---
kind: "section"
citation: "42 U.S.C. § 16131"
title: "42"
title_heading: "The Public Health and Welfare"
number: "16131"
heading: "Definitions"
release: "119-102"
date: "2026-07-12"
url: "https://uscodex.org/usc/42/16131"
units:
  - "Chapter 149 — National Energy Policy and Programs"
  - "Subchapter VII — Vehicles and Fuels"
  - "Part F — Diesel Emissions Reduction"
---

# §16131. Definitions


In this part:

- (1) **Administrator—** The term “[Administrator](/usc/42/15951.md?p=b-1)” means the [Administrator](/usc/42/15951.md?p=b-1) of the Environmental Protection [Agency](/usc/42/8262.md?p=1).
- (2) **Certified engine configuration—** The term “certified engine configuration” means a new, rebuilt, or remanufactured engine configuration—
  - (A) that has been certified or verified by—
    - (i) the [Administrator](/usc/42/15951.md?p=b-1); or
    - (ii) the California Air Resources Board;
  - (B) that meets or is rebuilt or remanufactured to a more stringent set of engine emission standards, as determined by the [Administrator](/usc/42/15951.md?p=b-1); and
  - (C) in the case of a [certified engine configuration](#2) involving the replacement of an existing engine or vehicle, an engine configuration that replaced an engine that was—
    - (i) removed from the vehicle; and
    - (ii) returned to the supplier for remanufacturing to a more stringent set of engine emissions standards or for scrappage.
- (3) **Eligible entity—** The term “eligible entity” means—
  - (A) a regional, [State](/usc/42/15951.md?p=b-2), local, or tribal [agency](/usc/42/8262.md?p=1) or port authority with jurisdiction over transportation or air quality;
  - (B) a [nonprofit](/usc/42/300s–3.md?p=3) organization or institution that—
    - (i) represents or provides pollution reduction or educational services to [persons](/usc/42/16451.md?p=12) or organizations that own or operate diesel [fleets](#5); or
    - (ii) has, as its principal purpose, the promotion of transportation or air quality; and
  - (C) any private individual or entity that—
    - (i) is the [owner](/usc/42/13641.md?p=4) of record of a diesel vehicle or [fleet](#5) operated pursuant to a contract, license, or lease with a Federal [department](/usc/42/15801.md?p=1) or [agency](/usc/42/8262.md?p=1) or an entity described in [subparagraph (A)](#3-A); and
    - (ii) meets such timely and appropriate requirements as the [Administrator](/usc/42/15951.md?p=b-1) may establish for vehicle use and for notice to and approval by the Federal [department](/usc/42/15801.md?p=1) or [agency](/usc/42/8262.md?p=1) or entity described in [subparagraph (A)](#3-A) with respect to which the [owner](/usc/42/13641.md?p=4) has entered into a contract, license, or lease as described in [clause (i)](#3-C-i).
- (4) **Emerging technology—** The term “emerging technology” means a technology that is not currently, or has not been previously, certified or verified by the [Administrator](/usc/42/15951.md?p=b-1) or the California Air Resources Board but for which an approvable application and test plan has been submitted for verification to the [Administrator](/usc/42/15951.md?p=b-1) or the California Air Resources Board.
- (5) **Fleet—** The term “fleet” means one or more diesel vehicles or mobile or [stationary](/usc/42/16121.md?p=3) diesel engines.
- (6) **Heavy-duty truck—** The term “heavy-duty truck” has the meaning given the term “heavy duty vehicle” in [section 7521 of this title](/usc/42/7521.md).
- (7) **Medium-duty truck—** The term “medium-duty truck” has such meaning as shall be determined by the [Administrator](/usc/42/15951.md?p=b-1), by regulation.
- (8) **State—** The term “[State](/usc/42/15951.md?p=b-2)” means the several [States](/usc/42/15951.md?p=b-2), the District of Columbia, the Commonwealth of Puerto Rico, Guam, the United States Virgin Islands, American Samoa, and the Commonwealth of the Northern Mariana Islands.
- (9) **Verified technology—** The term “verified technology” means a pollution control technology, including a retrofit technology or auxiliary power unit, that has been verified by—
  - (A) the [Administrator](/usc/42/15951.md?p=b-1); or
  - (B) the California Air Resources Board.

## Source credit

(Pub. L. 109–58, title VII, § 791, Aug. 8, 2005, 119 Stat. 838; Pub. L. 110–255, § 3(a), June 30, 2008, 122 Stat. 2423; Pub. L. 111–364, § 2(a), Jan. 4, 2011, 124 Stat. 4056.)

## Notes

### Editorial Notes

### Amendments

2011—Par. (3)(C). Pub. L. 111–364, § 2(a)(1), added subpar. (C).

Par. (4). Pub. L. 111–364, § 2(a)(2), inserted “currently, or has not been previously,” after “that is not”.

Par. (8). Pub. L. 111–364, § 2(a)(6), added par. (8). Former par. (8) redesignated (9).

Par. (9). Pub. L. 111–364, § 2(a)(5), struck out “, advanced truckstop electrification system,” after “retrofit technology” in introductory provisions.

Pub. L. 111–364, § 2(a)(4), redesignated par. (8) as (9). Former par. (9) struck out.

Pub. L. 111–364, § 2(a)(3), struck out par. (9) which defined “State” to include the District of Columbia.

2008—Par. (9). Pub. L. 110–255 added par. (9).

### Statutory Notes and Related Subsidiaries

### Effective Date of 2011 Amendment

Pub. L. 111–364, § 4, Jan. 4, 2011, 124 Stat. 4061, provided that: General Rule.—Except as provided in subsection (b), the amendments made by section 2 [amending this section and sections 16132 to 16134 and 16137 of this title] shall take effect on October 1, 2011. Exception.—The amendments made by subsections (a)(4) and (6) and (c)(4) of section 2 [amending this section and section 16133 of this title] shall take effect on the date of enactment of this Act [Jan. 4, 2011].”