Recommendation
Staff recommends that the Mayor and Council award a rider bid (Prince George's County Contract No. 821-H(A)) to Proshot Concrete, Inc., of Florence, Alabama, in the amount of $454,940, for storm sewer culvert rehabilitation.

Discussion
Project Description
This project will rehabilitate 11 large diameter corrugated metal pipe (CMP) culverts in various locations throughout the City. The rehabilitation work consists of paving the invert (lower section) of the pipe with a high-strength concrete liner. The primary goal of this project is to repair the corrugated metal pipe to provide structural strength to the culverts and provide a smooth channel to convey flow.

The scope of the work includes installing new reinforced concrete inverts, filling the voids beneath the culverts, and addressing separated joints throughout the culverts. The location of the 11 culverts to be rehabilitated is provided (Attachment A).

Due to the work being performed within nontidal wetlands (streams), authorization from the Maryland Department of the Environment (MDE) and the U.S. Army Corps of Engineers is required. As of May 4, staff has received seven of the 11 required written authorizations from the MDE and the U.S. Army Corps of Engineers to conduct the work. The remaining four authorizations are anticipated by the time the contract is issued, as no issues are expected.

Background
Rockville conducted a study completed by KCI Technologies, Inc. on 18 large diameter CMP structures in 2005. KCI presented Culvert Inspection Reports that recommended repairs to many of the inspected culverts. The inspection reports identified 11 culverts in need of rehabilitation due to damage to the inverts of the pipe. Two culverts identified in the KCI Inspection Reports, located near the intersection of Nelson Street and College Parkway, were rehabilitated in July 2007. Since the KCI Culvert Inspection Reports, staff identified two additional large diameter CMP culverts on Watts Branch Parkway that also are in need of repair. The remaining nine large diameter CMP culverts identified for rehabilitation in the report along with the two additional identified by staff will be repaired through this contract.

CMP was used extensively in the City in the 1970s and 1980s as a less expensive alternative to concrete storm drain pipes. Over time, the metal pipes rust and erode. In some cases, the invert of the pipes has completely eroded away and the streams are flowing underneath the structure. The culverts provide structural support to the roadway above. As the pipe corrodes away the structural integrity of the culvert decreases. In some cases, transverse cracks appear in the roads above the failing CMP culverts thus indicating evidence of the decreasing structural strength of the CMP pipe.

Montgomery County has many similar problems with corroding CMP pipes and has begun a rehabilitation program. The County has procured the services of Proshot Concrete, Inc. to perform various rehabilitations. The City has previously utilized a separate rider contract through Montgomery County for Proshot Concrete, Inc. to perform the rehabilitation at the Nelson Street culverts.

Mayor and Council History
This is the first time this item has been brought before the Mayor and Council.

Procurement Information

In accordance with Section 17-71 of the City Code, Cooperative Procurement; (b) The City may contract with any contractor who offers goods, services, insurance, or construction on the same terms as provided other state or local governments or agencies thereof who have arrived at those terms through a competitive procurement procedure similar to the procedure used by the City.

Fiscal Impact
Adequate funds are available in the Storm Sewer Rehabilitation CIP Project, 330-850-8A41-0426.

Next Steps
The Purchasing Division will issue a contract to Proshot Concrete, Inc. Construction is anticipated to begin June 2009 and be completed by September 2009.

Attachments

Department Head:



Craig Simoneau, P.E.; , Director of Public Works
Approved on: 05/07/2009

City Manager:

Scott Ullery, City Manager
Approved on: 05/08/2009