February 21, 2007 | General

Becoming A Zero Emissions Brewery

BioCycle February 2007, Vol. 48, No. 2, p. 29
Diverting 600 tons annually from landfills turn hops, grains, pallets, cardboard, glass, office paper and shrink wrap into major savings – and great beer!
Molly Farrell Tucker

ALMOST AS FAMOUS for reducing its waste as for making great beer, Mad River Brewing Company of Blue Lake, California is renowned for its Steelhead and Jamaica ales as well as its ten Waste Reduction Awareness Program (WRAP) awards from the state’s Integrated Waste Management Board. The microbrewery currently recycles or reuses 98 percent of its residuals with a goal of generating zero waste.
Bob Smith – Mad River’s founder, brew master and general manager – started the brewery in 1989 after ten years of planning. Smith grew up in the San Francisco Bay area, earning a Bachelor of Science degree in botany at Humboldt State University in Arcata. Two years later, he came back to Blue Lake, a small town near Arcata (pop. 1,300), located a few miles inland from the Pacific Ocean and 235 miles north of Sacramento.
It took more than a year to build the brewery and begin operations. Much of the original plumbing, electrical and sheet metal were recycled materials collected during the long lead up to construction. “I worked for 15 years as an electrical contractor and was close friends with a plumbing contractor so I had many opportunities to collect salvage or surplus materials,” Smith says. Mad River Brewing is a closely-held corporation with 35 shareholders, with Smith holding about ten percent of the stock.
The brewery estimates that it diverts 600 tons of materials from landfills annually including hops and grain, pallets, cardboard, glass, office paper, bags and shrink wrap and saves $44,000 in the process. The cost of diverting these materials is approximately $10,000 annually. Humboldt County’s landfill is closed, and the brewery’s solid waste is hauled to either Anderson, California or to Central Point, Oregon. “The major cost involved with this disposal is the transport,” says Smith. “Fees at the dump sites are about $19 per yard but the local waste companies charge about $90 per ton for waste disposal because of the transfer and hauling expense.”
The brewery generates less than one cubic yard of trash per week. Smith explains: “We now have a two-yard dumpster which we usually fill about halfway. The most significant portion of the brewery’s waste are organics. Part of why I chose this business is because we’re able to divert a tremendous amount of waste and have by-products that others can use, including spent barley malt, yeast, and spent hops.” The company gives away many of its brewing by-products to farmers, gardeners, and homeowners. Over ten tons per week of spent barley malt, hops, and yeast are fed to local livestock, used as a soil amendment, or composted.
For the past five years, an organics hauler and cattle rancher, Keith Winiger, has been collecting an average of 20,000 pounds a week (one million pounds a year) of the brewery’s spent barley malt in a 10-yard dump truck. The spent barley malt is a wet but solid material with the fibrous consistency of oatmeal mixed with sawdust. Winiger delivers most of it to dairy farmers as much as 20 miles away. “A significant portion of the spent barley malt is fed to dairy and or beef cattle,” notes Smith. Winiger composts the remainder at his cattle ranch near Fortuna, California. Local gardeners also come to the brewery to get smaller quantities of the spent grain to use as a soil and compost supplement for their gardens, and farmers with chickens, pigs and geese collect the spent grain for feed.
The brewery also finds uses for the 10,000 pounds of spent hops produced each year through the brewing process. The hops are either hauled by Winiger to his ranch and composted or fed to cattle, or used by local growers to mulch their blueberry and raspberry patches. “The hops provide natural acidification for the soil, keep weeds down and deter pests,” explains Smith. “The high nitrogen content from barley protein adhering to the spent hops also helps with soil nutrition as it breaks down.”
About 50,000 gallons a year of yeast and waste beer are used by a local rancher as a soil amendment which also adds supplemental moisture during the summer. “The pasture gets 40 inches of rain a year but virtually all of it falls between October and March,” notes Smith. Yeast is collected from the fermentation process and waste beer from cleaning the beer tanks and kegs; they are combined in a holding tank. The mixture is pumped into 200-gallon plastic totes that are in a metal framework. The totes are transported by brewery employees to a nearby pasture and applied as a soil amendment.
Most of the brewery’s metal waste goes to a scrap yard for reuse, including damaged stainless steel beer kegs, broken aluminum ladders, aluminum cans collected from the company’s break room, old motors, and gear boxes. The metal is separated by type, such as stainless steel, aluminum, regular steel, copper or brass. “One man who works with a group of inner city teenagers in Oakland, California collects metal so the teenagers can manufacture belt buckles and pocket knives to sell, to fund the operation of a youth shelter,” says Smith.
