40 CFR 13.32 - Standards for termination.
(a) The Government cannot collect or enforce collection of any significant sum from the debtor, having due regard for available judicial remedies, the debtor's ability to pay, and the exemptions available to the debtor under State and Federal law;
(b) The debtor cannot be located, there is no security remaining to be liquidated, the applicable statute of limitations has expired, and the prospects of collecting by offset are too remote to justify retention of the claim;
(c) The cost of further collection action is likely to exceed the amount recoverable;
(d) The claim is determined to be legally without merit; or
(e) The evidence necessary to prove the claim cannot be produced or the necessary witnesses are unavailable and efforts to induce voluntary payment have failed.