Surroundings is a plural count noun—which also has the singular count noun form surrounding—and it is not a mass noun. There are some quick and dirty tests, wait that is another website. There are some tests that tend toward reliability that can be performed to distinguish a mass noun from a count noun.
Excursis: First, a disclaimer. Nouns aren't really mass and/or count. Speakers of the language put their nouns to mass usage or count usage, or sometimes both (light vs lights). Sometimes the use that speakers (I am using speakers rathers than users to avoid the pairing of the subjects users with the verb use, which can be dulling and distracting, much like this aside). And, over time, speakers may begin to put a noun to a different usage. Emails is an example of a plural count noun, whether some of us don't like it. Or to be consistent: I should say that many speakers use email as a count noun (I have received 44 emails today). Nevertheless, henceforth I'm gonna say that a noun "is" mass and/or a noun "is" count because that is the way people usually talk about nouns, at least in this setting.
So, there's another noun, called news, which we can look at, along with surroundings. This will help us compare and contrast, always a pleasant passageway.
I. Can the noun be used with a plural verb?
1a *The news are on TV.
That sounds ugly. Even in GB, where they sometimes speak wonkily, often about football teams, as if a single team is I dunno what, Alice: the team are playing well today. So, la, 1a,1 sounding ugly to this speaker/writer, gets an asterisk (*) before it, meaning it's not "grammatical." Let's just try that one more time, this once with a past tense plural verb:
1b *The news which were on TV fifty years ago said that Jimmy Hendrix's various entourages were all as good as the other.
The most important part of that sentence is, for us, for now2
1bii *The news which were on TV fifty yers ago said blah blah or wah wah
Again, or thrice now, news has not worked with a plural verb. If you don't agree with this, then well, just hold on to your Hosses, there're others that're otherly used.
I bet youre thinking it's time to take a look at our surrounding (or should that be surroundings?) and see if its... if the word's copastetic with a plural noun.
1c The surroundings are on TV.
Hmmm.....it sounds fine to me. Some folks might have to think before they ken what the sentence means. That might sound like a caviar to some, so let's pass to
1d The surroundings at the Jimi Hendrix fest were all copastetic.
which by backtreading we can get
1cii The surroundings were so copastetic that they were on the 10 o'clock news.
La, de, dah: The surroundings are, the surroundings were: Fine and Jimi.
Test I Results:
News has failed the plural verb test: that strongly suggests that it's used as a mass noun;
Surroundings has passed the plural verb test: this suggests strongly that it's used as a count noun.
II. Can the Noun Be Used with the Indefinite Article?
2a Look ma! *A news is being broadcast on TV right now.
Not possible. Not with news as a noun. Compare
2b Look pa! A surrounding is being broadcast on TV right now.
Eh, what, junior. A what, junior?
2c A surrounding, pa. A surrounding that constantly stimulates thought and speech is being broadcast on TV right now.
NB that stimulates is a singular-form verb, as is is. Both agree with a surrounding. For much collaborating evidence of this, see, for example, many uses of a surrounding that followed by a singular verb.
Test II Results
News has failed the test using the indefinite article before it, again strongly suggesting it is a mass noun, or that it being used as a mass noun; while
Surroundings has passed the test using the indefinite article before its singular form, strongly suggesting it is being used as a count noun; and along the way showing that it does have a singular form.
The third and last test that this answer will consider is
III. Do you use how many or how much with the Verbs in Question?
3a *How many news do you have to watch before you find out whether Man City have defeated Liverpool?
No. But compare:
3ai How much news do you have to watch...
As for our other word, there's
?3b How many surroundings do you have to experience before you are convinced as to which one is the best for you?
I put a question mark (?) before this one, because some people might not like it; although I find it "unremarkable", which is geek-speak for "fine and dandy." But...if how many leaves you unsure, try the bare many:3
3c 'Mr Spectator' himself was a carefully balanced persona, a man at ease in many surroundings (the coffee-house, the theatre, or the financial Exchange), not as a participant,...
Test III says that how many and many work with count nouns; and how much and much work with mass nouns (compare my usage, above, of 'much evidence'). Our application of this test corresponds with the conclusion, which is stated below-ward.
CONCLUSION: applying the three tests to the words news and surroundings very strongly suggests that native speakers use the former as a mass moun; and the latter as a count noun. Along the merry brick way, we've seen that surroundings does indeed occur in the singular.
Finally, to further buttress the conclusion, so that it won't fall down upon these words, note that the Oxford English Dictionary (OED) has no head entry (lemma) for surroundings, plural. There is a head entry for surrounding, singular; with definitions for both the singular and plural forms. This, again, supports strongly the answer that surroundings is a count noun, and that it occurs in both the singuar and plural as a count noun.
Per the OED, in its singular form, surrounding has the meaning of
A number of persons standing around; a body of attendants; entourage.
with two examples, one being
Their games were watched with much interest by a surrounding of Southerns.
(Daily News (London), 1891)
Which word surroundings can be replaced by entourage, if not that of Jimi Hendrix, at least that of the "Southerns" who have invaded the roostages of this answer's footnotes, found at the foot of this answer; for answers, like Southerns, have feet.
For the plural, the OED gives the definition:
Those things which surround a person or thing, or in the midst of which he or it (habitually) is; things around (collectively); environment.
Notice the word things.
If someone is looking for the CONCLUSION here, I'll repeat that surroundings is a plural count noun—which also has the singular count noun form surrounding—and it is not a mass noun.
1 There is no typo or misprint here. I am saying 'So, la2, [sentence #]1a, sounding ugly...'.*
2 For we will get back to Jimi's entourage in the course of this coursefully coursing answer. Meantime, you'll want to return to Exhibits 1b and 1bii. Sorry I can't throw a switch and like Luke hyperlink you there—or then—to a link far far away.
3 Not to be confused with this 'bare mini'. After spectating that article you'll want to beat a retreat to Exhibit 3c.
*Donut make me try'n splain-it ag'in; asn it aint worth't. Jussn you now sen'ents 1A issen' grammatik. Nah like 'issen, witch be grammatik.†
† Nor iz there a wasted word in this entyre awnsah. Essepn may b Jimi. Jimi maybbe wassid. O a' leese wasin' aweigh. Who Jimi? Jimi witta ON-TOUR-AHGE. ‡Lawhssy, Clayyair, yussa gonna plum where me yout a'clymen up teeztairs. Yuza yusta not yussa woh me ou' wen we waz yussa yoh yondr youngn acomin-by n tat bye-n-by we be sweete bye. §Dear reader, please return to the text of the answer and ignore these Southerns; the remembrance of things past has called forth my dialect antique to climb out of my sublimated conscious; but we will overcome.