Memorandum

City of Lawrence

Utilities Department

 

TO:

David L. Corliss – City Manager

Cynthia Wagner - Assistant City Manager

Diane Stoddard - Assistant City Manager

FROM:

Philip Ciesielski – Asst. Director of Utilities

CC:

Dave Wagner – Director of Utilities

Mike Lawless – Deputy Director of Utilities

Beth Frailey Krishtalka – Assistant to Director

Mark Hegeman – Utilities Operations Superintendent

Dave King – Utilities Maintenance Superintendent

Bob Brower – Utilities Operations Superintendent

Date:

December 4, 2013

RE:

Agenda Item – Execute Engineering Services Agreement and Authorize Tapping Saddle Installations for Project UT1316 Concrete Water Transmission Main Assessment

 

Please include the following item on the City Commission Agenda for consideration at the December 10, 2014 meeting:

 

Authorize the City Manager to Execute an Engineering Services Agreement in the amount of $243,478.00 with Black & Veatch for engineering and pipe assessment services related to Project UT1316 Concrete Watermain Assessment.

 

Authorize the execution of a purchase agreement with Hanson Pressure Pipe in the amount of $59,430.00 for the purchase and installation of 4 tapping saddle access points and one drain point on the concrete water transmission mains.

 

Project Description: The Department of Utilities water distribution and transmission main network consists of approximately 500 miles of pipe. The mains range in age from 123 years to less than 1 year; in diameter from 2” to 36”; and are made from a variety of materials including ductile and cast iron, PVC, transite and concrete.

 

Concrete transmission mains make up approximately 12.6 miles of the system (map attached). These mains were constructed during the 1950’s and late 1970’s and range in diameter from 16” to 36”. While these mains have traditionally been reliable structures for the Department there is a history of catastrophic failures of similar pipe across the country. The critical nature of the concrete mains to convey raw water to the Clinton WTP as well as move large quantities of treated water from both the Clinton and Kaw WTPs to various areas of the distribution system makes the accurate assessment of their existing condition and expected remaining service life a high priority within the Department’s work plan. In addition, due to the large pipe diameters and the volume of water being transported through these mains, failures often result in localized flooding, property damage, public health concerns and disruption of service.

 

Recent developments in technologies such as acoustic, electromagnetic and video allow condition assessments to be made on entire lengths of pipe with the pipe in service. These assessment techniques can quantify the current overall structural condition of the pipe, locate active leaks, and locate and quantify areas of corrosion damage and loss of reinforcing pre-stressing wires due to corrosion and breakage. The results of these assessments will provide the information necessary to design and execute any immediate repairs and form the basis for a longer term ongoing evaluation and rehabilitation program.

 

Project History:

On November 11, 2009 City Commission authorized advertisement of an RFP for engineering services related to the project. The RFP requested proposals from firms experienced in the assessment of concrete pressure pipe. The anticipated scope of services included:

1.     A desktop analysis of available design, manufacturing, construction and operational information.

2.     Comparison of the desktop analysis results to nationwide historic concrete pressure pipe failure information.

3.     Prioritization of the mains, using the above results, for field assessment based on susceptibility to degradation and risk of failure.

4.     Selection of the appropriate field assessment technique(s) for each main.

5.     Assistance in advertising and selecting a qualified pipeline field assessment contractor.

6.     Management and inspection of the pipeline field assessment contractor’s activities.

7.     Review and evaluation of the pipeline field assessment data.

8.     Establishment of a repair, rehabilitation, replacement and monitoring program and budget based on the results of the desktop and field assessments.

 

On December 18, 2009 in response to the RFP proposals were received from five (5) firms. Proposals were received from Bartlett & West/Schiff Associates; Black & Veatch; Burns & McDonnell/BG Consultants; Shafer, Kline & Warren/Evanco and Simpson, Gumpertz & Heger.

 

On February 9, 2010 the City Commission authorized staff to negotiate an Engineering Services Agreement with Black & Veatch. These initial services include Tasks 1 – 4 above.

 

On September 28, 2010 the City Commission authorized the City Manager to execute an Engineering Services Agreement with Black & Veatch in the amount of $37,000.00.

