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HomeMy WebLinkAbout17 - Semeniuk Slough Preliminary Engineering StudyCITY OF NEWPORT BEACH CITY COUNCIL STAFF REPORT Agenda Item No. 17 March 8, 2005 TO: HONORABLE MAYOR AND MEMBERS OF THE CITY COUNCIL FROM: Public Works Department Robert Stein 949 - 644 -3311 rstein @city.newport- beach.ca.us SUBJECT: SEMENIUK SLOUGH PRELIMINARY ENGINEERING STUDY — AMENDMENT NO. 1 TO PROFESSIONAL SERVICES AGREEMENT WITH NOBLE CONSULTANTS, INC. RECOMMENDATION: Approve Amendment No. 1 to the Professional Services Agreement with Noble Consultants, Inc. (Noble), of Irvine, California for professional services to develop a restoration project with the Corps of Engineers at a fee of $20,000, and authorize the Mayor and City Clerk to execute the Agreement. DISCUSSION: Noble has completed its preliminary study for dredging the slough. The sampling program found that the material in the slough is unsuitable for beach or nearshore ocean disposal unless blended with an appropriate quantity of beach quality sand. The study outlines three options: 1. Develop a stand alone dredging project performed by the City. This option envisions disposal would be accomplished by use of small dewatering plants to enable trucking of dried sediment to an inland disposal site or loading dump scows at a nearshore mooring for disposal at the LA -3 disposal site. The cost is estimated at $800,000 to $1,000,000 exclusive of permitting, engineering and construction administration expenses. 2. Develop a partnered dredging project with the Corp of Engineers which would include the Semeniuk Slough and Newport Slough. The Corps of Engineers has found the shoaled material within the western Newport Slough contains about 70% sand. Blending this with the finer Semeniuk Slough material may make a nearshore disposal option more feasible. SUBJECT: Semeniuk Slough Preliminary Engineering Study — Amendment No. 1 to Professional Services Agreement with Noble Consultants, Inc. March 8, 2005 Page 2 The feasibility of this plan would depend on obtaining approval from the regulatory agencies. 3. Develop a conceptual plan that would meet the Corps of Engineers criteria for an ecosystem restoration project. This strategy would seek to include a restored Semeniuk Slough and adjoining wetlands as part of a broader federally authorized ecosystem restoration project. The objective of this strategy would be to include Semeniuk Slough as part of a larger public trust that would be charged with the management, operation and maintenance of the wetland's ecological assets. Noble believes there is a real possibility that federal funds can be made available to initially endow a conservancy for this mission. The process is initiated with formulation of the initial project restoration plan. This preliminary study would be wholly funded by the Corps and the results would determine a general scope and the federal interest in pursuing a more detailed feasibility study. A subsequent feasibility study along with design and construction would occur under a cost sharing agreement with the Corps. The City's cost obligations could be funded through the State Proposition 40150 funding program. Staff recommends that Noble continue its conversations with the Corps of Engineers to ascertain the feasibility for an ecosystem restoration project (Option 3). Environmental Review: This project falls under the Information Gathering class of projects and is therefore categorically exempt per CEQA Guidelines, Article 19, Section 15306. Public Notice: Not applicable to this preliminary study. Funding Availability: Funds for this project are available in the following account: Account Description Tide and Submerged Land Pre ared by: Robert Stein Principal Civil Engineer Account Number Amount 7231- C5100719 $20,000.00 Submitted by: nS G. Badum Works Director Attachments: Amendment No. 1 Noble Recommendations Report Dated January 24, 2005 ►I ►I • C A .1 ► • ►li DATE: March 9, 2005 TO: Mayor and City Council Members FROM: Public Works Department SUBJECT: March 8, 2005 Council Agenda Item No. 17 Attached are the missing documents from the above referenced Council item: • Amendment No. 1 with Noble Consultants • Noble Recommendations Report Dated January 24, 2005 c: Homer Bludau LaVonne Harkless Stephen Badum f: \users \pbw \shared \masters \memo master.doc City of Newport Beach Public Works Department AMENDMENT NO. 1 TO PROFESSIONAL SERVICES AGREEMENT WITH NOBLE FOR SEMENIUK SLOUGH THIS AMENDMENT NO. 1 TO PROFESSIONAL SERVICES AGREEMENT, entered into this day of , 20 , by and between the CITY OF NEWPORT BEACH, a municipal corporation, (hereinafter referred to as "City ") and NOBLE CONSULTANTS, INC., whose address is 2201 DuPont Drive, Suite 620, Irvine, California, 92612 -7509, (hereinafter referred to as "Consultant'), is made with reference to the following: RECITALS A. On June 22, 2004, CITY and CONSULTANT entered into a Professional Services Agreement, hereinafter referred to as "Agreement', for to investigative the feasibility of interagency project coordination with the Corps of Engineers for dredging Semeniuk Slough, hereinafter referred to as "Project'. This Agreement is scheduled to expire on December 31, 2005. B. City desires to enter into this Amendment No. 1to reflect additional services not included in the Agreement or prior Amendments and to extend the term of the Agreement to December 31, 2006. C. City desires to compensate Consultant for additional professional services needed for Project. D. City and Consultant mutually desire to amend Agreement, hereinafter referred to as "Amendment No. 1 ", as provided here below. NOW, THEREFORE, the parties hereto agree as follows: 1. Consultant shall be compensated for services performed pursuant to this Amendment No. 1 according to "Exhibit A" dated February 17, 2005 attached hereto. 