Auburn  University  Organic  Waste  Utilization    

Final  Report  Sustainability  Capstone  

SUST  5000    

Contributions  to  all  sections  by:  Paul  Drenning  Simon  Gregg  Cameron  Cobb  

     

 

 

 

 

 

 

 

Executive  Summary      

Colleges  and  universities  around  the  country  are  modernizing  their  waste  management  programs.  Many  of  these  changes  incorporate  sustainability  to  treat  waste  not  as  something  to  simply  dispose  of,  but  to  utilize.  This  goal  can  be  achieved  through  composting  or  anaerobic  digestion.  Universities  create  large  quantities  of  waste  in  many  different  forms,  including:  municipal  solid  waste  (organic  waste),  yard  waste  from  landscaping,  animal  manure  and  bedding,  food  waste,  and  others.  Much  of  this  waste  can  be  used  as  a  feedstock  in  either  composting  or  anaerobic  digestion  to  create  useful  end  products.  Traditionally,  almost  all  of  this  waste  is  landfilled  generating  a  large  carbon  footprint  with  the  emission  of  harmful  greenhouse  gases  released  during  decomposition.  Approaching  waste  management  from  a  different  perspective  centered  on  environmental  responsibility,  this  waste  can  be  diverted  from  landfills  and  allowed  to  decompose  in  a  controlled  setting.  

Auburn  University  is  in  a  unique  position  to  take  advantage  of  new  technologies  and  management  strategies  to  improve  the  current  waste  management  system.  Facilities  Management  and  the  Waste  Reduction  and  Recycling  Department  have  already  made  great  strides  towards  starting  and  expanding  a  thriving  recycling  program.  Initial  studies  preformed  in  2013  suggest  that  approximately  1,000  tons  of  organic  matter  is  generated  annually  by  Auburn  University  campus  operations.  To  take  it  a  step  further,  some  of  the  same  equipment  and  logistical  planning  force  can  be  applied  to  capture  waste  produced  in  dining  halls,  landscaping,  and  many  other  locations  as  feedstock  for  composting  or  anaerobic  digestion.  Several  universities  have  already  proven  that  such  systems  can  function  effectively  on  a  college  campus.  When  planned  thoroughly  and  tested,  the  programs  that  these  universities  have  started  have  been  instrumental  in  reducing  and  virtually  eliminating  the  large  footprint  due  to  food  and  yard  waste.  

Compost  processing  systems  can  range  from  the  simple  static  pile  to  the  high-‐tech  in-‐vessel  system.  Some  universities  use  a  combination  of  different  systems  to  completely  decompose  the  waste  material  into  a  usable  product,  compost.  The  most  common  processing  system  is  the  windrow.  Windrows  are  essentially  extended  piles  covering  many  acres  that  can  handle  large  volumes  of  feedstock.  Equipment  is  necessary  to  start  this  process,  though  some  require  more  investment  than  others.  On  the  higher  end  of  investment  is  the  in-‐vessel  system.  In-‐vessel  processing  systems  can  be  as  simple  as  a  modified  dumpster  to  provide  aeration,  or  as  advanced  as  a  continuous-‐flow,  vertical  composting  tower.  It  is  recommended  to  start  small,  but  think  big.  Once  the  composting  program  has  shown  its  efficacy  and  the  system  is  fully  comprehended,  the  potential  for  expansion  is  limitless.  

Additional  technology  allows  for  the  conversion  of  organic  matter  to  electricity.  Anaerobic  digestion  is  essentially  composting  without  the  availability  of  free  oxygen.  Microorganisms  in  the  four-‐step  decomposition  process  break  down  organic  matter  from  large  molecules  to  volatile  fatty  acids  and  finally  methane  and  carbon  dioxide  or  biogas,  a  flammable  gas.  Anaerobic  digestion  is  a  complex  process  and  there  are  many  design  and  operational  parameters  that  must  be  considered.  Initial  estimations  for  the  available  energy  from  1,000  tons  annually  of  current  known  feedstock  suggest  that  about  1.5%  of  the  annual  electricity  demand  in  2014  could  be  offset  with  anaerobic  digestion.  University  of  California  Davis  and  their  anaerobic  digestion  facility  have  reported  comparable  results  suggesting  that  this  estimation  is  valid.    

 

i    

Table  of  Contents  Executive  Summary  .............................................................................................................................................  2  Introduction  ..........................................................................................................................................................  1  Site  Selection  .........................................................................................................................................................  2  Feedstocks  .............................................................................................................................................................  4  Logistics  .................................................................................................................................................................  6  Cornell  Best  Management  Practices  ........................................................................................................  6  EPA  Guide  on  Collecting  Yard  Waste  .......................................................................................................  9  Texas  State  Pilot  Project  ..........................................................................................................................  11  

Composting  Process  ..........................................................................................................................................  13  Pile  ...............................................................................................................................................................  13  Windrow  .....................................................................................................................................................  14  In-‐Vessel  .....................................................................................................................................................  15  Case  Studies  ...............................................................................................................................................  19  

Required  Equipment  .........................................................................................................................................  23  Size  Reduction  Equipment  ......................................................................................................................  23  Turning  Equipment  ..................................................................................................................................  23  

Anaerobic  Digestion  ..........................................................................................................................................  25  Case  Studies  ...............................................................................................................................................  29  

Conclusions  .........................................................................................................................................................  32  References  ...........................................................................................................................................................  33  Appendix  A:  Environmental  Management  Plan  ...........................................................................................  35  Appendix  B:  Water  Assessment  Plan  .............................................................................................................  36  Appendix  C:  Waste  Collection  ..........................................................................................................................  37  Appendix  D:  Texas  State  Pilot  Economic  Data  ..............................................................................................  38  Appendix  E:  Waste  Characteristic  ..................................................................................................................  41  Appendix  F:  Anaerobic  Digestion  Waste  Approximation  ...........................................................................  42  Appendix  G:  Anaerobic  Digestion  System  Design  ........................................................................................  43    

1  

Introduction    

Auburn  University,  as  a  land  grant  university,  plays  a  significant  role  in  the  development  of  ideas  and  technology  within  the  southeast  region  of  the  United  States.  Auburn  University  currently  sends  the  majority  of  its  organic  waste  to  a  landfill  site  in  Salem,  AL.  This  practice  is  unsustainable  because  it  continuously  requires  additional  space  to  deposited  this  material  and  upon  decomposition  it  will  produce  harmful  greenhouse  gas  emissions  (GHG).  Studies  show  that  diversion  of  organic  waste  to  other  forms  of  treatment  can  be  profitable  and  beneficial  to  the  environment  as  well  as  generate  societal  improvements  by  reducing  GHG.  Auburn  University,  in  coordination  with  Chartwells  and  the  Waste  Reduction  and  Recycling  Department,  conducted  a  study  in  2013,  which  determined  the  availability  of  approximately  1,000  tons  of  university  generated  organic  waste  annually.  Diversion  of  this  waste  has  the  potential  to  provide  economic,  social  and  environment  benefits  for  Auburn  University  by  the  reduction  of  transportation  cost  and  tipping  fees  associated  with  the  current  waste  management  system  as  well  as  the  surrounding  area  by  the  reduction  of  greenhouse  gasses.    

In  2009,  Auburn  University  illustrated  its  commitment  to  sustainability  with  the  acceptance  and  signing  of  the  Climate  Action  Plan  (CAP).  CAP  outlines  areas  of  improvement,  priorities  toward  improvements  and  targets  for  the  reduction  of  harmful  environmental  practices.  An  Excerpt  from  CAP,  Waste  Initiative  2  as  seen  below,  illustrates  the  university’s  understanding  and  commitment  to  more  sustainable  practices.      

Waste  Initiative  2:  Reduce  campus  emissions  associated  with  solid  waste  decomposition  through  composting  (applies  to  Food  and  Dining,  Landscape  Services,  Animal  production).  

 

W.2.1:  Working  with  the  College  of  Agriculture,  evaluate  the  potential  for  a  campus-‐wide  industrial  composting  facility.  Such  a  facility  should  be  sized  and  developed  to  handle  as  many  streams  from  campus  as  possible  (landscape  waste,  dining  services  waste,  animal  wastes,  and  compostable  plastics).  This  will  likely  require  the  consideration  of  a  high-‐temperature  composting  facility.  

