R2016-15 PROFESSIONAL ENGINEERING SERVICES AGREEMENT SWTP CLARIFIERS

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DEPARTMENT OF WATER MANAGEMENT Memora�dum No. 2016-OS February 9, 2016 TO: Mayor Julie Moore Wolfe and City Council FROM: Tim Gleason, City Manager �/� Keith Alexander, Director of Water Management fv Jerry Stevens, P.E., Engineering Services Coordinator SUBJECT: South Water Treatment Plant East Clarifiers Conversion City Project W2016-03 SUMMARY RECOMMENDATION: Council adopt the attached Resolution authorizing a Professional Engineering Services Agreement with Crawford, Murphy and Tilly, Inc. for South Water Treatment Plant East Clarifiers Conversion at a cost not to exceed $871,000. BACKGROUND: The South Water Treatment Plant has four large outdoor concrete and steel clarifiers that are critical to the facility's operation. In them, Lake Decatur water is mixed with several chemicals and compounds to begin the water purification process. The clarifiers operate in pairs. The primary clarifiers perform the initial purification process and the secondary clarifiers perform the final clarification of the water before flowing into the South Plant filter room. If any clarifier becomes inoperable, it disrupts 50% of the Water Plant's purification process. At least two of the clarifiers are always operating 24 hours per day, 7 days per week, and are continuously exposed to the elements. See Attachments A and B for clarifier photos. When the clarifiers were constructed in 1988, they were the best available technology at that time. Due to age, frequent use and continuous exposure to the elements, the two east clarifiers need to be completely rebuild or replaced with today's best available technology, which is a claricone system. The operational advantages and cost savings of claricones are: • They are a remarkably simple and highly durable design that doesn't require large complex constantly moving components that eventually wear out. Components that can be eliminated if claricones are constructed include 28 year old mixing systems, process piping, valves and actuators. • Significant reduction in the amount of maintenance staff hours and maintenance expenses. • Significant reduction in the amount of electricity used and the South Water Treatment Plant's carbon footprint. • Moderate reduction in the amount of water purification chemicals used.