Food Waste Composting for Urban Agriculture in Milwaukee
Food waste being composted. Photo:WUWM/S. Bence
Hypothetical task force Report prepared for the U.S. Department of Agriculture, Wisconsin Sustainable Agriculture Research and Education (SARE) Program
UW-Madison Task Force Members:
Kelsey Busch, Senior, Biology with Certificates in Global Health and Environmental Studies
Jessica Kanter, Senior, Biology
Communities worldwide have identified compost as means to combat global climate change and also to improve efficiency in waste management. The City of Milwaukee, via a 2 year USDA grant is working to implement such a program and has a pilot program underway. This policy analysis serves to inform city officials on ways in which to address implementing a city-wide program from the perspective of policy and legislation. Nearly 200 municipalities within the United States already have such composting programs and serve to inform those getting a later start in the game with both good and bad examples. San Francisco serves as the best example of a successful mandated city-wide composting program. Other cities such as Portland Oregon have implemented programs with the aid of extensive educational campaigns, necessary to inform the public on proper practices. Three sides identified as areas of policy focus are: 1. Policies regarding supply of, 2. Policies regarding production of, and 3. Policies regarding demand of composted organic waste. We approached this analysis from those three lenses, policy recommendations regarding them are provided.
It has been estimated that every year approximately 1/3 of all food produced for human consumption is wasted (FAO, 2013). Food waste accounts for about 21% of our overall waste, and in 2010 alone, each person sent 218.9 pounds of food to landfills for disposal (City of Milwaukee DPW). Not only does food waste constitute a missed opportunity to improve food security, but food also takes an enormous amount of natural resources and energy to create. U.S. food production alone accounts for 70% of global water use and 13.5% of global greenhouse gas emissions (City of Milwaukee DPW). In addition to heavy emissions from the production of food, organic matter decomposing in an anaerobic environment in a landfill produces a significant amount of methane and heavily contributes to global greenhouse gas emissions. The UN’s Food and Agriculture Organization (FAO) states that food waste around the world is the third largest source of global greenhouse gas emissions behind China and the USA (FAO, 2013)
|Figure 1:in 2013, 37 million tons of food waste was generated worldwide with only 5% being divertedSource: city.milwaukee.gov.|
The fact of the matter is, there is a huge potential for reducing these emissions by diverting food waste from landfills through composting. More than 95% of food waste that could be composted ends up in landfills (City of Milwaukee DPW). Wisconsin alone generates 500,000 tons of compostable material each year (Wisconsin DNR, 2017). Compost is very beneficial to soil health, as it helps to replenish soil with microorganisms and nutrients, and adds moisture content. Compost can sequester carbon and stabilize it in an organic form (Wisconsin DNR, 2017). It's contribution to soil fertility and plant growth reduces the need for synthetic fertilizers. This makes compost a marketable soil amendment that can be used in urban agriculture and green infrastructure (Schone & Allen, 2016).
Our project focuses on a 10-zip code area of Milwaukee, Wisconsin. As measured over a four-year period in 2008 – 2012, Milwaukee County has a poverty rate of 20.9% (Curtis et al., 2014). This is compared to Wisconsin’s overall poverty rate of 12.5%, and the United State’s overall poverty rate of 14.9%. Milwaukee is also within the congressional district of Wisconsin with the highest food hardship rate in the state. Food hardship is defined as the percentage of households that report not always having money to buy food to feed their families. Milwaukee’s district food hardship rate is 21.8% (Curtis et al., 2014). Therefore, demand exists for a community-based food value chain. Already, Milwaukee is home to more than 177 community gardens and 85% of Milwaukee is zoned for urban agriculture (Environmental Collaboration Office). There is great potential to improve local food security through urban gardening, in which compost will be a great resource to improve the health of degraded soil.
In an effort to divert food waste from landfills and improve soil health in Milwaukee for urban farming, the objective of our research was to assess Milwaukee’s policies and plans to describe current and potential supply, production, and demand for compost in Milwaukee. Based on our findings, we developed suggestions for the city of Milwaukee to successfully operate a large-scale food waste composting operation.
Supply of Compost
There are currently five active sites participating in composting in the surrounding Milwaukee area, including Blue Ribbon Organics, OCRF, Purple Cow Organics, Growing Power, and Kompost Kids. Paired with collectors such as Compost Crusaders and Sanimax for Blue Ribbon Organics specifically, and Compost Express collecting for community compost sites within gardens and schools, the workings for composting to start and be successful are already in place. Milwaukee has a current compost capacity of 20,150 cubic yards, while the compost output is estimated to be about 19,000 cubic yards. This small margin between the output and capacity thresholds, along with growing interest from the community, warrants an increase in suppliers to meet demands.
