We’re all Irish this week, right? Well, if Irish means green, then these breweries really fit the bill. And by green, I mean they’re finding new ways to decrease water use, treat wastewater and even generate renewable energy.

Included here are a few breweries that have signed a Climate Declaration created by Ceres, a nonprofit sustainability advocacy administration. By doing so, the breweries acknowledge the risk — and opportunity — associated with climate change. They hope to send a message to policymakers and work together to reduce water and energy needs in the brewing industry.

So on this St. Patty’s Day, raise a glass of sustainability and see how breweries across the country are taking water and wastewater issues seriously:

The Alchemist, a small family-run brewery in Waterbury, Vermont, uses wastewater with high organic content for composting. The brewery has also installed a moving bed biofilm reactor to reduce BOD and keep pH levels consistent. According to a Vermont Public Radio report, the brewery is carefully considering its wastewater operations as it plans a new facility in Stowe.

“We really don’t produce much garbage,” says Alchemist co-founder Jen Kimmich to NPR. “For us, we’ve really been focused on side-streaming as much wastewater — tank wash, the liquids and the biosolids from the bottom of our fermenters — as much as possible and we compost an incredible amount of water.”

RedHook Brewery, a craft brewery based in Portsmouth, New Hampshire, was named a 2014 Safer Chemistry Champion by the Washington Department of Ecology for reducing water use by 54,792 gallons per year. The brewery has also reduced soap needed for lubrication, cut the use of antimicrobial disinfectants and reduced the chemicals needs to treat its wastewater.

Sierra Nevada, based in Northern California, features an onsite wastewater treatment plant that captures methane for energy use. The onsite plant, which was built to reduce demand on the municipal system, pretreats wastewater before discharging to the municipal system. The brewery’s effluent is similar in composition to residential effluent.

The brewery has also reduced water use by improving leaking pipes, pumps and valves and equipment upgrades. In 2005, Sierra Nevada became the first brewing operation to install hydrogen fuel cells.

New Hampshire’s Smuttynose Brewing Company captures methane from wastewater and uses it for electricity. The brewery is mindful of its environmental impact and partners with the Piscataqua Region Estuaries Partnership.

Widmer Brothers Brewing is experimenting with a small-scale microbial fuel cell that generates electricity from the brewery’s wastewater. The brewery has also restored more than 9 million gallons of water to Oregon streams through Waster Restoration Credits. The brewery’s Columbia Common Ale is a water-neutral beer, meaning 100 percent of the water used to produce it is offset.

Want to learn more about sustainability in the brewing industry? Take a look at the other breweries in the Climate Declaration.