Aaron1124
You don't need to get overly-worried or hysterical (as some here) about the mold. People in hurricane country see this regularly, and deal with it.
...in the meantime, while you await action (or not) from your landlord, get an empty hand sprayer (a used laundry pre-stain treatment sprayer, window cleaner sprayer -- whatever one you have available) and make a simple chlorine BLEACH ("Clorox" or other brand, doesn't matter -- bleach is bleach) solution to deal with that mold. Yes, I know as I've been through a hurricane and black mold began the very next day! Actually, just about EVERYONE living on the Gulf Coast knows about black mold! Even though you're not in hurricane country (Washington state), mold is mold! And you do live in a "Rain Forest state" so there's lots of moisture up there for molds, moss, algae and so on...;-)
Anyway, for the time being -- AFTER YOU TAKE GOOD PICTURES OF IT ALL (of course) as you may need the "evidence" later -- mix up the bleach solution I mentioned (meaning, 10% bleach & 90% water...that's ALL you need, more than 10% bleach is a waste) and spray/wet-down the mold areas (no need to SOAK through the sheetrock -- AVOID that as it will soften the gypsum). It kills mold quickly.
So, you CAN take care of surface mold yourself: Whatever/wherever you see mold, spray it. It's dead. Period.
Problem is what's in the air vents or inside the walls (as hurricane country people ALSO know) and to fix THAT the sheetrock needs to be removed, any insulation (which if wet is also probably modly), a fungicide solution is then sprayed all over the interior (and now exposed) stud wall cavities, it's all left to dry, and finally new insulation and sheetrock is installed.
As for vents, a professional vent-cleaning service would be best, but still, for health reasons you could spray what mold you can see from looking in there and kill what you can get to.
Yes, doing the WHOLE "repair" thing IS costly -- that is, IF the mold was that bad and spraying it alone won't get it all -- and a landlord may not want to spend the $$, but maybe he has insurance for that...except, IIRC (at least in the hurricane-prone coastal areas), water/flood insurance policies USUALLY do NOT include black mold (not sure, you may need to add a "mold rider" or "mold floater" to your flood/wind policy), but since you're NOT in hurricane country, maybe your landlord's Home/Business insurance policy WILL cover mold issues and as a result, the repairs required to replace the moldy materials.
But FOR NOW, you should act on your own (as mentioned, for health reasons) to kill the stuff you can see (and so it doesn't mature enough to release mold spores into the air you breath!) -- so just use the bleach solution wherever you see the stuff. Then you've a bit more time to wait to see what the landlord will do (if anything).
But also as mentioned, take good pictures of it all first! And, you may need to get a HVAC pro to check out your vents...if so, you'll have his written "estimate" (or report) you can keep as evidence, also.
PICTURES will be the only evidence you'll have after you spray the mold and it's gone. So if you have to go to court to prove you had mold in the first place for such reasons as the landlord does nothing about it, or, won't let you leave saying you're breaking the lease and so it'll COST you for doing that, or, charges you big-time for breaking the lease if you DO leave anyway (lease-breaking $$ penalties are in EVERY lease/renter's contract, so look at YOUR lease to find that info) -- for some OTHER reason you end up in court (or dealing with the Health Department) -- you will have PICTURES to show them, or the judge! Breaking a lease can be VERY COSTLY...black mold causing you to break the lease SHOULD be a defense to that -- but IANAL (although I DO play one in JP Court on occasion). Still, it SHOULD be a valid defense as it's a HEALTH issue! And don't be afraid to go to Small Claims (AKA: Justice of the Peace Court) if your landlord becomes unreasonable -- let him "tell it to the judge" if he wants lots of $$ from you (if you leave) for breaking the lease. Show the judge your pics and say you were concerned about our family's health and HAD to leave (if the landlord did nothing to fix the problem). It's my guess the judge will rule in your favor. I've been to those courts 3 times and won my case every time.
But at least give your landlord enough time and every opportunity to do the right thing, whatever it may be (such as, IF the sheetrock needs replacing, or the vents cleaned) -- as you must do that as per the law (give him written notice, time to respond, etc. -- the law spells the process out -- look research tenant/landlord law online). I'm just saying if he does nothing and/or plays hardball, don't be intimidated -- go to court.
I just glanced at your pics, but do not see a serious mold issue on your sheetrock like I (and everyone else) had in Galveston after Hurricane Ike -- you'll KNOW the difference -- so what we did was "mitigate" the mold issue until the crews could come in and redo it all (rip out all the moldy sheetrock & insulation, spray the studs, let it all dry, then reinstall new insulation & sheetrock. You're sheetrock looks pretty good, it's just around the windows and such where water has gotten in to let the mold grow...just spray it and see if it comes back. Not saying there isn't any mold inside the walls at the bottom (sill plate) areas, but from the outside, it doesn't look bad. Whatever is causing the LEAKING (water to get in), however, is definitely an issue and need fixing ASAP.
While ANY mold is bad, YOUR situation (IMO) isn't as bad as it looks as you can spray that surface mold and kill it quickly. If the mold is in your HVAC VENTS then that is more serious and needs a professional cleaning. But for the other stuff in your pics, just SPRAY IT, leave it for about 30 minutes, then wipe the area down, let it dry and see if it comes back.
And of course, FIX THE LEAKS to keep water out...or else it probably WILL come back!
As for the sheetrock, mold doesn't feed on the gypsum in the sheetrock (AKA: wallboard/gypsum-board), it feeds on the outside PAPER of the sheetrock when it gets wet. So it's just on/in the paper...so spraying it with the 10% bleach solution I told you about (and, which is a staple in hurricane country emergency supplies: BLEACH) kills it immediately, and any black stains of the mold are gone, At most, you will just see an outline of where it was. Then just keep an eye on those places to see if it returns, if so, there may be some in the wall cavities, and you have to go further to be sure by looking in the walls -- yes, the only way to do that is remove the sheetrock.
Anyway, after you take action NOW by spraying with the 10% bleach solution all the mold you can SEE (and then wipe it up), you can wait (and do so less worried) to see what the landlord decides to do about the sheetrock (removal, if necessary) and re: cleaning the AC vents. But ALSO ask him about how the water is getting in...maybe all he needs to do is remove/replace the (apparently failed) outside caulking.
Otherwise, all the mold you see and spray will be dead immediately and will not be a current health hazard.
Good luck...