Title
Change Order to the Construction Contract for the NW 22nd Street Milling and Resurfacing Project (B)
This involves a request to approve a Change Order for the construction contract, NW 22nd Street Milling and Resurfacing Project, in order to provide a better final product and to compensate for unknown site conditions.
Explanation
On November 15, 2012, the City Commission approved staff's recommendation to award a bid to R.E. Arnold Construction, Inc., for the NW 22nd Street Milling and Resurfacing project in accordance with approved plans and specifications.
Change Order #4 includes several items. The price change and justification are included in the attached details and presentation. A basic outline of changes is shown below.
Unsuitable material was found during the pipe installation under NW 1st Avenue and NW 22nd Drive which caused the unsuitable material to be excavated and replaced or face a high probability of premature roadway and pipe failure. "Earthwork - Cut" item was added for an increase of $19,698.48. "Earthwork - Fill" item was added for an increase of $12,625.47.
Additional measures were deemed necessary to ensure the bus stop near the discharge of the pipe installation was not a safety concern due to steep slopes and drop offs. Quantity of "Concrete Class NS, Gravity Wall" item was overrun for an increase of $1,533.60. Quantity of "Concrete Ditch Pavement, 4 Inch" item was overrun for an increase of $729.00. "Hand Rail" item was added for an increase of $1,542.13.
The slopes behind the widened sidewalk were steeper than the survey showed. This caused it necessary to add curb to the back of the sidewalk in order to tie into natural grade at a reasonable slope. Quantity of "Concrete Curb and Gutter, Type D" item was overrun for an increase of $9,040.
The sidewalk adjacent to the installed ADA ramp at the NE corner of 5th Avenue and 20th Street was severely cracked and did not meet ADA compliance for slope. This concrete was removed and replaced. Quantity of "Removal of Existing Concrete Pavement" item was overrun for an increase of $102.02. Quantity of "Concrete Sidewalk, 4" Thick" item was overrun for an increase of $409.37.
Sections of curb and gutter were identified as not providing positive drainage. Curb and gutter were expected to be replaced in full, but the bid prices were too high for this. Selective reconstruction was performed to correct ponding. Quantity of "Remove Existing Concrete Curb and Gutter" item was overrun for an increase of $1,387.25. Quantity of "Concrete Curb and Gutter, Type F" item was overrun for an increase of $4,475.
One driveway needed to be repaved in order to properly drain to added curb and gutter. Quantity of "Concrete Sidewalk, 6" Thick" item was overrun for an increase of $305.42.
The speed table at 5th Avenue and 22nd Street was modified in the field to enhance performance and durability. The approach ramps were lengthened to provide proper transition and the joints into the surrounding pavement were constructed with a butt joint as opposed to paving them on top of the existing pavement which would have led to raveling at the joint. Quantity of "Asphalt Concrete Friction Course, FC-9.5, Traffic B, Speed Tables, 22nd Street" item was overrun for an increase of $1287.00. "Speed Table Trench Joints" item was added for an increase of $1,305.25.
A conflict between the proposed stormwater pipe and an existing wastewater pipe that was not identified in the survey caused a manhole to be installed to drop the wastewater line to avoid the conflict. The yard in which the manhole was installed needed to be restored after the construction. "Zoysia Grass" item was added for an increase of $439.88.
A section of the road began to fail after the first lift of asphalt was poured. This was probably caused due to base failure. The asphalt and base materials were removed and replaced. "Road Base Rework" item was added for an increase of $3,333.00
A second milling operation was required in order to get the pavement to the designed grade. Therefore there was additional effort to adjust manholes and water valves than originally planned. "Adjust Manholes & Valves" item was added for an increase of $2,940.
The designed quantity of fence was 223 linear feet; however the bid quantity was 233 linear feet. Quantity of "Fencing" item was underrun for a decrease of $318.20.
Fiscal Note
The original awarded amount for this project was $674,674.30. Change Order #1 was for a total of $132,362.75. Change Order #2 was for a total of $57,281.37. Change Order #3 was for a time extension only with no contract amount modification. Change Order #4 is for a total of $60,834.67. The total construction cost including all change orders is $925,153.09. The second lowest bidder for this project submitted a bid price of $947,483.08. The original budget for this project was $1,120,000
Recommendation
The City Commission: 1) authorize the City Manager to execute Change Order #4 for the NW 22nd Street Milling and Resurfacing project; and 2) modify the purchase order as necessary, not to exceed the construction cost of $925,153.09.