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<br />,f" . <br /> <br />...... <br /> <br />VD <br /> <br />EXHIBIT <br /> <br />A <br /> <br />155 Grand Avenue, <br />Suite 700 <br />Oakland. CA 946\2 <br /> <br />510903.6600 <br />510.903AS601 <br />vaengJneerlflg.com <br /> <br />09-0722 <br /> <br />December 1, 2009 <br /> <br />Javier Sierra <br />Engineering and Construction <br />City of Redwood City <br />1017 Middlefield Road <br />Redwood City, CA 94064 <br /> <br />SUBJECT: <br /> <br />Seaport Centre Storm Pump Station, Discharge Pipeline Condition Assessment <br />Proposal for Corrosion Engineering Services <br /> <br />Dear Javier: <br /> <br />V&A is pleased to submit this proposal to perform a condition assessment of the pump discharge header <br />for the Seaport Centre Storm Pump Station. The 42-inch diameter steel pipe extends approximately 75 <br />feet between the three 30-inch pump discharge pipelines and to the outlet into Redwood Creek. The <br />exposed portion of the pipeline is painted and the buried portion of the pipeline is cement mortar coated. <br />The scope of work is based on our visit to the site and includes a confined space entry into the pipe, <br />ultrasonic thickness measurements and evaluation of the cathodic protection system. <br /> <br />The confined space entry into the header will visually evaluate the interior of the 30-and 42-inch pipelines <br />to the extent that is safely accessible. The condition of the pipe interior will be documented with digital <br />still and video photography. Corrosion or lining damage will be documented by measuring the distance <br />from the blind flange and the position around the circumference. <br /> <br />Metal loss due to internal corrosion will be recorded using an ultrasonic thickness (UT) gauge from the <br />exterior of the pipeline. Damage to the lining and corrosion of the pipe is expected to be near the pump <br />discharge pipelines. The UT measurements will determine the remaining thickness of the header pipeline <br />at locations that were identified during the confined space entry. <br /> <br />Pipe-to-soil potentials measured on the discharge header indicate the pipeline has a cathodic protection <br />system. A post mounted junction box located on the north side of the pump station building appears to be <br />a cathodic protection anode test station. The condition assessment will include an evaluation of the <br />cathodic protection (CP) system including measuring pipe-to-soil potentials, anode current output and <br />electrical isolation at the 42-inch dielectric insulating flange. V&A will submit a report with the results of <br />the confined space entry, UT measurements, CP evaluation and recommendations for internal and <br />external corrosion control of the pipeline. <br /> <br />It is our understanding that the City will remove the blind flange from the end of the header pipeline and <br />will lock out operation of the pump station for the 8 hour duration of the confined space entry. <br /> <br />OAKLAND SAN DIEGO HOUSTON SEATTLE <br />