Prior to January 1, 1994, how many gallons of water did residential tank-type toilets use per flush cycle?

Prior to January 1, 1994, residential tank-type toilets typically used 3.5 gallons of water per flush cycle. This was a standard measurement during that time, reflecting the design and plumbing technology available before the introduction of more stringent water conservation regulations. The 3.5-gallon flush volume was common in many older toilet models, which were designed for effective waste removal but not necessarily with water conservation in mind.

In 1994, regulations under the National Energy Policy Act mandated that new toilets must use no more than 1.6 gallons per flush, which was a shift aimed at promoting more efficient water use. Understanding this historical context helps in recognizing how plumbing standards have evolved over time towards greater efficiency and sustainability.