Polluted Passivity

Here's a link to a helpful page on the passive voice, a problem for many young writers.

The following sentence contains a canonical, eventive (or dynamic) passive voice construction. Notice that, contrary to the more familiar and straightforward subject-acting-on-object structure, the object of the action (the river) is the subject of the sentence while the actor, the one performing the action, is the object:

The river was polluted by the factory farmers.

A simple inversion of the subject and object produces this better result in the active voice, where the actor (the intensive rearing of animals) is the subject of the sentence:

The factory farmers polluted the river.

(Don't confuse the passive voice with the past tense. “The factory farmers polluted the river” uses the active voice to describe a past action.)

A long-time hunter of passive voice constructions, I stumbled recently over a couple of troublesome look-alikes. Here’s my attempt to clarify the grammatical distinctions between the following passive-looking creatures (so that I might take better aim in the future). I'll place my current, no doubt incomplete, view in parentheses. Comments/corrections/clarifications welcome.

The river was polluted.
(As above, an eventive (dynamic) passive or stative (static) passive, depending on the meaning; that is, either someone polluted the river or the river was in a polluted state as a consequence of someone or something acting on it.)

That is a polluted river.
(A so-called “adjectival passive.” As I understand it, while adjectival passives are not true passives (because participial adjectives, not verbs), they can contribute to the overall passivity of a sentence. This sentence may be indistinguishable in this instance from the stative passive above, “That river is polluted.”)

Don't swim in a polluted river.
(An imperative containing either an adjectival passive or stative passive.)

He is bearded.
(A self-reflexive adjectival passive?)