Waste Composition Studies Understanding the Results. Ted Siegler DSM Environmental Services, Inc. Windsor, VT

Transcription

1 Waste Composition Studies Understanding the Results Ted Siegler DSM Environmental Services, Inc. Windsor, VT

2 Overview 6/14/2016 DSM Environmental Services, Inc. 2

3 Two Ways to Assess What is in the Waste Stream Top down approach US EPA mass balance of production and use Bottom up approach State and regional waste characterization studies There has been a fair amount of discussion about the accuracy of the EPA approach, but very little about the alternative of waste characterization studies This presentation attempts to provide you with a fundamental understanding of how waste characterization studies are done, their benefits and limitations, and how we should interpret the results 6/14/2016 DSM Environmental Services, Inc. 3

4 Disclaimer I am going to present the results of waste characterization studies carried out for the Connecticut DEEP, the Rhode Island Resource Recovery Corporation, and the Delaware Solid Waste Authority While the data are publically available, none of these entities have reviewed this presentation the opinions and conclusion are those of DSM only All of these studies have been carried out by a three firm team: DSM Environmental Services, Inc. MidAtlantic Solid Waste Consultants Cascadia Consulting Group In all but one of these, DSM has been the Project Manager, but the overall work is the result of the three firms working together 6/14/2016 DSM Environmental Services, Inc. 4

5 Typically What One Thinks of About Waste Characterizations Studies Hand Sorting 6/14/2016 DSM Environmental Services, Inc. 5

6 But There is Really A Lot More To It You can only hand sort mixed solid waste but landfills receive lots of other wastes which are not well understood and difficult to sort Bulky wastes C&D wastes Sludge and street sweepings MRF residue Industrial by-products 6/14/2016 DSM Environmental Services, Inc. 6

7 The First Mistake Assuming that you can apply the results of hand sorted waste to the total landfilled in a state Mixed solid waste represents only 49 percent of waste disposed at the Rhode Island Resource Recovery Landfill 6/14/2016 DSM Environmental Services, Inc. 7

8 Why Is This Important It is often stated that organics are 40 percent of what is disposed in landfills or WTE facilities This is accurate for mixed solid waste residential and commercial wastes However only 49% of disposal at the RIRRC Landfill in 2015 was mixed solid waste Which means if you multiply 40% by 100% you will be off by 50%! The reality is that while 40% of MSW disposed in RI is organic, only 20% of what was disposed at the landfill was organic waste The same can be applied to data on quantities of recyclables 6/14/2016 DSM Environmental Services, Inc. 8

9 Residential and Commercial Wastes Are Not The Same Waste characterization studies often report the composition of residential waste and commercial waste using the same hand sort data and material types That is accurate as long as one understands that residential waste is relatively homogeneous while commercial waste is not That means that while the analysis of the commercial waste may be statistically accurate the data reflect huge swings in the types of waste being delivered from commercial sources. 6/14/2016 DSM Environmental Services, Inc. 9

10 Comparison of Delaware 2015 First Season State-Wide Results Residential Commercial (ICI) 6/14/2016 DSM Environmental Services, Inc. 10

11 Variations Between Samples is Not The Same As Variations Between Generators There can obviously be a significant amount of variation among samples when you are sorting pound samples out of a packer truck that might contain 8 10 tons That variation is expressed in the confidence intervals presented with the results However, that is not the same as variations between generators As the following slides will illustrate, there is a huge difference between a grocery store and an office building for example 6/14/2016 DSM Environmental Services, Inc. 11

12 Comparison, Large Retail and Grocery Source: Delaware Solid Waste Authority, Fall 2015 Sort Large Retail Grocery 6/14/2016 DSM Environmental Services, Inc. 12

13 Why Is This Important? While it is nice to know that commercial waste delivered to a landfill is comprised of 10 percent corrugated and 20 percent food waste, it is more important to know who is generating it, and what management opportunities exist to divert it. Who would think that convenience stores generate more food waste than a grocery store? Unless you take the time to identify specific generator categories and sort that waste, you can t make reasonable decisions about who to target for waste diversion activities. 6/14/2016 DSM Environmental Services, Inc. 13

