Survey to Estimate Residential Solid Waste Generation

In preparation for renegotiation of contracts with its haulers, the Broward County, Fla., waste management authority commissioned a sample survey designed to produce a “statistically defensible” estimate of the total weight of solid waste generated annually by the typical residential unit in a target area consisting of about 40,000 such residences. At the time of the study, initiated on Oct. 1, 1990, the annual unit weight figure used for contractual and payment purposes was 1,837 kg/yr/residence (4,050 lb/yr/residence), with an unknown margin of error. The survey, using a selection scheme and estimation methods based on full probability sampling, was completed on Sept. 30, 1991. It produced estimated annual figures of 1,378.92 kg/yr/residence (3,040 lb/yr/residence) of regular household trash and garbage, 89.85 kg/yr/residence (198.1 lb/yr/residence) of bulk trash, and 37.92 kg/yr/residence (83.6 lb/yr/residence) of recyclable material—a total of 1,506.69 kg (3,321.7 lb) per year, per residential unit, and a reduction of 18% from the earlier contractual figure. Furthermore the rigorous statistical procedures that were employed permitted the estimation of a standard error of 30.89 kg (68.1 lb) for the overall weight.