 

W.2.2:  Work  with  campus  animal  production  facilities  (poultry,  swine,  beef  cattle)  to  compost  animal  waste  through  campus-‐wide  composting  facility.  

Similarly,  in  a  separate  initiative,  CAP  calls  for  the  reduction  of  GHG  emissions  associated  with  purchased  electricity  and  on-‐campus  stationary  energy  production.  This  paper  will  focus  on  these  initiatives  providing  an  analysis  of  available  resources,  possible  processes  for  the  diversion  of  organic  waste  and  the  reduction  of  GHG  emissions,  composting  and  anaerobic  digestion,  and  recommendations  upon  the  best  steps  for  improvement.  Also  included  are  summaries  of  other  universities  that  have  successfully  implemented  similar  technologies  for  handling  organic  waste.  In  achieving  the  initiatives  describe  in  the  CAP,  Auburn  University  has  the  opportunity  to  provide  leadership  and  expertise  across  the  southeast  and  the  country  in  developing  a  more  sustainable  future.  

2  

Site  Selection    

Proper  placement  of  facilities  for  organic  waste  management  will  be  integral  to  the  success  of  its  operations.  As  highlighted  by  Table  1,  considerations  when  choosing  a  waste  handling  facility  location  include  the  ability  to  properly  manage  stormwater  runoff,  resource  transportation  and  storage,  and  the  influence  of  operations  on  the  surrounding  areas.  Organic  waste  is  high  in  nitrogen  and  phosphorous  these  nutrients,  along  with  sediments,  represent  significant  pollutants  in  surface  waters  that  can  lead  to  eutrophication  and  dead  zones  in  downstream  water  bodies.  Only  sites  where  stormwater  runoff  can  be  collected  and  treated  in  detention  ponds,  settling  pools,  or  constructed  wetlands  will  be  suitable  for  these  operations.  Site  modification  is  possible  to  create  these  features  at  a  proposed  location,  but  close  proximity  to  streams  or  lakes  as  well  as  large  elevation  changes  across  the  site  will  induce  significate  cost  associated  with  site  development.  See  Appendix  A  and  B  for  more  information  concerning  proper  environmental  management  and  stormwater  planning  for  composting  facilities.  

Table  1:  Considerations  when  choosing  a  Site  

Is  the  site  

l Away  from  ponding  areas  or  drainage  patterns  (High  and  Dry)?  

l At  least  300  feet  from  streams,  lakes,  waterways,  etc.?  

Does  the  location  provide  

l Suitable  access  to  sawdust  storage?  l Clearance  from  underground  and  overhead  

utilities?  l Minimal  interference  with  other  farm  

traffic?  

Does  the  site  have  

l Runoff  collection  and  available  treatment  areas?  

l All-‐weather  access  to  the  compost  area?  l All-‐weather  compost  pad?  

Has  the  producer  considered  

l View  from  neighboring  residences?  l Prevailing  winds  for  the  site?  l Bio-‐security  precautions?  l Aesthetics  and  landscaping?  

 

Location  of  facilities  central  to  production  sources  of  feedstocks  will  be  vital  to  the  success  of  operations.  The  chosen  site  should  provide  easy  access  to  material  handling  vehicles  with  minimal  commutes  to  and  from  resource  generation  points.  On-‐site  storage  is  crucial  so  that  operations  can  continue  at  constant  rates  during  intermittent  delivery  of  materials.  Storage  of  organic  waste  as  well  as  bulking  agents  such  as  wood  chips  or  sawdust  will  be  necessary.  Large  transport  vessels  will  need  to  maneuver  the  site  seamlessly  so  height  restrictions  posed  by  trees  or  overhead  utilities  should  be  considered.  Additional  storage  for  operational  equipment  and  other  necessary  tools  should  be  ensured.    

Proximity  to  neighborhoods  or  other  highly  populated  areas  should  be  considered.  Decaying  organic  matter  handled  properly  will  not  smell;  however,  it  can  cause  odorous  smells  that  create  a  nuisance  down  wind.  Care  to  locate  operations  in  an  area  absent  of  close  neighbors  would  be  advised.  Additionally,  if  a  site  is  in  a  visible  location  or  if  it  is  to  be  a  flagship  for  technology  and  innovation  care  should  be  taken  to  maintain  strong  aesthetic  appeal  with  pleasing  landscaping  and  site  up  keep.  

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Two  possible  sites  for  facility  operations  have  been  identified.  Site  A,  seen  in  Figure  1,  is  the  previous  location  of  the  Auburn  Wastewater  Treatment  Plant.  It  is  located  just  a  short  distance  from  Auburn    

Figure1:  Site  A,  previous  waste  water  treatment  site  

University  main  campus  and  is  centrally  located  for  organic  waste  being  produced  on  campus  or  at  surrounding  agricultural  sites.  Site  B,  seen  in  Figure  2,  is  university  property  on  north  College  St.  near  the  E.W.  Shell  Fisheries  Unit.  Auburn  owns  large  tracks  of  land  in  the  north  Auburn  area.    A  5  to  10  acre  site  would  be  feasible  for  these  organic  waste  management  operations.  Auburn's  campus  is  beautiful  and  a  composting  facility  in  close  proximity  could  be  a  challenge  to  maintain  the  same  visual  appeal  as  the  rest  of  the  university.  Site  A  is  also  small,  only  about  3  acers  which  leaves  little  room  for  expansion  of  future  operations.  Considering  aesthetics,  transportation  and  storage,  stormwater  management,  and  the  potential  for  expansion  of  operations  site  B  would  be  the  best  location  for  these  facilities.  

 

Figure  2:  Site  B,  North  Auburn  area  

4  

Feedstocks    

When  designing  a  waste  management  system,  it  is  important  to  have  a  thorough  understanding  of  the  resources  being  managed.  In  accordance  with  Waste  Initiative  2  of  the  AU  Climate  Action  Plan,  a  preliminary  study  of  known  available  feedstocks  and  possible  future  feedstocks  for  organic  waste  management  was  conducted.  Organic  waste  feedstocks  can  be  grouped  in  several  categories:  agricultural,  industrial,  and  community,  illustrated  by  Figure  3.  

 

Figure  3:  Feedstock  Categories  (Kothari  et  al.,  2014)  

Auburn  University,  with  its  extensive  agriculture  roots,  has  a  wide  variety  of  agricultural  feedstocks,  some  industrial  feedstocks,  and  community  based  feedstocks  available  for  management.  Agricultural  feedstocks  known  to  currently  be  available  for  management  include  animal  bedding  and  fisheries  waste.  Information  gathered  by  a  previous  study  conducted  by  the  Waste  Reduction  and  Recycling  (WRRD)  in  2013  found  that  approximately  505  tons  or  7,484  cubic  yards  of  animal  bedding  are  available  for  management  annually.  This  waste  is  mostly  hay  with  some  animal  manure  throughout.  Currently  the  treatment  method  for  this  waste  is  unknown.  Because  of  its  high  hay  content  (carbon)  and  lower  manure  content  (nitrogen)  this  waste  could  be  vital  in  mixing  procedures  to  achieve  carbon  to  nitrogen  ratios  needed  for  proper  decomposing  of  waste  streams.  

Auburn  University  E.W.  Shell  Fisheries  Centers  produce  highly  variable  quantities  of  organic  waste.  Wastes  include  dead  fish  carcasses  and  vegetable  waste.  The  fisheries  unit  can  produce  up  to  one  ton  of  fish  carcasses  at  a  time  in  large  fish  kills,  but  usually  waste  of  this  nature  averages  about  20  pounds  per  week.  Vegetable  waste  averages  about  one  large  trashcan  per  week.  Currently,  fresh  dead  fish  are  frozen  and  given  to  the  raptor  center  as  bird  feed  while  the  remainder  of  the  fish  waste  is  composted  with  wood  chips.  This  system  relays  on  students  to  provide  all  of  the  labor  associated  with  preparation  of  the  compost  material.  This  allows  fisheries  students  the  opportunity  to  get  hands  on  experience  using  a  backhoe  to  turn  the  compost  piles  approximately  once  a  month.  Vegetable  waste  is  disposed  of  in  vermiculture  beds  with  excess  vegetable  waste  added  to  the  compost  pile  with  the  dead  fish.  The  finished  compost  is  available  free  of  charge  to  students  and  faculty.  However,  the  finished  compost  can  contain  fish  bones  and  spines  requiring  special  care  when  handling  (Personal  Communication  Karen  Veverica).    

