HOUSTON - Sandia Drilling Company, Ltd, L.L.P. and Sandia Drilling of Texas, L.L.C., Bossier City, La., oil drilling companies, violated federal anti-discrimination laws when their supervisors and other employees subjected two African-American and a Hispanic worker to a racially hostile work environment, the U.S. Equal Employment Opportunity Commission (EEOC) charged in a lawsuit it filed today. The companies also fired one discrimination victim in retaliation for complaining, the agency said.