All of the brewery’s paper, glass, wood, and most of its plastics are reused or recycled. Mad River Brewing generates a significant amount of cardboard through the case boxes and shipping boxes that materials and supplies are shipped in. Large sheets of corrugated and noncorrugated cardboard from shipping boxes and craft paper are given to landscapers for use as organic weed barriers. “The cardboard is placed on the ground as a barrier with a limited life span and can be covered with organic mulch material, such as ground bark, to control weeds and erosion,” says Smith. The brewery also provides landscapers with the burlap and woven poly hop sack material that the 200 pound hop bales come wrapped in. Approximately 1,200 of the corrugated cardboard case boxes that Mad River ships its bottled beer in are reused each year by Resale Lumber Company in Arcata.
On site, the brewery collects used six pack carriers from consumers for reuse. Any remaining cardboard, chipboard, and kraft paper is deposited into a two-cubic-yard dumpster located right in front of the brewery. All office paper goes into a separate container. A recycling service that works with the Arcata Community Recycling Center collects the cardboard and paper weekly. Brewery employees stuff the used stretch wrap into “minibulk shipper bags”. These heavy, woven plastic bags are used to ship 1,600 to 2,000 pound quantities of organic malt to the brewery. The bags measure four feet by four feet by five feet tall and weigh about 300 pounds when full. The filled bags are then taken to the Arcata recycling center where the stretch wrap is compressed into large bales (800 to 1,000 pounds each) for shipping. The empty “minibulk” bags are then used by the recycling center to store aluminum cans and plastic containers. The recycling center also uses the “minibulk” bags to ship recyclable materials to reprocessors.
“We help the Arcata Community Recycling Center by knowing what types of containers and items are used in their operations and direct those things to the center,” says Smith. “I go down and talk to people at the recycling center and try to understand what their operation entails and what they can use from the brewery.”
The brewery collects bubble wrap from a local outdoor store and reuses it for packaging material. “We use it to pack glassware for shipping in our mail order department and when shipping beer samples to distributors, retail account prospects, beer tastings and contests,” says Smith. “We have never bought shipping peanuts or any other packing, and have only packed with reused stuff.”
Recycled, ground-up concrete has been used at the brewery for grading and construction fill. A local heavy construction company, Kernen Construction, has a materials yard one mile from the brewery where it receives recyclable paving, roofing and fill materials, including concrete, for reprocessing and sale.
Local companies are reusing many of the wooden pallets that are used to ship materials to the brewery. “We need really good, solid pallets to ship out our beer,” Smith explains. “We can’t use the pallets that come in with the cardboard and kegs because they aren’t sturdy enough.” The pallets were being sent to a local cogenerating plant to be burned as fuel to generate electricity and hot water. Now, two local seafood processing plants collect the pallets from Mad River Brewing each December, repair them and use them to ship out crab products. “The seafood plants come with trucks and clean us out every year,” notes Smith. “They come at the end of December because the crab season starts in January.” Pallets that are too damaged to be repaired and reused are brought to a tub grinding site, where they are ground up into mulch.
The brewery periodically tracks the number of gallons of water required to produce one gallon of beer. It has reduced the amount of water from 14 gallons to an average of 7.9 gallons. The reductions were achieved through a brewery-wide audit of water usage, reconfiguring standard water use routines, equipment changes, and adjusting equipment for lowest usage. “Some of the water now gets used up to three times due to recovery efforts,” notes Smith.
Brewery employees are responsible for making sure that materials are reused and recycled whenever possible. Most employees have custodial and maintenance duties and are regularly updated on company waste management practices through the use of chalkboards, staff meetings and memos. “We try to make it clear to our employees and the public that social and environmental responsibility is something we prioritize,” says Smith. For years, Mad River has provided free guidance and information to help other businesses and breweries in Blue Lake, Arcata, and Eureka and elsewhere start their own waste reduction, recycling and reuse programs.
A wastewater treatment plant was built at the brewery to process 5,000 gallons of wastewater per day from the beer manufacturing operation. The treatment system, part of which is housed in a greenhouse, was constructed to minimize the impact on Blue Lake’s municipal wastewater treatment plant, the Blue Lake Sewer Plant.
