TETRA TECH, INC-2020-075-01 - Laserfiche WebLink

Home Browse Search

In conjunction with the signing of the plans by the regulatory agencies or receipt of approved permit, Tetra Tech recommends a meeting occur to finalize the cost implications of the backfill and pavement replacement requirements, construction restrictions, traffic control, and other factors which could affect the cost of construction. A memorandum of understanding will be prepared after the meeting and distributed to the attendees for their concurrence. This approach will minimize the potential of change orders to the contractor as a result of requirements added during the construction phase. Utility Coordination: We propose to perform our utility research and investigation immediately upon issuance of the Notice to Proceed for each pipeline. During Design we will contact USA Dig -Alert, send preliminary, second, and final utility notices, field walk the alignment, pothole if necessary, and identify critical utilities. The USA markings for the geotechnical investigation will also be used to verify the location of the existing utilities. In addition, the actual potholing activities will be monitored to assist in the investigation of hazardous materials. The potholing services will be completed by use of the vacuum extraction method, thereby minimizing pavement damage and traffic disruption. In addition, a field walk must be completed to look for evidence of infrastructure (e.g., valve cans, trench patch, vaults, etc.) as some utility owners do not belong to USA Dig Alert, and others respond with only partially complete information. We have learned to take the extra steps to verify potential underground infrastructure. Hazardous Waste: Our previous experience on the West Basin Municipal Water District and Long Beach Water Department projects, have made us sensitive to the negative impacts associated with the discovery of hazardous materials within the pipeline trenches. These materials, if not properly planned for in the contract documents, could have a disastrous effect on the schedule and cost of pipeline projects. Our geotechnical investigation borings will be done on the proposed alignment and will include a sniffer to minimize the potential of finding unknown hazardous materials during construction. The goal is to avoid the hazardous material, but if it must be encountered, it is important to be aware of it, quantify the amount and type and estimate the cost to dispose of it. Traffic Control: When the proposed pipeline alignments are located within highly traveled streets, traffic control will be a major concern of the regulatory agencies. Traffic control plans will be prepared with the objective of providing the contractor with adequate room for safety as well as efficient operation while providing the least possible disruption to the traveling public. We believe that traffic control is a key design element and it will be completed together with the design of the pipeline. Alignment Selection: Proposed pipeline alternative alignments will be evaluated relative to the following items: • Utilities • Hazardous Materials/High Groundwater • Constructability • Traffic Impacts • Community Impacts • Permit Requirements In addition, when the proposed pipelines cross signalized intersections which are highly traveled, the intersections need to be evaluated as to whether bore and jack operation or open - cut construction will be the most beneficial solution. During the preliminary design phase, we will prepare sketches of the proposed bore and receiving pit locations and corresponding traffic control concepts. It should be noted that if the intersections are bored, the streets will not be able to be open to traffic at the end of each work day. Construction Phasing: Construction phasing will be a key element of the project specifications. We will work with the regulatory agencies to minimize the impacts of the construction to the adjoining properties. We are sensitive to their concerns regarding construction impacts and the concerns of the TETRA TECH Page 111