Source Trial Policy
This guidance document is advisory in nature but is binding on an agency until amended by such agency. A guidance document does not include internal procedural documents that only affect the internal operations of the agency and does not impose additional requirements or penalties on regulated parties or include confidential information or rules and regulations made in accordance with the Administrative Procedure Act. If you believe that this guidance document imposes additional requirements or penalties on regulated parties, you may request a review of the document.

Form #:  18-010
Guidance Documents
Revised: 5/9/18
SizeFile Name
23 KB 18-010 Source Trial Policy.pdf


NDEQ air construction and operating permits issued to sources typically require performance testing for some emission units. Valid test results help demonstrate compliance with permit limits, emission inventory, and future permitting actions. Test results are usually considered valid as long as the source continues to operate under conditions representative of those in which the test was conducted. Trials of new process materials or methods or changes to controls at a source may trigger an evaluation by NDEQ under Title 129, Chapter 34 Section 001 to determine if prior testing would still be considered representative as well as whether additional performance testing is needed.

The following policy is intended to clarify how the NDEQ’s Air Quality Division (AQD) evaluates trials under that rule. The AQD supports owner and operator interests in production at a source and efficiency improvements in their processes, while maintaining compliance with regulations. This policy addresses the use of trials at a source to accomplish those goals. However, please note that if there is a reasonable possibility that a proposed trial will violate any applicable permit condition or State or Federal regulation, then the trial cannot be accepted.

The AQD recommends the following procedure when a source wants to conduct a trial without triggering a subsequent review by the AQD under Chapter 34. A source conducting a trial will provide the AQD a written request that outlines the length, scope, and objectives of the trial at least 30 days before the start of the trial. A schedule for conducting performance testing during the trial must be included if the trial is scheduled to last longer than 30 days.

The AQD will evaluate representative engineering test data obtained during the trial period in considering whether to waive the performance testing requirement. The waiver will only be considered if the information is submitted in a timeframe that allows the AQD sufficient time to review and evaluate the data.

Within 60 days following completion of the trial, the source must provide a report to the AQD detailing results to the objectives of the trial. Any emissions data gathered during the trial must be included in the report along with source operational parameters.

For subsequent trials on an emission unit being conducted during any 12 consecutive calendar months, performance testing will be required, regardless of the length of the trial.

This trial policy does not apply to emission units using a qualified CEM system for pollutants potentially affected by the trial. Nothing in this policy waives the right of the AQD to require testing under Title 129, Chapter 34. This trial policy does not supersede or replace any regulatory requirement to apply for and obtain a permit.

Produced by: Nebraska Department of Environmental Quality, P.O. Box 98922, Lincoln, NE 68509-8922; phone (402) 471-2186. To view this, and other information related to our agency, visit our web site at http://deq.ne.gov.