Renting a house, water pipe break-who pays the overage on water bill? Renter or owner?

Its not your responsibility. And if you can prove the mold and mildew are at harmful levels (there are test for this) you can get out of your lease. I think its time to get a lawyer.

Who ever has their name on the water bill.

Sounds like a bad landlord to have!!! You should get more than one bill, about 3 would be fine to show the landlord how much your water bill normally is, and explain nicely that he needs to pay the rest, or take it off your rent. Get the answer in writing if he says he will pay!!!! If he refuses to pay, you are stuck. You could hold it out of your rent with a letter explaining the exact amount held and why. He would have to take it to small claims court to get the money back. That costs the landlord a few hundred bucks plus time off work. Doubt he will want to do that.

if you alert the city (water company) to what happened they usually take care of it (this happened to me) you have to write what happened what date..ect... usually the CITY cannot hold you responsible for something like that unless you caused the pipe 2 break, which is highly unlikely. so go back to the water company, tell them what happened they know a family doesnt use that much water, have your dates with you and when someone came to fix it about the mold, the landlord needs to fix that, that is very dangerous to your health to live with

time to find another house to rent

The landlord should put you up somewhere while it is being repaired. His insurance would cover the costs. If $260 a month is high (it is to me) you should have alerted the landlord or the city immediately as something was wrong. As a tenant you have a responsibility to let the landlord know immediately if something is not right so that it can be repaired and to minimize the damages. There was also probably a low pressure situation that you should have noticed in the faucets, shower, etc The landlord should have a professional service clean the damaged area and treat for any mold growth while you are living somewhere else. As a landlord, I personally would probably work out something with you on the water bill. But I believe you are actually responsible for the bill by law.

The person on the bill pays it. If the landlord requires you to move out with a vague timeline I would consider simply moving out permanently. You have to look out for your family's interest. Don't forget this is a totally unforeseen problem to the landlord, too, so he is at his wits' end. But he should have insurance to cover all damages, including loss of rental income.

The owner is not required to pay any of the water bill - not fair, but legal. SORRY!

You have grounds for a "constructive eviction", which is where you can notify the landlord and move out permanently, with the lease void, except for the return of the deposits. You can move sometimes within a few hours of the situation is that bad. And no water for 2 weeks, and an 80,000 gallon leak in12 days is that bad ... ... look up the residential landlord and tenant laws for your state and get the papers sent out NOW. It's under "Failure to maintain". The landlords legal responsibility is to maintain the premises in a habitably condiiton,and a swimming-pool's worth of water under the house is NOT habitable. As for the bill, you may have to pay it, but you can sue the landlord for the difference the broken pipe made because of the failure to maintain - the difference between last year and this year is reasonable. You can also sue for return of the rent for the time the place is uninhabitable.