Memorandum

City of Lawrence

Public Works

TO:	Charles Soules, P.E., Public Works Director
FROM:	Matt Bond, P.E., Stormwater Engineer
DATE:	June 26, 2017
RE:	Maple Street Pump Station

During the public comment portion of the June 20, 2017 City Commission Meeting, it was stated that this project had come in under budget by Ted Boyle the President of the North Lawrence Improvement Association.  Mr. Boyle also inquired as to when the “directing the flow of water to the pump” by City forces would begin.

It should be noted that this project was originally listed in the 2005 North Lawrence Drainage Study (NLDS) at a cost of $4,375,000.  The actual total construction cost for the Maple Street Pump Station was just under $6,080,000. The construction was funded from two sources: General Obligation (G.O.) bonds in the amount of $2,000,000 and $4,080,000 from Infrastructure Sales Tax. 

Furthermore it should be noted that this project was bid twice.  Bids were originally received on March 3, 2015 from two (2) bidders listed in the table below.  The base bid included the pump station at 6^th & Maple Street and the downstream system under the railroad and through the levee to the Kansas River.  In addition to the base bid, contractors also provided an alternate bid for the additional storm sewer work upstream from the pump station. The alternate bid included extending the storm sewer from the pump station north along the west side of 6^th Street and then east along the south side of Lincoln Street to Lyons Park.

March 3, 2015 Bid Letting Results
CONTRACTOR	Engineer’s Estimate	Nowak Construction, Inc.	BRB Contractors
BASE BID TOTAL (river levee to pump station)	$4,128,379.00	$6,525,544.00	$5,947,275.00
ALTERNATE BID (pump station to park)	$1,047,267.00	$1,503,376.00	$1,589,338.00
GRAND TOTAL	$5,175,646.00	$8,028,920.00	$7,536,613.00

Due to the lowest bid significantly exceeding the engineer’s estimate, City Staff recommended that the bids be rejected.  The City Commission formally rejected the bids at its March 10, 2015 City Commission Meeting. 

Subsequently City Staff and Bartlett & West Engineers, Inc., the design engineer for the project, discussed potential ways with the bidding contractors to reduce costs.  The following design changes were implemented into the revised plans after getting direction from the City Commission to do so at its May 5, 2015 meeting:

Ø Modified the hydrologic criteria to reduce the overall design flow from 195 cfs to 100 cfs. This resulted in reducing the necessary pumping capacity of the pump station and the corresponding storm sewer pipe sizes while still maintaining the return design frequency at a 10-year return period for peak design flows.  Staff and Bartlett & West Engineers, agreed that with the sandy soil types as well as the open and relatively flat road side ditches in North Lawrence justified the use of a lower range of the American Society of Civil Engineers (ASCE) runoff coefficients for the basis of the design flow.

Ø Utilized submersible pumps which are more readily available than the previously specified unique vertical turbine pumps.  This also resulted in higher upstream flow line elevations for the storm sewer system which in turn lowered installation costs.

Ø Allowed the reuse of excavated soil as backfill for storm sewer installation.

Ø Added polypropylene pipe as an alternate to concrete pipe for the storm sewer.  Allowing alternate pipe materials provided additional competition between pipe suppliers.

Ø Specified the reconstruction the entire width of 6^th Street as an asphalt road instead of replacing half of the road in concrete.

Although the above changes were implemented into the redesign of the project, and the rebid of the project did result in a lower total cost, it unfortunately was once again higher than the engineer's estimate that Bartlett & West Engineers, Inc. developed.  The results of the September 1, 2015 rebid are shown in the table below.

September 1, 2015 Bid Letting Results
CONTRACTOR	Engineer’s Estimate	Nowak Construction,Inc.	BRB Contractors
BASE BID TOTAL	$3,752,114.00	$4,179,157.00	$4,716,880.00
BASE BID (RCP OPTION)	$736,005.00	$942,559.00	$859,980.00
BASE BID (POLYPROPYLENE OPTION)	$646,705.00	$1,107,710.00	$912,720.00
BASE BID + RCP OPTION TOTAL	$4,488,119.00	$5,121,716.00	$5,576,860.00
BASE BID + POLY OPTION TOTAL	$4,398,819.00	$5,286,867.00	$5,629,600.00
ALTERNATE BID	$501,445.00	$460,071.50	$513,281.00
ALTERNATE BID (RCP OPTION)	$368,725.00	$355,844.00	$281,975.00
ALTERNATE BID (POLY OPTION)	$292,520.00	$394,754.00	$284,455.00
ALTERNATE BID + RCP OPTION TOTAL	$870,170.00	$815,915.50	$795,256.00
ALTERNATE BID + POLY OPTION TOTAL	$793,965.00	$854,825.50	$797,736.00
GRAND TOTAL BASE + ALTERNATE (W/RCP OPTIONS)	$5,358,289.00	$5,937,631.50	$6,372,116.00

Ultimately the City Commission awarded the contract to Nowak Construction Inc. in the amount of $5,937,631.50 at its September 15, 2015 meeting. A Change Order in the amount of $141,549.16 was approved by the City Commission at its November 1, 2016 which brought the final cost of the pump station to $6,079,180.66.

The original scope of the Maple Street Pump station project, listed as System 6 in the NLDS, included new storm sewer at the following locations: along 7^th Street from Lincoln to Hickory, along 6^th Street from Lincoln to Lyon Street and additional storm sewer along Lincoln Street west of 6^th Street.  In order to save on construction cost it was decided to have the City’s Stormwater Crew complete some of these recommendations rather than included them in the bid construction project. 

It was also determined in order to prioritize when and where additional work would be completed to first observe watershed flow patterns upon the completion of the pump station. This is the work that Mr. Boyle was referencing during the public comment portion of the city commission meeting.

Now that the pump station has experienced several rainfall events it has been determined that the area along Perry Street between 4^th and 6^th Streets (refer to the red lines on attached map exhibit) will be the next location to receive improvements.  The work will include the regrading of the ditch on the south side Perry Street between 4^th & 5^th Streets and the installation of an enclosed storm sewer on the south side of Perry between 5^th & 6^th Street.  All of the work will be completed within the current street right of way. The completion of this project is dependent upon the remaining stormwater maintenance funding as well as its potential impact upon an existing 8” water line that was installed in 1922.  The Department of Utilities is currently reviewing the potential impact to the existing water line.  The estimated cost for the storm sewer work is approximately $40,000-$45,000 including labor, materials, right of way restoration and equipment costs. Construction of the project will take approximately three to four weeks to complete.  Work could begin as early as the fall of 2017 provided the existing water line is not adversely affected and does not need to be replaced/relocated.  It should be noted that if the water line is affected, relocating it is not in the Department of Utilities budget for 2017 and would have to be considered in 2018.