Ongoing and New Construction Projects
Ongoing and New Construction Projects
Projects planned for Fiscal Year 2020 are as follows:
Gravity Pipeline Rehabilitation Project
Field Service Staff continues CCTV inspections of the collection system. As a result, significant defects are continuously being discovered in numerous pipeline segments that require rehabilitation or repair to prevent Sanitary Sewer Overflows (SSO). Staff uses the Repair Priority List to maintain a listing of gravity pipeline and manhole defects requiring repair or rehabilitation. The FY20 Gravity Pipeline Rehabilitation Project will consist of open trench construction to correct 11 defects discovered during CCTV inspections and to realign the Quebrada line. The realignment of the Quebrada line is a high priority because that line has major sags resulting in heavy grit and grease accumulation. The replacement will facilitate the abandonment of the deficient line and significantly improve maintenance operations. The FY20 appropriation is for project design and construction.
Leucadia Pump Station Rehabilitation
The Leucadia Pump Station is located at the District’s campus at 1960 La Costa Avenue. In 2014, a pump station condition assessment was conducted to evaluate all pump station components (controls, electrical, mechanical, and structural). As a result of the assessment, it was recommended that improvements be constructed for the pump station. Original improvements to be completed include installing suction piping in the emergency overflow wet well for by-pass pumping; replace broken valve on surge valve air piping and install unions for disconnection; replace check valves; replace scrubber fan housing and fan; spot repair wet well lining; replace fresh air fan and duct with new fiberglass reinforced plastic fan and ductwork; and perform an assessment of the concrete floor and walls in the pump station to determine the existence and extent of potential concrete deterioration.
During the design of the project, LWD staff discovered extremely high levels of hydrogren sulfide (H2S) at the discharge end of the Leucadia Force Main. LWD staff and the District Engineer evaluated and field tested several operational adjustment to reduce the H2S levels. However, no significant H2S reduction resulted from the field tests. It was determined that that an evaluation and redesign of the mechinical system was required to reduce the H2S levels. As a result, the project transformed into a major pump station rehabilitation project requiring revisions of the orginal scope to include evaluation and replacement of pumps, piping, discharge header and check valve configuration. LWD staff worked with the engineers to develop and finalize additional project objectives and incorporated them into the project's original scope. For Fiscal Year 2019, $1,132,000 was included in the budget. The estimated completion date for this project is spring of 2020.
Poinsettia Station Gravity Pipeline Project
The San Diego Association of Governments (SANDAG) and the North County Transit District (NCTD) will construct an underground passenger tunnel to link both sides of the passenger platform at the Poinsettia Train Station in Carlsbad. To accomplish this, the train tracks will be shifted to the west. As a result, the District will have to extend the casements protecting the Lanikai Gravity Trunk Sewer and Secondary Effluent Force Main (B1) which run under the train tracks. Additionally, in coordination with SANDAG and NCTD, the District will construct a second parallel encased gravity pipeline under the tracks as part of this project. This will enable the construction of the second parallel line to be accomplished under the permits issued for the Poinsettia Station project, saving the District considerable time and costs. This project was completed in February 2020.
Batiquitos Force Main Discharge Section Replacement Project
The District has completed two force main replacement projects. During the contruction of these projects, it was observed that the ends of the metallic force mains sustained significant internal corrosion due to exposure to air when the flow transition fromn pressurized to gravity. Therefore to prevent future spills from a line failure due to corrosion, LWD staff budgeted funds to relace the end of the Batiquitos Force Main. The estimated completion of construction is fall of 2019.
Diana Pump Station Upgrade Project
The Diana Pump Station (DPS) is located off Highway 101 on Diana Street in Encinitas. DPS was constructed as a submersible pump station in 2010. The 2018 Asset Management Plan recommended that an upgrade of the pump station be completed to include pump control upgrade, replacement of the main breaker and pump replacement. Currently, the pump station does not have an emergency generator for operation during a loss of power. The installation of an emergency generator for the pump station will be assessed. If deemed viable, the installation of the generator will be included in the project.