is anticipated to be drilled next to the existing lift station using caisson construction technique. The existing lift station will be kept in service while the new wet well is being constructed. A tri- plex submersible pump station is proposed to provide additional storage working range for the pumps and for a more efficient pumping operation. This will reduce the number of hourly starts and reduce the excessive wear on the pumps. The tri- plex station pumps would also be smaller, in the range of 36 hp to 50 hp. Fencing and landscaping improvements will be part of the project. Staff intends to meet with the adjacent property owners to work with them on a mutually acceptable plan. Consultant Proposals Staff emailed request for proposals (RFP) to three consultants for final design and construction services. On May 16, 2013, staff received proposals for the work from the consultants. All firms submitted a proposal which is summarized as follows: Mr. Todd Gerhardt June 10, 2013 Page 3 Barr Foth WSB & Engineering Infrastructure Assoc., Inc. & Environment Submitted prior to the ✓ ✓ ✓ �- deadline Proposal format ✓ F ✓ ✓ Transmittal letter submitted ✓ ✓ ✓ Consultant team identified ✓ �✓ ✓ Understanding of project ✓ ✓ ✓ Estimate of hours and fees ✓ ✓ ✓ for each task Total Fee $53,000 $57,628 $46,667 All firms met the minimum qualifications for the project. WSB & Associates had the lowest proposal. WSB has worked on other lift station projects for the City. The most recent project was improvements to lift station 3 on TH 7. They were also the engineer that assisted the City with the design of the 2012 street reconstruction project in the Minnewashta Height neighborhood. Their work has been acceptable. The contract would be a time and materials based work not -to- exceed amount. As with all engineering contracts, the consultant must submit periodic invoices for staff review prior to processing. The consultant will be required to submit timesheets verifying the hours worked on the project and expense sheets. Staff will review the invoices and expense sheets for accuracy and conformance to the contract. Schedule The tentative schedule for the project is as follows: Neighborhood Meeting July 2013 Award of Construction Contract September 23, 2013 Construction Start October 7, 2013 Substantial Completion December 13, 2013 Final Completion June 13, 2014 Attachments: CIP sheet 0 Capital Improvement Program 2013 rhru 2017 City of Chanhassen, MN Project # SS-023 Project Name Lift Station 10 Improvements Account #1 701-7025 - Account #2 Account #3 Account #4 Department Sanitary Sewer Improvements Contact PaulOehme Type Improvement Useful We Category Utilities Priority . n/a Description Total Project Cost: $360,000 [his project would increase the wet well capacity, replace the pumps with more efficient pumping sequencing and replace the outdated electrical )anel of the lift station. Justification Lift Station 10 has a large sewer shed which is located on the west side of Lotus Lake in the Carver Beach area. The station is one of the largest he City maintains. Currently Lift Station 10 has a significantly undersized wet well capacity. The pumps cycle continuously which causes )remature wear on the pumps and motors and is very inefficient. Also, the small wet well does not allow much time for the utility department to •espond if station problems occur. The lift station is located next to Lotus Lake, which could lead to environmental problems if an accident were 0 occur. Expenditures 2013 2014 2015 2016 2017 Total Construction 360,000 360,000 Total 360,000 360,000 Funding Sources 2013 2014 2015 2016 2017 Total Sewer utility Fund 360,000 360,000 Total 360,000 360,000 91