The remainder is groundwater. Patterns of water use for retail and commercial establishments vary widely, but often include water for sanitary and landscaping needs. The number of employees often is a significant factor in business water use. Partly because water use patterns vary significantly among businesses, water audits tailoring conservation measures to particular needs are an effective strategy for reducing business water use. Under the Groundwater Management Act, ADWR sets goals for per capita water use by municipal water providers, but cannot regulate individual customers.
Large providers can choose among four water conservation programs.
Most often selected is the Total GPCD program, which sets targets for reductions in per capita water use for each water provider based on an analysis of conservation potential for that provider. Small providers, which account for four percent of total municipal water use, are regulated differently than large providers. Small providers are required to reduce waste and encourage conservation, but they generally lack the resources to implement conservation programs. In the past twenty years, however, effluent use has increased and CAP water has arrived in the area.