14 Comparison, Grocery and Convenience Stores Grocery Convenience Store 6/14/2016 DSM Environmental Services, Inc. 14

15 Down and Dirty How Do We Carry Out A Waste Characterization Study 6/14/2016 DSM Environmental Services, Inc. 15

16 Key Components Study Design Materials Categories Truck counts, by delivery type Hand sorting of representative samples of residential and ICI waste Visual analysis of bulky and C&D waste streams Turning percentages into tons 6/14/2016 DSM Environmental Services, Inc. 16

17 Study Design Establish your goals What types of waste are you interested in learning about Residential Single Family, Multi-Family ICI Waste In aggregate or by generator type Note that multi-family and some condominium and mobile home park waste is defined as commercial waste by most haulers and will come in mixed with business waste C&D Wastes Bulky Wastes 6/14/2016 DSM Environmental Services, Inc. 17

18 Decide and Define Your Materials Categories 6/14/2016 DSM Environmental Services, Inc. 18

19 Truck Counts It might be surprising, but it is often not known what percent of waste entering a facility is residential and what percent is commercial Since we typically want to sample residential waste separate from commercial waste we need to figure this out One way to accomplish this is to do surveys of truck drivers by truck type Rear loading packer trucks Front loading packers Roll-offs In each case asking the driver whether his/her load is residential or commercial and if there is a mix what the percent is The survey data can then be used to allocate tonnage delivered by truck type 6/14/2016 DSM Environmental Services, Inc. 19

20 Selecting Trucks for Sampling The key to statistically valid sample data is random selection of trucks to take samples from Followed by random sampling of the load We typically can sort approximately 10 samples per day If we want 5 residential and there are 50 residential trucks expected We take every 10 th truck Once the waste has been dumped we employ a random sampling procedure to acquire the pound sample Clock face Grid with random number generator 6/14/2016 DSM Environmental Services, Inc. 20

21 Self Haul Loads The methodology for sampling remains the same if we are attempting to sort material brought in by residents and small businesses We can get a rough count of the number of users during a day from the facility operator Decide how many samples we can sort in a day Collect all of the waste from each Nth vehicle 6/14/2016 DSM Environmental Services, Inc. 21

22 Hand Sorting Rhode Island Resource Recovery 6/14/2016 DSM Environmental Services, Inc. 22

23 Hand Sorting Barnstable, MA Transfer Station 6/14/2016 DSM Environmental Services, Inc. 23

24 Hand Sorting Issues Very wet loads can distort the quantities of paper, especially Decision has to be made as to whether to adjust weights to account for moisture Minimum size We typically sort on a screen with everything falling through the screen defined as other or organics This can include a fair amount of broken glass, shredded paper, small pieces of plastics Food or beverages in container Need to empty liquids from PET containers especially or weights are distorted Food a decision needs to be made on whether to scrape out food or leave it in, and into what category to sort containers filled with food This can distort the food or organics data because this food in most cases would not be recovered under any system Hazardous wastes We see very little hazardous waste, and e-waste 6/14/2016 DSM Environmental Services, Inc. 24

25 C&D and Bulky Wastes Can not be hand sorted or at least a large enough sample could not be sorted to be meaningful We use visual analysis method Record volume by major material And then volume of each sub-material in the major materials Converted to pounds/tons based on density by material type, confirmed by volume and weight of the load 6/14/2016 DSM Environmental Services, Inc. 25

26 C&D and Bulky Waste Visuals Bulky Waste Load C&D Load 6/14/2016 DSM Environmental Services, Inc. 26

27 Reporting the Data By Percent 6/14/2016 DSM Environmental Services, Inc. 27

28 By Tons Requires Allocation of Tons By Type of Waste/Generator Source, Delaware Solid Waste Authority 2007 Waste Composition Study 6/14/2016 DSM Environmental Services, Inc. 28

29 Residential Tons Disposed, Delaware c /14/2016 DSM Environmental Services, Inc. 29

30 Applying the Data Rhode Island, /14/2016 DSM Environmental Services, Inc. 30

31 Composition of Combined Residential and ICI Waste, Rhode Island, 2015 Material Category Management Category 6/14/2016 DSM Environmental Services, Inc. 31

