use of dash

[BobSmith]

Is this a proper use of the dash?

Should "as well as" be removed?

The contamination of the aquifer, the cessation of the water supply, the loss of animal and plant life, as well as the disruption of farming–these things would harm the people of the U.S.

TIA

[bhaisahab]

Is this a proper use of the dash?

Should "as well as" be removed?

The contamination of the aquifer, the cessation of the water supply, the loss of animal and plant life, as well as the disruption of farming–these things would harm the people of the U.S.

TIA

I never use dashes for punctuation but, as far as I remember, it's supposed to have spaces before and after.

[BobSmith]

I never use dashes for punctuation but, as far as I remember, it's supposed to have spaces before and after.

As far as I can tell, it only has spaces when "used between equal weighted words in a compound adjective", or when expressing range, or when it "stand[s] for the words and, to, or versus between two words of equal weight" - columbia.edu

That source also says "Use a dash at the beginning and end of a series separated by commas" which I guess is the rule I'm trying to apply to the original sentence, though I still can't tell if it is correct in the manner I first posted.

[bhaisahab]

As far as I can tell, it only has spaces when "used between equal weighted words in a compound adjective", or when expressing range, or when it "stand[s] for the words and, to, or versus between two words of equal weight" - columbia.edu

That source also says "Use a dash at the beginning and end of a series separated by commas" which I guess is the rule I'm trying to apply to the original sentence, though I still can't tell if it is correct in the manner I first posted.

You may well be right, as I said, I never use them in punctuation.

[Raymott]

As far as I can tell, it only has spaces when "used between equal weighted words in a compound adjective", or when expressing range, or when it "stand[s] for the words and, to, or versus between two words of equal weight" - columbia.edu

That source also says "Use a dash at the beginning and end of a series separated by commas" which I guess is the rule I'm trying to apply to the original sentence, though I still can't tell if it is correct in the manner I first posted.

I'd say that you sentence is good. As opposed to bhaisahab, I like dashes -- I use them often. I always leave a space on both sides, whether I use two hyphens or one hyphen or a proper em or en dash. But it's only absolutely necessary when using one hyphen - if a space is not left it becomes a hyphen.
In more formal writing, say for a university assignment, I'd use proper dashes, but given the relative difficulty of producing them in this editor, I generally use one or two hyphens instead.

There are various styles of orthography. You've quoted Columbia University's style guide, but you'll find that not all publishing houses and universities recommend the same style.

[Barb_D]

There are em-dashes, en-dashes, and hyphens.

Your example is a good time to use an em-dash.