Buildings & Grounds Maintenance

This page has Stanford-specific recycling information. For general information on recycling, please click here.

History

Students started the recycling program at Stanford University in 1978 as a class project. Eventually, ASSU assumed responsibility for collections. PSSI often helped the students by loaning bins and equipment. In 1991, PSSI was asked to operate the recycling program and continues to do so today.

Overall Program

Stanford University has a comprehensive waste reduction and diversion program. We recycle glass, metal, plastic, paper, yard waste, food waste, wood waste, electronic scrap, concrete, and construction and demolition waste. In addition, fallen trees are ground into wood chips, tree trimmings are chipped into mulch, and the Grounds Department practices grasscycling by leaving grass clippings on the grass.

Material Collected

The first of the three chasing arrows in the recycling symbol represents the supply of recyclable materials placed in the recycling bins. We have three streams of recyclable materials coming to our facility. First is corrugated cardboard which is collected in green frontloader dumpsters outside of most buildings. Second is mixed paper which includes all paper that tears and is not contaminated by food or oil. Mixed paper is collected in carts or slim jim bins throughout the campus usually near high generating areas such as copiers and mail boxes. Lastly, bottles and cans are collected in carts or slim jim bins throughout the campus. The following can be placed in these bins: aseptic containers, aluminum and tins cans, aluminum foil, glass bottles and jars, juice/milk cartons, and plastic #1 PETE, #2 HDPE bottles and containers and plastic #3-7 bottles. Plastic bags and bubble wrap are also collected at five locations on campus and are also allowed in our mixed paper bins so that the material stays dry. Some of the items not recycled on campus include polystyrene, Pyrex, test tubes, and ceramic mugs.

Collections

After the recyclable material is placed in the recycling bin, PSSI crews collect the material. Corrugated cardboard is collected with a frontloader truck that used to collect garbage. The plastic wheeled carts and slim jim bins containing mixed paper or bottles and cans are emptied weekly by a two person crew and a special frontloader truck that has two compartments - one for mixed paper and one for bottles and cans.   

Processing

After we collect the material, we begin the process of preparing the materials to be shipped for use as a raw material or feedstock. Most of the material is brought to our processing yard to be sorted into various categories and remove contamination.

Paper is our largest category, making up about 70% of material by weight that we sort through. Once corrugated cardboard is collected in a frontloader truck, it is hauled directly to a nearby paper mill to be made into new paper products. The rest of the paper is sorted using our sorting line into the various grades of paper depending on the market. Sometimes we sort out contamination and sell the material as a high grade mixed paper or we sor the paper into white paper, newspaper,magazines, and low-grade mixed paper. The markets can change each month. Each of these commodities is stored in large roll-off containers until we are ready to ship to market.

Bottles and cans are sorted using various pieces of equipment on our sorting line. First, tin cans are pulled off automatically using a large magnetic head. Next, plastics are sorted into #1 PETE Plastic, #2 HDPE Clear, and #2 HDPE Colored , and #3-7 Plastic and contamination is removed by two of our sorting staff. Aluminum cans and foil are blown off the line into a chamber by using an air blower. Lastly, glass is colored sorted by one of our sorting staff into clear, green, and brown. Broken glass goes into a bin at the end of the sorting line to sold as Mixed Glass. The rest of the glass is stored in large half round containers that we made for this purpose. The aluminum and tin cans are flatten by a can crusher and stored in large roll-off containers. Plastics go through a perforator before being baled into cubes for easier handling.

Our sortline is efficient, requires less people to handle the material, and keeps up worker productivity by being a challenge to our employees.

Markets

Once the material has been sorted and cleaned of contamination, we sell it to local vendors. The materials are delivered using roll-off trucks. 

Paper

Most of the paper is delivered to secondary fiber processing facility in the area, then sold to domestic and international paper mills. Paper is recycled using a water pulping process which is why we need to keep oil and food contamination out of the paper stream. Each type of paper requires a recipe card. First the paper is placed on a large conveyor belt to the top of the mill. Contaminants are filtered out. Water is added to the paper and mixed, turning the paper to pulp. The pulp is pressed to squeeze out the water and then dried and rolled. The paper is cut to specifications and sold. Recycled paper can be used to make all kinds of new paper including paper towel, cereal boxes, linerboard, and writing paper. 

Metal

After being separated and flattened, tin cans, aluminum cans, and aluminum foil are shipped to a local scrap metal yard. Aluminum is the most economically efficient material to recycle because of the expense and energy consumption used to make aluminum cans. Bauxite must be shipped from Russia to the U.S. and then transported to aluminum smelters where it is melted. If you only recycle one thing, recycle aluminum cans. Over 90% of all aluminum cans bought in California are recycled.

Tin cans are actually steel cans with a tin coating to prevent oxidation. Tin cans are taken to a de-tinning plant where the tin is stripped from the steel using a heat and chemical process. Both tin and scrap steel are melted and made into a new steel product. The Steel Recycling Institute says that it is the most recyclable because steel can always be melted down and made into something else. You need old steel to make new steel. Both types of metals can be made into new cans, car parts, and anything else made of metal.