32 Composition of Bulky Waste Loads Rhode Island, 2015 Material Category Management Category 6/14/2016 DSM Environmental Services, Inc. 32

33 Top Ten Materials, Bulky Waste Rhode Island, /14/2016 DSM Environmental Services, Inc. 33

34 Composition of Construction & Demolition Waste Delaware Solid Waste Authority, Summer /14/2016 DSM Environmental Services, Inc. 34

35 Detailed Composition, Delaware C&D 6/14/2016 DSM Environmental Services, Inc. 35

36 What About the Composition of Recyclables You can sort materials collected for recycling using the same methodology But the materials don t necessarily sample as well Light weight materials tend to tumble off the pile Heavier, broken glass sinks to the bottom of the pile So collecting representative samples is more difficult, introducing more error to the results 6/14/2016 DSM Environmental Services, Inc. 36

37 Composition, Single Stream Recyclables Connecticut DEEP, /14/2016 DSM Environmental Services, Inc. 37

38 Detailed Composition, CT Single Stream Materials 6/14/2016 DSM Environmental Services, Inc. 38

39 Caution You Cannot Determine Recycling Rates By Combining Recycling and Waste Data Almost every state has in-flows and out-flows of waste and recycling As such you can not add up the total quantity of material recycled in the state from a waste composition study and compare it to the amount of material disposed in the state Although plenty of people do! In almost every case it is in fact a best estimate created by trying to adjust for imports and exports Rhode Island comes close for municipal waste because there is a single landfill and a single MRF and all municipal waste and recycling must be delivered to these facilities Delaware is even better because virtually all of the municipal and commercial waste is disposed at DSWA facilities And there is mandatory reporting of all recycling activity in the state 6/14/2016 DSM Environmental Services, Inc. 39

40 Recovery Rates An Alternative Definition of Recovery Rate Can be calculated for a single recyclable material, or for all recyclable materials accepted in a program Primarily used to assess the performance of residential programs, but can be used to evaluate commercial or transfer based recycling programs as well For a single material the quantity of newspaper delivered to the Transfer Station for recycling divided by the quantity of newspaper delivered for recycling plus the quantity of newspaper thrown away with the trash Summing the recovery rate for each recyclable material accepted at the Transfer Station/Recycling Drop-Off results in an overall recovery rate for all recyclable materials at that Transfer Station/Recycling Drop-Off. 6/14/2016 DSM Environmental Services, Inc. 40

41 Benefits of Recovery Rate Analysis Is independent of the numerator and denominator of recycling rates Simply measures what percent of the materials you are asking residents to recycle are being recycled as opposed to being thrown away Can be significantly less costly than a waste characterization study You are only sorting what you are targeting in your programs Can be carried out by transfer station staff, by other municipal employees, or contract employees Establishes a baseline to measure how well users of the transfer station are doing, and where improvements can be made, or communications improved Identifies contamination issues that can be addressed in the future 6/14/2016 DSM Environmental Services, Inc. 41

42 Example of Recovery Rate Analysis Recovery Rate, Monday, July 21, Worcester Categories Recycling Trash Total Rec Rate (lbs) (lbs) (lbs) (%) Steel Cans % AL Deposit % AL Expanded % AL Other % PET Deposit % PET Exanded % PET food/other % PET Cups % HDPE Bottles % HDPE Expanded % Plastic Tubs/Lids % Glass Deposit % Glass Expanded % All Other Glass Bottles % Mixed Paper Recyclables % Total % 6/14/2016 DSM Environmental Services, Inc. 42

43 Using Recovery Rate Data to Calculate Recycling Rates Simple add in the trash that you separated and you have the recycling rate Recyclables / Recyclables + Trash Maximum achievable recycling rate Recyclables set out for recycling + recyclables in trash / all recyclables and trash 6/14/2016 DSM Environmental Services, Inc. 43

44 Questions Ted Siegler DSM Environmental Services, Inc. P.O. Box 2 Windsor, VT (802) ted@dsmenvironmental.com 6/14/2016 DSM Environmental Services, Inc. 44