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HomeMy WebLinkAboutNC0026573_Biosolids Investigation_20140311 CITY OF MORGANTON WWTP BIOSOLIDS EROSION The City of Morganton (CITY) is nearing completion of an improvements project at their Wastewater Treatment Plant (WWTP). The project included the addition of a concrete equalization basin located near the eastern boundary. Immediately east of the basin, slope grading was performed for approximately 80- feet with an elevation increase of approximately 22 feet. Upon completion of the basin and associated grading, heavy rains caused partial failure of the slope and in the process exposed a deposit of biosolids. It is our understanding that the biosolids have been in place for approximately 30 to 40 years. Freese and Nichols, Inc. (FNI) will provide services to evaluate alternatives to stabilize the slope and prepare the design of the preferred alternative. In addition, FNI will evaluate disposal options and quantities of the biosolids, perform required groundwater testing in accordance with NCDENR requirements, and will coordinate these activities with the CITY and NCDENR as applicable. A detailed scope of work is provided below: BASIC SERVICES: FNI shall render the following professional services in connection with the development of the Project: Preliminary Design 1. Ground Water Testing – Ground Water samples will be collected from three (3) test holes. The location of the test holes will be coordinated and approved by the CITY and NCDENR. The following contaminates, which are indicators of leachate from wastewater and/or biosolids, will be tested for each sample:  Nitrate  Nitrite  Ammonia-Nitrogen  E. Coli  Fecal Coliform Upon completion of the testing, FNI will prepare a memorandum outlining the testing locations, procedures and results to be submitted to NCDENR for review. FNI will coordinate with NCDENR to determine if monitoring is required and options for biosolids disposal. Extended groundwater monitoring is not included in this scope. Should it be determined that further monitoring is necessary, specific requirements will be coordinated with NCDENR and the CITY. A coordination meeting with NCDENR at their Regional Office in Asheville, if required, is included in this scope. Upon completion of this task and approval from the CITY, FNI will proceed with subsequent tasks. 2. Evaluate Alternatives – Based on the geotechnical information obtained (Special Services), FNI will evaluate up to three (3) alternatives to stabilize the slope. For each alternative, the amount of biosolids removal will be quantified. 3. FNI will prepare a Preliminary Design Memo (PDM) outlining the evaluated alternatives and the recommended improvements including: a. Evaluation of stabilization alternatives considered; b. Biosolids disposal quantities and alternatives; c. Preliminary Opinions of Probable Construction Costs; d. Recommended improvements; e. Mitigation and ground water monitoring requirements (if applicable). FNI will meet with City staff to discuss the PDM and receive their comments. Upon CITY approval, FNI will proceed with the Final Design. Final Design Design submittals shall be provided by FNI to the CITY at 60% and 90%. The submittals shall include construction drawings, specifications, contract documents, bid proposal, updated schedule, and updated opinion of probable construction costs. Also included in each submittal will be a comment tracker showing all previous comments received from the City and FNI’s response. Three (3) copies of these items shall be submitted to the City at each of the submittal dates. FNI will meet with City staff at each milestone to receive and discuss their comments. Upon CITY approval of the 90% submittal, prepare final construction plans, specifications, contract documents, and opinion of probable construction cost for the project. Provide the OWNER with five (5) copies of the final design submittal. Bidding and Construction Phase Upon completion of the design services and approval of “Final” drawings and specifications by the CITY, FNI will proceed with the performance of services in this phase as follows. 1. FNI will distribute Bid Document to prospective bidders. 2. Assist the CITY by responding to questions and interpreting bid documents. Prepare and issue addenda to the bid documents to plan holders, if necessary. 3. FNI will assist the CITY in the opening, tabulating, and analyzing the bids received. Review the qualification information provided by the apparent low bidder to determine if, based on the information available, they appear to be qualified to construct the project. Recommend award of contract or other action as appropriate to be taken by the CITY. 4. Furnish OWNER ten (10) sets of conformed plans and contract documents for construction. 5. Conduct one (1) pre-construction meeting for the Project to discuss the project schedule for construction. 6. Provide limited construction phase engineering assistance. When requested by the CITY, FNI will visit the site and consult with the CITY and the contractor to resolve unusual or unexpected construction problems. The Basic Services includes a maximum of two (2) site visits. Site visits in excess of this number can be made as a Special Service. FNI shall conduct a final project inspection with the CITY and prepare recommendations concerning items that FNI observes during the final inspection that require additional work or adjustment. Provide written responses to request for information on clarifications. Observe the progress and the quality of work to determine in general if the work is proceeding in accordance with the Contract Documents. In performing these services, FNI will endeavor to protect the CITY against defects and deficiencies in the work of Contractors; FNI does not guarantee the Contractor’s performance, nor is FNI responsible for the supervision of the Contractor’s operation and employees. FNI shall not be responsible for the means, methods, techniques, sequences or procedures of construction selected by the Contractor, or the safety precautions and programs incident to the work of the Contractor. FNI shall not be responsible for the acts or omissions of any person (except his own employees or agent) at the project site or otherwise performing any of the work of the Project. 7. Review the contractor’s shop drawings and related submittals with respect to the applicability of the detailed work, when complete, to be a properly functioning i ntegral element of the project designed by FNI. The CITY will provide document control for the Project. FNI will review documents at the request of the CITY. 8. Revise the construction drawings in accordance with the information furnished by construction Contractor reflecting changes in the Project made during construction. Two (2) sets of prints of “Record Drawings”, CAD Files, and PDF Files shall be provided by FNI to the CITY. SPECIAL SERVICES: FNI shall provide the following professional services in connection with this Project, as authorized by the OWNER, which are not included in the above described basic services, as follows: 1. Geotechnical Investigation a. Drill up to four (4) test holes. Two (2) of the holes will be to a depth of 20-feet and two (2) to a depth of 30-feet. b. The following laboratory testing will be performed on the samples obtained:  Atterberg Limits (liquid and plastic limits)  Percent passing the No. 200 sieve  Dry unit weight and moisture content tests  Unconfined compressive strength tests 2. Topographic Survey a. Prepare a limited Topographic Survey depicting one foot contour lines of the area to be improved. Survey will include existing conditions of the project area and will include the location of the geotechnical borings and the groundwater sampling locations. b. The survey will be horizontally tied to the North Carolina State Plane Coordinate System under the North American Datum of 1983 (NAD83). Vertically, the project will be tied to the North American Datum of 1988 (NAD88). The project’s units will be the U.S. Survey Foot. Additionally, the survey will be performed based on the Rules of Standard Practice as outlined by the North Carolina Board of Registration for Engineers and Land Surveyors.