Glass

Glass is cleaned to remove contaminants, crushed into a powdery form, heated until it becomes liquid, and then remolded into a new product. Contaminants, such as plate glass, ceramics, and rock, are a problem for glass processors because they can cause major defects in the final glass product. Paper labels are not a problem because they burn off in the process. What is glass made of? Glass is made from old glass (called cullet), sand, limestone, and soda ash. The markets for glass have been steadily declining since most of the products that used to be in glass containers are now in plastic containers. Glasphault is made when glass is mixed with asphalt to make a road surface more reflective.

Plastics

Once plastics have been sorted into the different types, they are chipped into small pieces and then put through a water bath to remove contaminant stuck to the plastic. Once they are cleaned, they are heated to a liquid form and put through an extruder that turns them into small plastic pellets which are then shipped to a company that makes them into a new products.

Plastics must be separated into the seven types of consumer plastics. All plastics cannot be melted together because they have different melting points. Each kind of plastic has different properties that makes it desirable as a packaging, i.e. it may hold up well in cold temperatures, it may keep out odors, or it may not allow carbon dioxide to escape. The number inside chasing arrows on the bottom of the container does not mean that the container is recyclable, it only identifies the type of plastic it is made of. Locally, plastic #1 and #2 are widely recyclable and new, but small markets are opening up for plastics #3-7, mainly plastic lumber. The only way for more plastics to be recyclable is for more manufacturers to use recycled plastic in their manufacturing process to make new products. It used to be that there was not enough demand for recycled plastics but the tide is turning. The domestic manufacturers who use recycled plastics to make new products are very concerned that there is not enough plastic to meet their needs since the demand for this material off-shore is so high.

Diversion

In 1994, Stanford University diverted 31% of its waste from the landfill. In 2000, we were diverting 50% of our waste from the landfill. In 2013, we diverted 64% of our waste! Thanks to the campus community, Stanford has been able to increase its diversion level every year. Future projects include food waste composting, expanding bottles and cans recycling, and expanding electronic scrap recycling.

Benefits of Recycling

Recycling has many positive attributes to society including conservation of natural resources, a cleaner environment, reduction of landfill deposits, and expansion of an industry that can create thousands of jobs in California in the years ahead. 9 jobs are created for every 15,000 tons of solid waste recycled into a new product whereas only 1 job is created for every 15,000 tons to the landfill. In addition, recycling contributing $8 billion to the national economy. In California alone created 34,000 jobs and contributed over $1.6. billion to economy.

Closing the Loop/Buy Recycled

If the true potential of recycling as both an environmental protection and economic stimulus is to be realized, consumers are the answer. With increase demand for recycled content products, the value of recycle material may outstrip the cost of recycling. This in turn will foster businesses to manufacture recycled-content products. If you are not buying recycled products, you are not recycling because you are not closing the loop or completing the process. Buy Recycled - you are sending a powerful message to the companies of the products you buy.

Zero Waste

According to Zero Waste International Alliance, “Zero Waste is a goal that is ethical, economical, efficient and visionary, to guide people in changing their lifestyles and practices to emulate sustainable natural cycles, where all discarded materials are designed to become resources for others to use. Zero Waste means designing and managing products and processes to systematically avoid and eliminate the volume and toxicity of waste and materials, conserve and recover all resources, and not burn or bury them. Implementing Zero Waste will eliminate all discharges to land, water or air that are a threat to planetary, human, animal or plant health.” Learn more about Zero Waste on ZWIA's website at http://zwia.org/.

Creating Jobs from Discards

The philosophy of Zero Waste creates jobs from discards by viewing used materials as valuable resources instead of garbage in need of disposal. A pile of "trash" represents jobs, financial opportunity, and raw material for new products, as recycling industries create many more jobs than waste disposal companies. Research shows that, per ton, sorting and processing recyclables alone sustains ten times more jobs than landfilling or incineration. Some recycling-based paper mills and recycled plastic product manufacturers employ 60 times more workers on a per-ton basis than do landfills. Check out "Zero Waste: A New Systems Approach Gaining Global Ground" to see the source of this information and to learn more about jobs from discards and zero waste.

Sustainability

In October 1999, world population passed the 6 billion people mark. The number of people living on our planet is growing at an extremely rapid rate, as world population reached one billion in 1804, three billion in 1960 and then doubled in just 40 years to 6 billion before the year 2000 (Environmental News Service). Population growth forces the planets limited resources to provide for more people, as demand for food, water and other necessities increase. A study by the Sri Lanka based International Irrigation Management Institute predicted that one fourth of the world's people will face chronic or recurring shortages of fresh water by the year 2050. Crop lands continue to shrink, and global per capita grain output has been stagnant for more than a decade (Environmental News Service). 

To achieve a sustainable future, we must not only control population growth but also reduce consumption in industrialized countries. While America has fewer people than many undeveloped countries, we have a significant impact on the planet because Americans use many more resources than the people of undeveloped countries. For example, Americans use about 100 gallons of water per person per day for personal purposes such as drinking, cooking, washing, and disposing of wastes, compared to a world average of 22 gallons per person per day. Including irrigation and all other uses, Americans use 1,350 gallons per person per day, much higher than the worldwide average of 475 gallons (Water Resources: Agriculture, the Environment and Society). Even though Americans account for only 5 percent of the world's population, the U.S. consumes 26% of the world's energy and create 25% of the world's carbon dioxide emissions (American Almanac, New Consumers). The nations of the world must join together to control population growth and reduce consumption to prevent environmental destruction and ensure a healthy planet for ourselves and future generations.

Remember, it is not trash until you trash it and it is not waste until you waste it.