According to Carol Perkins, director of marketing, the Sumas plant had already achieved ISO 9001: 2000 certification on its commercial modified line in August 2001. "The fact that this plant's second line, which manufactures our Cambridge 50, 40 and 30 and Marathon 30 and 20 shingles for the residential market has also received this certification simply underscores the plant - and our company's - total commitment to quality," she says.