Certifications: Methods for EPA Compliance Monitoring: Hach TNTplus Vial Chemistries for COD (Hach Method 8000), Free and Total Chlorine (SM 4500-Cl G), Chromium VI (SM 3500-Cr B, D), Iron (Hach Method 8008), Ortho- (EPA 365.1) and Total Phosphate (EPA 365.1, 365.3), Ammonia (EPA 350.1), Fluoride (EPA 340.1) and Nitrite (EPA 353.2) are equivalent to the respective method referenced in