In 2006, the United States Environmental Protection Agency released the Long Term Enhanced Surface Water Treatment Rule (LT2ESWTR). This new rule requires surface water treatment facilities to either filter their water or install an additional barrier for microrganisms as a multi-barrier disinfection strategy. The city of New York needed to comply with the LT2ESWTR by 2011. Engineers working on the Catskill/Delaware project evaluated a new filtration plant but the cost of installing a 2.2 billion gallon per day (BGD) filtration facility was significantly greater than other alternatives. After evaluation of available technologies, it was decided that UV was the most practical and cost-effective solution. In 2005, Trojan Technologies was selected as the manufacturer for the UV portion of NYC drinking water project. In 2009 and 2010, Trojan delivered 56 TrojanUVTorrent™ UV units to the Catskill/Delaware UV Facility.