The Government Management Reform Act of 1994 requires that the Department of Energy (DOE) annually submit audited financial statements to the Office of Management and Budget (OMB). A departmentwide audit was conducted to determine whether there was reasonable assurance that DOE's consolidated Fiscal Year (FY) 1999 financial statements were free of material misstatements. We conducted a portion of the departmentwide audit at the Richland Operations Office (Richland); Office of River Protection (ORP); CH2M Hill Hanford Group, Incorporated (CH2M Hill); Bechtel Hanford, Incorporated (Bechtel); and Fluor Hanford, Incorporated (Fluor) and its subcontractors. The audit disclosed an error, as of September 30, 1999, in the Environmental Liabilities account. Richland's Environmental Liabilities account was understated because the cost estimates for closure of single shell tank farms had not been updated to reflect current engineering estimates. We recommended that Richland adjust the Environmental Liabilities account and that management review other project cost estimates to determine if estimates were based on the best available data. Management concurred with the recommendations and implemented corrective actions.