The characterization of the methanogenic microbial commu-nity is two-phase leach-bed biogas reactor system operated withplant biomass and the mesophilic-operated digestion system wasfound to be a well-suited method for the methanization of triticalesilage [40]. The methanogenic archaea diversity of a biogas reactorsupplied with swine feces as sole substrate under mesophilicconditions was investigated [41]. In this study, they found thatmethanobacterial instead of methanomicrobial are the most pre-dominant methanogenic archaea in the biogas reactor fed withswine feces as sole substrate. A group of microorganisms such asactinomyces, Thermomonospora, Ralstonia and Shewanella areinvolved in the degradation of food waste into volatile fatty acids,whereas Methanosarcina and Methanobrevibacter/ Methanobacter-ium mainly contribute in methane production [42]. High concen-tration of organic acid like acetic acid (45000 mg/L) and butyricacid (43000 mg/L) in the biodigester has been found to inhibitthe growth of microorganisms [43].

3.2. Feedstock

This section covers the main issues relating to feedstock foranaerobic digestion, including choice of feedstock, maintainingquantity and quality. The nature and potential sources of feedstockin an interaction with other parameters are also covered. Fig. 3illustrates the influence of various interrelated process factors onfeedstock choice. Anaerobic digestion is capable of recoveringrenewable energy from a wide range of feedstock. The feedstockneeds to be: (i) biodegradable – as is the case for most organicmatter; (ii) non woody – feedstock with a high proportion oflignocellulosic material (iii) balanced in macro and micro nutrients

– as is the case for most waste derived organic matter. Therefore,feedstock can range from readily degradable wastewater to com-plex high-solid waste. Even toxic compounds may be degradedanaerobically depending on the technology applied. One impor-tant requirement is that a particular waste/wastewater containinga substantial amount of organic matter should finally be convertedinto main products such as, methane and CO2. Fig. 4 shows thesources of eligible feedstocks available on this earth. Fig. 5 showsan overview of the various feedstocks assigned to the differenteligible sources [44].

In general, animal manure, sewage sludge, and food waste [45]are generally treated by liquid/wet AD, while organic fractions ofmunicipal solid waste (OFMSW) [46] and lignocellulosic biomasssuch as crop residues and energy crops can be processed throughsolid substrate/dry AD. Agriculture accounts for the largest poten-tial feedstock and most current applications. It mainly includesagro-industrial wastes, namely animal farm wastes, agriculturalwastes and industrial wastes associated with agriculture and foodproduction. Table 2 is showing the characteristics and operationalparameters of the most important agricultural feedstocks [47].

Most of the agriculture wastes/crop residues rich in carbohy-drate, which exist mostly as the polysaccharides cellulose andhemicelluloses, are not readily available for immediate fermenta-tion. Cellulose, hemicelluloses, and lignin are covalently linkedwith each other which protect the potentially available carbohy-drates from degradation. Therefore, pretreatment is required forthe utilization of carbohydrates in lignocellulosic biomass [48,49].Over the years, a number of different methods, including diluteacid [50], steam explosion [51], lime [52] and ammonia [53,54]have been developed for the pretreatment of lignocellulosicbiomass. The main purpose of pretreatment is to remove ordecrease the crystallinity of cellulose, and increase the surfacearea for microbial action [55].

Liew et al. [56] worked on the methane production from fallenleaves as a feedstock through simultaneous alkali treatment inDAD. They found that sodium hydroxide (NaOH) plays veryimportant role in the delignification of lignocellulosic biomassand also by increasing the alkalinity the buffering capacity of DADincreases. The methane yield was found to be highest i.e. 82 L/kgvolatile solids (VS) at NaOH loading of 3.5% and substrate-to-inoculum (S/I) ratio of 4:1. However, at S/I ratio of 6:2 with NaOHloading of 3.5% methane yield could be increased and was found tobe the maximum. Also, reduction of about 35% in biogas yield wasfound at S/I ratio of 6:2 and NaOH loading of 3.5% when the TScontent increases from 20% to 26%. Teater et al. [57] studied themost suitable pretreatment conditions to convert AD fiber intoethanol by an alkali pretreatment of AD fiber. The main objectiveof the study was to compare the suitability of AD fiber from a

ANAEROBIC DIGESTION

AGRICULTURAL WASTES

INDUSTRIAL WASTE AND

WASTEWATER

MUNICIPAL BIOWASTE

ENERGY CROPES

Fig. 4. Sources of eligible feedstock for anaerobic digestion [44].

Feedstock

AGRICULTURE

• manure (cattle,pig,poultry)

• energy crops• algal biomass• harvest remains

COMMUNITIES

• OFMSW• MSW• Sewage sludge• Grass clippings/garden

waste• Food remains etc.

INDUSTRY

• food/beverage processing• dairy• starch industry• sugar industry• pharmaceutical industry• cosmetic industry• biochemical industry• pulp and paper• slaughter house/rendering

plant etc.

Fig. 5. Categorization of various feedstocks from different sources [47].

R. Kothari et al. / Renewable and Sustainable Energy Reviews 39 (2014) 174–195 179

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Community  organic  waste  feedstocks  currently  available  include  Auburn  University  Facilities  landscaping  waste,  Auburn  University  pre-‐consumer  food  waste  and  Auburn  University  special  projects  construction/demolition  waste.  AU  Facilities  landscaping  waste  was  determined  to  produce  approximately  232  tons  or  1,225  cubic  yards.  This  waste  is  mostly  comprised  of  grass  clippings  and  leaves  as  well  as  high  cellulose  and  lignocellulosic  biomass.  This  waste  could  also  be  valuable  in  reaching  the  proper  carbon  to  nitrogen  ratios,  as  woody  material  is  high  in  carbon.  However,  cellulosic  and  lignocellulosic  rich  materials  require  some  pre-‐treatment  prior  to  anaerobic  digestion  so  these  materials  would  have  to  be  further  studied  as  to  their  intended  use  and  the  proper  pre-‐treatment  (Kothari  et  al.,  2014).  Currently,  this  waste  is  stockpiled  on  facilities  property  near  the  Resident  Overflow  (RO)  parking  lot.  The  material  is  shredded  and  blended  in  efforts  to  reach  closer  to  optimal  ratios  for  decomposition;  however,  the  piles  are  not  actively  maintained  and  are  only  turned  on  convenience.  This  likely  produces  instances  when  internal  pile  conditions  become  anaerobic  producing  carbon  dioxide  and  methane.  Some  of  this  material  is  used  on-‐campus  in  plant  beds.  As  a  potential  feedstock  there  are  concerns  with  the  use  of  herbicides  and  pesticides  on  this  material  prior  to  waste  treatment  as  these  chemicals  could  become  contaminates  and  inhibit  the  growth  of  microorganisms  in  the  decomposition  process.    

Pre-‐consumer  food  waste  is  a  resource  receiving  major  focus  in  terms  of  management  of  organic  waste.  Several  stakeholders  including  Chartwells,  Auburn  University  Waste  Reduction  and  Recycling  Department,  and  the  Auburn  University  Climate  Action  Plan  have  express  interest  in  better  management  of  this  resource.  The  previous  study  concluded  that  in  2013  there  were  249  tons  or  362  cubic  yards  available  annually  for  management.  This  material  is  currently  disposed  of  at  the  Salem,  Alabama  landfill  where  it  undoubtedly  produces  carbon  dioxide  and  methane  under  anaerobic  conditions  within  the  landfill  pit.  This  material  represents  a  key  feedstock  for  treatment  by  alternative  methods  as  its  higher  nitrogen  content  and  also  the  higher  moisture  content  will  be  suitable  for  blending  with  drier  high  carbon  material.  

Special  projects,  construction  and  demolition  debris,  was  included  in  the  2013  study.  This  represents  about  24  tons  or  94  cubic  yards  of  the  available  organic  waste  for  management.  This  waste  is  assumed  to  be  wood  or  other  materials  associated  with  landscaping  disruption  during  construction.  This  material  would  have  to  be  thoroughly  screen  prior  to  any  treatment  process  to  ensure  no  inert  containments  enter  the  treatment  stream.    

