自1967年以来，安大略省环境部一直使用安大略省休伦湖处理厂进行替代处理模式的中试和全面试验，这可能会扩大可使用直接过滤的水质范围，尤其是澄清直接过滤过程的限制。尽管休伦湖工厂达到了其设计的浊度限值，但不太可能选择直接过滤模式来满足修订后的浊度限值。休伦湖的高浊度、高残留铝以及三氯化铁的使用也被报道。包括1个参考表格。

Since 1967 the Lake Huron treatment plant in Ontario has been used by the Ontario Ministry of the Environment for pilot plant and fullscale tests of alternate treatment modes that might broaden the range of water qualities where direct filtration can be used and, more particularly, for clarification of direct filtration process limitations. Although the Lake Huron plant met the turbidity limits for which it was designed, it is unlikely that direct filtration would be the mode selected to meet the revised turbidity limits. Also covered are Lake Huron's high turbidity, high residual aluminum, and the use of ferric chloride. Includes 1 reference, tables.