I understand that when Congress passes a law, that law is recorded in
a set of books known as The United States Code (or USC), and I also
understand that new USC laws cannot be enforced until new regulations
are issued. Those regulations implement the USC laws, and are recorded
in the set of books known as The Code of Federal Regulations (or CFR).
 My question is: With respect to environmental protection, how does
USC Title 42, Chapter 55 relate to/with 40 CFR, Chapter I (e.g., How
would one know that the EPA is to enforce the regulations implemented
in CFR for USC, etc.?)

Hello,

Statutes (laws passed by Congress and recorded in the USC) generally
specify which department or agency is to carry them out. Regulations
in the CFR usually specify which USC section provides authority for
the regulation.

The laws in Chapter 55 of Title 42 that pertain to the EPA mention the
agency directly, so let me use another example that isn't so easy. Say
you were looking at the Clean Air Act, which begins at 42 USC 7401.
The first section is just a statement of purpose, but the second, 42
USC 7402 (http://www4.law.cornell.edu/uscode/42/7402.html) starts the
discussion of what the government is to do. The section says "The
Administrator shall encourage..." Other sentences discuss what "the
Administrator" is to do.

How do we find out who this "Administrator" is? Every part of the code
has a "definitions" section that answers that type of question. If you
look at the top of the page for 42 USC 7402, you'll see the hierarchy
of code parts that leads to that section. If you click on "Part A,"
you'll come to a list of sections, but no definitions section.  Back
up to "Chapter 85," and you'll see a link for "GENERAL PROVISIONS."
That's what we want. Click on it, and you'll see Section 7602 is
definitions. The second line of the section specfies that
"Administrator" is short for the administrator of the EPA. Now that
you know the EPA is in charge of carrying out the Clean Air Act, you
can look for clean-air regulations in the EPA's section of the CFR.

Going from CFR section to USC section works the same way. Clean-air
regulations start at Section 50.1 of Title 42 of the CFR
(http://www.access.gpo.gov/nara/cfr/waisidx_01/40cfr50_01.html). That
section is a definitions section, which defines the "Act" mentioned in
the regulations as the Clean Air Act and gives the relevant USC
sections (which, in this case, actually lead to a cross-reference to
another part of the code).

In the regulations for another law, the Endangered Species Act, the
relevant USC section is given in the "Scope and purpose" section (50
CFR 424.01). For regulations about automobile tires, statutory
authority is spelled out in the "Scope" section (49 USC 574.1). In all
three examples, the first section of the part of the CFR contains the
USC reference.

The Government Printing Office's online CFR
(http://www.access.gpo.gov/nara/cfr/cfr-table-search.html) includes a
search function, so if you did not know where in the CFR to find EPA
regulations, you could do a search on "Environmental Protection
Agency."

I hope this answer meets your needs. If not, please request
clarification.

Search strategy:

US Code
://www.google.com/search?sourceid=navclient&q=US+Code

CFR
://www.google.com/search?sourceid=navclient&q=cfr

Thanks so much for the swift, concise and comprehenisive reply!

Each law is usually quite specific as to which Agency has
regulatory/enforcement authority.  For environmental laws, this is
often, but not always, the EPA.  The Department of Interior, the Army
Corps of Engineers, and the President's Council on Environmental
Quality (just to name a few) also have considerable environmental
authority.  For major environmental laws like the Clean Air Act or
Clean Water Act, EPA is charged with most of the responsibility for
regulation writing.