In order for Milwaukee to increase its capacity to supply compost, composting sites need to be more accessible geographically and economically. A sharing of knowledge on how to compost, where to compost, and why you should care about composting are all important dialogues to raise awareness and interest.
A 12-month pilot study program was conducted by Milwaukee’s Department of Public Works (DPW) that provided participants with a 64-gallon cart for composting at no cost and charged $12.75 per month as a service collection fee. Blue Ribbon Organics conducted processing services, while Compost Crusader provided collection services on a weekly basis from April to November, while biweekly collection occurred from December to March. This program was available for limited residents in the Bay View, East Side, Riverwest, and surrounding areas, including 28,000 eligible households. However, only 659 people filled out an interest form for the program, and 490 completed the authorization form. The pilot study also allowed for an online survey for those who chose not to participate to explain why. There were 128 people that filled out the survey and near 70% of the public listed the cost of the program as the main deterrent for participating. From this, half the people said they would be willing to pay about $5 per month, whereas the other half were not willing or able to pay for this service. The collection for this pilot study is about half way through, so revisiting the results to measure the progress and evaluate the success rate would be of interest (Organics Collection Pilot Study).
Alternatively, Compost Express prides itself as being “Greater Milwaukee’s first curbside compost pick up service” by providing compost collection for $8 per month. The company states that many people living in the suburbs were not composting due to lack of knowledge, space, or time, so by providing a bucket to fill with organic kitchen scraps and food waste and having collection right outside the person’s door, they hoped to incentivize composting. They have partnered with various schools, restaurants, landscape companies, nutritional and wellness programs, and gardens throughout the surrounding areas to supply compost to, with hopes to continuously increase expansion (Compost Express).
Policy Analysis of Compost Production
According to Milwaukee’s Solid Waste Regulations CH 79, composting means the controlled biological reduction of yard waste to humus (City of Milwaukee, 2015). However, the Wisconsin DNR website (Wisconsin DNR, 2017) states that compost is made from yard materials and other organics, like food scraps. Therefore, Milwaukee Solid Waste Regulations must be updated such that their definition of composting includes more than yard waste, and better matches with the Wisconsin DNR website.
Wisconsin State Legislature Chapter NR 502 includes a section outlining compost regulations for food residuals and source-separated compostable materials. There are currently no state regulations on small-scale, home composting operations of fewer than 50 cubic yards, besides needing to be done in a “nuisance-free and environmentally sound manner” (2017). Facilities for composting source-separated materials that exceed 50 cubic yards but do not exceed 5,000 cubic yards are exempt from environmental review and monitoring, additional operational standards, and construction documentation. They still must, however, receive an operating license from the DNR, follow minimum operational standards, and comply with locational criteria (NR 502.12 (3), 2017). Farm facilities accepting off-site material must limit the combined volume of off-site material accepted to 10,000 cubic yards unless they obtain a license, and they must fulfill all requirements for maintaining a composting facility in NR 502.12. The volume of food residual inputs may not exceed 25% of total combined volume of raw material inputs.
Currently, Milwaukee has three large-scale composting sites monitored by the DNR that accept food scraps. They include Blue Ribbon Organics, OCRF, and Purple Cow Organics, all of which produce compost and soil amendments for market sale (Allen, 2017). These sites primarily use turned windrow operations to create their compost, which involves stacking raw materials into long piles that are turned regularly to aerate. The Wisconsin DNR requires that windrows are designed and maintained to ensure adequate oxygen availability at all times to the process does not become anaerobic (NR 502.12.10(d)).
|:Windrows of composted material at Blue Ribbon Organics Farm in Caledonia, WI. Source: http://fox6now.com/2017/01/08/new-trash-trend-milwaukee-tests-organics-collection/compost5/#main.|
Because windrow composting typically requires lots of land, tends to produce leachate – a liquid released during composting that can contaminate local groundwater – and often has odors, these sites are subject to the DNR’s locational criteria (EPA, 2016). Section 502.12.8 states that compost facilities cannot be located in any of the following areas:
- Within a floodplain
- Within 5 feet of the seasonal high groundwater table
- Within 250 feet of any private water supply well, or within 1,200 feet of any public water supply well.
- Within 250 feet of any navigable river or stream.
- Within 1,000 feet of the nearest edge of the right-of-way of any state trunk highway, interstate or federal aid primary highway, or the boundary of any public park or state natural area unless the facility is screened by natural objects, plantings, fences or other appropriate means so that it is not visible from the highway, park or state natural area.