Several  other  known  feedstocks  currently  exist;  on  campus  poultry  houses  generate  organic  waste  in  the  form  of  litter  and  carcasses  but  the  quantity  and  quality  of  this  waste  is  unknown  currently.  Similarly,  university  operations  involving  cattle  or  swine  would  be  valuable  contributors  to  the  treatment  stream.  Interesting  to  note  is  the  Thompson  Bishop  Sparks  Alabama  Animal  Diagnostic  Laboratory.  Located  in  Auburn,  Alabama,  this  lab  has  an  unknown  system  described  as  “similar  to  a  pressure  cooker”,  but  has  the  ability  to  reduce  animal  tissue  to  the  point  of  the  absence  of  DNA.  The  laboratory  does  diagnostics  on  animal  tissues  to  determine  the  presents  of  diseases  such  as  “Mad  Cow”  or  White  Tail  Deer  Syndrome.  These  tissue  need  to  be  disposed  in  a  way  that  does  not  permit  the  spread  of  these  disease  (Personal  communication  with  DR.  D.G.  Pugh).  This  material  could  be  nutrient  rich  and  useful  in  a  system  such  as  anaerobic  digestion  as  long  as  the  digested  material  met  applicable  state  legislation  for  post  processing  use.    

Although  currently  there  are  no  know  industrial  feedstocks,  expansion  of  management  processes  could  locate  feedstocks  within  that  category.  Possible  other  feedstocks  for  future  growth  and  expansion  of  an  organic  waste  management  system  could  include  expansion  to  post  consumer  food  waste  from  Auburn  

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University  including  compostable  plastics  and  ‘’to-‐go’’  containers  and  partnerships  with  Auburn  City,  Opelika  City  and  Lee  county  to  provide  additional  pre-‐  and  post-‐consumer  food  waste,  landscaping  waste,  or  agriculture  waste.  In  all  cases  of  accepting  new  feedstocks,  a  thorough  understanding  of  the  feedstocks  and  their  effect  on  the  existing  and  future  systems  must  be  gathered  prior  to  resource  processes.    

Logistics    

Colleges  and  universities  are  well-‐equipped  with  the  knowledge  and  resources  to  provide  leadership  and  develop  logistical  models  to  approach  the  environmental  challenges  surrounding  waste  management  as  well  as  promote  change  through  the  education  of  citizens.  Colleges  and  universities  around  the  nation  are  developing  and  implementing  environmental  programs  that  include  landscaping,  foodservice,  transportation,  and  waste  management  to  increase  campus  environmental  stewardship.  To  take  a  step  further,  these  environmental  programs  provided  the  opportunity  for  new,  innovative  hands-‐on  learning  experiences  rather  than  traditional  textbook  and  lecture  learning.    By  creating  more  sustainable  campus  practices,  academic  institutions  can  demonstrate  to  students  the  importance  of  environmental  stewardship  so  they  can  bring  these  lessons  to  others  outside  of  the  campus  community.  To  reach  the  goals  of  a  sustainable  campus,  universities  must  act  on  ‘‘closing  the  loop  to  become  a  self-‐contained  facility  that  grows  its  own  food,  generates  its  own  electricity,  and  recycles  its  own  waste.’’  To  create  a  functioning  sustainable  waste  management  system,  administrators  must  invest  time  in  planning  logistical  operations.  Collection  and  transportation,  when  planned  adequately,  enable  a  composting  system  to  operate  smoothly,  and  can  enable  an  innovative  learning  environment  (HortTechnology,  2011).    

Cornell  Best  Management  Practices    

Cornell  University  has  taken  the  lead  in  sustainable  waste  management  practices  in  the  United  States.  Cornell’s  Waste  Management  Institute  created  an  invaluable  instructional  database  that  universities  and  institutions  can  refer  to  for  advice  and  best  management  practices  in  establishing  a  compost  program.  The  following  are  excerpts  from  Cornell’s  collection  and  transportation  guides  presenting  the  qualities  of  their  composting  program  proven  effective:  

Separation    Prior  to  composting  food  scraps,  all  of  the  “All-‐You-‐Care-‐to-‐Eat”  dining  halls  on  Cornell’s  campus,  except  one,  had  installed  pulpers  which  ground  up  food  scraps  prior  to  sending  them  into  the  wastewater  waste  stream.  When  the  decision  was  made  to  start  composting,  this  made  post-‐plate  separation  at  these  dining  halls  easy.  Students  need  only  bring  their  plates  to  the  dish  collection  area  where  CU  staff  scrape  the  remains  into  a  trough  which  leads  directly  to  the  pulper.  The  pulped  scraps  then  travel  down  a  pipe  from  the  dish  room  to  a  dewatering  machine.  Once  dewatered,  the  solids  are  collected  in  32-‐35  gallon  yellow  plastic  barrels  on  casters  and  the  water  goes  down  the  drain.  Note  that  food  scraps  can  be  composted  whole  or  pulped  but  this  system  was  in  place  before  composting.  Pre-‐consumer  food  scraps  and  other  compostables  are  also  collected  in  the  yellow  plastic  barrels  and  wheeled  down  to  the  loading  dock  for  pick-‐up  by  Farm  Services.  CU  staff  washes  the  cans  with  a  can  washer.  The  custodians  who  

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bring  the  barrels  down  to  the  loading  dock  police  them  for  items  that  do  not  belong.  If  they  see  something  that  does  not  belong,  they  will  take  care  of  it.  If  it  becomes  consistent,  or  there  is  too  much  to  take  care  of,  they  will  bring  it  to  the  manager’s  attention  and  it  will  be  discussed  at  the  daily  staff  meeting.  In  addition  to  collecting  compostables,  the  dining  halls  also  collect  recyclables  in  blue  plastic  barrels,  and  trash  in  gray  plastic  barrels.    In  the  retail  dining  facilities  (i.e.  a  la  carte  dining  and  takeout  services),  only  pre-‐consumer  organic  material  was  being  composted  until  2006.  During  the  academic  year  of  05-‐06,  a  student  decided  to  set  up  post-‐consumer  composting  at  one  of  the  dining  halls  as  a  project  for  a  class.  The  project  turned  out  to  be  too  big  for  one  person,  so  she  encouraged  CU  Dining  to  hire  students  to  run  post-‐consumer  composting  at  these  facilities.  In  the  fall  of  2006,  Cornell  Dining  hired  two  students  as  Sustainability  Coordinators.  They  have  been  very  busy  organizing,  setting  up  and  educating  dining  establishment  patrons  on  post-‐consumer  separation.    Each  of  these  facilities  has  a  post-‐consumer  separation  station  set  up  where  patrons  separate  the  compostables,  from  the  recyclables,  from  the  trash.  The  Student  Sustainability  Coordinators  have  awareness  campaigns  at  the  dining  halls  for  a  week  at  a  time  to  help  teach  patrons  what  is  compostable  and  what  is  not.  There  is  also  extensive  signage  above  the  stations.  At  Martha’s,  a  retail-‐dining  establishment  that  just  started  post-‐consumer  separation,  a  new  separation  station  was  put  in  which  coordinators  feel  may  help  improve  separation.  The  space  for  food  scraps  and  serviceware  collection  is  set  apart  from  the  rest  of  the  spaces  by  being  labeled  in  yellow  with  a  big  yellow  circle  around  where  compostables  are  deposited.  In  addition,  they  have  changed  the  word  “trash”  to  “landfill”  to  help  bring  home  the  idea  of  where  non-‐compostables  are  going.    Cornell  Dining  is  committed  to  reducing  its  carbon  footprint.  This  prompted  going  “trayless”  at  select  dining  locations,  which  has  significantly  reduced  food  waste  and  water  usage,  and  making  available  Freshtake  Grab-‐‘n’-‐Go  products,  which  are  packaged  using  compostable  containers  and  labels.  In  addition,  they  are  using  compostable  plates  and  cups  and  are  looking  into  corn  and  potato-‐based  plastic  to  stock  utensil  dispensers.  Cornell  has  a  green  purchasing  task  force  to  help  get  better  rates  for  compostables  (http://www.sustainablecampus.cornell.edu/getinvolved/getinvolved.cfm).  The  things  that  are  not  compostable  at  Cornell  Dining  are  third  party  food  products  such  as  sushi  containers,  potato  chip  bags  and  the  plastic/foil  packets  containing  some  condiments.  The  plastic  tops  and  straws  for  fountain  drinks  are  also  not  compostable.    In  2007,  the  Cornell  Sustainability  Council  pushed  for  the  Statler  Hotel,  independent  of  Cornell  Dining,  to  compost.  There  are  4  kitchens  at  the  Statler,  which  prepare  meals;  staff  and  students  sort  compost  in  the  kitchen.  They  also  use  a  color-‐coded  bin  system:  yellow  for  compostables,  blue  for  recyclables  and  gray  for  trash.  Student  training  consists  of  a  broad  overview  when  they  come  to  work  in  the  kitchen  and  “on  the  job”  training.  Servers  sort  from  the  trays,  cooks  sort  when  they  cook  and  dish  machine  operators  sort  when  they  clean  up.  Patrons  also  sort  using  separation  stations.  In  2008,  a  new  café  opened  in  Mann  Library  called  Manndible.  It  is  run  by  an  independent  business  renting  space  at  CU.  If  Cornell  had  not  had  something  in  place  for  composting  already,  Manndible  would  have  had  their  compostables  picked  up  by  Cayuga  Compost.  Most  everything  at  Manndible  is  compostable.  Consumers  tend  to  get  confused  with  the  takeaway  containers;  i.e.  is  this  one  compostable,  or  is  it  plastic?  Signage  has  helped,  but  many  people  still  tend  to  miss  it.    The  following  excerpt  describes  the  pre-‐consumer  waste  collection  system  at  the  newly  started  composting  program  for  the  Culinary  Institute  of  America:  

