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Abstract. LTV Steel Mining Company decided in 1991 to close an open pit !aconite mine in northeastern Minnesota, using a passive treatment approach consisting of limiting infiltration into the stockpiles and wetland treatment to remove metals. Over 50 million metric tons of sulfidecontaining waste had been stockpiled adjacent to the mine during its 30 years of operation. Drainage from the stockpiles contained elevated levels of copper, nickel, cobalt and zinc. Nickel is the major trace metal in the drainages, and prior to closure annual median concentrations ranged from 1.5-50 mg/L. Copper, cobalt and zinc are also present but are generally Jess than 5% of the nickel values. Median pH ranges from 5.0 to 7.5, but most of the stockpile drainages have pH greater than 6.5.Based on the chemical composition of each stockpile, a cover material was selected. The higher the potential a stockpile had to produce acid drainage, the lower the permeability of the capping material required. Covers ranged from oveiburden soil removed at the mine to a flexible plastic liner. Predictions of the reduction in infiltration ranged from 40% for the native soil to over 90% for the plastic liner. Five constructed wetlands have been installed since 1992 and have removed 50-90% of the nickel in the drainages. Total capital costs for all the infiltration reduction and wetlands exceeded $6.5 million, but maintenance costs are less than 1 % of those for an active treatment plant.Since mine drainage problems can continue for over a hundred years, the lower annual operating costs should pay for the construction of the wetland treatment systems within seven years. LTV plans to have a fully passive treatment system for its entire mine by the year 1998.

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The Hecox Hardware store in Ontonagon County, Michigan, as it appeared in 1910 (above) and 2003 (below). The business has been in continuous operation for 95 years under five different owners in three different narrow storefronts on the town's main commercial street. Its most recent incarnation, Chapman's Hardware, includes three narrow aisles instead of one wide one, puts more merchandise within easy reach of the customer, and displays fewer goods that might require the assistance of a salesperson. The modern floor plan may make for efficient shopping, but the large display racks screen customers from seeing each other, salespersons and the store as a whole. Shoppers can move in and out of the new store quickly, but the open center of the old store provided a place to congregate and chat, which patrons did frequently enough to make the store itself a social center for the surrounding community. Top photograph courtesy of the Ontonagon

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