For two decades, Alberto Rodriguez has worked in the same cavernous garage along the border between Queens and Brooklyn, surrounded by the clang of metal and the rumbling of engines awaiting repair.

It turns out that he has also been toiling amid potentially dangerous levels of radiation.

Mr. Rodriguez’s shop, Los Primos Auto Repair and Sale, is one of six businesses at the intersection of Cooper and Irving Avenues in Ridgewood, Queens, that have been targeted for demolition as part of a cleanup plan released recently by the Environmental Protection Agency. The businesses are within a Superfund site, the term for sites covered by a program that finances the cleanup of hazardous waste.

The small, triangle-shaped tract, hemmed in on one side by an abandoned rail spur, does not look particularly active; the federal plan described it as occupied by, among other things, a “dilapidated warehouse.” But for business owners like Mr. Rodriguez, who have turned the block into a one-stop shop for automotive needs — it also houses a tire shop, a motorcycle repair shop and another auto repair shop — the proposed plan threatens to uproot well-established livelihoods.

While Mr. Rodriguez acknowledged that the contamination needed to be dealt with, he said that “when you move, you have to start again. The customers, they don’t follow you.”