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Upcycling Food Waste into Fertilizer: Q&A with California Safe Soil


You’ve heard of recycling leftover food scraps into a soil amendment for farms, but now a California startup is transforming food waste from grocery stores into a fertilizer that can compete with conventional nitrogen-based soil conditioners that leach chemicals into groundwater, rivers and oceans.

We interviewed Dan Morash, founder of West Sacramento-based California Safe Soil (CSS), to learn more about how its Harvest-to-Harvest (H2H) fertilizer saves resources, reduces pollution and improves soil.

TriplePundit: How is your product, H2H, environmentally responsible?

Dan Morash: It makes productive use of something that is otherwise being wasted. Each 1,000 pounds of food waste generates 700 pounds of carbon dioxide and methane greenhouse gas emissions, as well as hydrogen sulfide – swamp gas – which is poisonous and leaches into ground water. We cut greenhouse gas emissions by reducing truck traffic, since our facilities are located near the supermarkets [where CSS picks up food waste], rather than in remote locations.

On the farm side, farms can cut their use of nitrate fertilizer and still increase crop yield, reducing the rate of nitrate runoff into groundwater.  H2H can be delivered directly through drip lines to the crop root zone. Drip line technology is over 90 percent efficient in [transporting water]. The alternative technology, flood irrigation, is less than 50 percent efficient. Now, farms have every incentive to convert to drip, since they can deliver water, fertilizer and organic material, all through their drip lines.

3p: What is the process to turn food waste into fertilizer? How is it similar or different from the processes undertaken at conventional commercial composting facilities?

DM: We use heat, enzymes and mechanical action to pull the nutrients from food – similar to human digestion. The product contains the same nutrients that enter your blood stream and sustain your body.  The process takes only three hours, including pasteurization, which is done for food safety. Composting takes three months. Over that time, microbes metabolize the nutrients in food and produce the aforementioned 70 percent conversion to carbon dioxide and methane emissions. Compost has many positive benefits, such as improving soil tilth and water-holding capacity. However, most of the nutrients are gone by the time the process is completed.

3p: Since food waste degrades in three months with traditional composting and three hours with your process, does your process require more energy and other resources than conventional composting?

DM: Food waste doesn’t degrade with our process. Enzymes cut long-chain molecules, like proteins, fats and carbohydrates, into short-chain molecules, like amino acids, fatty acids, and simple sugars – which are ubiquitously available to organisms that live in the soil. Our process requires electricity to run our equipment and warm water to heat our digester. It is not energy intensive, especially compared with the energy used to transport food waste to remote composting locations and the energy required to turn and aerate compost windrows.

3p: Where are you currently collecting food waste?

DM: Safeway, Save Mart, Nugget Markets, Whole Foods and Grocery Outlet [in the West Sacramento area].

3p: You’re currently collecting food waste for free, but plan to charge customers for that service in the future. How will you make your collection cost-competitive with garbage company rates?

DM: By charging less than the garbage companies charge. We can do this because our facilities are located near the supermarkets, compared to remotely located landfills, and because we produce a valuable finished product, so we do not just rely on “tip fees” charged to customers for our financial viability.

3p: How much food waste have you collected and converted into fertilizer since you started the company?

DM: We have been running a pilot plant in West Sacramento for nearly two years, where we have collected approximately 1,000 tons of food waste, which we have converted to 200,000 gallons of fertilizer – enough for 4,000 acres of sustainable farming for one year.

3p: Where do you sell H2H? Who are your biggest customers?

DM: Our target markets are California farms [that grow] almonds, strawberries, leafy greens/vegetables, tomatoes and wine grapes... We also expect to sell retail through a retail supplier of organic fertilizers.

3p: What benefits does the H2H fertilizer offer? What were the findings of the independent research trials on H2H conducted at the University of California, Davis?

DM: We have shown crop yield increases from 10 to 40 percent in our target crops. We have also shown significant increases in soil organic matter. Tests show that farmers can save money by using H2H and reduce their use of nitrate fertilizers and compost.

3p: Ninety percent of the food waste you collect is converted into fertilizer. What happens to the remaining 10 percent?

DM: It has tested very well as an organic pig feed. We have a balanced diet, which gets chewed, cooked, digested and pasteurized. The solids are easy for pigs to digest and popular with the pigs. Farmers get a higher conversion ratio – more pig and less manure – than with conventional feed.

3p: What are your company’s plans for the near future?

DM: We are about to announce an agreement in principle with a major supermarket: It will provide us with all the produce, meat, deli and bakery items it can’t sell or donate from all its stores. This will result in the construction of two CSS commercial-scale projects, starting later this year.

Image credit: Dan Morash

Passionate about both writing and sustainability, Alexis Petru is freelance journalist based in the San Francisco Bay Area whose work has appeared on Earth911, Huffington Post and Patch.com. Prior to working as a writer, she coordinated environmental programs for Bay Area cities and counties. Connect with Alexis on Twitter at @alexispetru

Alexis Petru headshotAlexis Petru

Passionate about both writing and sustainability, Alexis Petru is freelance journalist and communications consultant based in the San Francisco Bay Area whose work has appeared on Earth911, Huffington Post and Patch.com. Prior to working as a writer, she coordinated environmental programs for various Bay Area cities and counties for seven years. She has a degree in cultural anthropology from UC Berkeley.

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