- Within 10,000 feet of any airport runway used or planned to be used by turbojet aircraft or within 5,000 feet of any airport runway used only by piston type aircraft
In addition to these restrictions:
- Facilities more than 50 cubic yards but less than 5,000 cubic yards may not be located within 250 feet of any navigable lake, pond, or flowage, or within 100 feet of land owned by a person other than the owner or operator of the facility.
- Facilities larger than 5,000 cubic yards may not be located within 500 feet of any navigable lake, pond, or flowage, or within 250 feet of land owned by a person other than the owner or operator of the facility.
Because of these criteria, all of these larger sites must be located outside the city of Milwaukee – Blue Ribbon Organics is 20 miles away in Caledonia, and Purple Cow Organics is nearly 90 miles away in Middleton. This creates the need for transportation with large trucks, contributing to greenhouse gas emissions and operation costs.
There are also operational standards in relation to food scrap composting that larger composting facilities must comply with (502.12.10 (b)). (1) Food residuals from canned, frozen, or preserved fruit or vegetables must be incorporated into windrows within 72 hours of receipt at the facility. (2) Food residuals not from canned, frozen, or preserved fruit or vegetables shall be incorporated into windrows on the same day they are received. (3) All food residuals shall be managed to prevent access by dogs and wild animals. Therefore, legislature takes precautions for reducing any odors or pests that might be associated with large-scale compost facilities.
Precautions are also taken to prevent harmful runoff and water pollution associated with composting. Design standards (502.12.11) for facilities over 50 cubic yards are as follows:
In addition to these licensed sites that process food scraps from Milwaukee, Growing Power and Kompost Kids are smaller, non-profit composting sites that are exempt from licensing (Allen, 2017). Growing Power uses vermicomposting in both bins and static piles windrows. This means that worms are used to breakdown the organic material and create worm castings. It takes worms about 12 weeks to process compost into worm castings, which have NPK ratios of a strong fertilizer, and the perfect pH for planting vegetables (Growing Power, n.d.). Annually, Growing Power composts over 40 million pounds of food waste from Lakefront Brewery, coffee grounds from local cafes, and produce from food banks. Kompost Kids has 11 community compost sites throughout Milwaukee, including community gardens that compost on-site, or drop off facilities that bring compostable material to bigger sites, such as Blue Ribbon Organics. Two of their compost drop off facilities include City of Milwaukee Drop Off Centers. While there is indication that these Drop Off Centers accept food scraps on Kompost Kids’ website, there is no indication on the City of Milwaukee’s website that food scraps are accepted.
|Will Allen (founder of Growing Power) preparing compost Source: http://www.growingpower.org/education/what-we-grow/compost/.|
Finally, finished compost may be designated and distributed as class A compost if it meets the following requirements (502.12.16):
- 1. Windrow method utilizing periodic aeration and mixing. A temperature of 55°C, or 131°F, shall be maintained in the windrow for at least fifteen days. The windrow shall be turned at least five times during the high-temperature period.
- 2. Mechanically aerated static pile method utilizing mechanically forced aeration. The temperature of the compost pile shall be maintained at a continuous minimum of 55°C, or 131°F, for at least three consecutive days.
- 3. In-vessel method utilizing mechanical mixing of compost under controlled conditions. The minimum retention time in the vessel shall be 72 hours with the temperature maintained at 55°C, or 131 °F.
Demand: Compost Markets and Applications
A marketable end product available to individuals, businesses, and government is the end goal of the composting process. A city the size of Milwaukee will inevitably produce more compost than could be used merely by the urban agriculture community, which is quite rich, there are around 180 community gardens in the city and large urban farms such as Growing Power and Cream City Farms. While the development of local agriculture is the primary focus of this grant, it is one of many markets for the sale of compost, all of which must be considered to ensure the economic success of this program.
Organic waste is processed by private companies and these companies must remain competitive for a city wide program to be effective in achieving its goals. One way this can be achieved is the potentially enormous demand the Milwaukee Metropolitan Sewerage District has for compost. The Green Vision plan proposed by MMSD intends to achieve 740 million gallons of stormwater runoff capture by 2035 (MMSD, 2013). One of their proposed mechanisms is soil amendments: a process which increased the capture rate of soils by adding compost. This is one of the most cost effective, and logistically manageable routes to achieving their goals and it is calculated that $46 million in soil amendments could achieve 22% of the storm water capture as set by the MMSD Green Vision plan (MMSD, 2013).
