Appropriate $3.6 million; and authorize rehabilitation of the Etiwanda Hydroelectric Plant (Approp )

Transcription

1 Board of Directors Engineering and Operations Committee 7/8/2014 Board Meeting Subject Appropriate $3.6 million; and authorize rehabilitation of the Etiwanda Hydroelectric Plant (Approp ) Executive Summary This action authorizes rehabilitation of deteriorated needle valves, the scroll case, and the tailrace at the Etiwanda Hydroelectric Plant. This facility generates 23.9 megawatts (MW) of power under peak-flow conditions and is Metropolitan s largest power producer on an annual basis. Timing and Urgency Recent inspections and testing conducted at the Etiwanda Hydroelectric Plant have identified that the turbine s six needle valves have deteriorated. The valves require frequent adjustment of their hydraulic operating pressure to allow continued operation, which increases wear on other mechanical components. Coatings on internal surfaces of the scroll case and tailrace have also deteriorated. These items need to be addressed to minimize future plant downtime and the resulting loss of revenue, and to reduce the risk of costly urgent repairs. Staff recommends moving forward with the work at this time to take advantage of a planned shutdown of the facility due to the relining project on the upstream Etiwanda Pipeline. This project has been reviewed with Metropolitan s Capital Investment Plan (CIP) prioritization criteria, and is categorized as an Infrastructure Rehabilitation project. Funds for this action are available within Metropolitan s capital expenditure plan for fiscal year 2014/15. Details Background In the early 1970s, Metropolitan embarked on a program to develop hydroelectric power generating plants throughout the conveyance and distribution system. Sixteen small hydroelectric plants have been constructed to date, ranging in capacity from 1 MW to 29.7 MW. These plants have produced an average of $24 million in annual revenue over the past seven years, and are a reliable source of green energy. The Etiwanda Hydroelectric Plant was constructed in 1994 and has been in continuous service since that time. The plant receives untreated State Water Project (SWP) flows from the Department of Water Resources Devil Canyon facility via the Rialto and the upper Etiwanda Pipeline. Flow exiting the hydroelectric plant is conveyed to the Weymouth plant through the lower reach of the Etiwanda Pipeline and the Upper. The Etiwanda Hydroelectric Plant can produce up to 23.9 MW of electricity with its single turbine. Depending on pipeline flowrates, daily revenues can range from $5,000 to $28,000. When the hydroelectric plant is shut down, flows are diverted through a separate pressure control structure in order to maintain raw water deliveries to the Weymouth plant. The Pelton-wheel turbine at the Etiwanda Hydroelectric Plant has operated reliably since it was commissioned 20 years ago. However, the performance of some mechanical components has recently diminished. The plant operates under unique conditions of near-constant daily use for peaking of electrical generation. Further, the 8-1

2 7/8/2014 Board Meeting 8-1 Page 2 frequently operated needle valves of the Pelton turbine exhibit a higher rate of wear and accumulation of depositsparticularly in raw water-than valves used in Metropolitan s other type of turbines (i.e., Francis turbines). As such, the Etiwanda Hydroelectric Plant requires more frequent heavy maintenance. The turbine relies on six 36-inch needle valves to open and close, which can either send water through the turbine or shut the flow off completely. These valves operate in raw water service and have deteriorated through continuous use. Over the past three years, the needle valves have required adjustments to their hydraulic operating pressure that extend beyond the planned design parameters. These adjustments burden other mechanical components, which must then deviate from their own intended design. Two of the needle valves have been placed under a limited special operating condition to be used only as a last resort. In addition to the deteriorated needle valves, recent inspections have identified that coatings on internal components of the turbine, including the scroll case and tailrace, have deteriorated. Water travels through the scroll case to the needle valves and then exits through the tailrace. The scroll case and the tailrace have areas with blistered and delaminated coatings which expose the metal to accelerated rates of corrosion and eventual loss of steel. Aside from minor repairs, these components have not been recoated since their original installation. Staff recommends refurbishing the scroll case and tailrace areas in conjunction with the needle valve repairs. The estimated life of the new coatings is approximately 20 years. There is currently an opportunity to address these identified deficiencies while the hydroelectric plant is out of operation due to the Etiwanda Pipeline relining project. While the plant is shut down, staff will also assess the condition of mechanical and electrical components which can only be accessed via disassembly of the equipment. If necessary, staff will return to the Board for authorization of any additional needed repairs. Etiwanda Hydroelectric Plant Rehabilitation Construction ($3,600,000) Planned activities include disassembly of the needle valves; replacement of worn or damaged valve components; sandblasting and recoating of the valve body; cleaning and recoating of the plunger, spring, actuator shaft and deflector plate; fabrication of new retaining rings; blasting the deteriorated coating from the internal components of the turbine; inspecting the steel condition and repairing corroded areas as needed; and recoating the metal at the turbine scroll case and tailrace areas. All work will be performed by Metropolitan forces, with technical support from Fuji Electric Co. during the unstacking and reinstallation of the generator unit. Fuji Electric Co. fabricated and installed the needle valves during the original construction, and has proprietary knowledge of their design and operation. The requested funds include $2.39 million for the Metropolitan force activities described above; $400,000 for materials and supplies; $55,000 for equipment use; $90,000 for metallurgical and coating testing; $150,000 for project management activities and preparation of record drawings; $230,000 for technical support by Fuji Electric Co.; and $285,000 for remaining budget. The technical support by Fuji Electric Co. will be provided through an agreement awarded under the General Manager s Administrative Code authority. This action appropriates $3.6 million and authorizes rehabilitation of the Etiwanda Hydroelectric Plant. This work is included within capital Appropriation No , the Hydroelectric Power Plant Improvements appropriation, which was initiated in fiscal year 2008/09. With the present action, the total funding for Appropriation No will increase from $4,617,000 to $8,217,000. The total estimated cost to complete the rehabilitation of the Etiwanda Hydroelectric Plant, based on the deficiencies identified to date, ranges from $3.3 million to 3.6 million. This project has been evaluated and recommended by Metropolitan s CIP Evaluation Team, and funds are available with the fiscal year 2014/15 capital expenditure plan. See Attachment 1 for the Financial Statement and Attachment 2 for the Location Map. Project Milestone October 2014 Completion of rehabilitation of the Etiwanda Hydroelectric Plant

