AURORA, Colo. -- A Wal-Mart supercenter here will turn fresh produce, deli, meat, bakery and dairy food waste into compost and experiment with used cooking oil as a potential heating source.
The tests are two of more than 50 environmentally friendly measures being tried in the supercenter that opened earlier this month. The Aurora location is Wal-Mart's second ecologically friendly experimental store. The first one, launched in July in McKinney, Texas, is testing the two recycling projects along with 24 other experiments.
Wal-Mart Stores created the ecologically friendly store format to learn more about how it and the entire industry can improve environmental sustainability, according to the retailer. The company plans to focus more attention on reducing energy costs and adopting environmentally sound practices as it opens new stores, said Lee Scott, the retailer's chairman and chief executive officer, in a recent speech.
"As we start building new stores, we are committed to developing a new prototype that will be 25% to 30% more efficient and produce 30% less greenhouse gas emissions than current stores and it will be operational within the next four years," Scott said in the speech.
Officials are watching the experiments closely. Information relating to both stores' energy efficiency is collected, monitored and compared to that of nearby traditional Wal-Mart supercenters. In addition to sharing results with the retail industry, general public and government agencies, Wal-Mart will apply the findings to future stores, the retailer said.
"The experiments in this experimental store will help us evaluate some new technologies which we hope will save energy, reduce maintenance and add more profits to the bottom line," Wal-Mart spokeswoman Tara Stewart said. "All this while we do our part to save the environment for future generations."
The Aurora store's fresh food handlers are being educated about the types of waste that are appropriate for composting. Wal-Mart will begin separating its organic waste in the Aurora store next month when the 30-day training period ends.
"There is a learning curve with new stores," said Bob Yost, vice president of new business development, A1 Organics, Eaton, Colo. "We can compost any organic material that is carbon-based or once living. We're training the staff on how to properly separate the waste."
In addition to creating compost for Wal-Mart's Aurora store, A1 Organics works with some of Whole Foods Market's and Wild Oats Markets' Colorado stores, Yost said.
Though many types of waste -- ranging from cake to soda pop, and untreated and unpainted wood -- are appropriate for composting, fruits and vegetables usually make up a big portion of retailers' organic food waste, he said.
"When fruit is sorted, presale, [retailers] often have apples that are bruised and don't meet the quality standards or they'll have to discard some of the lettuce they use to prepare a salad in the deli," Yost said.
Waste that is appropriate for composting will be collected in specially marked containers that are emptied into a 10-ton compactor in the back of the store, Yost said. Once the compactor is full, its contents will be taken to A1 Organics' facility where the material will be broken down by microorganisms to a point where the compost can be safely applied to the environment. The process takes between 90 and 120 days. Wal-Mart plans to have the compost packaged so that it can be sold in its stores.
The retailer is currently exploring composting "leftovers" from food consumed in the store, according to Yost. The process is known as post-sale composting. The Aurora store features a Subway restaurant and a Papa Murphy's Take 'N' Bake Pizza.
"[Wal-Mart] said they're wide open to [the post-sale composting idea]," Yost said. "I've been very impressed with [the retailer's] willingness to incorporate some of [A1 Organics] new ideas."
Although vegetable oil used in Wal-Mart's deli would be appropriate for composting, the experimental stores have other plans for it. When the McKinney store requires heat, vegetable oil that's used for things like frying chicken will be collected and stored in a 100-gallon tank in the kitchen area. The oil from that tank will be pumped to an 800-gallon tank located in the back of the store, according to Mike MacDonald, research engineer, Oak Ridge National Laboratories, an Oak Ridge, Tenn.-based company that is monitoring the results of the experiments at the McKinney site. (ORNL is a U.S. Department of Energy lab.)
The used vegetable oil will then be pumped to a 100-gallon tank in the store's boiler room where it will be mixed with waste engine oil from the store's Tire and Lube Express.
"The deli and Tire and Lube Express areas are on different sides of the building, so the oil has to be pumped to [the central location of] the bio-fuel boiler," Stewart said. "The vegetable oil and the motor oil are stored separately and then combined in the bio-fuel boiler to be burned when heat is needed."
When heat is not required, used vegetable oil is "hauled off by contracted recyclers and recycled in [Wal-Mart's] normal way," Stewart said. "All stores recycle used oil, cardboard, paper, plastic bags, film, car batteries, photo processing waste and more."
Although the vegetable oil heating system has been tested at the McKinney store, there has yet to be a need for heat in either store. Based on results of the initial test, the process needs work before it will be up and running, MacDonald said.
"It's still missing some key valves that are required for it to work properly, but it's a pretty darn interesting experiment," he said. "[ORNL] watched the design evolve and [the system] has gotten a lot more complicated."
Wal-Mart is doing a similar test at the Aurora store. The heat generated in the boiler is directed into the heating, ventilation and radiant floor heating systems. Once it's fully operational, it could reduce the Aurora supercenter's use of natural gas by just under 22,000 therms per year, according to Wal-Mart's estimate.
