Specifications include, but are not limited to: Pima County is seeking Statements of Qualifications (SOQ) for a Design-Builder (D-B) for the Tres Rios Wastewater Reclamation Facility (TRWRF) Sidestream Anammox Treatment Process (3ANOMX). The TRWRF renewed discharge permit requires it to meet new Ammonia limits. To address this new ammonia limit, the TRWRF must make modifications to the existing process to ensure compliance throughout the year. A key process for targeting ammonia reduction is the centrate side stream waste generated through the dewatering of anaerobically digested bio-solids. The centrate side stream waste typically contains ammonia concentrations of 1,000 mg/L and a volume between 300,000 – 500,000 gallons each day which represent almost 30% of the daily ammonia load processed at the TRWRF. This return flow poses challenges for recycling into the treatment process and controlling nitrogen removal and therefore should be the easiest and very possibly the only process modification necessary for achieving long term compliance with the new ammonia limit.