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    “It’s  a  very  simple  operation,”  says  Becky  Oetjen,  recycling  coordinator  for  the  Institute.  “Each  food  preparation  station  has  three  very  small  counter  containers  to  separate  waste,  reusable  scraps,  and  compostable  scraps.  The  compostable  scraps  are  dumped  periodically  into  32-‐44  gallon  containers  placed  near  the  workstations.  The  larger  containers  are  emptied,  at  least  once  a  shift,  into  a  20-‐yard  open  box  located  in  a  common  area  outside  the  kitchens.  The  open  box  is  pulled  from  the  site  twice  a  week  and  taken  to  the  composting  site.  The  only  special  equipment  we  have  is  color-‐coded  bins—gray  for  trash,  yellow  for  mixed  recyclables,  and  blue  containers  for  ‘food  waste  only’.  All  bins  are  on  4-‐wheel  dollies.  The  food  bins,  especially,  can  get  cumbersome  for  the  students  due  to  the  weight  of  the  food,  so  we  are  in  the  process  of  building  a  ramp  to  make  dumping  into  the  collection  container  easier.”  (Cornell  Waste  Management  Institute,  1996).    Collection  and  Mixing    Five  days  a  week,  Monday  through  Friday,  a  Cornell  Farm  Services  staff  member  picks  up  the  compostables  from  dining  facilities.  Some  sites  get  the  service  3  times  a  week,  and  others  five.  Prior  to  starting  off  on  the  pick-‐up,  the  truck  is  lined  with  six  to  eight  inches  of  bedding  material  consisting  of  sawdust  and  horse  manure.  This  material  is  built  into  a  dam  at  the  rear  of  the  truck  bed  to  prevent  liquid  from  leaving  the  truck.  The  dump  truck  they  use  has  a  lift  onto  which  the  yellow  “compostables”  barrel  is  strapped  and  the  contents  are  dumped  into  the  truck.  The  first  run  on  Mondays,  in  which  they  pick  up  from  7  of  the  11  dining  halls  and  retail  facilities,  takes  about  an  hour  and  a  half  and  yields  around  3.5  tons  of  organics.  This  is  unloaded  at  the  compost  site  next  to  the  end  of  the  windrow  where  a  pile  of  sawdust,  straw  and  chips  (carbon  source)  is  ready  for  later  mixing.  The  second  run  takes  approximately  one  hour  and  yields  around  2.5  tons  for  a  total  of  6  tons  of  food  and  compostable  items.    Designing  a  Collection  System    Collecting  biodegradable  (compostable)  materials  such  as  food  scraps,  and  other  organics  separately  from  non-‐compostable  materials  at  the  site  of  generation  is  called  source  separation.  In  other  words,  organic  materials  that  are  acceptable  for  composting  are  kept  separate  from  those  materials  that  are  recycled,  reused,  incinerated,  or  landfilled.  There  are  several  advantages  to  separating  compostable  materials  at  the  source—a  higher  recycling  rate  can  be  achieved,  and  a  cleaner,  more  usable  or  marketable  end  product  is  produced.    The  collection  system  is  a  critical  component  of  any  food  scrap-‐composting  program.  The  procedures  and  materials  used  to  source  separate  compostables  at  the  site  and  transport  the  materials  to  the  primary  collection  containers  should  be  well  thought  out  and  specific  to  a  facility’s  particular  needs.  The  primary  objectives  of  the  collection  system  are  to:  

ü Maximize  the  capture  rate  of  compostable  materials.  ü Eliminate  nonorganic  contaminants  such  as  plastic  wraps,  rubber  bands,  glass,  and  metal.  ü Minimize  labor  and  space  requirements.  

Collection  systems  within  different  businesses  will  vary  according  to  the  specific  needs  of  each  business,  space  limitations,  and  general  layout  of  work  areas.  In  grocery  stores  and  food  service  institutions,  for  example,  collection  containers  can  be  placed  at  workstations  in  the  produce,  deli,  bakery,  and  dairy  departments.  In  cafeterias,  containers  can  be  placed  near  tray  and  silverware  recovery  stations  if  collecting  plate  scraps,  and  in  the  kitchen  where  preparation  scraps  are  generated.  Containers  should  be  

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conveniently  located  at  points  of  generation  and  clearly  labeled.  Easy  access  to  all  collection  containers,  i.e.,  “food,”  “recyclables,”  and  “trash,”  will  help  prevent  contamination.    Collection  Containers    Some  businesses  will  be  able  to  utilize  containers  already  on  hand,  while  others  will  have  to  add  additional  containers.  In  a  school  cafeteria  pilot  composting  project,  administrators  felt  that  it  would  be  easier  for  students  to  separate  materials  into  different  colored  containers—green  cans  for  food  scraps,  red  cans  for  recyclables,  and  brown  for  trash.  In  this  case,  the  purchase  of  additional  containers  was  required.  Whether  color-‐coded  or  not,  all  collection  containers  should  be  well  labeled.    If  you  are  not  composting  on-‐site,  you  will  have  to  consider  storage  space  availability  between  pickups.  If  there  are  several  days  between  pickups,  you  may  also  need  to  consider  refrigeration  space.  Refrigeration  will  prevent  odors  and  slow  the  decomposition  of  material,  especially  during  warmer  weather.  In  addition,  transportation  and  composting  processing  costs  will  affect  the  economic  feasibility  of  the  program.  Costs  will  vary  based  on  frequency  of  collection,  distance  to  the  processing  facility,  and  tipping  fees  (Compost…  because  a  rind,  pg.  11-‐12).  See  Appendix  C  for  examples  of  collection  containers  and  a  data-‐recording  sheet  to  track  waste  quantities.    EPA  Guide  on  Collecting  Yard  Waste    The  following  excerpt  communicates  the  importance  of  an  optimized  collection  system:         The  cost,  ease,  and  effectiveness  of  implementing  a  composting  program  is  affected  by  the  method  chosen  for  collecting  the  compost  feedstock.  Communities  can  select  from  a  variety  of  collection  systems  to  develop  a  composting  program  to  meet  their  specific  needs.  Programs  can  be  designed  to  collect  just  yard  trimmings,  or  yard  trimming  and  MSW.  Collection  can  occur  at  curbside,  where  the  municipality  picks  up  the  materials  directly  from  household  or  through  drop-‐off  sites,  where  residents  and  commercial  producers  deliver  their  compostable  material  to  a  designated  site.  Most  communities  will  want  to  build  on  their  existing  refuse  collection  infrastructure  when  implementing  a  composting  program.  This  will  ease  the  implementation  of  composting  practices  into  a  communities  overall  MSW  management  program  and  help  to  minimize  costs  (EPA,  1994).    The  EPA  designed  their  composting  information  to  pertain  primarily  to  municipalities;  however,  universities  and  other  similar  institutions  can  gain  valuable  insight  into  efficient  logistical  operations.  Proper  planning  accommodating  for  the  multifaceted  requirements  of  a  composting  program  combined  with  creative  changes  necessary  for  a  college  campus  will  ensure  that  collection  infrastructure  is  satisfactory  to  capture  maximum  volumes  of  compostable  waste.    When  developing  a  yard  trimmings  collection  program,  administrators  must  account  for  seasonal  changes  in  waste  production.  In  the  largely  temperate  climate  of  the  southeast,  collection  can  take  place  throughout  the  year.  Grass  can  be  collected  spring  through  fall,  though  some  landscape  programs  permit  grass  leavings  to  bolster  nutrient  quality  of  the  soil.  Leaves  can  usually  be  collected  during  the  fall  season  of  October  through  December,  then  again  in  the  spring.  Brush  is  typically  collected  in  the  spring  and  fall.  Depending  on  the  season,  grass,  leaves,  and  brush  can  be  efficiently  collected  together.  However,  the  brush  will  have  to  be  processed  into  smaller  pieces  though  a  shredder  or  grinder  to  allow  for  more  rapid  decomposition.  According  to  the  EPA  there  is  two  main  ways  to  collect  source-‐separated  

