Field Technical Assistance and Policies

Approved Procedures for the Analysis of Field Parameters

These procedures are intended to provide the approved procedures and requirements for measurement of field parameters. You may refer to the approved method reference, instrument manufacturer's manual or other resources for additional information. 

Field Parameter Revision Date
Total Residual Chlorine  August 2013
pH  April 2013
Dissolved Oxygen  April 2013
Temperature  May 2016
Specific Conductance  June 2016
Settleable Residue  April 2013

 

Field Laboratory Policies

A document entitled Quality Assurance Policies for Field Laboratories has been created to outline general policies and interpretive rules pertaining to field laboratories. These policies are regarded as required quality assurance practices and are meant to clarify existing legislative rules or to provide guidance where a legislative rule does not exist. They are intended to insure data produced is accurate, reliable and documented appropriately. This document can be viewed by clicking the link below.

Quality Assurance Policies for Field Laboratories (10/02/2013)

Preservation and Hold Time Memo (06/20/2007)

In-line Meter Calibration/Verification (01/01/2006)

 

Tools for Field Laboratories

The following table contains tools for field laboratories. 

Item Revision Date Description
Example Benchsheet for Field Analyses 10/02/2013 An example of a worksheet used to record the information used to generate field testing results.
Fixed Pipettor Calibration Worksheet 05/21/2009 An Excel® spreadsheet for use when calibrating fixed-volume mechanical volumetric liquid-dispensing devices.
Adjustable Pipettor Calibration Worksheet 05/21/2009 An Excel® spreadsheet for use when calibrating adjustable volume mechanical liquid-dispensing devices.
Total Hardness (mg/L CaCO3) Calculator 06/16/2010 An Excel® spreadsheet for calculating Total Hardness (mg/L as CaCO3) using the Calcium and Magnesium values reported by your certified contract laboratory.
Free Available Chlorine (FAC) Curve Calculator 03/17/2017 An Excel® spreadsheet for calculating the correlation coefficient and percent recoveries of standards used to verify the instrument calibration. The worksheet may also be used to document the process and satisfy record retention requirements.

Total Residual Chlorine (TRC) Curve  Calculator

03/17/2017 (low)     03/17/2017 (reg) An Excel® spreadsheet for calculating the correlation coefficient and percent recoveries of standards used to verify the instrument calibration. The worksheet may also be used to document the process and satisfy record retention requirements.

 

Guidance for Field Laboratories

The following table provides additional guidance for field laboratories. 

Item Revision Date Description
LDO Daily Calibration Verification 06/16/2009 A document describing the procedure for verifying the calibration of Luminescence Dissolved Oxygen (LDO) meters with solubility table.
Pipettor Calibration Procedure 07/30/2009 An example gravimetric procedure for determining the measurement error of mechanical liquid-dispensing devices.
Total Residual Chlorine Instrument Sensitivity Letter 08/14/2001 A letter from the NC DWQ Point Source Branch Supervisor to NPDES Permittees requiring the use of instruments that will detect levels below permit discharge requirements.
Total Residual Chlorine Compliance Limit Memo 05/01/2008 A memo from the NC DWQ Point Source Branch Supervisor to NPDES Permittees regarding the TRC Compliance Limit of 50 µg/L.
Total Residual Chlorine Detection and Compliance Level Letter 03/11/2015 A letter from the NC WW/GW Laboratory Certification program restating the Division's policies for Total Residual Chlorine Detection and Compliance Levels.
Stormwater Permitting Letter on Field Lab Certification Requirements 02/14/2008 Only facilities classified in accordance with Classification of Water Pollution Control Systems Rules found in 15A NCAC 08G .0300 must be certified, however, monitoring of discharges under an NPDES permit (including stormwater) must be conducted in accordance with 40 CFR Part 136.
Corrective Action Response to Audit Findings Form 06/07/2017 A form describing the corrective action response and documentation needed for labs to address Findings from audits. There is an example of a lab's response after the report has been received and also for a Finding that is corrected before the report has been written.

 

Link to National Pollution Discharge Elimination System (NPDES) Permitting Guidance and Directions for Completing a Discharge Monitoring Report (DMR). Look under Compliance Forms. You can also find a link to the Significant Figures and Their Use on DMRs document there.

DMR Parameter Code Descriptions -   [NOTE: The parameter code for any Fecal coliform regardless of technology (e.g., Colilert-18, MF, MPN/100 mL, etc.) code is now 31616]

DMR Units of Measure Descriptions - 2015

DMR Sample Type Code Descriptions - 2015

The following documents published by EPA are good sources for general guidance in performing internal audits of NPDES permitted facilities. NPDES Compliance Inspection Manual (Interim revised version from January 2017); NPDES Compliance Monitoring Inspector Training (August 1990); Handbook for Analytical Quality Control in Water and Wastewater Laboratories (March 1979)

Link to USEPA STORET Legacy Data Center. Questions can be directed to the STORET Help Desk at STORET@epa.gov.