An unlicensed and unqualified well driller who tapped into a pressurized aquifer in southwest Vancouver last year triggered an uncontrolled flood of water that is threatening as many as a dozen multimillion-dollar homes.

For more than six months, millions of litres of water a day have been flowing out of the ground at 7084 Beechwood St. onto public property, prompting concerns about erosion and the possibility of a sinkhole that could affect several homes.

Despite efforts by the homeowner and consultations with hydrogeologists to halt the breach, the leak has only increased in volume from 800,000 litres a day to more than two million litres.

It is now so serious that the city has issued evacuation alerts for homeowners on either side of the property and says as many as a dozen homes could be ordered evacuated.

"This is a serious situation," Vancouver city manager Sadhu Johnston said Wednesday morning. "We are quite nervous about a sinkhole."

Johnston said the incident occurred in September when the owner of the property hired a contractor, Libo Sun, "on a handshake" to build a new house.

The contractor hired Geoenergia Projects (Canada) Inc., a Port Coquitlam company, also on a handshake, to install a geothermal loop to heat the home, he said.

But according to the provincial water branch and a consulting hydrogeologist, Geoenergia wasn't qualified to do the work, and it punctured a large regional aquifer, triggering one of the largest uncontrolled artesian well spills in the province.

According to Johnston, the driller "freaked out," packed up his equipment and not only abandoned the site but also fled the country. Attempts to reach the company, which advertises it now operates in Italy, were unsuccessful.

A check of the company's provincial registration status shows its directors, Tomasso and Armando Mascetti, live in Frosinone, Italy, which is near Rome, and that the company is listed as not in good standing. Johnston also said the driller was not "licensed, bonded, insured or anything else."

The city says the builder didn't indicate on his plans he intended to install a geothermal loop. The city also doesn't require permits for such installations but says it refers builders to the provincial government for consultation to make sure they know what is underground.

Both the city and the provincial ministry responsible for water regulations have since issued orders to the homeowner, Feng Lin Liu, to fix the breach.

Johnston said Liu has been cooperative and has hired a company, B.C. Groundwater Consulting Services, to fix the problem. The company is trying to install several relief wells to control the flow before it can try shutting down the puncture.

Johnston said although Liu is responsible for the accident and the B.C. government oversees the Water Act, the city is concerned about the mounting expense.

In January, Vancouver city council was alerted to the problem when staff asked for an order declaring the leak a nuisance. That allows the city to fix the problem and charge the costs against the property if Liu were to default, Johnston said.