1 Va. Admin. Code § 30-41-9999
Manual for the Certification of Laboratories Analyzing Drinking Water: Criteria and Procedures Quality Assurance, Fifth Edition, January 2005 (EPA-815-R-05-004)
Supplement 1 to the Fifth Edition of the Manual for the Certification of Laboratories Analyzing Drinking Water, June 2008 (EPA 815-F-08-006)