Trouble could be brewing for the B.C. Lower Mainland's burgeoning craft beer industry, as Metro Vancouver claims microbreweries are overwhelming the sewage system.

The region wants bylaw changes that could force brewers to pay to deal with organic matter produced through fermentation, saying many of the new businesses are pumping out more than just great suds.

"Part of making beer is the waste products are very organic and have quite a high strength from a sewage perspective," Fred Nenninger, a manager in Metro Vancouver's wastewater division, said.

According to Nenninger, the organic waste produced by beer brewing is tough to treat and contributes to odour and corrosion in sewer systems.

Graham With, a brewer at popular Vancouver craft brewery Parallel 49 and a wastewater engineer, said his microbrewery planned for waste issues.

But, With said, many small breweries don't have the money to install testing equipment or containment tanks.

"It could break some of the smaller breweries or, alternatively, they're going to have to screen everything that goes down the drain."