Part 50 or Part 58

Two parts of Title 24 of the Code of Federal Regulations govern the environmental review of a project assisted by the Department of Housing and Urban Development (HUD). Under part 50, HUD performs the review. Under part 58, a responsible entity (a state, a local government, an Indian tribe or another body the part names) takes on HUD's duties and its certifying officer signs. Which part applies turns on the program that funds the project and on a few exceptions in the text.

Who the rule binds

Part 50 implements the National Environmental Policy Act (NEPA) and the related environmental requirements for HUD's own actions: every HUD policy action and every HUD project action (24 CFR 50.1(a), (d)). The HUD approving official, "the HUD official authorized to make the approval decision", "shall make an independent evaluation of the environmental issues" and makes the environmental finding, where applicable (24 CFR 50.2(a), 50.11(a)).
Part 58 instructs recipients and other responsible entities on conducting the review and on getting a request for release of funds approved (24 CFR 58.1(a)). It applies where a statute lets them assume HUD's environmental duties, in the sentence quoted below. Its list, which begins with the word include, names Community Development Block Grants (CDBG); the HOME Investment Partnerships Program; homeless assistance grants; lead-based paint hazard grants; public housing and HOPE VI; section 8 assistance that a public housing agency administers ("except for assistance provided under part 886 of this title"); special projects; FHA's Multifamily Housing Finance Agency Pilot Program; self-help homeownership; Indian and Native Hawaiian housing block grants, with "Federal Guarantees or Financing for Tribal Housing Authorities"; Indian housing loan guarantees; and Housing Opportunities for Persons with AIDS (24 CFR 58.1(b)). Several entries are limited by fiscal year, kind of grantee or land status.
The responsible entity is the recipient, with one condition: outside CDBG, HOME, the lead grants and the homeless grants made to states and local governments, the recipient must itself be "a state, unit of general local government, Indian tribe or Alaska Native Village, or the Department of Hawaiian Home Lands" (24 CFR 58.2(a)(7)). Otherwise the text designates one. For a public housing agency it is the local government, and for a non-profit or other entity the local government, tribe or Alaska native village, where the project is located "that exercises land use responsibility" or, where HUD determines that infeasible, the county, then the State. For a housing finance agency it is the State or a local government, tribe or Alaska native village "whose jurisdiction contains the project site" (24 CFR 58.2(a)(7)(ii)).
The certifying officer is "the official who is authorized to execute the Request for Release of Funds and Certification" (24 CFR 58.2(a)(2)). By that certification the officer is, for NEPA, the "responsible Federal official", and must "be subject to the jurisdiction of the Federal courts" (24 CFR 58.13).

What it asks

The program. Where the program is one part 58 reaches, "the responsible entity must assume the environmental responsibilities for projects under programs cited in § 58.1(b)", the tribes' choice below excepted (24 CFR 58.10). Part 50 applies to HUD's project actions generally, and its own decision points name, among others, "Project mortgage insurance or other financial assistance for multifamily housing projects (including sections 202 and 811), nursing homes, hospitals, group practice facilities and manufactured home parks" (24 CFR 50.17(a)(1)). A question about part 50's reach goes to HUD's Assistant Secretary for Community Planning and Development (24 CFR 50.1(d)).
Legal capacity. A responsible entity that believes it lacks the legal capacity "must contact the appropriate local HUD Office or the State for further instructions"; capacity is determined case by case (24 CFR 58.11(a)). Part 50 applies when the recipient claims that lack and HUD approves the claim (24 CFR 50.1(d)).
A tribe's choice. An Indian tribe "may, but is not required to, assume" the review under the 1996 Native American Housing Assistance and Self-Determination Act (other than title VIII) or the section 184 loan guarantee program, deciding for each Act separately and in writing. If it formally declines, HUD keeps the duties and part 50 applies (24 CFR 58.4(c)).
HUD steps in. HUD may at any time reject the use of a responsible entity in a particular case "on the basis of performance, timing or compatibility of objectives", or where it has found environmental deficiencies. If a responsible entity that is not the recipient objects to doing a review, or HUD determines it should not, HUD may designate another or "may itself conduct the environmental review in accordance with the provisions of 24 CFR part 50". Where, in some programs, a recipient objects to the designated entity on those three grounds, HUD determines who reviews (24 CFR 58.11(b), (c), (d), 58.77(d)(1)).
States. For a project funded through a State, the State exercises HUD's part in approving a local government's certification and request for release of funds (24 CFR 58.4(b)).

What it means for the Phase I and the consultant

Neither part names a Phase I Environmental Site Assessment (ESA), so neither says who receives one. Each says who performs the review it would feed.

Under part 58 the responsible entity keeps the environmental review record (24 CFR 58.38). Where it reviews for a recipient, "the recipient must provide the responsible entity with all available project and environmental information" (24 CFR 58.71(b)).
Under part 50 HUD program staff conduct the review. An applicant or its contractor may collect the data and studies, and HUD may use them "provided HUD independently evaluates the information" (24 CFR 50.32).
The decisive facts are not Phase I findings. They are the funding program, who the recipient is, which government exercises land use responsibility at the project's location, and whether a tribe has assumed the review. Under ASTM E1527-21 the user tells the environmental professional why the Phase I is wanted; failing that, the professional assumes the purpose is to qualify for a landowner liability protection and says so in the report (E1527-21, 6.8).
Use of the report by others. Neither part uses the word reliance, and the standard puts the contractual and legal obligations among the professional, the user and other parties outside its scope (E1527-21, 4.9).

What the rule says

This part applies to activities and projects where specific statutory authority exists for recipients or other responsible entities to assume environmental responsibilities.

24 CFR 58.1(b), edition revised as of April 1, 2025

This page is general reference for environmental professionals. It does not review any project. The regulation is the authority, and the determinations of HUD or of the entity responsible for the review govern.