Many of the early generation 6-litre toilet models sold in North America performed poorly and failed to meet consumer expectations for flushing performance. Yet virtually all of these models met all of the prevailing performance requirements to become certified. Water utilities were concerned over the negative customer feedback they were receiving regarding toilet fixtures that they had encouraged (through rebates) their customers to install. In response, 22 U.S. and Canadian utilities and other water interests, recognizing that toilet certification did not guarantee a high level of performance, sponsored the development of the independent Maximum Performance (MaP) Testing Program. This is now considered the de facto methodology for toilet performance testing throughout North America.