Abstract
A rapid composting system was designed by ENGR215 Team 6 to find a better use for the green waste generated at the Humboldt Coastal Nature Center. Below is a detailed page on the process and cost of building the rapid compost system.
Problem Statement
The Friends of the Dunes invites volunteers every week to remove invasive plants in the Humboldt Coastal Nature Center. Each week, a volume of approximately 6’x6’x6’ of green waste is generated and shipped off the site to be taken care of miles away. In an effort to manage the waste on site, rather than shipping it, a rapid composting system was designed.
Criteria
Criteria | Weight | Constraint |
Cost | 4 | Less than $400 |
Ease of Use | 7 | Usable by untrained volunteers |
Educational Value | 6 | At least volunteers learn more about rapid compost systems |
Effectiveness | 9 | Must be able to process about 6’x6’x6’ of yard waste every 14-21 days |
Labor Intensity | 5 | Cannot require more maintenance than 1-2 times a week for 2-3 hours each day |
Availability of Amendments | 2 | Bought locally and cheaply |
Aesthetics | 6 | More professional than a tarp |
Safety | 10 | Non-toxic and will not spontaneously combust |
Durability | 8 | Stable for at least one year |
Description of Final Project
The rapid compost system is a three chamber structure insulated with beach grass bales. The structure is 4'x5'2"x15' and each chamber is 4'x4'x4'. The beach grass will provide insulation necessary to regulate the internal temperature of the system. To protect the bales from rain, a lime plaster will surround the structure. A corrugated metal roof will also add extra protection from rain.
Materials Cost
Materials | Unit Cost($) | Quantity | Subtotal($) | Tax($) | Total($) |
Our own materials | Cost | Number of units | C times Number of Units | taxes | time taxes |
Our own materials | 4.49 | 1 | 4.49 | 0.40 | 4.89 |
Our own material | 2.99 | 12 | 35.88 | 3.23 | 39.11 |
Total | $ Total |
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Design Cost
Figure 8: Time Invested
Test Results
Add some numbers and results of compost system.