TORONTO -- Canada and the United States are failing to mitigate the threat chemical pollution poses to the Great Lakes despite a well-intentioned water quality agreement hammered out almost three years ago, environmentalists say.

To express their concern, about two-dozen environmental groups on both sides of the border are sending a letter Monday to the heads of the Great Lakes executive committee, which oversees the agreement.

The letter, along with a new report from the Canadian Environmental Law Association, says a binational subcommittee tasked with tackling the pollution problem has made little headway.

"The (sub-committee's) go slow approach is completely out of sync with the scale and the urgency of the problem," the paper concludes.

"We cannot wait decades to stop these chemicals getting into the lakes and then having to launch massive cleanup efforts -- if that is even possible."

The panel, which is scheduled to meet this week in Chicago, was set up in 2012, when Canada and the U.S. renewed an agreement aimed at protecting and improving the lakes' water quality and the basin's ecosystem.

The Great Lakes Water Quality Agreement leaves it to the subcommittee to come up with so-called chemicals of mutual concern. To date, it has identified only four toxins for listing. However, environmental organizations have a list of more than 500 such chemicals.

"By adding four chemicals every three years...it will take us more than a century to list all of the chemicals of concern in the Great Lakes," they state.

"However, listing is just the first step: Each listed chemical will need an action plan for virtual elimination of discharges to the lake."

While the paper praises the water-quality agreement for emphasizing prevention, it warns that the current approach doesn't cut it.

The committee has fallen into an administrative and bureaucratic malaise, the report finds. Each side is left to decide how it will deal with chemicals that are listed, and Canada appears set to adopt a management rather than a zero-discharge program.

Among their recommendations, the groups want the two governments to expand their list of chemicals of concern significantly and to set up a scientifically credible process for adding and prioritizing the listings.

Current scientific thinking is increasingly coming to the conclusion that there are no safe limits for many chemicals but Canada only has management plans for seven of them.

"We are just scratching the surface of the problem," they say.

Both governments also must focus on consumer products -- flame retardants used on household items or chemicals used in personal care products are examples -- that have become an increasingly important source of toxins in the water, the report urges.

"To this date, (they have) been very slow to address those concerns," Fe de Leon, a researcher with the law association, said in a weekend interview.

Most importantly, the paper calls for an urgent shift to stop toxins getting into the water. The need is demonstrated by the fact that chemicals such as PCBs and mercury are still found in the lakes despite decades of trying to manage them, de Leon said.

"The current risk-focused management approach has simply been a failure," the report states.

Ultimately, the two countries will have to commit more resources to the pollution problem but, the report concludes, longer-term cost-savings will result from fewer health and environmental problems.

"We need to get started now with bold action, not baby steps," the paper states.