The City of Lancaster (City) operates two water treatment plants and a 620-mile distribution system. Water is piped from the Susquehanna River about a mile to the water treatment plants, and then is pumped another 6 miles from the treatment plants to the Oyster Point Reservoir. From the reservoir it is gravity fed over 7 miles to the City. All of these are 42 steel transmission mains, are 3/8 thick, and were installed in 1956. In 2013, the City started preliminary design to address the lack of redundancy and vulnerability of its transmission system. This Susquehanna Large Diameter Replacement Main Project originally consisted of 5 phases of construction from the Susquehanna River to the western city limits of Lancaster. The purpose of the project is to provide system resiliency, given that the sole transmission main from the Susquehanna Water Treatment Plant is over 60 years old, and to also provide additional pressure during peak demand periods. The existing 42-inch main has had numerous breaks and supplies 66% of the total consumptive flows. Phase 1 of the transmission main installation project, from the Oyster Point Reservoir into the City, was completed in 2021. The City intends to proceed with the next two phases in the following prioritization order: Phase 3: Raw Water Transmission Main from the Susquehanna Low Service Pumping Station on the Susquehanna River to the Susquehanna Water Treatment Plant (approximately 8,000 linear feet of large diameter piping). Phase 2: Finished Water Transmission Main from the Susquehanna River Treatment Plant to the Oyster Point Reservoir (approximately 30,350 linear feet of large diameter piping). Time is of the essence. The City has applied for $26 million of ARPA grants through the Commonwealth Financing Agency (CFA) for this project. All construction must be complete by September 30, 2026. The Bidding assistance and assistance during construction will be addressed after the design; this work need not be priced for this RFP submittal. Consultants must prioritize the work to apply for permits ASAP, especially the railroad crossings. Design will proceed even if Lancaster does not get grant funding. The objective of this Request for Proposals (RFP) is to contract with an engineering firm (the Consultant) to provide professional engineering services for the detailed design of the water mains and other related work for Phases 2 and 3 of the Susquehanna Large Diameter Replacement Main Project. Services include, but are not limited to surveying, geotechnical work, utility location, preparation of drawings, plans and specifications for bidding and construction purposes, permitting, and other engineering duties related to water main design and installation for Phases 2 and 3, based on an evaluation of potential routes, costs and design considerations prepared by ARRO contained herein.