AWWA MTC61103

The City of Parsons, Kansas started up a new surface water treatment plant utilizing an ultrafiltration process in the fall of 2001. The plant operates on a creek source with moderate total organic carbon (6-12 mg/L), and elevated levels of iron (0.5-1.5 mg/L) and manganese (0.1-0.5 mg/L). In 2003, the City began evaluating options for meeting future capacity requirements in the most cost-effective manner, in order to increase plant capacity from 3 mgd to 4.5 mgd. As part of the evaluation, the City mobilized two 1-mgd demonstration-scale membrane filtration systems which operated from July 2003 through June 2004. These were installed and started up on a fast-track basis and operated in parallel with the original system to ensure adequate production through the summer of 2003. The demonstrated operation of the three production-scale systems in parallel during a nine month period beginning in July 2003 served as the basis for selecting a membrane system supplier going forward for the plant expansion project. One of the alternate systems was selected for the upgrade, necessitating a carefully-staged changeout of the membrane equipment utilizing temporary piping connections, cleaning systems, and other ancillary equipment. The first 2-mgd of replacement equipment was installed, tested, and started up within 3 weeks during July 2004. Conversion of the original 3 mgd ultrafiltration system to the replacement 4.5 mgd system was executed within 6 months, while maintaining a firm plant capacity of 3 mgd. This paper discusses lessons learned in executing installation, startup, and operation of the two alternate systems in parallel with the original system, as well as logistics involved in retrofitting a membrane system into an operating treatment plant on a fast-track basis. These lessons are valuable for utilities considering retrofit of membrane filtration systems into existing plants where production must be kept uninterrupted. Includes table, figures.