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N TETRATECH Man Hong (Eric) Yuen, RE., S.E. Structural Project Manager 3.1 MG Reservoir Seismic Strengthening, City of El Segundo, CA, 2010 — Mr. Yuen served as Structural Design Engineer who provided the seismic strengthening design of the reservoir in the design phase and structural observations in the construction phase. Tetra Tech prepared preliminary and final design construction plans, specifications and cost estimates for the seismic retrofit of an existing 3.1 MG concrete potable water storage tank, originally constructed in 1948. The seismic strengthening included the addition of reinforcing steel and shotcrete to the exterior walls, plywood roof sheathing and structural steel shear transfer frames around the tank perimeter between the roof and the wall shell. Safety upgrades included the design of new roof mounted guard railing. Structural observations, special inspection by a deputy inspector, and material testing were provided as part of Tetra Tech's construction phase services. Reservoir 1010-1 Piping Seismic Retrofit, City of Ontario, CA, 2009 — Mr. Yuen served as Structural Designer for the design of piping retrofits and pipe supports at the inlet and outlet pipes of an existing circular welded steel tank. Flexible, double -ball expansion fittings were added to both the inlet and outlet piping. The pipe supports were bolted to the flanges of the flexible expansion fitting closest to the tank. The pipe supports are designed to resist the forces from the weight of the pipe, seismic loads and thrust loads. These pipe supports are not anchored to the concrete foundation directly; instead, they are attached to steel base plates that are welded to the existing steel tank floor plate. This design allows the tank to move independently of the foundation to prevent damage at the pipe to tank connection during earthquakes. Our analysis also included a check of the adequacy of the existing concrete thrust blocks buried in the ground to make sure that they have sufficient capacity to resist lateral seismic and thrust forces. Seismic Evaluation of Ten Water Storage Reservoirs, City of Ontario, CA, 2009 — Mr. Yuen served as Design Engineer for the evaluation of four out of six buried flat bottom rectangular concrete reservoirs. Tetra Tech performed seismic and safety evaluations on ten of the City's twelve water storage reservoirs. The purpose of the evaluations was to determine what improvements would be necessary for each reservoir in order to meet current seismic design standards and OSHA requirements, as well as the estimated cost of the improvements (engineering design, construction inspection, and construction). The ten reservoirs included six buried flat bottom rectangular concrete reservoirs, two above grade flat bottom circular reservoirs (one concrete, and one steel) and two hopper bottom reservoirs with wood framed roofs. Plant 224 Reservoirs and Pump Station, Suburban Water System, City of Whittier, CA, 2012-2014 — Mr. Yuen served as design engineer for the new construction of two separate above ground concrete rectangular reservoirs and the replacement of an existing Pump Station to accommodate the City's need for increased water storage capacity. Mr. Yuen was involved in the comprehensive design of both reservoirs with water storage capacities of 4.69 MG and 2.37 MG, respectively during the design phase. Mr. Yuen also reviews shop drawings, responds to RFIs, and performs structural observation during the on -going construction phase of this project. Rawlings Reservoirs, City of Tustin, Tustin, CA, 2012 — Mr. Yuen served as structural Design Engineer for the two prestressed, circular 3.5 MG concrete tanks located on a tight site, where space for excavation and material stockpiling during construction presented many challenges. Shoring for excavations was anticipated up to 35 feet in depth would be required during construction. As the structural design engineer, Mr. Yuen helps in the shop drawings review process and does structural observations in the construction phase. Reservoir 7A Replacement, City of Pomona, CA, 2009 — Mr. Yuen served as structural design engineer of the reinforced concrete ring foundation for a new 32-foot high, 76-foot diameter circular steel tank to replace the existing tank. The design of the tank and foundation conformed to the AWWA D100-5. The design of the foundation considered hydrostatic loading and seismically induced hydrodynamic forces. The scope of this project also included the design of the supports for the inlet and outlet piping. The piping and pipe supports designed to allow the tank to move independently of the buried portion of the piping. This mitigates the damage which may occur at the pipe to tank connection as a result of earthquakes. Page 2