Composting Strategy in Mines Park

Acknowledgements

Project Advisor: Prof. Leslie Light

Technical Advisor: Dave Wann

Video

Elevator Pitch

We are a senior design team of 3 students working with the Lauren Poole of the School of Mines Sustainability Department to increase sustainable habitats on campus by introducing a compost system at Mines Park. Since the project began in August 2020, the team has engaged with residents, interfaced with the Mines Park greenhouse team, conducted surveys, implemented a pilot composting program, and introduced a full-fledged composting system. This unique design challenge not only encouraged team members to apply engineering skills that they had learned at Mines, but it also concentrated on utilizing public relations and marketing skills to increase resident involvement. Overall, the team hopes that the work completed this year will provide long-term benefits as Mines Park residents incorporate sustainability into their lives.

Design Approach

The team began the design process during the initial client meeting. We were given a composting life cycle assessment done for the Sustainable Engineering Design course the previous year for commercial composting equipment to study. Through studying this report, we concluded that commercial composting equipment— machines that automatically screen, shred, turn, and sift organic material— would not be applicable to the Mines Park community; plus, this method was also not possible with our given budget.

From the beginning, we were determined to make our project as immersive as possible. Stakeholder engagement has been very important to the team because without active participants, no composting would occur. The team researched apartment-friendly composting methods and found that tumblers, dumpsters, and bins were the most popular options. Additional analysis further revealed that tumblers and bins were the most cost-effective option.

Based on an interest survey, we found that roughly 20 percent of Mines Park residents were interested in participating. Using this information and comparing numbers with the composting model in Harmony Village, we were able to determine how many bins and tumblers we would need to serve the Mines Park community.

We sought to validate these numbers by implementing a pilot program, introducing a tumbler composting unit on-site; during the time of operation, measurements for volume, pH, temperature, and fertility (nitrogen, phosphorus, and potassium) were taken.

One final visit to Harmony Village and a conversation with our Technical Advisor revealed to the team that tumblers were not needed in order for the system to be successful, as the tumblers were only being used as collection devices and not for actual tumbling. With future operations in mind, we decided to remove the tumblers from the system in order to eliminate an extra step. Ultimately, we concluded that we would utilize metal composting bins that we would make design modifications to.

Design Solution

Many stakeholders expressed great concern over pest and bear populations in Golden being attracted to the compost. However, this should not be a problem as long as proper composting methods are followed by maintaining the proper green-to-brown ratio of organic material, in which there are 3 browns for every 1 green; with this ratio, undesirable odors will be prevented and the compost quality will be improved.

Green material is nitrogen-rich and will be donated from Mines Park residents in the form of food scraps. Brown material is rich in carbon and will be provided by the greenhouse in the form of their dried and dead plant material once they are fully operational; until then, the Mines Horticulturist will be providing the compost system with dry material. The rate of production will depend on the season but will take up to one month in the winter and as little as one week in the summer. The resulting soil will be given to the Mines Park greenhouse garden beds upon completion; meanwhile, it will be distributed throughout the campus beds.

Next Steps

This past year, the team concentrated on introducing composting to Mines Park to increase sustainability on campus. With these composting bins now implemented in the community, future steps will involve providing educational opportunities to those interested in composting. Not only will this continue to focus on resident engagement, but the future design team can focus on designing smart technology to incorporate into the composting system. This technology will automatically take measurements for parameters such as pH, temperature, and fertility (nitrogen, phosphorus, and potassium) to transform this composting system into a smart lab. From this, students and residents will have the opportunity to learn how various inputs interact in the composting process. 

Additionally, the Composting Strategy team will be merged with the Mines Park greenhouse team, which will allow for increased communication and collaboration. With this merge, the integration between composting and gardening will be more streamlined and new ideas will grow.

Meet the Team