Introduction

Perchlorate, a chemical component of rocket-fuel that is used in explosives, was found in drinking water wells in the city of Aberdeen, Maryland, late last year.¹ The chemical interferes with the body's uptake of iodine, disrupting thyroid function. Low thyroid levels interfere with brain development in fetuses, infants, and children.² Aberdeen's small but vigilant band of environmental activists were alarmed, although no one doubted the source of the contamination. Aberdeen abuts the 72,500-acre U.S. Army Aberdeen Proving Ground (APG), one of the largest weapons proving grounds in the country.³

Given APG's size and prominence, it is surprising that last year's perchlorate discovery was only the second time chemicals from the base had been found in municipal water supplies.⁴ In the 1990s, trichloroethane was found in water supplies derived from the Perryman well fields.⁵ The Army agreed almost immediately to erect a $ 2.2 million groundwater treatment plant near Perryman,⁶ and most citizen activists expected similarly rapid action to clean up the perchlorate. This happy ending was not to be.