--- title: Audit, Compliance and Risk Blog | STP | NSR description: NSR | STP's blog giving insight into audit, compliance and risk issues for EHS, business and accounting. --- [![Specialty Technical Publishers](https://blog.stpub.com/hubfs/STP-logo-white-orange.png)](http://www.stpub.com/) - [My Account](http://stponline.stpub.com) - 1-800-251-0381 # Audit, Compliance and Risk Blog ## [EPA revises regulatory methodology for determining whether source modifications trigger “new” source review](https://blog.stpub.com/epa-revises-regulatory-methodology-for-determining-whether-source-modifications-trigger-new-source-review) Posted by [Jon Elliott](https://blog.stpub.com/author/jon-elliott) on Mon, Nov 02, 2020 - [Tweet](https://twitter.com/share) [![](https://blog.stpub.com/hubfs/chemist-3836150_1920.jpg) ](https://blog.stpub.com/epa-revises-regulatory-methodology-for-determining-whether-source-modifications-trigger-new-source-review) When are changes to an existing system so extensive that they produce a “new” system? This question is conceptually important in any evolving organization, and can have important regulatory consequences if requirements for “existing” systems are substantially different than those for “new” systems. Emissions regulations under the Clean Air Act (CAA) contain many such situations, and on October 22 the US Environmental Protection Agency (EPA) adopted changes to the “project emissions accounting” it uses to decide whether modifications to an existing major source are so extensive as to trigger preconstruction New Source Review (NSR) requirements. This revision codifies into regulations a policy changed announced in 2018. [Read More](https://blog.stpub.com/epa-revises-regulatory-methodology-for-determining-whether-source-modifications-trigger-new-source-review) 0 Comments [Click here to read/write comments](https://blog.stpub.com/epa-revises-regulatory-methodology-for-determining-whether-source-modifications-trigger-new-source-review#comments-listing) Tags: [EPA](https://blog.stpub.com/topic/epa), [CAA](https://blog.stpub.com/topic/caa), [Environment](https://blog.stpub.com/topic/environment), [PSD](https://blog.stpub.com/topic/psd), [NSR](https://blog.stpub.com/topic/nsr) [All posts](https://blog.stpub.com/all) ### Follow Me ### Subscribe by Email ### Browse by Topic Area - [Accounting & Tax ](https://blog.stpub.com/topic/accounting-tax) - [Business & Legal ](https://blog.stpub.com/topic/business-legal) - [Corporate Governance  ](https://blog.stpub.com/../?Tag=Corporate+Governance) - [Environmental ](https://blog.stpub.com/../?Tag=Environmental) - [Global ](https://blog.stpub.com/../?Tag=Global) - [Health & Safety ](https://blog.stpub.com/topic/health-safety) - [Internet ](https://blog.stpub.com/../?Tag=Internet) - [Transportation ](https://blog.stpub.com/../?Tag=Transportation) ### Browse by Tag - [Environmental (344)](https://blog.stpub.com/topic/environmental) - [Business & Legal (309)](https://blog.stpub.com/topic/business-legal) - [Environmental risks (300)](https://blog.stpub.com/topic/environmental-risks) - [Health & Safety (296)](https://blog.stpub.com/topic/health-safety) - [EPA (283)](https://blog.stpub.com/topic/epa) - [Terms & Conditions](https://stphub.stpehs.com/wp-content/uploads/2021/01/STP-Terms-of-Use-Dec-20.pdf) - [Privacy Policy](https://stphub.stpehs.com/wp-content/uploads/2020/12/STP-Privacy-Policy.pdf) - [License Agreement](https://stphub.stpehs.com/wp-content/uploads/2021/01/STP-License-Agreement-Dec-20.pdf) - [Sitemap](http://stpub.com/sitemap) - [Support](http://stpub.com/support) © 2021 STP ComplianceEHS - All rights reserved