The Decades-Long Battle Over Low-Flow Toilets — Half as Interesting

Quick Overview

The 1992 Energy Policy Act mandated low-flow toilets in the US, initially leading to poorly performing models that caused widespread frustration and clogs. However, the introduction of the MaP (Maximum Performance) Test by Bill Gauley and John Koeller revolutionized toilet design, leading to significantly more powerful and efficient low-flow toilets that now use less water while performing better than older high-flow models, despite political attempts to reverse these regulations.

Summary

Key Points: The 1992 Energy Policy Act mandated new US toilets use no more than 1.6 gallons per flush, down from 3.5-7 gallons. Early low-flow toilets were poorly designed, leading to weak flushes, clogs, and consumer frustration. The MaP (Maximum Performance) Test, developed by Bill Gauley and John Koeller, introduced a quantifiable standard for toilet performance using soybean paste. Toilet manufacturers innovated significantly, leading to modern low-flow toilets that perform much better than older models while still using less water. Average MaP scores for toilets increased from 336 grams in 2003 to 882 grams in 2017, with many models now flushing over 1000 grams. Current low-flow toilets typically use 1.28 gallons per flush, saving substantial amounts of water and energy. Despite political attempts to reverse regulations, existing laws prevent weaker standards, ensuring continued efficiency improvements in toilets.

Context: In the early 1990s, the United States faced concerns about water consumption, leading to the passage of the Energy Policy Act of 1992. This legislation mandated a significant reduction in the amount of water new toilets could use per flush. Initially, this led to widespread consumer dissatisfaction as manufacturers struggled to adapt, producing inefficient low-flow models. This period of poor performance created a negative public perception of water-saving toilets.

Detailed Analysis

In the early 1990s, the average American toilet used 3.5 to 7 gallons of water per flush. The 1992 Energy Policy Act, signed by President George H.W. Bush, mandated a maximum of 1.6 gallons per flush for new toilets, effective in residential buildings by 1994. This rushed transition led to poorly designed low-flow toilets that often failed to clear waste effectively, resulting in frequent clogs and consumer dissatisfaction, with many resorting to importing older high-flow models from Canada or buying them at yard sales. The problem stemmed from manufacturers simply reducing water volume without redesigning the internal mechanics, leading to weak flushes and residue buildup. The existing certification test was also inadequate, only requiring 79% of test materials (paper, sponges, plastic balls) to be flushed, and provided no performance score to consumers. To address this, Bill Gauley and John Koeller developed the MaP (Maximum Performance) Test, which measures how many 50-gram tubes of soybean paste (representing solid waste) a toilet can flush in one go, along with toilet paper. Their benchmark for a good toilet was 250 grams, based on the largest single waste produced by a healthy man. Initial MaP tests in 2003 showed an average of 336 grams, with many failing the 250-gram benchmark. This new, more rigorous testing incentivized manufacturers to innovate, leading to redesigned toilets with features like powerful jets and improved bowl-cleaning mechanisms (e.g., Toto Drake model's diagonal water streams). By 2017, the average MaP score had risen to 882 grams, with many modern toilets capable of flushing 1000 grams or more, all while adhering to the 1.6-gallon limit. Current models typically use even less, around 1.28 gallons per flush, which could save 260 billion gallons of water annually if universally adopted in the US. Despite these advancements, political figures like Donald Trump have publicly criticized low-flow toilets and attempted to roll back efficiency regulations, though existing laws prevent new standards from being weaker than previous ones, and manufacturers have not utilized loopholes to produce less efficient products.