Ottawa Centre MP Paul Dewar wants the federal government to reduce the amount of tritium in drinking water after reports that large amounts of the radioactive element entered the Ottawa River in recent months at the Chalk River nuclear facility.

Dewar has tabled a motion in the House of Commons that would limit tritium exposure in drinking water to 100 becquerels per litre immediately and to 20 becquerels per litre after five years.

A becquerel is a unit of radioactivity. Dewar's proposed guidelines match those of a scientific advisory committee to the Government of Ontario, he said in a statement released Friday.

"As radioactive hydrogen, tritium cannot be filtered out of water," Dewar said. "Immediate federal action is required to end the practive of dumping tritium in the river and strengthen the regulations on tritium levels in drinking water.

The Tritium Awareness Project says the AECL nuclear plant released 28 trillion becquerels of tritium into the Ottawa River, the capital's source of drinking water, in December and February.

The federal government has a voluntary tritium guideline of 7,000 becquerels per litre of drinking water. But Dewar says the European Union and California have limits of 100 and 15 becquerels, respectively.

"The levels of radioactive tritium in Ottawa's drinking water are routinely two, three sometimes four times above background level for tritium, and this is because of these nuclear facilities on the banks of the river," Ottawa Riverkeeper Meredith Brown said this week.

The Canadian Nuclear Safety Commission said tritium releases from Chalk River have been controlled and monitored within environmental standards, and that the public faces no risk.