2018 Solid Waste Design Competition Problem Statement Q&A

The County ordinance states yard waste is to be delivered to a facility that recycles 95% of the materials delivered to the facility. Despite the ordinance requirements, the County is currently only achieving 80% by weight recycling rate in 2017. The table below summarizes the Yard Waste tonnage values for years 2015–2017 provided within the spreadsheet. There are no changes to the original spreadsheet data; however, a line for landscaping/agriculture uses has been added to the table below for clarity.

Please note, different models may treat yard waste/mulch used as cover or landfilled within LFGTE Systems differently.

Please disregard the last sentence within the PDF: “Historically, ALL of the mulched materials has been utilized for landfill cover or landfilled”.

In the weight-based model Honky Tonk County currently uses, yard waste is counted as recycled if it is diverted from direct disposal (landfilling). Honky Tonk’s recycled yard waste is currently mulched and used for landscaping/agriculture uses, used as daily landfill cover, or landfilled with a LFGTE system.

Please note, each model will determine recycling differently based on what happens to the material. This will be a major factor when determining the scenarios for improving the County's system and which recycling model to recommend. For yard waste, some models may not count mulch placed in landfills as recycled. Mulched yard waste is not a compost but there is a decomposition process and could have a colorant process, therefore appropriate assumptions should be made.

One of the challenges within each model is the classification of waste as well as how recycling, diversion, and processing are considered in the recycling rate calculation.

Honky Tonk County’s recycled food values are from non-profit programs to redistribute food and from commercial sector composting programs within the food industry that are not managed by the County. This is food that would have otherwise been thrown away. For the purpose of modeling the existing system, please assume 50% of the food waste currently recycled is sent to non-profit programs to redistribute food and the other 50% is being composted.

Similar to the response for Question 2, some models may not count food redistribution activities as recycling.

Each team will need to make appropriate assumptions and decide how to classify waste within the various models and which materials to leave out based on the model methodologies. Note that realistic and innovative assumptions in the scoring criteria of Design Report carry 20% points (refer to Judging form of previously published problem statement).

All the formulas and calculation checks for the “2017 Disposed Waste” tab are within the excel file so students should be able to follow the logic. The carpet and textile tonnages (12,712 and 18,786) within the “2017 Disposed Waste” tab are added together to yield the textile value (31,498) in the “Historical Tonnage Data” tab.

The values in question are the “% Landfilled per Generator”, which add up to 100% for each generator: single-family residential, multi-family residential and commercial. These values (in row 123 of the excel file) should not be added up across the three generator types. The line item below these values in the excel file (row 124) calculates the “% of Total Landfilled” which can be added: Single-Family Residential is 3.3%, Multi-Family Residential is 1.1% and Commercial is 1.2% = 5.6%. The value of 5.6% in Cell F123 is simply a reference to the value in Cell F124 as indicated in the cell’s formula. This applies to every material group within the “2017 Disposed Waste” tab.

Please use the author-date system.

Generally, recycling rates are calculated as follows: Total Recycled / (Total Recycled + Total Disposed) = Percent Recycling Rate. The WARM model coverts the material tonnage into a GHG equivalent which will in turn yields a different Percent Recycling Rate than a model based on tonnage, volume, etc. The method on how to use the WARM model to yield results is entirely up to each team.

Recycling rates are to be converted into a percentage form so that a side by side comparison of each model can be conducted.

The recycling credit material quantities in rows 66 through 73 of the sheet titled “Historical Tonnage Data” are included in the quantities in rows 5 through 23. For example, the tonnage of processed tires used in engineering applications is included in the tonnage of recycled tires, and the tonnage of yard trash used as landfill cover or within a LFGTE System is included in the tonnage of recycled yard trash.

The MSW DST is a lifecycle analysis tool, which was developed by a USA based non-profit organization with partners that are primarily in the USA. If the team can provide a non-USA governmental entity that uses this model to determine its recycling rate, then the model can be counted as international; otherwise, it could be counted as the “model of your choosing”.

As stated in Section 6 of the Problem Statement and Protocol Document, the maximum number of pages is limited to 30 pages. Tables and figures can be provided as attachments in addition to the 30-page limit. There is no page limit on the attachments (tables and figures).

There is no page limit on attachments/appendices.

Either is acceptable. The projections are used in the fourth task and therefore it is up to the team to determine the level of detail needed to perform the scenario analysis.