Leveraging Alternative Delivery and Innovative Funding to Achieve the City of Memphis's Vision - Process Upgrades at the T.E. Maxson WWTF

Introduction With the City of Memphis (City) facing new requirements for effluent disinfection and mounting needs for improvements within the plant-wide process train, the City began looking for a path forward that would allow multiple construction packages to be developed as funding became available. Working with CDM Smith to leverage alternative delivery and multiple innovative funding options-including the Water Infrastructure Finance and Innovation Act (WIFIA) and State Revolving Fund (SRF)-the City is implementing over $250M in plant upgrades to ensure compliance well into the future for our citizens. The City owns and operates the T.E. Maxson Wastewater Treatment Facility (Maxson WWTF), which is a trickling filter/activated sludge WWTF. Originally constructed in 1975, the facility has a rated capacity of 90-mgd, with an average daily flow of approximately 70-mgd and a peak-hour flow of 170-mgd. In 2009, the City began negotiating a new NPDES permit that included requirements for the addition of disinfection to the treatment process. A disinfection evaluation involving extensive bench- and pilot-scale testing of multiple alternatives was conducted from 2011 to 2015. It was determined the facility was nearing its biological treatment capacity due to heavy industrial loading, and that further process improvements would both improve the efficacy of the disinfection process and add much needed treatment plant capacity. In late 2015, as part of an open solicitation for alternative delivery support, CDM Smith was retained as the Designer/Construction Manager at Risk (DN/CMAR) (Progressive Design-Builder) to evaluate, design, and construct facility improvements to address these critical issues for the City: - Reduction of plant-wide odor - Increased biological capacity to expand the treatment capacity to the permitted 90-mgd at the current elevated loadings/concentrations - Design and implementation of a disinfection process; ultimately selecting peracetic acid (PAA), resulting in one of the largest installations in the world - Meet or exceed Minority and Women-Owned Business (M/WBE) goals and encourage local job growth These goals led to a set of plant improvements, including the following major components: - Improvements to the existing headworks facility - Upgrades to the existing trickling filters to include new forced air ventilation system, plastic media, and distributor arms - Conversion from coarse- to fine-bubble diffused air system in aeration tanks - Construction of a new RAS re-aeration tank and blower building - Two new secondary clarifiers - Construction of a new disinfection tank and implementation of PAA disinfection - Plant-wide odor control improvements - Miscellaneous electrical, instrumentation, and SCADA improvements throughout the facility At the time of alternatives selection, the City had not procured funding for the entire construction project. Discussions were held over multiple months regarding prioritization, timing for regulatory compliance, construction duration, and schedule impacts for acquiring funding. The City intended to leverage Tennessee SRF and the new WIFIA program to fund the improvements. The joint efforts of the City and CDM Smith staff resulted in $85M (three separate loans) in funding from SRF and ~$150M in funding from WIFIA. To expedite construction, the design was separated into individual guaranteed maximum price (GMP) proposal packages. This allowed the City to acquire funding in smaller, more attractive loans from SRF as opposed to one large loan that was not likely to be approved. These smaller packages also improved the ability for local and M/WBE firms and contractors to bid on smaller, more manageable portions of the work. Ultimately, the recommended scope of improvements was broken into five design packages. Additionally, the contract structure did not allow the self-performance of construction work, which drove the strategy to deliver the packages while maximizing opportunities for local and M/WBE sub-contractors. Unique Features of CMAR During Construction Pioneering construction-phase services were performed in development of the proposed GMP for project construction. Key items included: - A value engineering assessment at the 30-percent completion stage to optimize the design recommendations for the facility. This workshop resulted in over $30M in potential savings. The DN/CMAR team presented the results and recommendations to the City, and the City selected which items to pursue as design was completed. - Assistance with obtaining funding that included preparation and submission of a WIFIA loan package for the overall program and assistance with procuring SRF loans. Outreach with SRF began early in design and throughout package approval, bidding, and construction. The team was proactive in obtaining approvals and meeting the construction requirements. - With five separate packages, standard specifications were developed for use throughout all packages for ease of management and construction delivery. - At the preliminary design stage, a Risk and Opportunity Register was developed and managed throughout construction to aid in the development of the project contingency. The DN/CMAR team and the City held a risk workshop to identify all risks and opportunities and included them into a register that helped establish the contingency for each package. An overall project schedule was also maintained related to the design milestones, funding availability, and impacts between the packages. Currently, construction has been ongoing for approximately four years, with the overall construction schedule showing three years remaining based on the timing of the projected funding. Conclusion The use of DN/CMAR project delivery allowed the City to secure funding by packaging the work, expediting construction, increasing the number of local and M/WBE subcontractor bid opportunities, and phasing in the process improvements at the Maxson WWTF, ensuring a successful project.