It took about a week for environmental groups to focus on last week's Keystone pipeline spill in South Dakota, but now that they have, it could spell trouble for the owner TransCanada.

Jeff Tittel, the director of Sierra Club New Jersey who is leading a fight against the company on the East Coast, said Friday that last Saturday's leak in South Dakota is a major reason why no TransCanada lines should be approved in the United States.

The leak has not been contained, he said, and it has spilled 17,000 gallons of oil from Canada's tar sands. Sierra is using the spill to underscore why President Obama rejected TransCanada's application to build one of the most politically-charged energy projects in the last decade, the Keystone XL pipeline.

Tittel points out that the "disaster is a stark reminder that all pipelines are prone to leaks and often under-detected. This spill is one of the reasons President Obama rejected the Keystone XL pipeline and it's why he should reject all dangerous fossil fuel pipeline proposals."

The Keystone pipeline that sprung a leak makes up the domestic end of the pipeline system that Keystone XL was to be part of, hauling oil from Canada hundreds of miles south to refineries on the Gulf of Mexico.

TransCanada has put out updates in the last two days detailing its work with federal and state regulators to find the leak, which it says spilled 400 barrels of oil since Saturday, or 16,800 gallons. On Friday afternoon, a TransCanada update said they identified the leak. The portion of the Keystone pipeline from South Dakota to Oklahoma has been closed for a week due to the spill.

"TransCanada engineers are currently evaluating an appropriate repair method in conjunction with Pipeline and Hazardous Materials Administration," spokesman Mark Cooper said in a statement. "Following the completion of the repair, we will be working with the PHMSA on returning the pipeline to service."

"TransCanada must be held accountable and contain this leak as soon as possible," Tittel said in response to the event.

"Leaks like these pose real health concerns by polluting our waterways and releasing toxic fumes into the air," he added. He said the oil it is hauling is also "extremely flammable, can contaminate drinking water sources, and can cause devastating fires."

Tittel said he will continue to monitor TransCanada's progress as his group wages a fight against several new pipelines that he says pose threats to New Jersey's water supplies. TransCanada Corp. has purchased Columbia Pipeline Group Inc. for $13 billion, who owned multiple pipeline proposals in New Jersey.

TransCanada's Keystone I pipeline has now leaked 17,000 gallons of tar sands crude oil in South Dakota since Saturday. The pipeline has already leaked 35 times in its first year of operation, including a spill of 21,000 gallons in North Dakota. After the incident, TransCanada has shut down a section of the pipeline.

TransCanada was the company who proposed the Keystone XL oil pipeline that was rejected by the federal government in 2015.

"The TransCanada's Keystone I leak is worse than originally thought, spilling 17,000 gallons of tar sands crude oil since Saturday," Tittel said. "TransCanada has yet to even pinpoint the source of the leak, and was not even reported by the pipeline's detection system.