A broad scale application of insect control would be a good place to start.
Might be good to treat your dogs regularly with a flea deterrent - many on the market today or just drop applications every so often to the pet. If there are no pets to feed on the fleas may disappear. I believe the vets have the most powerful concoctions, but cheaper brands are available at the pet stores. We get ours at pet smart and it works quite well.
diatomaceous earth - just sprinkle it on your lawn http://www.richsoil.com/diatomaceous-earth.jsp
also, bathe your dogs in dawn dishwashing liquid. it kills both fleas & ticks, its cheaper, works better & is safer than frontline.. i have 4 dogs, trust me, it works :)
You'll need to treat your lawn and your dogs. For another organic option in addition to diatomaceous earth, consider using beneficial nematodes.
@A-1 Watkins Pest & Termite Control just posted these helpful tips for getting rid of fleas http://www.hometalk.com/678484/fleas
Diatomaceous Earth (DE)...all around the yard.
Also ask for the 'edible' DE and get each dog 'puffy' and put some in your hands and blow it gently into their fur.
Wear sunglasses for protection...or other safety glasses.