Over fifty percent of the drinking water in use today has its source in underground water supplies.¹ These groundwater sources are hydrologically related to surface waters, however, since surface water charges groundwater reservoirs and groundwater feeds springs and surface streams.² Protection of one of these water sources, therefore, is meaningless without concomitant measures to protect the other.

Groundwater aquifers, whose importance has traditionally been neglected under water pollution statutes, in 1974 received partial regulatory protection under §1424(e) of the Safe Drinking Water Act.³ This Article will discuss the section's scope and meaning and will analyze the first application of §1424(e) by the Environmental Protection Agency (EPA) to protect a groundwater source.