 

In August 2011 Black & Veatch issued the Final Report for the project which included Tasks 1 – 4 above, as well as provided budget estimates to execute the recommend physical condition assessments and analysis plan. The final cost for this phase was $29,471.59.

 

Project Status:  The Final Report provided a prioritization of 20 discrete pipe sections, totaling 12.8 miles, based on physical factors; diameter, length, age, material and manufacturing standard: functional factors; alignment environment, number of distribution connections and size of area served: and impact factors; number of previous leaks, and loss of level of service. Four (4) of the top five (5) prioritized segments are associated with the Clinton Water Treatment Plant raw water and high service discharge systems. These four (4) pipes total 6 miles in length.

 

These pipes, manufactured and installed in the late 1970’s, are at the greatest risk of failure due to the manufacturing design standard in place at their time of construction. The design standard altered the criteria specifying the prestressing wire properties and pipe structural design. The prestressing wire associated with this vintage of pipe has been shown to be susceptible to failure by the process of hydrogen embrittlement. Data compiled and distributed in the 2008 American Water Works Association Research Foundation report “Failure of Prestressed Concrete Cylinder Pipe” shows that of all reported failures (25,215) for pipes installed from prior to 1955 to 2007, approx 60% (15,352) are related to pipe manufactured under this standard. (typical cross-section of prestressed concrete cylinder pipe)

 

Based on the results of the Final Report staff included $650,000 in the 2014 Capital Improvements Plan Budget to continue the project. Staff are recommending the physical assessment and analysis phases of the project be initiated for the Clinton Water Treatment Plant three (3) of the pipe segments noted above (Clinton Raw Watermain) (Central Service Discharge) (West Hills Discharge). The physical analysis will be carried out by robotic inspection equipment which travels through the dewatered pipe. The equipment provides video of the pipe interior and acquires structural condition information by the use of magnetic fields impressed on the pipe and return magnetic field received. The information from the magnetic field measurements quantifies the number and location of prestressing wire breaks. These areas can then be analyzed to determine the remaining structural strength of the pipe.

 

The work is proposed to be carried out in coordination with the current Clinton Water Treatment Plant Electrical and Mechanical Improvements Project. The current Clinton WTP project will have the raw water transmission main out of service, exposed and accessible for the pipeline assessment equipment. The high service discharge lines will be taken out of service as necessary to carry out the inspections.

 

In addition to ranking high in the prioritization results of the report, these pipes are recommended for physical analysis for the acquisition of information related to their condition for use in the design decision process related to the proposed reconstruction of Wakarusa Drive from Bob Billings Parkway south to Clinton Parkway. Approximately 5,220 linear feet of this pipe is within the proposed Wakarusa Drive project limits (see attached map). The results of the physical condition assessment will provide an indication of the remaining useful life of the pipe and any immediate rehabilitation needs. The remaining useful life and rehabilitation costs will be used to determine the cost vs benefit of rehabilitating the existing pipe and protecting it during construction, designing the road improvements around it, or replacing the pipe in an alignment not impacted by the road projects.

 

Staff have negotiated a scope of services and fee with Black & Veatch to provide the necessary engineering and pipe assessment activities. Black & Veatch are teamed with Pure Technologies who will provide the robotic equipment and condition assessment of the pipes. Black & Veatch is identifying inspection requirements, providing inspection preplanning, on site assistance and engineering support during the inspection process and analysis of the condition inspection results and recommendations for any required rehabilitation or replacement of deficient pipe.

 

Hanson Pressure Pipe has provided the recommended quote to supply and install the necessary access points on the pipes. Due to the proprietary nature of the concrete pressure pipe the pipe manufacturer, Hanson Pressure Pipe, is being sole sourced for the installation of these appurtenances.

 

Project Funding: The project is funded from the 2013 nonbonded Capital Improvement Program.

 

Action Request: Authorize the City Manager to Execute an Engineering Services Agreement in the amount of $243,478.00 with Black & Veatch for engineering and pipe assessment services related to Project UT1316 Concrete Watermain Assessment.

 

Authorize the execution of a purchase agreement with Hanson Pressure Pipe in the amount of $59,430.00 for the purchase and installation of 4 tapping saddle access points and one drain point on the concrete water transmission mains.

Thank you for your assistance. Please advise if you have any questions.