The City of Phoenix Clean Palm Program Valorising a costly waste stream

A difficult to dispose material

Palm trees are a common species in tropical or desert landscapes and are often planted as ornamental features of cities. The leaves of these trees - called palm fronds - arise from either natural shedding or through trimming of palm trees. They are difficult to shred and grind into mulch, or process into compost due to their tough, fibrous nature. If handled improperly, there is also a risk of germination and growing of new palm trees through the process. As a consequence, palm frond material often ends up in landfill. In the city of Phoenix municipal waste stream alone, an estimated 34,000 tons are discarded in this way each year.

Waste = Food

The city of Phoenix has identified the diversion of palm frond waste as a way of moving closer to its goal of 40% diversion from landfill by 2020, and as an opportunity for innovation and to stimulate the local economy. To tackle this significant loss of biological nutrients, a Transforming Trash into Resources Request for Proposals was created.

Soon after, the city was approached by a company called Palm Silage, a California business that uses palm fronds, dates (that are rejected by the market), canola, wheat mids and rice bran to create highly nutritious food for horses, sheep, cows and other livestock.

Clean Palm Program

Palm Silage have now signed a 30-year operating and lease agreement with the city of Phoenix, where it will be working closely in a public-private collaboration. Palm Silage is creating a new business venture, which includes leasing 10 acres of land at the city of Phoenix's circular economy hub called the Resource Innovation Campus. The campus is the site for one of the city’s waste transfer and material recovery facilities, but also has some plots set aside for potential waste innovators.

In the first phase of the project Palm Silage will collect, dry and grind the palm fronds, which are then transported to different processing sites, mostly located in California. During the second phase, the company will transfer manufacturing of the end product to the Phoenix campus. The new manufacturing facility is expected to be ready in 2019.

After a thorough process of acquiring permits and setting up the land for processing palm fronds, the city started diverting palm fronds in December 2017 and Palm Silage began their initial on-site operations in April 2018.

To boost the volume of palm fronds collected, the city of Phoenix has started to market the project to all landscapers through the establishment of a Clean Palm Program. The program provides a discounted tipping fee at the transfer station to landscapers that deliver ‘clean’ palm loads that are free from other organics or solid waste materials.

Challenges

The main challenges associated with setting up the project related to the unusual feedstock, that meant it was difficult to find potential partners due to a lack of companies using palm fronds as ingredients for their products. Having identified Palm Silage, the city of Phoenix then relied on a strong collaboration with the company to market to the particularly niche and ‘early adopter’ audience.

The other challenge related to collecting environmental permits, which was a lengthy and at times a difficult process. The main hurdle to overcome was rezoning of land in order to free up a manufacturing site for the company. Palm Silage finally recently received their air quality permit in Spring 2018.

Benefits and Opportunities

The Clean Palm Program has the potential to reduce costs for the City of Phoenix, generate economic activity including jobs for its citizens and reduce pressure on natural resources.

Diverting 34,000 tons from the municipal landfill will mean a 3% waste diversion rate, which represents a significant contribution to the city's 2020 target. Financially, the city's municipality could save an estimated $170,000 annually in costs for hauling and landfilling palm fronds.

In terms of revenue and job creation, Palm Silage could create $10 million in sales and up to 12 jobs with their Phoenix business.

From an environmental perspective, the use of diverted palm fronds and unsellable dates reduces land use and water consumption needed to grow traditional feeds such as corn, soybean meal, and alfalfa hay. When compared to the resources needed to grow alfalfa, Palm Silage has projected, over the next five years, to save 27.2 billion gallons of water (over 40 thousand Olympic swimming pools) and 5,800 acres of farmland.