The Census of Retail Trade, Wholesale Trade, and Service Industries contain such statistics as number of establishments, employment, payroll, operating expenses, and capital expenditures for each State and its important metropolitan areas, counties, and places, by SIC groups and individual users. Chambers of Commerce are a possible source of names and addresses of local commercial users, especially users that are likely to attract tourists, such as zoos, ski areas, water parks, hotels, motels, and major restaurants. Diagram of commercial water use. Each of these three groups requires a different approach. Primary data acquisition is important with the first group, secondary data acquisition is important with the second group, with small components of primary and derived data.
Approaches using derived data are important with the third group.
Data on deliveries from water suppliers and releases into wastewater-collection systems, as well as identification of major commercial users, may be available from the utilities. Consumptive use in the form of evaporation, usually during outdoor use but also from washwater and food preparation, are estimated from withdrawal, delivery, release, and return flow data or from information supplied by the commercial facility. If there is no State program that regulates withdrawals for fish hatcheries, snow making, or amusement parks, it may be necessary to make onsite measurements. Other potentially large users, such as airports, hotels and resorts, shopping malls, hospitals, laundries, office buildings, and business parks, are more likely to meter their withdrawals or public water-supply deliveries. Consumptive use may be determined by installing flow meters at key points in the wastewater-collection system to monitor commercial wastewater releases and comparing the results with the withdrawals and deliveries.