Codes and equipment evolve over time. I have been a master plumber since 1979 and have seen ongoing improvements in plumbing fixtures. The move to “go green” and meet Leadership in Energy and Environmental Design (LEED) requirements has also affected the design and manufacture of plumbing fixtures.
When I entered the plumbing trade, toilets used an average of five gallons of water each time they were flushed. Later on, the water conservation demands brought the use of three-gallon-per-flush toilets. After that the usage went down to 1.6 gallons per flush.
The use of low-flush and ultra-low flush fixtures did not go smoothly in the beginning. Since drainage piping was designed and installed for a larger flow of water, when a toilet was flushed the low-flush toilets often clogged piping or had to be flushed twice when flushing solids. This defeated the purpose of 1.6-gallon flush toilets.
Toilets are not the only plumbing fixtures that have been updated in design. Lavatory faucets that use about half has much water as old faucets did are now common. The same is true of shower heads. All in all, the goal to make plumbing function with the use of less water has been ongoing.
