"We are all guilty, the town is as guilty as anyone else out there," said Brome Lake Mayor Richard Wisdom. "We're being proactive, we're going to use the bylaws and enforce what has to be done."

A Friday press conference began with an explanation of a $150,000 study carried out by Teknika, that in turn looked at the various studies carried out over the last 20 years to identify the sources of phosphorus, the main nutrient for cyanobacteria, the toxic blue-green algae that caused such problems in many Townships lakes last summer.

"Without phosphorus, there will be no cyanobacteria in a lake," said Pierre Bertrand of Teknika. He estimated that about 2,500 kilos of phosphorus come in from Brome Lake's various tributaries each year.

The good news is that 80 per cent of the lake's water drains out into the Yamaska River each year. So if you stop phosphorus coming in, the lake will be much cleaner within a couple of years.

The municipality is planning a number of strategies, starting this summer with shoreline protection. The days of having a nice lawn down to the water's edge will be over, with cutting forbidden and shorelines left in their natural state for 10 metres. Fertilizer and pesticide bylaws will be strengthened yet again, and the municipality's water patrol will be watching. Photos of lakeside residences will give the town an idea of where action is most required.

Motorboat owners will also have to make some changes. As of the end of this year, two-cycle outboard motors made before 2004 will be banned. As well, the "No wake zone" will be extended from 100 to 150 metres from shore, keeping the faster boats in deeper water. Boats within that zone must not exceed 10 km/h. Starting next year, boaters will require a permit, with the system reviewed in 2011.

Ice fishing will also undergo changes. As of this coming winter, cars and trucks will no longer be allowed on the lake. And the 2007-'08 season will be the last during which snowmobilers will have free rein on the ice.

"We've had problems with people leaving fishing shacks out on the lake, and then when the ice melts they just sink," Wisdom said.

Brome Lake's three golf courses will also be under the looking glass: Because golf courses fall under provincial regulation, the municipality will seek to reach a deal with the Quebec environment ministry for a systematic follow up on Inverness, Lac Brome and Knowlton golf clubs.

The town itself will be looking into reducing sewage runoff, namely in the western end of Fisher's Point, Robinson and Rock Island Bays, and Foster village. Meanwhile an engineering firm will begin a systematic inspection of septic systems around the lake, visiting about 75 residences this year.

Municipal infrastructures are also on the "to do" list, namely when it comes to dealing with overflow during heavy rains. Any rainwater overload is currently dumped directly into the lake. Pumping stations will be certified and catchments will help deal with the excess. Culverts that drain directly into the lake will be a thing of the past.

"Phosphorus tends to bind to dirt particles," explained Bertrand. "If you reduce the dirt particles, you reduce the phosphorus."

But for the plan to succeed Brome Lake will also have to look to its neighbours. Only 25 per cent of Brome Lake's watershed lies within the municipal boundaries. This year the town will aim to create an intermunicipal committee, made up of representatives of Brome Lake, West Bolton, South Stukely and St-Etienne de Bolton.

A case in point is the Quilliams waterway, which runs in from West Bolton through the Quilliams-Durrell nature reserve. It's responsible for 55 per cent of the 2,500 kilograms of phosphorus that comes into the lake every year. Bertrand said one gram of phosphorus provides enough food for 500 grams of algae. Coldbrook, which begins at the Mill Pond in downtown Knowlton, brings in another 25 per cent of the phosphorus load.

This summer biologists will venture up the various tributaries in an attempt to find the sources of the phosphorus. Discussions will then be held with the municipalities, and Mayor Wisdom said the Quebec farm union -- the UPA -- may also have a role to play in helping farmers deal with needed changes.

"Eighty per cent of phosphorus is from farming," Teknika's Bertrand said. "That's not us, that's a Quebec government statistic."

Some other aspects of the plan:

- Further work will be done to define and protect wetlands, which act as a filter for lakes and rivers, working with groups like the Appalachian Corridor, the Brome Lake Land Foundation and Renaissance Lac Brome.

- Following the $150,000 study, the town has earmarked a further $220,000 to put towards the lake cleanup.

- A communications plan concerning good environmental practices will target lakeside residents.

- Two-thirds of household phosphorus output comes from detergents. The communications plan will discuss available alternatives.

Bertrand cautioned that residents shouldn't expect to see instant results. Last summer an algae bloom closed the lake in mid-August, something which might well happen again this year. The process will take several years at least.

Wisdom said he's expecting some people will be angry with a plan that will force them to make changes in their lifestyles. But he argues the changes are necessary.