Description

1.1 This practice provides a set of instructions for estimating the environmental load of residential water, as it is discharged from a residence. The environmental load is calculated based on the number and type of fixtures in the home, the common household chemicals used, and the number of people in the home. While the format is broadly applied internationally, the parameters stated herein reflect North American averages and would need to be modified if used elsewhere.

1.1.1 Averages Method-The Averages Method provides an estimate of the annual environmental load for the average U.S. single-family home based on 2000 U.S. Census2 and 2007 U.S. Census Data3 and U.S. EPA/625/R-00/008 characterization of residential wastewater flows.4

Note 1: Census 2000, taken April 1, 2000, counted 281 421 906 people in the 50 states and the District of Columbia. The questionnaire included seven questions for each household: name, sex, age, relationship, Hispanic origin, race, and whether the housing unit was owned or rented. In addition to these seven questions, about 17 percent of the households got a much longer questionnaire including questions about ancestry, income, mortgage, and size of the housing unit.