The following table provides a list of interpretive rules and policy statements issued by the NC WW/GW Laboratory Certification Branch (LCB). They are meant to clarify existing legislative rules or to provide guidance where a rule does not exist. Where multiple editions of a single reference source may be approved for reporting purposes and where these approved methods may have conflicting or unclear requirements, the NC WW/GW LCB may adopt a single policy based on a single edition to provide consistency in analytical reporting. Even when citing an alternate reference edition, laboratories must adhere to the NC WW/GW LCB policy requirement. 

Policy names with an asterisk (* ) beside them notate that the policy could be applicable to Field Laboratory certification, depending upon the parameter methods on the laboratory's Certified Parameter Listing

Parameter Policy Revision
General Quality Control Correlation Coefficient for Linear Calibration Curves * 12/2014
General Quality Control Electrode Slope/Efficiency Documentation  10/2013
General Quality Control Electronic Signature and Data Storage Policy * 4/2020
General Quality Control Factory Set Curve Verification * 10/2018
General Quality Control Manual Integration 4/2010
General Quality Control Sample Collection, Preservation and Receipt Requirements * 2/2022
General Quality Control Temperature-Measuring Devices Used for Laboratory Operations Policy * 8/2021
General Quality Control Titrant Standardization * 5/2019
General Quality Control Traceability Documentation Requirements for Chemicals, Reagents, Standards and Consumables * 3/2020
General Quality Control SW-846 Method Implementation 7/2020
General Quality Control Analytical Balance Weights Verification * 4/2020
General Quality Control Matrix Spike 5/2020
General Quality Control Chemical, Reagent, Standard and Consumable Expiration Policy* 4/2022
General Quality Control Duplicate Sample Analyses for Field Parameters Policy* 3/2020
General Quality Control Mechanical Volumetric Liquid-Dispensing Devices Calibration Policy* 7/2021
General Quality Control Second Source Standard 9/2021
Ammonia/Fluoride Distillation* 4/2019
Bacteria Quanti-Tray Sealer Check 1/2022
Bacteria Fecal Coliform MF Consumables Testing 8/2021
Bacteria Fecal Coliform MF Reporting 5/2019
Bacteria Bacteriological Sample Bottle Sterility Test 1/2022
Bacteria Coliform MF Culture Positive 6/2022
Bacteria Bacteriological Reagent Water Testing 2/2018
Bacteria Fecal Sludge MPN Analysis Protocol 8/2021
BOD/CBOD Flagging QC Failures in BOD Data 8/2021
BOD/CBOD BOD - Checking DO Meter for Drift 8/2021
BOD/CBOD Reporting Limit Policy 8/2023
BOD/CBOD Neutralizing Total Residual Chlorine in BOD Samples 8/2021
Chlorophyll Chlorophyll Sample Collection, Preservation and Holding Time Policy  2/2020
Dissolved Oxygen Dissolved Oxygen Meter Calibration Policy * 4/2020
Free Available Chlorine FAC Hold Time * 6/2019
pH SW-846 pH Calibration Verification * 2/2020
Residue TSS Reporting Limit 9/2014
Residue TS and TDS Reporting Limit  3/2009
Residue Method Blank Requirement for Residues  7/2021
Residue Anti-static Device Requirement for Total and Total Dissolved Solids 6/2021
Residue Residue Oven Temperature Documentation 7/2021
Turbidity Turbidity Standards * 12/2007
TRC  Total Residual Chlorine - Sealed Standards in a Field Setting * 10/2017
VAR Option 3 DO Measurement  9/2018
VAR Option 3 Minimum Sample Volume 9/2018
VAR Option 3 Documentation Requirements 6/2022


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