Castro Valley Intern’s Adopt 3 Bins Project Conclusion

After a year of at home waste audits and sorting through 3 bin data, Earth Team Castro Valley's project determined how effective sorting instructions and education is in reducing our waste stream contamination and encouraging proper sorting.

Throughout the semester, Earth Team Castro Valley has been hard at work conducting at home waste audits and tracking data on the 3 bin system. This project determined how effective sorting instructions and education is in reducing our waste stream contamination and encouraging proper sorting. With plans to roll out the program for the public come fall 2022, Castro Valley High interns led the pilot program by making adjustments to material and organizing data to measure the project’s success. 

Designing a Welcome Packet for Project Participants

Interns began learning about waste sorting in Alameda County and the global recycling system at the beginning of the semester. CVH interns then took the information they learned and created a welcome packet. The welcome packet was designed for folks who sign up to participate in the Adopt 3 Bins program in Alameda County to clarify the sorting and recycling process. CVH interns included an introduction with contact information, basic recycling instructions, useful tips, as well as in depth information on what happens to our recycling bins after they have left the curb. 

The Welcome Packet was designed to clarify sorting instructions and explain the Adopt 3 Bins Program along with what is asked from participants. These 4 pages are examples from the 9 page full welcome packet

Creating a System for Consistent Data Collection

In addition to the welcome packet, interns brainstormed ways to collect data from the at home waste audits. Interns asked themselves critical thinking questions such as, “what data do we want to collect that will support answering our sorting questions?” and “how do we make data collection from all participants consistent across the board?”. Through trial and error, CVH Earth Team interns designed the Earth Team Biweekly Waste Audit: a google form to collect data from participating community members. Participants record data on their 3 bins biweekly for Earth Team to then analyze and track contamination levels. The final google form includes 3 parts with questions regarding each bin- recycling, compost, and trash. 

In part one of the waste audit google form, the question asks participants to audit their at home recycling bin. The questions asks for material type, a description of the item, the quantity, as well as the type and quantity of the contamination found. 

Participants were asked in part two to check their compost for contamination, which is waste that is not placed in the correct bin. The section also asks participants how much they used their compost bin by estimating their filled volume percentage.

In the third and final part of the google form, participants checked their trash bin for contamination that could have been otherwise composted or recycled, as well as what the most common materiel was found in their trash bin.

Each question on the google form was carefully thought out and tested by Castro Valley High Earth Team interns. After conducting five biweekly waste audits at their own homes and tweaking their google form questions along the way, interns finalized their google form questionnaire.

Interpreting the Data and Examining the Results

For each question on the waste audit google form, CVH Earth Team Interns created a graphic representing the results from the data. Interns concluded that throughout their project, contamination in the recycling and trash bin decreased during the ten week testing period (5 biweekly waste audits). Interns noticed an increase in compostable materials being properly sorted in the compost bin rather than thrown in the trash bin. Ultimately, CVH interns concluded that the results from their at home waste audit trial had shown a positive reduction in contamination and an increase in proper sorting! Concluding their project, interns wrote that “by launching this program [to the public] next school year, we expect to see an improvement in waste sorting in our community” -Castro Valley High Earth Team.

Waste Audit Data Visuals

Each circular ring represents a response on the google form to the corresponding fill percentage. Comparing week 1 to week 5: week 1 saw an overall low volume percentage of the compost bin being filled, whereas the progression to week 5 shows more participants filling up the volume of their compost bin
Each leaf represents a yes or no response to having found contamination in the trash. Leafs growing up represent no contamination found. Leafs growing down represent yes contamination was found. In a linear progression, week 2 shows most responses as finding contamination, but by week 5, the leafs are growing up, showing more people were finding no contamination in their trash bin
Waste audit data found that the most common material type found in the trash bin was plastic

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