The potential for long term, steady demand, by MMSD has a direct impact on questions regarding the economic viability of individuals opening processing centers across the city in order to receive and process the supply of organic waste collected across the city. Additionally, expanding urban agriculture in the city would require a steady source of compost during the growing season. Addition of compost as soil amendments on degraded land makes possible the cultivation of foods on otherwise undesirable land as well as Brownfields. Most of the city, 55%, contains low-infiltration soil types (MMSD, 2013). Over the course of the next 20 years there is the potential to not only improve storm water capture but also to cement the viability of a municipal compost program.
Post-construction soil amendments are also a potentially large market. Requiring construction companies to attain a certain amount of organic material on recently disturbed grounds would improve storm water capture on this otherwise poorly infiltrated land. The production of sod and turf also benefits from the application of high organic matter compost. Urban silviculture requires amendments in the same manner (Platt et al., 2014). Landscape restoration and carbon sequestration can be improved and promoted by the addition of compost. There are no shortage of non-agricultural uses for compost, concern over demand and the economic viability of city-wide programs can be ameliorated via education on the many uses of compost and addressing the economic, environmental and social benefits derived from converting otherwise landfilled waste into a rich organic humus.
Case Study: San Francisco's Mandatory Recycling and Composting Ordinance
As previously discussed, organic or compostable waste that is buried in anaerobic conditions of landfills creates methane gas – a greenhouse gas 21 times more potent than carbon dioxide in the atmosphere. Therefore, 20% of San Francisco’s plan to reduce climate-changing emissions comes from diverting additional solid waste from landfills (Mandatory Recycling and Composting, 2009, p.2). The city set a goal of achieving 75% diversion from landfills by 2010 and zero waste by 2020 (SF Environment, 2016).
San Francisco has an agreement with the Altamont Landfill in Alameda County for waste disposal of up to 15 million tons. In 2007, the rate at which trash was being disposed of at the Altamont Landfill only left the city of San Francisco with 3 million tons of capacity, out of an initial 15 million (Mandatory Recycling and Composting, 2009, p.3). Continuing at this rate, the city would have only had five more years to use this landfill before they would have to look elsewhere for disposal. Knowing a new landfill contract would increase disposal costs, San Francisco made it a goal to increase the diversion of compostable material to extend the life of the landfill contract.
Thus, in 2009, an ordinance amending the San Francisco Environment Code added Chapter 19, entitled “Mandatory Recycling and Composting Ordinance”. This ordinance requires everyone in San Francisco to separate their refuse into recyclables, compostables, and landfill trash. Sec 1903 of the ordinance reads: “all persons in San Francisco must source separate their refuse into recyclables, compostables, and trash, and place each type of refuse in a separate container designated for disposal of that type of refuse. No person may mix recyclables, compostables, or trash or deposit refuse of one type in a collection container designated for another type of refuse”.
|Residential San Francisco streets lined with three color-coded bins: blue for recycling, green for compost, black for trash Source: http:https://sfenvironment.org/zero-waste-in-sf.|
Owners or managers of multifamily and commercial properties must provide “Adequate Refuse Collection Service”, meaning they must provide color-coded, labeled bins (blue for recycling, green for compost, and black for trash), and be serviced by a collector for recyclables, compostables, and trash. Owners or managers are also responsible for providing information and training for tenants, employees, contractors, and janitors on how to source separate recyclables, compostables, and trash (§§ 19 - 1904). Re-education must happen at least once a year.
Food vendors also must provide adequate refuse collection service, appropriate bins, and education. If food vendors provide disposable food ware, they must have at least one container for recyclables, compostables, and trash placed near a main exit (§§ 19 - 1905). This rule has compelled many fast food restaurants to distribute food in compostable containers, so customers can compost their residual food directly in its container.
If collectors find incorrect material in certain containers, they must leave a tag on the container, identifying the incorrect materials. If it happens again, they must leave a tag and send a written notice. If it continues happening, the collector may refuse to empty the container (§§ 19 - 1906). The Director of the Department of Public Health and the Director of Public Works may impose administrative fines for violations that fall under each of their jurisdiction. These fines are up to $100 for small businesses and single occupancy homes, and up to $1,000 for large businesses or multi-unit buildings (§§ 19 – 1908).
The Ordinance was passed in June 2009, and organics collection began in October. The San Francisco Department of Environment emphasized making the effort to educate first, and they were not allowed to apply fines for noncompliance until 2011 (Platt, 2016). Due to the choices for both a leniency period and to conduct outreach tailored to local conditions, residents have had time to adjust to the policy and adopt the habit. If, after the process of education and warnings, noncompliant parties continue to improperly source separate materials, fines can be applied. As of 2016, fines remain at their 2009 level.
