This study and report are an outgrowth of concerns that have developed over the past 10 years regarding the vulnerability of toilet flush valve seals (commonly termed flappers) to normal aging, to possible degradation caused by consumers’ use of in-tank bowl cleaning tablets, and to tampering and replacement. In addition, there is evidence that consumers may not be able to locate and install the proper replacement flappers when their original product fails.
It is the belief of many water conservation practitioners that these factors are resulting in seal failure, leakage, and excessive flush volumes in 1.6-gallons per flush (gpf) toilets. These, then, could result in a serious decline or “decay” in the water-efficiency of the toilet fixture, thereby negating the water savings that had been predicted by the water utilities subsidizing toilet replacements. However, the above scenario has only been partially documented and, as such, water utilities are uncertain as to the magnitude of such failures and resultant water losses.
This study is intended to supplement previous work in this area, answer questions about the frequency of seal failure and flush volumes of aging toilets, and provide a basis for further quantification of water losses (if any) resulting from seal failure.
In addition to the main objectives of the study, the City of San José also contracted for second visits to some of the residences within its service area that were subject to first visits and inspections. Between the first and second visits, the City contacted the first-visit customers by mail to encourage them to check for a toilet leak and replace their flapper. The second visit was designed to confirm that the customer received the letter and to determine what action the customer took in response. Exhibit B provides information on the results of the second visits.