Condition Assessment and Evaluation of the Moss Avenue Pump Station
Moss Avenue Pump Station (MAPS) is a 26 mgd capacity wastewater pump station conveying raw sewage into the Coastal Interceptor Sewer (CIS) owned by the City of Los Angeles. MAPS is located right next to the Santa Monica Beach Pier and must be operational at all times and comply with EPA Class I reliability criteria. MAPS expected to receive more flow from the Santa Monica Bay Dry Weather (Low Flow) Diversion projects. In addition, the CIS, which is expected to reach at maximum capacity within two years, impacts the MAPS force main capacity. LEE + RO performed an in-depth facility condition and functional assessment of mechanical, electrical, instrumentation + controls and SCADA, and structural components for wear and tear, corrosion, and odor control issues. LEE + RO then prepared a preliminary engineering report summarizing the results of assessment, future capacity needs, hydraulic analysis, and recommended capital improvement projects.
Earl Schmidt Intake Pump Station Settlement Investigation and Corrective Action, Santa Clarita Valley Water Agency
The Earl Schmidt Intake Pump Station was expanded in 2006 and included the addition of two new pumps. In less than a year of operation, a leak was discovered on the 54-inch diameter pump discharge manifold. In addition, the pump bearings kept failing due to excessive vibration and the Agency removed the pumps from service. The Agency engaged LEE + RO to investigate the cause of the problems and implement corrective measures. LEE + RO’s investigations revealed that defective construction created differential settlement which, in turn, resulted in the pumps and discharge headers being badly misaligned. LEE + RO’s $1.2 million corrective action design included reconstruction of the buried pump header and reinstallation of individual pump discharges to the header with flexible couplings.
Borregas Interceptor Sewer
LEE + RO assessed conditions of an existing corroded 6,000 LF, 33-inch diameter sewer and designed a 42-inch diameter VCP replacement sewer. The design and construction for this $4 million project involved major utilities such as a 36-inch diameter natural gas main, a 72-inch diameter storm drain, a 36-inch diameter recycled water main, 12-inch and 8-inch diameter potable water mains, a 6-inch diameter nitrogen gas supply line, a 12-kV power duct, and numerous lateral connections. The project also included a jack and bore crossing of a light rail line. Significant bypass pumping was required to maintain continuous sewage flows during the tie-in to the complex network of sewers at the wastewater treatment plant’s headworks structure.
Coastal Wastewater Treatment Plant and Wastewater Treatment Plant 3A headworks and Primary Treatment Upgrades, South Orange County Wastewater Authority
LEE + RO conducted a condition assessment and provided engineering design services for the upgrades at the Coastal Wastewater Treatment Plant and Wastewater Treatment Plant 3A . LEE + RO engineers performed a comprehensive field investigation for updating the Authority’s record drawings and accurately locating and quantifying the amount of aged and failing concrete and metallic equipment and components. Final design included replacement of sludge and scum collectors for three primary sedimentation basins, replacement of covers on the grit basins and primary sedimentation basins, repairing and restoring aged / spalled / corroded concrete around the grit basins and primary sedimentation basins and repairing leaky construction joints.