3 7/8/2014 Board Meeting 8-1 Page 3 Policy Metropolitan Water District Administrative Code Section 5108: Appropriations California Environmental Quality Act (CEQA) CEQA determination for Option #1: The proposed action is categorically exempt under the provisions of CEQA and the State CEQA Guidelines. The overall activities involve the funding, design, minor alterations and replacement of existing public facilities with negligible or no expansion of use and no possibility of significantly impacting the physical environment. Accordingly, the proposed action qualifies under Class 1 and Class 2 Categorical Exemptions (Sections and of the State CEQA Guidelines). The CEQA determination is: Determine that pursuant to CEQA, the proposed action qualifies under two Categorical Exemptions (Class 1, Section and Class 2, Section of the State CEQA Guidelines). CEQA determination for Option #2: None required Board Options Option #1 Adopt the CEQA determination that the proposed action is categorically exempt, and a. Appropriate $3.6 million; and b. Authorize rehabilitation of the Etiwanda Hydroelectric Plant. Fiscal Impact: $3.6 million in capital funds under Approp Business Analysis: This option will enhance reliability of the Etiwanda Hydroelectric Plant, reduce the risk of damage to other equipment, and reduce the risk of costly repairs and unplanned shutdowns. Option #2 Do not authorize rehabilitation of the Etiwanda Hydroelectric Plant at this time. Fiscal Impact: Increasing risk of loss of revenue of up to $28,000 per day Business Analysis: Under this option, the hydroelectric plant may remain in a special operating condition for an extended period of time, which would forgo an opportunity to minimize future plant downtime and the resulting loss of revenue. Staff Recommendation Option #1 Gordon Johnson Manager/Chief Engineer Engineering Services 6/17/2014 Date Jeffrey Kightlinger General Manager 6/24/2014 Date Attachment 1 Financial Statement Attachment 2 Location Map Ref# es

4 7/8/2014 Board Meeting 8-1 Attachment 1, Page 1 of 1 Financial Statement for Hydroelectric Power Plant Improvements A breakdown of Board Action No. 6 for Appropriation No for the rehabilitation of the Etiwanda Hydroelectric Plant¹ is as follows: Previous Total Appropriated Amount (Feb. 2013) Current Board Action No. 6 (July 2014) New Total Appropriated Amount Labor Studies & Investigations $ 1,493,000 $ - $ 1,493,000 Owner Costs (Proj. mgmt, record dwgs) 634, , ,000 Final Design 654, ,000 Metropolitan Force Construction 917,942 2,480,000 3,397,942 Professional/Technical Services 250, , ,000 Materials and Supplies 55, , ,000 Incidental Expenses 7,000 25,000 32,000 Equipment Use 27,000 30,000 57,000 Contracts 10,000-10,000 Remaining Budget 569, , ,058 Total $ 4,617,000 $ 3,600,000 $ 8,217,000 Funding Request Appropriation Name: Hydroelectric Power Plant Improvements Source of Funds: Revenue Bonds, Replacement and Refurbishment or General Funds Appropriation No.: Board Action No.: 6 Requested Amount: $ 3,600,000 Budget Page No.: 60 Total Appropriated Amount: $ 8,217,000 Total Appropriation Estimate: $ 16,178,200 ¹This action is the initial appropriation for rehabilitation of the Etiwanda Hydroelectric Plant. The total estimated cost for the project, including the current funds requested and future construction costs, is anticipated to range from $3.3 million to $3.6 million.

5 7/8/2014 Board Meeting 8-1 Attachment 2, Page 1 of 1 VENTURA COUNTY LOS ANGELES COUNTY CASTAIC LAKE Upper GARVEY Middle LOS ANGELES COUNTY LIVE OAK SAN BERNARDINO COUNTY Etiwanda Hydroelectric Plant Upper Pipeline SILVERWOOD LAKE SAN BERNARDINO COUNTY RIVERSIDE COUNTY Lower LAKE PERRIS PALOS VERDES LAKE MATHEWS DIAMOND VALLEY LAKE LAKE SKINNER RIVERSIDE COUNTY SAN DIEGO COUNTY