As federal officials begin an overhaul of the widely criticized system used to incarcerate immigrants awaiting hearings and deportation, their challenge includes a deep inconsistency in the amount paid to a hastily assembled network of private prisons and local jails that hold thousands of such detainees.

Contracts obtained by The Associated Press illustrate the problem in paper-heavy detail, and not all of the discrepancies can be explained by geography or differences in the cost of living. For example, a suburban Atlanta county is paid less than $43 per day to house an illegal immigrant, while a rural New Mexico county gets $97 a day – just a few dollars shy of the amount paid for a bed in Los Angeles.