The City of Minneapolis membrane ultrafiltration program is in the unique position of starting up one full-scale plant and procuring membranes for a second plant within the context of the draft Long Term 2 Enhanced Surface Water Treatment Rule. Minneapolis procured the membranes for its first 70-MGD ultrafiltration plant in 2001. At that time, membranes were considered by the State of Minnesota to be an Alternative Filtration Technology. Based on the results of the 7-month pilot testing program, the State of Minnesota granted the plant 4-log removal for Cryptosporidium, Giardia, and viruses. A turbidity performance requirement was also specified by the State. As the project moved through construction in 2004, the State indicated the regulatory reporting requirements for the full scale plant should be consistent with the newly-issued Draft Long Term Enhanced Surface Water Treatment Rule and associated Membrane Filtration Guidance Manual. Through a team effort between the City, its consulting engineer, and the equipment supplier, requirements of the draft rule were successfully incorporated into the control and monitoring of the fullscale plant. In 2004-2005, while the 70-MGD plant was moving through the final stages of construction into commissioning and start-up, the City was procuring membranes for a second, 95-MGD membrane plant. The City focused on incorporating lessons learned from the actual implementation of the new regulatory framework into the procurement of the membranes for its second plant. This paper presents the audience with lessons learned when procuring, piloting, designing, and operating membrane plants under the integrity requirements of the new rule. Details are presented regarding what utilities and regulators should consider in preparing contract documents, what should be demonstrated during pilot testing, and how to ensure accurate scale-up and implementation in a full-scale plant. Includes 2 references, figure.