I hate legalese and the ADA document is lengthy and open to interpretation. I just excerpted small subsections of the Act which is a PDF download.
-NW

AMERICANS WITH DISABILITIES ACT OF 1990, AS AMENDED
https://www.ada.gov/pubs/adastatute08.pdf

Following is the current text of the Americans with Disabilities Act of 1990 (ADA), including changes made by the ADA Amendments Act of 2008 (P.L. 110-325), which became effective on January 1, 2009. The ADA was originally enacted in public law format and later rearranged and published in the United States Code.

The United States Code is divided into titles and chapters that classify laws according to their subject matter. Titles I, II, III, and V of the original law are codified in Title 42, chapter 126, of the United States Code beginning at section 12101. Title IV of the original law is codified in Title 47, chapter 5, of the United States Code. Since this codification resulted in changes in the numbering system, the Table of Contents provides the section numbers of the ADA as originally enacted in brackets after the codified section numbers and headings.

[snip]

Sec. 12102. Definition of disability (p. 7)

As used in this chapter:

(1) Disability. The term "disability" means, with respect to an individual

(A) a physical or mental impairment that substantially limits one or more major life activities of such individual;
(B) a record of such an impairment; or
(C) being regarded as having such an impairment (as described in paragraph (3)).

(2) Major Life Activities
(A) In general. For purposes of paragraph (1), major life activities include, but are not
limited to, caring for oneself, performing manual tasks, seeing, hearing, eating, sleeping,
walking, standing, lifting, bending, speaking, breathing, learning, reading, concentrating,
thinking, communicating, and working.
(B) Major bodily functions. For purposes of paragraph (1), a major life activity also
includes the operation of a major bodily function, including but not limited to, functions of
the immune system, normal cell growth, digestive, bowel, bladder, neurological, brain,
respiratory, circulatory, endocrine, and reproductive functions.

(3) Regarded as having such an impairment. For purposes of paragraph (1)(C):
(A) An individual meets the requirement of “being regarded as having such an
impairment” if the individual establishes that he or she has been subjected to an action
prohibited under this chapter because of an actual or perceived physical or mental
impairment whether or not the impairment limits or is perceived to limit a major life activity.
(B) Paragraph (1)(C) shall not apply to impairments that are transitory and minor. A
transitory impairment is an impairment with an actual or expected duration of 6 months or
less.

Sec. 12113. Defenses (p. 13)

(a) In general. It may be a defense to a charge of discrimination under this chapter that an alleged
application of qualification standards, tests, or selection criteria that screen out or tend to screen out or otherwise deny a job or benefit to an individual with a disability has been shown to be job related and consistent with business necessity, and such performance cannot be accomplished by reasonable accommodation, as required under this subchapter.

(b) Qualification standards. The term "qualification standards" may include a requirement that an
individual shall not pose a direct threat to the health or safety of other individuals in the workplace.

(e) List of infectious and communicable diseases

(1) In general. The Secretary of Health and Human Services, not later than 6 months after
July 26, 1990, shall
(A) review all infectious and communicable diseases which may be transmitted through
handling the food supply;
(B) publish a list of infectious and communicable diseases which are transmitted through
handling the food supply;
(C) publish the methods by which such diseases are transmitted; and
(D) widely disseminate such information regarding the list of diseases and their modes of
transmissibility to the general public.

Such list shall be updated annually.

Sec. 12188. Enforcement (p. 39)

(b) Enforcement by Attorney General (p. 40)

(1) Denial of rights

(A) Duty to investigate
(i) In general. The Attorney General shall investigate alleged violations of this
subchapter, and shall undertake periodic reviews of compliance of covered entities
under this subchapter.
(ii) Attorney General certification. On the application of a State or local government,
the Attorney General may, in consultation with the Architectural and Transportation
Barriers Compliance Board, and after prior notice and a public hearing at which
persons, including individuals with disabilities, are provided an opportunity to testify
against such certification, certify that a State law or local building code or similar
ordinance that establishes accessibility requirements meets or exceeds the minimum
requirements of this chapter for the accessibility and usability of covered facilities
under this subchapter. At any enforcement proceeding under this section, such
certification by the Attorney General shall be rebuttable evidence that such State law
or local ordinance does meet or exceed the minimum requirements of this chapter.

(B) Potential violation. If the Attorney General has reasonable cause to believe that
(i) any person or group of persons is engaged in a pattern or practice of discrimination
under this subchapter; or
(ii) any person or group of persons has been discriminated against under this
subchapter and such discrimination raises an issue of general public importance,
the Attorney General may commence a civil action in any appropriate United States
district court.
(2) Authority of court. In a civil action under paragraph (1) (B), the court

(A) may grant any equitable relief that such court considers to be appropriate, including, to
the extent required by this subchapter
(i) granting temporary, preliminary, or permanent relief;
(ii) providing an auxiliary aid or service, modification of policy, practice, or procedure, or alternative method; and
(iii) making facilities readily accessible to and usable by individuals with disabilities;

(B) may award such other relief as the court considers to be appropriate, including
monetary damages to persons aggrieved when requested by the Attorney General; and
(C) may, to vindicate the public interest, assess a civil penalty against the entity in an
amount
(i) not exceeding $50,000 for a first violation; and
(ii) not exceeding $100,000 for any subsequent violation.