Questions have been raised about environmental dangers to La Brea residents if a US$1 billion aluminium smelter is sited there.

UNC senator Carolyn Seepersad-Bachan raised the matter as a motion on the adjournment of the Senate on Tuesday.

She asked for details on the Memorandum of Understanding (MOU) agreement signed between US-based aluminium producer Alcoa, Venezuela company Sural and the Trinidad and Tobago Government.

Six hundred acres have been cleared in the past three months at Union Estate for the industrial development.

One of the projects to go there is the smelter, Seepersad-Bachan said.

But she said there had been calls from several quarters over environmental concerns surrounding the building of a smelter at the site.

She said a smelter produced hydrogen fluoride gas which was toxic if it exceeded three parts per million in the atmosphere and asked for clarification on how issues like this would be addressed.

"The Union Estate is known for reverse winds and this is a serious issue for residents," she said.

She also wanted answers on the gas pricing arrangements for the smelter and suggested there were concerns about the supply of gas.

Trinidad's proven reserves could last only about 20 years and a smelter would require a reserve of about 40 years worth of gas, she added.

But Energy Minister Eric Williams responded that this country had more reserves than ever before and there was plenty more to come which would be more than enough to sustain a smelter project.

"Our exploration and production programme will bring more reserves," he said, adding that this country's cross-border initiatives with Venezuela could see that country's natural gas coming here as well.

The signing parties have agreed to come up with a plan for the smelter project by the end of this year and a certificate of environmental clearance will be required and will address any environmental concerns.

The MOU was signed on May 24.