The California operators of a chain of nursing homes that have been labeled the worst in the state of Washington have promised Washington lawmakers that improvements will be made soon. Tom Clark, Western regional president for Beverly Enterprises of Pasadena, said the chain--the largest nursing home operation in the country--is "committed to remain in Washington." Clark told a legislative committee that a number of the problems experienced by Beverly are because of its rapid expansion to 33 homes in Washington. At least eight of the homes have been cited in recent weeks for serious deficiencies ranging from improper dietary plans to poor patient care and sanitary problems. Mike Wills, head of nursing home licensing for the state Department of Social and Health Services, said he could not determine if Clark's promises were sufficient to deal with the problem. But Wills, who has called the chain the worst in Washington, said he was "pleasantly surprised" by Clark's announcement.