I would like to know if this is legal. Has anyone experienced this. We currently live in a building with 8 units. Our utility (water) keeps increasing every month. We were on vacation for a Month and still have to pay a $100 dollar water bill.

If it is in your lease and you signed it, then it is binding. Have you browsed through the information in LawInfo's Free Legal Resource Center to learn more about your issue yet? See: http://www.lawinfo.com/consumer.html and http://resources.lawinfo.com/en/index.html. You can certainly try to speak to a lawyer to determine what legal options may be available. In the meantime, you may be able to learn more on your own. Search the "Free Legal Resources" tab, or browse the Consumer Resources. Good luck.

It is not in my lease. The Manager sent me the Water Addendum yesterday, saying that they forgot to give this to me after I signed my lease May 31st. My lease was executed by the Manager at that time on 06/08. On this Addendum they forgot to have us sign there is the charge for the following:
Water
Gas
Sewer
Real Estate Tax
Pest Control
Admin Fee.

Now this new charge was suppose to take effect on the start of my new lease 08/01/2010, however they have been charging the pest control from 06/01/2010, and the Real Estate tax from 01/2010. This does not seem right as we never signed agreeing to any of this. Do we have the right to refuse this Water Addendum?

You can refuse to pay and then they could take you to court and the court will decide. Generally you cannot change a written contract orally or with an unsigned addendum. That being said, unless your lease says that all that is included a court may find that you should have known that you would need to pay something.

Would you recommend we seek and Attorney?

You may want to at least speak with one and show them your lease.