I have a 90 gallon performed pond and just a few weeks ago i put a lava rock basin to act as a Bio Filter. A few days later i was having a few bees that were on the lava rocks that were not submerged. Now i have at least 20 bees and a few wasps sitting on them during the day. I went out and got Poison free Bee and Wasp killer and that only worked for a few days. My two Questions are Why are the Bees hanging out on the lava rocks and how do i get rid of them

I think they are there for one or both reasons to get water and or because its cool.
To get rid of them make sure all rock is under water.

I agree, they probably have hives near by and are there for the water.

The bees are coming for water. My mother recently go us new honeybee hives a few months ago after a 10 year absence. We have two hives with 12,000 bees each! Needlesstosay, the girls (honeybee workers are all female) are all over the bird bath and my ponds. When I work on the ponds, they buzz all around me. I ignore them. As far as bees go, they are very docile. The beekeeper even picks them up without getting stung. You should find out what species are visiting your exposed lava rock for water. Some bees, wasps, and hornets aren't a problem while others are aggressive. The European hornets are the worst. They're huge, and, when I was stung a few years back, the pain lasted for two months (yes, months).
Anyway, if you lower the lava rock, they can't come there for water. You could also offer a water source elsewhere.
The "poison-free" poisons are meant to be used on the hive/nest and not individuals. If you can find a hive/nest, see http://www.fishpondinfo.com/pcare.htm#wasp for how to safely destroy a nest near the pond.

Here are some photos of our honeybee girls on the bird bath last weekend.

Thank you for the help, I tilted the basin so the lava rocks are under water and the the bees have al but disappeared from the basin. I also found out that the Bees are probly coming from one of my neighbors who has a Bee hive for the honey

Ok, if they are domestic honeybees, then they are pretty docile. They only sting if you literally try to squish them, they happen to crash/slam into your face or head (although one did that yesterday to me and didn't sting), or you stick your hand into their hive without protection. You might suggest to your neighbor that he set up a pond for the bees to get water. Maybe you can get some free honey for your suggestions!