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waste  for  composting:  curbside  collection  or  community  drop-‐off  points.  When  establishing  a  collection  program,  administrators  must  consider  the  program’s  convenience  for  the  served  public,  as  well  as  the  level  of  interest  displayed  by  citizens  participating  in  the  program.  A  drop-‐off  program  in  a  small,  densely  populated  community  with  residents  well  educated  about  the  importance  of  composting  (e.g.  a  college  campus)  might  garner  high  participation  rates.  By  contrast,  in  a  community  that  is  uninterested  or  uneducated  about  composting,  even  a  curbside  program,  which  is  typically  more  convenient  for  community  residents,  might  fail  to  bring  in  the  large  volumes  of  waste  desired  (EPA,  1994).    Communities  that  decide  to  collect  MSW  for  composting  can  opt  to  source  separate  or  commingle  this  material.  Source-‐separated  MSW  involves  varying  degrees  of  materials  segregation,  which  is  performed  where  the  MSW  is  generated.  Alternatively,  commingled  MSW  is  not  separated  at  its  point  of  generation.  The  decision  to  collect  source-‐separated  or  commingled  MSW  is  a  significant  one  and  affects  how  the  material  is  handled  at  the  composting  facility,  the  preprocessing  and  processing  costs,  and  the  quality  and  marketability  of  the  finished  compost.  There  are  distinct  advantages  and  disadvantages  to  each  system.  Source-‐separation  is  undeniably  the  most  effective  for  generating  an  uncontaminated  feedstock  source  due  to  upfront  separation,  but  it  can  be  less  convenient  to  residents  and  might  require  the  purchase  of  new  equipment  and/or  conjoiners.  The  main  benefit  to  a  commingled  MSW  stream  is  that  it  can  usually  be  done  with  existing  equipment  and  labor  resources  and  is  convenient  to  (lazy)  residents,  but  there  is  a  higher  potential  for  contamination  accompanied  by  higher  processing  costs  (EPA,  1994).      Concerning  avoiding  undesirable  materials  in  feedstock  collections:       Both  yard  trimming  and  collected  MSW  can  contain  materials  that  might  affect  processing  and  product  quality.  These  materials  can  include  glass,  metals,  beverage  containers,  plastics,  household  hazardous  waste,  and  other  undesirable  materials.  Collecting  crews  should  be  trained  to  recognize  and  separate  these  types  of  materials  whenever  possible.  Because  of  the  variety  of  materials  collected,  MSW  feedstock  is  likely  to  contain  larger  amounts  of  undesirable  materials  than  yard  trimmings  feedstock.  Although  yard  trimmings  can  contain  pesticides  and  herbicides  commonly  used  by  residents  and  business,  the  composting  process  will  break  down  many  of  these  substances,  limiting  their  impact  on  the  final  product.     Communities  can  take  steps  to  reduce  the  amount  of  undesirable  materials  in  the  feedstock.  These  include  passing  ordinances,  posting  warning  notices,  and  issuing  fines  for  mixing  non-‐compostables  with  compostables.  In  addition,  bagged  yard  trimmings  and  MSW  bins  can  be  opened  at  the  curb  to  detect  undesirable  materials.  Facility  employees  can  look  for  and  separate  out  unwanted  materials  (EPA,  1994).    In  an  EPA  conducted  study  of  30  communities,  24  have  curbside  collection  programs.  This  collection  system  was  particularly  advantageous  when  it  came  to  collecting  yard  waste.  Yard  trimmings  are  a  fairly  homogeneous  component  of  the  waste  steams  so  contamination  is  not  as  frequent  a  problem  as  with  collecting  food  waste  (EPA,  1994).  To  collect  the  yard  trimmings  and  debris,  communities  often  utilized  pre-‐existing  public  works  equipment  such  as  front-‐end  loaders,  refuse  packers,  and  dump  trucks.  Some  purchased  new  equipment  purposed  for  the  job,  such  as  vacuum  leaf  loaders  costing  approximately  $20,000.  The  collection  methods  vary  depending  on  the  type  and  amount  of  yard  materials  collected.  For  example,  during  the  fall  months  of  heavy  leaf  generation  many  of  the  communities  collected  the  leaves  loose  to  relieve  residents  of  the  hassle  of  bagging  the  leaves  with  the  added  benefit  of  reducing  liner  separation  at  a  later  stage  (EPA,  1994).    

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In  communities  that  provide  curbside  refuse  collection,  curbside  yard  collection  is  needed  to  divert  a  large  portion  of  waste  materials,  but  drop-‐off  programs  play  an  important  role  in  capturing  compostable  organic  waste.  Mobile  drop-‐off  centers  can  serve  several  municipalities  on  a  rotating  basis  and  provide  more  opportunity  for  a  larger  percentage  of  residents  to  contribute  their  waste  (EPA,  1994).    Auburn  University  Collection  System    Auburn  University's  current  waste  management  system  is  run  through  the  Facilities  Management  department.  The  Facilities  department  possesses  many  existing  facilities  and  equipment  that  could  be  adapted  for  use  in  a  more  expansive  MSW  and  yard  waste  collection  system.  A  combined  logistical  planning  administration  from  both  the  Facilities  and  Waste  Reduction  and  Recycling  Departments  at  Auburn  University  would  possess  the  capabilities  to  accommodate  for  the  increased  waste  flow  and  unique  processing  requirements  for  a  composting  program.  From  the  EPA's  study  of  30  communities  who  begun  their  own  composting  programs,  the  following  activities  have  proven  successful  in  enabling  communities  to  divert  large  portions  of  their  waste  through  composting:  

§ Provide  frequent  curbside  collection  of  yard  debris  for  composting  § Target  all  residential  buildings  for  yard  debris  collection  § Promote  and  encourage  backyard  composting  and  “don’t  bag  it”  programs  § Offer  collection  of  a  variety  of  yard  debris  materials  § Start  pilot  programs  collecting  food  discards  for  composting  § Increase  residential,  commercial,  and  institutional  participation  (strategies  include  mandates  

and  economic  incentives)  § Encourage  landscapers  and  businesses  to  compost  (Lessons  from  30  Communities,  35).  

