Well... if your dog is healthy, is on a good food, and is groomed often, he is probably just a shedder. I've had success with putting a light cotton shirt on my dog. It catches the hair most of the time, but its really too much trouble. I just vacuum constantly, and got a white couch cover.
You might also try using a product like Shed Stop. You just put that directly on your dog's food, and after a few weeks you should see less shedding. You can get it at places like www.valleyvet.com. Our Saint Bernard was losing mounds of hair, and we've seen a huge difference after just a little over a month. That along with regular brushing will help the most.
A lot of short haired dogs need to be deshed quite often to keep it to a minimum.
There were several short haired dogs that would come into the grooming shop I worked at. The first couple of times they had large amounts of dead hair (which is what comes out when you deshed a dog. It's the dead undercoat.). The dogs that came in on a regular basis, every 3-4 weeks, didn't have much dead coat after about 4 visit.
If you just deshed a little (or even what you might think is a lot) every now and then it's just going to keep building up. The dogs that would come in with a lot of dead coat; we'd spend 45-60 minutes desheding at a VERY high pase. Porbably getting out 2-3 times as much hair as you would normaly get out. So if you add that up it's like 3-4 hours of desheding every month for a regular basis. Once you get the majority of the coat out then it's just basi upkeep.
However you need the right tools and need to know the right way to use them (It makes a world of difference). A furminater, if she's shedding that much, wont work. Depending on her coat type, you'll need coat strippers of different sizes, shedding blades, and deshedding combs, you also might need the rubber deshedding scrubbers.
It all depends on her coat. You could try taking her into a Grooming salon so that they can get the majority of the coat out this time and then you can do the basic upkeep. Or even take her while she's getting rid of this winter coat. If she never got rid of her winter coat, I wouldn't be surprised if that's what's going on now.