Each person who generates phosphogypsum shall place all phosphogypsum in stacks. Phosphogypsum may be removed from a phosphogypsum stack only as expressly provided by this subpart. After a phosphogypsum stack has become an inactive stack, the owner or operator shall assure that the stack does not emit more than 20 pCi/(m2-sec) (1.9 pCi/(ft2-sec)) of radon-222 into the air.
[57 FR 23317, June 3, 1992, as amended at 65 FR 62158, Oct. 17, 2000]
Title 40 published on 2014-07-01
no entries appear in the Federal Register after this date.
This is a list of United States Code sections, Statutes at Large, Public Laws, and Presidential Documents, which provide rulemaking authority for this CFR Part.