 Keeping  these  goals  and  strategies  in  mind,  Auburn  University's  new  and  improved  waste  management  plan  will  be  capable  of  handling  the  MSW  and  yard  waste  streams  efficiently.    Texas  State  Pilot  Project    Texas  State  performed  a  pilot  study  on  composting  post-‐consumer  waste  in  dining  halls  on  campus.  This  study  provides  a  unique  example  to  examine  when  considering  including  post-‐consumer  waste  in  the  composting  program  at  Auburn  University.  This  situation  is  especially  relevant  for  determining  the  consumer  education,  awareness  campaigns,  and  manpower  required  to  effectively  collect  the  post-‐consumer  waste  without  excessive  contamination.  The  following  describes  the  program  at  length:    Logistics    Texas  State  University  recently  conducted  a  pilot  program  in  a  dining  hall  on  campus  to  compost  post-‐consumer  waste  in  which  students  source-‐separated  their  organic  waste  at  separation  stations.  This  study  is  valuable  to  see  which  strategies  met  with  success  working  with  college  students.  The  first  step  taken  to  implement  the  cafeteria-‐composting  program  was  to  meet  with  the  stakeholders  affiliated  with  the  student  center  food  court.  These  stakeholders  included  decision  makers  from  the  campus’s  food  service  provider  and  the  university  student  center  officials.  Together,  decisions  were  made  regarding  the  number  of  collection  containers,  pick-‐up  times,  and  impact  on  staff.  Food  and  recycling  sorting  sites  were  chosen  in  the  food  court  based  on  the  proximity  of  the  existing  trashcans,  space  availability,  and  ease  of  access  for  those  eating  at  the  dining  center.  Food  and  recycling  pick-‐up  sites  at  the  back  loading  dock  were  chosen  for  areas  that  would  cause  the  least  interference  with  the  loading  bays,  proximity  to  

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the  30  cubic  yard  trash  compactor,  and  ease  of  access  for  the  food  court  staff  and  the  student  coordinators.    It  was  determined  that  funding  was  needed  to  purchase  11  three  compartment  source-‐separating  bins,  as  well  as  a  utility  trailer,  and  to  hire  one  graduate  student  coordinator,  and  one  student  worker.  OTTO  Environmental  Systems  (Charlotte,  NC)  donated  ten  95-‐gal  carts  for  collections  (HortTechnology,  2011).    Education  was  an  extremely  important  component  of  this  pilot  program,  and  is  important  in  any  source-‐separated  collection  system.  Students  in  the  student  center  dining  area  were  educated  before  and  during  the  program  implementation.  Pre-‐education  took  place  by  setting  up  table  tent  flyers  in  the  dining  area  2  weeks  before  program  implementation.  These  flyers  informed  the  students  of  the  upcoming  composting  program.  The  table  tent  flyers  stated  the  program’s  objectives,  the  purpose  of  the  program,  and  instructions  on  what  items  went  into  each  bin.  Contact  information  for  any  questions,  comments,  or  concerns  was  also  posted.    A  logo  donated  by  the  university  marketing  team  was  created  for  the  Bobcat  Blend  composting  program,  to  provide  brand  identification  and  education  on  composting  to  the  student  body.  The  educational  signage  for  the  source-‐separation  bins  was  created  and  donated  by  the  student  center’s  marketing  team  and  was  designed  with  pictures  of  the  exact  food  and  beverage  items  sold  in  the  food  court,  so  participants  would  clearly  understand  into  which  bin  each  item  was  to  be  disposed.  There  were  a  total  of  three  signs  created:  organic  waste,  bottles  and  cans,  and  trash.  These  signs  were  placed  in  highly  visible  locations  directly  above  the  containers.  An  art  student  for  a  class  project  created  the  Bobcat  Blend  educational  poster.  The  poster  was  a  black  and  white  and  illustrated  the  purpose  of  the  program,  along  with  the  acceptable  and  non-‐acceptable  compostable  items.    During  the  peak  dining  hours  for  the  first  2  weeks  of  each  semester,  the  graduate  student  coordinator  and  a  student  worker  stood  by  the  source-‐separation  bins  educating  students  on  what  items  went  into  each  bin  as  well  as  the  purpose  and  benefits  of  the  program  (HortTechnology,  2011).    Processing  of  organic  residuals  took  place  10  miles  off  campus  at  the  Texas  State  University  Muller  Farm.  This  site  was  previously  used  as  an  alternate  grazing  source  for  the  livestock  kept  at  Texas  State  University  Freeman  Ranch.  Muller  Farm  is  125  acres  and  5  acres  was  allocated  for  the  compost  site.  Funding  for  construction  of  the  compost  site  was  obtained  through  a  grant  for  another  composting  project.  Of  the  5  acres  allocated  for  the  compost  site,  2.3  acres  was  transformed  into  a  catchment  pond  that  could  withstand  a  25  years  24  hour  rain  event.  The  remaining  2.7  acres  was  cleared  and  graded  so  the  retention  pond  would  capture  any  water  runoff  from  the  compost  piles.  Fences  and  gates  were  also  installed  to  keep  out  any  livestock  and  to  contain  feedstocks  used  for  composting.    The  compost  piles  were  created  using  25%  food  residuals  from  the  student  center  and  75%  wood  waste  donated  by  a  local  tree  company.  This  mix  was  blended  using  a  skid  steer  and  bucket.  The  piles  were  turned  four  times  annually  and  watered  with  the  captured  water  from  the  collection  pond  on  each  turn  (HortTechnology,  2011).              

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Economic  Data    Economic  data  was  collected  to  assess  the  cost  as  well  as  the  savings  associated  with  the  program.  Related  costs  included  include  start-‐up,  disposal,  educational,  collection,  transportation,  and  processing  costs.  See  Appendix  D  for  more  information.  

Composting  Process    

Pile    

Unaerated  static  piles  (passive  composting),  seen  in  Figure  4,  require  the  least  amount  of  maintenance.  This  method  consists  of  mixing  food  scraps  with  bulking  materials,  placing  the  mixture  in  piles  and  letting  the  piles  decompose  over  time.  Because  the  piles  are  not  turned,  the  initial  mixture  of  food  scraps  and  bulking  materials  must  be  porous  enough  to  allow  air  to  penetrate  and  circulate.  Static  piles  can  be  as  long  as  space  allows,  but  should  generally  be  no  higher  than  6  feet  or  wider  than  12  feet.  If  the  time  is  taken  in  the  beginning  to  get  the  mixture  right,  this  method  can  complete  the  composting  process  with  little  assistance,  although  in  some  cases,  it  may  be  necessary  to  apply  a  thick  layer  of  wood  chips  or  other  bulking  material  to  control  odor.  This  method  takes  longer  than  other  methods,  but  is  very  effective.  (Cornell  Waste  Management  Institute,  1996).  

 

 

Figure  4:  Unaerated  Pile  Diagram  

Aerated  static  piles  are  formed  essentially  the  same  as  passively  aerated  windrows,  but  the  network  of  pipes  is  attached  to  blowers  that  are  used  to  force  air  through  the  pile,  Figure  5.  Piles  can  be  bigger,  generally  5-‐8  feet  high  and  10-‐16  feet  wide.  The  width  of  the  piles  depends  on  the  layout  of  the  pipes;  some  piles  are  very  wide  with  multiple  pipes  running  through  them.  This  method  is  more  expensive  than  the  unaerated  pile  previously  mentioned  because  it  requires  additional  equipment  and  relies  on  electricity  to  operate  the  blowers.  However,  this  method  can  also  speed  up  the  composting  process.  (Cornell  Waste  Management  Institute,  1996).  

 

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Figure  5:  Aerated  Pile  

 

Windrow    

Turned  windrows  are  elongated  piles  that  are  agitated  or  turned  on  a  regular  basis  with  a  machine  such  as  a  front-‐end  loader  or  specially  designed  equipment,  Figure  6.  Regular  turning  and  mixing  of  the  materials  help  to  further  break  down  particles,  creating  more  surface  area  for  microbial  colonization,  faster  decomposition,  and  a  more  homogeneous  end  product.  Turning  and  mixing  also  increase  the  porosity  of  the  pile  and  release  trapped  heat,  water  vapor,  gases,  and  odors.  

 

Figure  6:  Windrow  and  Windrow  Turner  

Turned  windrows  can  vary  in  size,  depending  on  space  availability  and  type  of  material  being  composted.  The  recommended  size  is  5-‐6  feet  high,  10-‐12  feet  wide,  and  as  long  as  is  appropriate  for  the  site.  This  size  pile  has  advantages  in  the  winter.  Turning  and  mixing  a  pile  when  the  surface  is  frozen  can  introduce  ice  into  the  center  of  the  pile  and  cause  the  composting  process  to  slow  or  even  stop  completely.  Sometimes  it  may  be  necessary  to  stop  turning  for  a  while  until  temperatures  moderate.  With  this  size  pile,  the  center  will  be  insulated  and  composting  can  continue  even  when  temperatures  drop  below  freezing.  

