Radon mitigation in Symmes Township, OH

Symmes Township had 3,726 residents in 1970 and more than 15,000 by 2020. The township traces that jump to the 1979 completion of the I-275 loop, so much of its housing is 1980s and 1990s subdivision construction, and where those basements have since been finished into family rooms or bedrooms, the finished room is the level to test. A finished lower level also hides the slab: cracks, the floor-to-wall joint, and sometimes the sump sit behind carpet, framing, or built-ins, so the mitigation plan has to work around what cannot be opened up. Camp Dennison, in the Little Miami valley at the township's south end, is the older counterpoint, a community first settled in 1796 where each house's foundation needs its own look.

Municipal annexations between 1951 and 1988 left Symmes Township as two separate pieces totaling about 8.6 square miles in Hamilton County's northeast corner, bordered by Loveland, Indian Hill, Montgomery, and Sycamore Township, with Camp Dennison in the Little Miami River valley at its southern end.