A Colorado lawmaker has called for Congressional field hearings to discuss the staffing shortages at the maximum security prison in Florence, known as Supermax.Rep. Buffy McFayden, D-Pueblo West, said she learned Thursday that an arbitration judge deemed the penitentiary a "dangerous work environment." The arbitrator said that Supermax, the most secure federal prison in the United States, is understaffed and existing staff is being asked to cut corners.American Federation of Government Employees Local 1302 had said some of the "mission critical" posts at the prison were going vacant, leading to more assaults and threats from inmates. Arbitrator Joseph Lazar agreed, and ordered the Bureau of Prisons to lower inherent hazards at Supermax to the lowest possible levels. But he denied the union's request to order the Bureau to fill all the mission critical posts.Union official Mike Schnobrich said the ruling and a recent report by the Office of the Inspector General bolster the argument that Congress should allow more funding to properly staff prisons.The OIG report found the bureau has not effectively monitored the mail of terrorist inmates, in part because of a lack of enough translators, or proper intelligence training.The report said that said convicted terrorists used the mail for years to communicate and recruit other terrorists and suicide bombers on the outside. According to the report, three men involved in the 1993 bombing of the New York World Trade Center sent at least 90 letters to Islamic extremists between 2002 and 2004.The letters later surfaced in the hands of a terror suspect who used them to recruit suicide operatives.Sen. Ken Salazar this week wrote Attorney General Antonio Gonzales asking him to ensure that the Bureau of Prisons fixes security flaws at Supermax. Salazar said that the bureau failed to read all of the mail from the highest-risk prisoners and monitored less than half the telephone calls made by Supermax prisoners on the "alert list," which includes convicted terrorists.McFadyen and the corrections officers' union, American Federation of Government Employees Council of Prison Locals 1302, testified in May saying the prison is staffed below what the Federal Bureau of Prisons itself determined bare-bones levels.Union leaders had said staffing levels have fallen by 20 percent to 30 percent in six years because of federal budget cuts.On Friday McFadyen will meet with union members at the Capitol to celebrate the validation of their claims and to ask Congress to fix what is now a known problem.Supermax holds 400 of the most dangerous inmates in the federal prison system, including al-Qaida member Zacarias Moussaoui, 1993 World Trade Center bomber Ramzi Yousef, Unabomber Ted Kaczynski and Oklahoma City bombing conspirator Terry Nichols.It operates under the highest level of security, and inmates are released from their individual cells only one hour a day. Please watch 7NEWS Now at 4 p.m. for more on this story.