Mad River Brewing’s treatment system removes up to 95 percent of biological oxygen demand (BOD) and total suspended solids (TSS) in the brewery’s wastewater. The BOD of the brewery’s untreated wastewater is currently about 7,000. “Blue Lake has a population of about 1,300 and the wastewater treatment plant is sized for a population of 2,000 residents,” says Smith. “The brewery has the potential of generating 50 percent of the loading that goes into that plant. Our untreated wastewater would overload their system.”
The need for an on-site wastewater treatment plant became critical in 1996. “We grew here through the early 1990s and our production volume was in excess of what it is now, with no complaints from the City,” says Smith. In 1996, the state of California forced the Blue Lake wastewater treatment plant to shut down its intake head works and an Imhoff reactor treatment unit because of odor complaints from neighbors. Shutting down the Imhoff reactor, a two story septic tank, reduced the wastewater treatment plant’s capacity by 30 percent, says Smith. “The plant immediately had to start requiring industrial wastewater producers to pretreat their discharge. They told us in 1996 that we had six months to reduce our BOD count from 10,000 to 300. We were able to buy time, mostly by keeping communication open and being appropriately conciliatory.”
The brewery started searching for a solution and researched several technologies. “There were a number of treatment strategies we could have used, but we stressed that it had to be low-energy and an appropriate technology,” he adds.
A group of postgraduate engineering students at Smith’s alma mater, Humboldt State University, came up with the original design as a class project. Smith worked with a draftsman to increase the capacity of the original design. Construction of the wastewater treatment system began in 1997 and the system began full operation in 1999. The treatment plant was constructed using mostly off-the-shelf components such as plastic pipe, filter housings, valves, and sis standard residential septic tanks.
The septic tanks were installed in the ground, just deep enough to be covered with dirt, as the primary treatment phase for effluent from washing and brewing. The effluent is delivered to the underground tanks through drains located throughout the brewing and packaging areas of the brewery. “The floors in those areas slope to drains that connect to a drain piping system that collects only brewing wastewater,” explains Smith. (Bathroom waste exits the facility through a separate discharge point.)
The effluent is blended and goes through the underground tank system. Solids are separated out and then broken down through thermophilic anaerobic digestion. The wastewater leaves the underground tanks and the pH is adjusted and micronutrients are added. The resulting effluent is then run through a subsurface wetland consisting of two concrete basins, each 72 feet long, 10 feet wide and three feet deep. The basins are contained in a greenhouse that is 72 feet long and 22 feet wide. The greenhouse is covered with a recyclable, UV-resistant polyethylene film.
Each of the concrete basins is filled with 50 yards of gravel and planted with plants that can survive in the wastewater. Choosing the right plants has been trial and error. “We’ve planted papyrus, several species of bulrush, yellow flag iris, and calla lilies that are surviving, and at least a dozen other plants that couldn’t handle it,” notes Smith. “It’s a very difficult environment for plants so we haven’t been able to grow commercially beneficial plants or organic vegetables.”
The wastewater treatment system requires only 1.25 horsepower of electrical energy to operate. The brewery’s treated wastewater passes through a discharge meter, and then into the Blue Lake city sewer system. Smith says the brewery’s current BOD discharge level is 760. “The City government would like it to be at 300.”
The brewery’s treatment system requires constant monitoring and periodic maintenance. “The bacteria that metabolizes nutrients in the wastewater generates biomass that builds up a sludge material,” explains Smith. “This plugs up the porosity of the gravel beds and makes the treatment cells ineffective over time.” The gravel is removed from the basins every other year and replaced with new gravel. The used gravel is hauled to the materials yard of Kernen Construction. It is washed, graded and reused for paving projects and incorporated into concrete mixes.
The plants are removed from the basins when the gravel is replaced, and are replanted in the fresh gravel. Every two years, a septic tank service removes the buildup of solids from the underground anaerobic digester. The solids are composted by the septic service and sold as a bulk soil amendment for various agricultural and landscaping uses.
The brewery controls the amount of effluent that flows into the concrete basins, to ensure that the wastewater flows below the surface of the gravel and also covers the plants roots. “This is done so there is no odor or surface flow of effluent that could result in the growth of insects and pests,” explains Smith. “When you stand in the greenhouse, even though you have waste water flowing below you, the gravel you see is perfectly dry.”
Molly Farrell Tucker is a contributing editor to BioCycle.

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