2. Total additional compensation to Consultant for services performed pursuant to this Amendment No. 1 for all work performed in accordance with this Amendment, including all reimburseable items and subconsultant fees, shall not exceed Twenty Thousand Dollars ($20,000). 3. The term of the Agreement shall be extended to December 31, 2006. 4. Except as expressly modified herein, all other provisions, terms, and covenants set forth in Agreement shall remain unchanged and shall be in full force and effect. IN WITNESS WHEREOF, the parties hereto have executed this Amendment No. ton the date first above written. APPROVED AS TO FORM: Robin Clauson, City Attorney for the City of Newport Beach ATTEST: LaVonne Harkless, City Clerk Attachment: Exhibit A CITY OF NEWPORT BEACH, A Municipal Corporation M Mayor for the City of Newport Beach NOBLE CONSULTANTS, INC.: En Ron Noble President f: \users \pbw \shared \agreements \fy 04 -05 \noble - semeniuk slough- amend -1.doc =I NOBLE CJNSOLTANTS. INC.I PROJECT MEMORANDUM 22101 DUPONT DRIVE, SUITE 620, IRVINE, CA 92612 (949) 752 -1530 FACSMILE (949)752-8381 City of Newport Beach Semeniuk Slough Preliminary Engineering Study Job Number 782 -05 To: Robert Stein From: Jon Moore/ Larry Paul Date: February 17, 2005 RE: Implementation of Capital Improvement Project Cc: File I.le This memorandum summarizes our estimate of planning and engineering fees to take the Semeniuk Slough dredging project to the next level. As stated in our report, the most promising plan for the City involves inclusion of the Semeniuk Slough maintenance within a broader seeped project purpose of ecosystem restoration. Because of the challenges and uncertainties associated with this innovative strategy, the following study will be required to validate the concept and position the City to obtain federal and state sponsorship. FY 2004/2005 — Allocate $20,000 for the following tasks: 1. Further develop Newport Slough/Semeniuk Slough combined project scope with the Corps of Engineers to include the initiation of a Federal ecosystem restoration project. Investigate the cost sharing potential and grant opportunities for the local share. 2. Research the potential for nearshore disposal of dredge fill material. Research the linkage of nearshore disposal with the policy guidelines of the Federal/ State Sediment Master Plan. 3. Determine the resource /regulatory /stakeholder interests and concerns for such a project. = NOBLE CONSULTANTS. INC. PROJECT MEMORANDUM 2201 DUPONT DRIVE, SUITE 620, IRVINE, CA 92612 (949) 752 -1530 FACSIMILE 19491752 -8381 City of Newport Beach Semeniuk Slough Preliminary Engineering Study Job Number 782 -05 To: Robert Stein From: Jon Moore Date: January 24, 2005 RE: Recommendations Report Cc: Larry Paul Ron Noble IC .. This memorandum summarizes our findings and recommendations concerning the feasibility of maintenance dredging within the Semeniuk Slough. Our study has been conducted in accordance with the Scope of Services stipulated in our June 22, 2004 Agreement with the City. The purpose of our study was to furnish the City with a preliminary assessment of the project's feasibility and a recommended strategy to move forward. Our analysis was accomplished by performing a quick look survey of the quantity and characteristics of the sediments within the slough. We have also explored the potential for interagency cooperation and other cost sharing strategies that might be pursued to defray the capital cost of the project. Our specific scope of services consisted of the following tasks: 1. Conduct a limited sediment sampling and testing study to determine the physical and chemical characteristics of the material proposed for dredging. 2. Perform a one -day bathymetric survey of the eastern channel to document existing depths and enable a preliminary determination of dredging quantity. 3. Explore possible avenues of inter - agency coordination that might be available to the City to expedite the project and/ or reduce the financial burden of dredging and maintaining the slough. Task 1. Sediment sampling and testing The draft sampling and analysis work plan was submitted by MEC- Weston Solutions, Inc. to the regulatory agencies in September 2004. Comments were received from the Corps of Engineers and U.S. EPA on November 18, 2004. The agencies made minor changes to the field sampling program and requested that Tier 2 chemical testing be performed on the retrieved sediment samples. Five core samples were extracted in the field on December 13, 2004 using a hand - operated piston corer. All samples met refusal approximately five feet below the mudline. The material City of Newport Beach Semeniuk Slough Preliminary Engineering Study Recommendations Report January 24, 2005 