HBC BLOG

Stay informed on the latest developments in environmental law, from policy changes and regulatory updates to sustainability initiatives. Our blog provides expert insights, analysis, and practical guidance to help you navigate the ever-evolving landscape of environmental regulations. Check back regularly for in-depth articles, breaking news, and thought-provoking discussions on the issues that matter most.

DC Circuit Upholds Project Emissions Accounting

On July 28, 2026, the District of Columbia Circuit Court of Appeals (DC Circuit) released its decision in Environmental Defense Fund v. Environmental Protection Agency, No. 18-1149, a consolidated case hearing multiple challenges brought by environmental groups against EPA’s project emissions accounting (“PEA”) rule. In a significant win for EPA, the DC Circuit upheld the PEA Rule against all facial challenges to its validity, although it left open the possibility of an “as a

Jul 297 min read

AERMOD Update

Bill Jones with Blue Sky Modeling dropped a note that EPA has released the next update to AERMOD, the dispersion model used or the vast majority of ambient air analyses in the NSR world. The new model version is 26135. Most agencies will want to see that the most current version of AERMOD is being used so please be sure to check with your agency whether they will need any pending permit application models rerun. According to Bill, the update is not likely to affect most exist

Jul 131 min read

EPA relaxes preconstruction ERC requirements

On July 1, 2026, Aaron Szabo, EPA Assistant Administrator for Air and Radiation, released “Guidance on Clean Air Act Nonattainment New Source Review Emission Offsets” (2026 ERC Guidance) providing increased flexibility on when sources must have federally enforceable emission reduction credits (ERCs) in hand to permit and construct major NSR sources in nonattainment areas. ANALYSIS The 2026 ERC Guidance begins by noting that both Clean Air Act (CAA) Section 173(a)(1) and 173(c

Jul 64 min read

All Posts

DC Circuit Upholds Project Emissions Accounting

jmaiden

Jul 297 min read

AERMOD Update

jmaiden

Jul 131 min read

EPA relaxes preconstruction ERC requirements

jmaiden

Jul 64 min read

EPA "Begin Actual Construction" Proposal

On May 13, 2026, EPA released its proposed rule entitled “Begin Actual Construction in the New Source Review (NSR) Preconstruction Permitting Program,” 91 Fed. Reg. 26958. In the proposal, EPA is following up on its commitment, stated in the letter to the Maricopa County Air Quality Department, that it would release a proposed rule to standardize “begin actual construction” across the PSD, NNSR and tribal minor NSR programs. In a nutshell, the proposed rule would eliminate

jmaiden

May 207 min read

EPA "Begin Actual Construction" rule imminent

The Office of Management and Budget (OMB) has completed its review of the EPA's proposed rule that will address changes to the existing definition of "begin actual construction," according to an announcement on the OMB website. This means that the proposed rule should appear in the Federal Register in the near future. The new rule is anticipated to follow the lead of EPA's letter issued to the Maricopa County Air Quality Department. You can read about that guidance letter in

jmaiden

May 41 min read

EPA sends "Begin Actual Construction" to OMB

In our article on " A New Beginning for 'Begin Actual Construction' " in September 2025, we discussed the EPA's guidance in an individual source letter that relaxed the historic policy interpretation of "begin actual construction." Readers may recall that historically, EPA has taken the position that any construction at a PSD facility, except for limited ground-clearing activities, must be held in abeyance until the PSD permit is issued. In the September guidance, the EPA all

jmaiden

Mar 281 min read

EPA Ends Reactivation Policy Unless Major Modification

On September 18, 2025, Administrator Lee Zeldin issued a policy memorandum entitled “ New Source Review Program ‘Reactivation Policy .’” In the policy, Mr. Zeldin confirmed that the EPA would follow the Third Circuit’s decision in Port Hamilton Refining & Transp. v. U.S. EPA , will apply that decision nationwide, will not apply the “major modification” aspect of the policy to a facility that only restarts, but will apply to restarts that involve a physical change or change i

jmaiden

Dec 1, 20254 min read

EPA’s New e-Manifest Reporting Requirements: What Generators Need to Know

EPA recently issued a reminder regarding its e-Manifest Third Final Rule , published July 26, 2024. The rule finalizes a major shift: several manifest-related reports must be submitted electronically through the e-Manifest system starting December 1, 2025 . Below is a quick breakdown: 1. Exception Reports — Biggest Change for Generators Beginning December 1, 2025 , Large Quantity Generators (LQGs) and Small Quantity Generators (SQGs) must submit Exception Reports electronic

jmaiden

Nov 28, 20252 min read

"Second Guessing" Departs - Again

On September 15, 2025, EPA Administrator Lee Zeldin issued a memorandum, " EPA Policy on Enforceability and Use of the Actual-to-Projected-Actual Applicability Test in Determining Major Modification Applicability in New Source Review Preconstruction Permitting: Reinstatement of 2017 Memorandum ," (2025 Memo) which reinstated Administrator Pruitt's December 7, 2017 memorandum " New Source Review Preconstruction Permitting Requirements: Enforceability and Use of the Actual-to-P

jmaiden

Nov 20, 20254 min read