skip to main content | skip to footer
N.C. Department of Environment and Natural Resources

NC Department of Environment and Natural Resources
Water Quality - PT Requirements

Water Quality

Web Content Display Web Content Display

Proficiency Testing (PT) Requirements

Municipal, Industrial, Commercial and Other Laboratories

Under the NC WW/GW LC Rule 15A NCAC 2H .0800, laboratories must demonstrate proficiency for all certified parameters (for which a proficiency testing sample is available) each year and the graded results must be received in this office by September 30. Proficiency Testing samples must be obtained from an accredited vendor as unknowns. If performance evaluation samples are not available for a parameter, certification for that parameter may be based on the proper use of the approved procedure as determined by an announced or unannounced on-site inspection.

North Carolina Permittees will not be required to order Dishcharge Monitoring Report-Quality Assurance (DMR-QA) Study PT samples (you can read more about the NC DMR-QA PT Study Exemption on the Field Lab PT Page) and, therefore, will not be responsible for reporting data for their contract laboratories any longer. 

2014 PT Study Requirements

The following links describe proficiency testing requirements for commercial, municipal, industrial and other laboratories. A new Proficiency Testing Requirements document (see link below) serves as a guide to the PT sample requirements of the NC WW/GW LC program. In addition to clarifying the regulatory requirements for proficiency testing, this document answers many common questions concerning evaluation of PT sample results. Also included are important deadlines, penalties and corrective actions for proficiency testing sample failures. Highlighted changes, a condensed version of the proficiency testing requirements and an auditor's checklist may also be found in the links below.

NC WW/GW LC memo describing 2014 PT Requirements *new*

Proficiency Testing Requirements Document (February 20, 2012, Revision 1.2)

Highlighted Changes to PT Requirements for 2012 (February, 2012)

The "Cliff Notes" Version of Proficiency Testing Requirements (February, 2012)

List of Parameters and PTs Required 2014 update coming soon

Proficiency Testing Checklist (February, 2012)

Root Cause Analysis (RCA) and Corrective Action Report (CAR) Guidance (November, 2014)

NOTE: Last year we added aqueous and non-aqueous matrices to your certificate attachment. At this time, we will not require PTs specific to each matrix. A single PT in either matrix shall suffice for demonstration of proficiency for that parameter method technology. A specific matrix PT is required only in cases where a method is matrix-specific (e.g., EPA 9071B).

Proficiency Testing Providers

The laboratory must obtain samples that are part of an official study obtained from a proficiency testing sample provider recognized by The NELAC Institute (TNI) and approved by the NC WW/GW LC program. ACLASS and the American Association for Laboratory Accreditation (A2LA) have been designated  Proficiency Testing Oversight Bodies (PTOB)/Proficiency Testing Provider Accreditors (PTBA) by TNI. You may see the terms "A2LA-accredited provider" and "NELAC-accredited provider" used interchangeably. In any case, when accessing the list of providers on the websites, select from the "NELAC-accredited" list. Laboratories should check this list each time PT samples are ordered since the list changes periodically.

Link to current NC WW/GW LC and NELAC-approved A2LA Accredited Vendors of PT Samples

Link to current NC WW/GW LC and NELAC-approved ACLASS Accredited Vendors of PT Samples - This link takes you to a search page where you can find a list of approved PT providers by selecting Proficiency Test Provider - TNI Vol. 3 in the dropdown list under the Accreditation Standard field.

EPA Lab Codes

Since different accreditation programs use a wide array of laboratory identification systems, the PT providers need a singular means of identifying participant labs when grading and reporting PT results. This singular system of identification is your EPA Lab Code. Each certified laboratory must have an EPA Lab Code and this code must be documented on the results to the proficiency testing provider. Without this EPA Lab Code, the NC WW/GW LC program may be unable to credit the PT results to the correct laboratory. The EPA Lab Codes are assigned by the US EPA. The EPA contact for Lab Code assignment for PT studies is:

Mr. Charles Feldmann

US EPA, M/S 140

26 W. Martin Luther King Drive

Cincinnati, OH 45268

feldmann.charles@epa.gov 

Phone: 513-569-7671

Fax: 513-569-7191

EPA Lab Codes for Non-field Laboratories - updated 07/02/2013

Chlorophyll a Round Robin Study

Currently there are no performance evaluation samples for chlorophyll a that can be carried through an entire method from extraction to instrumental analysis.  Consequently, laboratories currently certified for chlorophyll a will be required to participate in a round robin with other government, academic, and commercial laboratories pursuant to North Carolina Administrative Code 15A NCAC 2H .0805 (c) (3). The round robin studies are designed to provide a measure of laboratory performance in the absence of vendor-supported proficiency testing. The reports provide an illustration of intra-laboratory and inter-laboratory precision as well as a best estimate of the central tendency of data reported by laboratories currently engaged in chlorophyll a testing. A copy of the Chlorophyll a Round Robin Study Standard Operating Procedure (SOP) can be viewed here.

38364 FEEDBACK

Your input is valuable to us. Please send us your feedback.

What type of feedback would you like to send?*

Ask a Question Report a Problem Have a Concern Make a Comment

(If you would like us to respond please include your phone or e-mail.)

Your Question has been sent. Thank you!

An internal server error prevented Your Question from being sent.
Please try again later, or call Toll-Free (877) 623-6748 for immediate assistance.

Please complete all highlighted items

Your Problem has been sent. Thank you!

An internal server error prevented Your Question from being sent.
Please try again later, or call Toll-Free (877) 623-6748 for immediate assistance.

Please complete all highlighted items

Your Concern has been sent. Thank you!

An internal server error prevented Your Question from being sent.
Please try again later, or call Toll-Free (877) 623-6748 for immediate assistance.

Please complete all highlighted items

Your Comment has been sent. Thank you!

An internal server error prevented Your Question from being sent.
Please try again later, or call Toll-Free (877) 623-6748 for immediate assistance.

Please complete all highlighted items

*If you are a DENR employee with an I.T. issue, please submit a DOTS ticket.