Several Pasco residents expressed concern Tuesday about activities at the Sunset Sand Mine and Landfill and an adjacent 76-acre property in Hudson. Both sites are owned by Golden Crown Enterprises. At a County Commission meeting Tuesday, the residents complained of noise from trucks at night, questioned what the land was being used for, and said they were worried about the safety of their drinking water. "We don't really understand what's going on out there," said Francis Burns of Brentwood Mobile Park. The Sunset landfill, off New York Avenue and Hicks Road, was plagued two years ago with potentially dangerous hydrogen sulfide emissions and a stubborn fire. County Administrator John Gallagher said his office would meet with the residents to address their concerns.