Page 2 of encountered was fine grain sediment. It is estimated that more sandy material underlies the more recent deposits. Per sampling protocol, the collected core samples were mixed into a single composite. All Tier 1 and 2 chemical tests were completed in the laboratory by January 10, 2005. Results of the grain size analysis are summarized below: % gravel content 12 % sand content 26.6 % silt content 30.5 % clay content 41.7 Based on this information, approximately 72 percent of the shoaled material is unsuitable for beach or nearshore ocean disposal unless blended with an appropriate quantity of beach quality sand. However, the composite sediment sample tested clean for chemical contamination as all parameters were either not detected or measured at low levels. The more detailed report on the results of the sediment sampling and testing study that was performed by MEC- Weston Solutions is attached to this memorandum. Task 2. Preliminary Assessment of Dredging Volume A condition bathymetric survey of the eastern section of Semeniuk Slough was conducted on August 19, 2004. The results of the survey were submitted to the City on September 27, 2004. In general, the existing depths within the channel were found to be between the elevations of —1 and —2 feet, MLLW. The field sampling indicates that dense native sands may exist about 5 feet below existing mudline. This could represent the natural slough channel bottom. Therefore, a preliminary project depth of —5 feet, MLLW was selected for dredging. Because of the controlling depths in the west end of the slough near the Santa Ana River, dredging to deeper elevations in Semeniuk Slough may result in decreased circulation and flushing and creation of more stagnant water near the bottom. The approximate dredge quantity associated with a center of channel box cut to the preliminary project depth limit is 20,000 cubic yards. Task 3. Strategic Planning Assessment Alternative strategies to address the Semeniuk Slough channel maintenance problem have been reviewed and assessed by Larry Paul. Candidate plans that may be considered thus far include the following options: City of Newport Beach Semeniuk Slough Preliminary Engineering Study Recommendations Report January _'d. 2005 Page 3 of a) Develop a stand alone dredging project performed by the City. Under this strategy, the City would prepare and implement a municipally funded maintenance dredging capital improvement project to remove the accumulated sediment in the most economical and environmentally acceptable manner. Dredging would most likely be accomplished by a small hydraulic suction dredge, clamshell dredge, or combination of both methods. The grain size of the sediment within the Semeniuk Slough means that the dredged material will need to be disposed off site. Feasible options to accomplish this task include incorporation of small dewatering plants to enable trucking of dried sediment to inland disposal sites or loading dump scows at a nearshore mooring. In the latter case, the dredged material would be transported by barge for ultimate disposal at the offshore LA -3 disposal site. The benefits of a self - funded maintenance dredging project are that the City would control the timing, design, and construction process from start to finish. However, the principal disadvantage is having to absorb the high project cost. We estimate that the hydraulic dredging and dewatering method would be the least expensive and most viable option for a stand alone project. However, even that alternative would cost the City between an estimated $800,000 to $1,000,000 exclusive of permitting, engineering, and construction administration expenses. The ocean disposal method would cost considerably more because of the inefficiencies associated with hydraulically filling dump scows and the uncertainties associated with conducting construction activities in the open ocean. b) Develop a partnered dredging project with the Corp of Engineers which would include the Semeniuk and Newport Sloughs. The Corps of Engineers has found that the shoaled material within the western Newport Slough area may contain as much as seventy percent sand. Blending the finer grained sediments within the Semeniuk Slough area with the coarser grained material in the western channel may make a nearshore disposal option more feasible. Therefore this strategy would seek ways to beneficially combine the dredged sediments from both areas and implement a joint City and Corps dredging project. The feasibility of this plan would critically depend on obtaining approvals from the regulatory agencies to allow disposal of a blended sediment mix in the nearshore ocean waters. Benefits for this strategy would include sharing of design and construction costs, reducing overall efforts for securing regulatory entitlements, and making the Semeniuk Slough material potentially more attractive for nearshore disposal. Ultimately it would also help to reduce the sediment loading from the Newport Slough into the Semeniuk Slough. Land ownership issues and responsibilities for future operation and maintenance work for the entire slough and adjacent wetlands area will be important factors to resolve if this strategy is pursued. City of Newport Beach Semeniuk Slough Preliminary Engineering Study Recommendations