Residential property owners receive blue recycling and green compositing carts free with their trash service, and the recycling and composting service is provided with this trash service at a flat rate. However, they can reduce the size of their landfill bin to save money. Apartments and businesses pay a reduced rate for recycling and composting services, and can reduce their landfill service costs if they recycle and compost everything correctly, by reducing the size of their bin and the frequency of their pick-up (SF Environment, 2016).
Recology is the refuse collection company in San Francisco. They are a private, 100% employee owned resource recovery company, with pick-up service running from 1-7 days a week. Compostables are brought to Jepson Prairie Organics, located east of Vacaville, CA - 55 miles away from San Francisco. This is one of the largest food scrap composting operations in the nation, processing around 100,000 tons of organic material (Recology Organics, n.d.). Food scraps and yard trimmings are fed into a grinder, mixed to attain a an ideal ratio for decomposition, and placed into an Engineered Compost System (ECS), developed specifically for Jepson’s specifications. Compost remains in the ECS for 30-45 days, then placed into windrows for curing (Recology Organics, n.d.). On top of pick-up service, Recology provides educational programs to the communities they serve.
Based on the success in San Francisco, Milwaukee can learn that convenience and education are incredibly important in terms of starting an effective composting collection service. The color-coded bins make it easier for people to make a conscious choice about where to put their waste. They also have spent a lot of time and money on education, and they offer a lot of useful information on their website. The SF Zero Waste program is fully funded from refuse rates, which are about $34 per residence per month. The cost of collection is entirely offset by selling recyclables and compost to facilities that repurpose and sell these materials back to the community. The fact that residents can receive a discount on their refuse rates by switching to a smaller back landfill bin is a big incentive for people to comply. Finally, the risk of receiving fines for non-compliance is another incentive for people to educate themselves about how to properly sort their compost.
Summary of Recommendations
Supply: The following are recommendations addressing policies to support the supply of compost.
- Increase funding to educate people through school systems, community programs, etc. on the importance of composting and how to participate to gain popularity.
- Incentivize companies or programs such as community gardens, restaurants, schools, landscape/building businesses, etc. to participate in the supply and demand chain for composting.
- Allow for subsidies of compost collection companies to either lower their prices or provide free services to people that cannot afford monthly service fees.
- Require city garbage collection or waste removal services to offer composting bins and services for everyone to increase willingness to participate.
- Introduce tax breaks or greenhouse gas emission taxes of farms to incentivize using higher soil quality through composting.
Production: The following are recommendations addressing policies to support the production of compost.
- Rewrite city Solid Waste Ordinances to include food waste as compostable material. Remove food waste from the city definition of garbage.
- Update the City of Milwaukee’s website so reflect current information on where food scraps may be composted. Kompost Kids lists drop off sites that accept food scraps, however, the city does not include those sites as eligible.
- Incentivize large processors of organic materials, ie. breweries, food processors, to utilize on-site in-vessel composting systems.
- Retrofit current city composting sites to be able to accept food waste.
- Investigate how the city may benefit from the Recology/San Francisco business/city model. Large centralized collection of organic waste and food scraps which is distributed from that location to smaller operations. Potential to reduce traffic of city food waste collectors and provide easy access to smaller operations from distribution center.
Demand: The following are recommendations addressing policies to support the consumption of locally produced compost.
- Prioritize purchase of compost for the purposes of urban agriculture including urban farms, community gardens, by offering carbon credits in the form of reduced pricing.
- All projects requiring soil amendments and native landscaping regarding Green Vision 2035 should prioritize sourcing from compost producers processing municipal organic waste.
- City projects requiring soil remediation due to disturbance or restoration such as parks, green infrastructure, urban silviculture, or any such city project requiring soil, should source compost from producers receiving municipal organic waste.
- Provide 5 gallons of compost annually to city residents who contribute food scraps to local composters.
- Require post-construction soil amendments on disturbed land to be comprised of predetermined amount of organic waste.
- Educate citizens on the benefits of incorporating compost into sod and turf applications, as well as in their own gardens and yards.>
Our research is to be incorporated into a larger plan that pulls together research from multiple sectors. This includes farmer surveys, on-farm compost trials, and engineers developing new compost systems. Therefore, our contribution was one piece of a larger project attempting to improve the supply of commercial compost in Milwaukee by diverting food waste from landfills. In terms of our policy analysis, future steps would include conducting more interviews with policy makers, food waste haulers, and composters for further suggestions. In addition, we have compiled the regulations of where compost sites can be located, so it would be relevant to look at how Milwaukee is zoned for compost sites closer to the city.
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