Report January 24, 2005 Page 4 of 5 c) Develop a conceptual plan that would meet the Corps of Engineers criteria for an ecosystem restoration project for both the federal and city portions of the slough. This strategy would seek to include a restored Semeniuk Slough and adjoining wetlands as part of a broader federally authorized ecosystem restoration project. As envisioned, the project would expand the scope of dredging to improve channel circulation and create mudflat and habitat for threatened and endangered species. In so doing the existing Santa Ana River Marsh area would be enhanced and additional ecosystem benefits would be realized for the entire project area. Upon completion of the initial construction, the newly restored wetlands would present a very attractive and valuable resource that could then be adopted by a conservancy to operate and maintain. The objective for this strategy would be to include the Semeniuk Slough as part of a larger public trust that would be charged with the management, operation, and maintenance of the wetland's ecological assets. The third party trust could be funded from a federal endowment, included within a public conservancy of the lower Santa Ana River Area Public agencies, or set up as a special private conservancy. The endowment's responsibilities could be defined to include- enhancement and further building of habitat areas, preservation of water quality and circulation within the waterways, and regular maintenance of the depths in the slough. There is the real possibility that federal funds can be made available to initially endow a conservancy for this mission. The process is initiated with formulation of the initial project restoration plan. This preliminary study is wholly funded by the Corps, and the results will determine a general scope and the federal interest in pursuing a more detailed feasibility study. The probable federal authority whereby the Corps of Engineers could participate in restoration of the wetlands is their small project ecosystem program. Under this agreement, the feasibility study, design, and construction for the project are cost shared. However the City's cost obligation could be funded through the State Proposition 40/50 funding program as administered by the California Coastal Conservancy. Determination of the feasibility and ultimate implementation of this strategy will be more time consuming because of the more complex partnering relationships, level of stakeholder involvement, and the vagaries associated with the federal budget allocation and funding process. A variation of this strategy would be to initiate the plan using federal monies and complete the project under state sponsorship. Under this scenario, a request for a federally funded project restoration plan can be completed within this federal fiscal year. If a favorable conceptual ecosystem restoration plan is developed by the Corps, the City may then elect to request state grant funding assistance to complete project design and construction without federal involvement. The advantage of this approach is that the overall project schedule could be accelerated. City of Newport Beach Semeniuk Slough Preliminary Engineering Study Recommendations Report January 24, 2005 Page 5 of 5 4. Recommendations The results of the sediment chemistry and laboratory testing of the Semeniuk Slough sediments indicate that the material is not contaminated. However the physical grain size is predominately silt and clay which makes it incompatible for beach or nearshore ocean disposal. The blending of the fine grain Semeniuk Slough material with coarser sand could conceivably make it suitable for deposition in the nearshore, but it is unlikely that sufficient volumes of sand can be found nearby to attain the necessary coarse grain to fine grain ratios. Given the nature of the Semeniuk Slough sediment, it would be more appropriate to utilize the material to create additional local habitat. As discussed above, there are a number of potential strategies that the City may pursue to dredge the Semeniuk Slough. Options range from performing the maintenance work entirely at the City's expense to more creative and less certain approaches that involve multipurpose project objectives and enlisting responsible third party involvement. Of the three strategies studied we recommend that the City pursue Option C. This plan proposes to pursue state and federal agencies involvement to dredge the Semeniuk Slough as part of a larger ecosystem restoration project within the lower Santa Ana River wetlands area. The strategy, if proven viable, would not only remove the accumulated sediments from the sloughs, but it would also result in improved tidal circulation, better water quality, and enhanced habitat. As envisioned, the project would have a nominal cost implication for the City. In addition it could engender wide stakeholder support and provide easier avenues to obtain regulatory approvals. The potential to obtain a federal operation and maintenance endowment would also make the project more attractive for creation of a conservancy which would provide for the permanent maintenance of the slough in perpetuity. Attachment: Report, Sampling and Analysis of Semeniuk Slough Sediment. Prepared by MEC- Weston Solutions, Inc., January 2005.