Passively  aerated  windrows  are  similar  to  static  piles,  but  air  is  supplied  to  the  composting  materials  through  open-‐ended  perforated  pipes  placed  under  each  windrow.  Cooler  air  is  drawn  into  the  pipes  by  a  chimney  effect  as  hot  gases  rise  upward  out  of  the  windrow.  This  method  requires  placing  the  compost  mixture  on  a  porous  foundation  (sawdust,  wood  chips,  straw,  or  finished  compost)  to  absorb  

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moisture  and  insulate  the  windrow.  A  covering  layer  of  sawdust,  wood  chips,  or  finished  compost  is  also  needed  to  insulate  the  pile,  and  helps  to  absorb  moisture,  odor,  and  ammonia,  and  to  discourage  flies.  Because  there  is  no  turning  and  remixing  in  this  method,  the  materials  must  be  thoroughly  pre-‐mixed  before  being  placed  in  the  windrow.  Windrows  constructed  in  this  method  generally  are  4-‐6  feet  high,  no  wider  than  10  feet,  and  can  be  any  length.  (Cornell  Waste  Management  Institute,  1996).  

Bins  

Bins,  using  wire  mesh  or  wooden  frames  allow  good  air  circulation,  are  inexpensive,  and  require  little  labor.  Three  chamber  bins  allow  for  faster  compost  production  utilizing  varying  stages  of  decomposition.  Bin  composting  is  typically  used  for  small  amounts  of  food  waste.  A  bin  composting  pile  could  also  be  valuable  as  a  demonstration  pile  for  educating  students  and  faculty.  For  example,  Auburn  University,  along  with  many  other  universities,  has  an  Arboretum  on  campus  to  advocate  connection  with  and  education  of  nature.  Implementing  a  small  compost  pile  in  a  bin  construction,  like  the  examples  shown  in  Figure  7.  A  shed  with  installed  bins  or  stand  alone  bins  would  provide  a  valuable  visual  example  of  the  composting  process  in  action  (University  of  Georgia  Cooperative  Extension,  2012).  

 

Figure  7:  Bin  Composting  Systems  

 

In-‐Vessel    

In-‐vessel  systems  can  take  many  different  forms,  from  highly  mechanical  systems  that  can  produce  compost  ready  for  curing  in  20  days,  to  fairly  simple  containers  that  may  use  forced  air  or  mixing  within  the  container  to  expedite  the  process.  One  in-‐vessel  system  utilizes  bay  enclosures  with  some  mechanical  means  for  mixing,  moving,  and  aerating  the  compost—windrow  turners,  forced  aeration,  agitated  beds,  or  paddle  wheel  turners  are  most  often  used.  This  system  can  consist  of  multiple  bays,  approximately  6-‐7  feet  wide  and  6  feet  high,  and  can  be  as  long  as  180  feet.  It  may  also  be  equipped  with  automatic  controls  for  regulating  aeration,  moisture,  odors,  temperature,  and  turning.  

Another  type  of  in-‐vessel  system  is  a  transportable  container  that  can  process  material  on-‐site  or  be  hauled  off  to  another  location  to  complete  the  composting  process.  These  modular,  airtight  composting  vessels  usually  include  computerized  aeration  systems  for  moisture  and  temperature  control,  and  built-‐

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in  recordkeeping,  mixing,  loading,  and  screening  equipment.  But,  some  may  be  as  simple  as  multiple  bins  with  perforated  piping  for  aeration.  

Containerized  composting  systems  are  generally  used  when  it  is  essential  to  move  a  lot  of  material  through  quickly,  where  odor  may  be  a  problem,  i.e.,  in  urban  areas,  or  where  space  is  limited.  In-‐vessel  systems  can  provide  excellent  process  control  for  composting  food  scraps  and  other  organic  materials  that  are  difficult  to  handle,  and  offer  the  advantage  of  protection  from  severe  weather.  (Cornell  Waste  Management  Institute,  1996).  The  following  pictures  provide  examples  of  the  many  different  forms  in-‐vessel  composting  systems  can  take:  

Medium-‐Scale:  aerated,  batch  or  continuous  flow  units  

 

Figure  8:  On-‐site  induced-‐aeration  batch  flow  composting  units  

Shown  in  Figure  8  on  the  left  is  a  rotating  drum-‐composting  unit  that  excels  at  mixing  compost  by  turning  at  a  constant  rate.  The  system  on  the  right  is  a  batch-‐flow  unit  produced  in  the  United  States.  The  pipe  at  the  base  leads  to  an  aeration  fan,  which  is  connected  to  a  biofilter.  An  electric  motor  drives  the  auger  mechanism,  which  is  installed,  above  the  vessel.  A  hatch  at  the  side  of  the  unit  permits  the  collection  of  finished  compost.  This  system  can  be  difficult  to  operate;  however,  due  to  the  human  labor  required  to  mechanically  turn  the  compost  in  the  unit.  

Large-‐Scale:  aerated,  batch-‐flow  containerized  units  

Figure  9:  Modified  roll-‐off,  aerated,  batch-‐flow  units  

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Figure  9  highlights  a  modified  roll-‐off,  batch-‐flow,  containerized  composting  unit  produced  in  the  United  States  made  from  little  more  than  a  dumpster.  Air  is  forced  by  an  aeration  fan  into  the  base  of  the  container,  and  air  exiting  the  surface  of  the  compost  mass  is  discharged  into  a  pipe  at  the  top  (left).  This  process  air  is  then  directed  towards  a  biofilter,  housed  within  a  smaller  container.  The  photograph  on  the  right  shows  how  the  containers  are  transported  and  unloaded,  with  the  assistance  of  a  roll-‐off  truck.  

 

Figure  10:  Modified  transportable  composting  container  

Shown  in  Figure  10  is  an  example  of  a  large-‐scale,  on-‐site  batch-‐type  composting  unit  produced  in  Western  Australia.  A  modified  transport  container  houses  a  removable  vessel,  which  contains  the  compostable  organics.  The  transport  container  is  fitted  with  an  aeration  fan,  biofilter  and  temperature-‐monitoring  unit  (left).  Process  control  is  similar  to  the  systems  manufactured  in  the  United  States,  shown  previously.  The  photograph  on  the  right  shows  how  the  internal  vessel  is  positioned  inside  the  transport  container  with  the  assistance  of  a  mobile  carriage.  This  in-‐vessel  system  is  unique  due  to  the  flexibility  in  processing  location  due  to  its  mobile  equipment  (Recycled  Organics  Unit,  2007).  

Large-‐Scale:  Continuous-‐flow,  vertical-‐composting  systems  

 

Figure  11:  Vertical  tower  composting  container  

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Figure  11  displays  examples  of  in-‐vessel,  continuous-‐flow,  vertical  composting  technology  currently  utilized  in  Australia  and  New  Zealand.  The  unit  on  the  left  consists  of  a  5  cubic  meter,  insulated-‐wall  composting  tower  with  a  blending  unit  and  screw  auger  transfer  mechanism.  The  picture  on  the  right  shows  a  similar  unit  with  a  25  cubic  meter  capacity.  The  small  land  area  occupied  by  these  systems  provides  location  flexibility  at  a  higher  capitol  cost.  

Continuous-‐flow,  horizontal  composting:  

 

Figure  12:  Large-‐scale,  horizontal  composting  system  

Figure  12  illustrates  an  example  of  a  modular,  continuous-‐flow,  horizontally  mounted  in-‐vessel  composting  system  used  in  New  Zealand.  This  technology  is  available  in  a  range  of  sizes  and  can  process  between  1  and  10  tons  of  compostable  organics  per  day  (Recycled  Organics  Unit,  2007).  

The  important  point  to  note  from  the  many  different  examples  provided  is  exactly  that  there  are  many  different  types  of  in-‐vessel  composting  systems,  and  careful  consideration  must  be  made  before  making  the,  typically  large,  capital  investment  in  purchasing  an  in-‐vessel  unit.  There  are  two  main  approaches  to  the  different  types  of  in-‐vessel  units:  centralized  and  de-‐centralized.  The  centralized  approach  would  involve  a  high  investment  into  a  system  with  a  large  processing  capacity  that  can  handle  the  entire  waste  stream.  A  de-‐centralized  approach  would  be  to  purchase  multiple  smaller  units  that  can  handle  the  waste  volumes  for  specific  generation  points.  This  approach  could  work  particularly  well  on  a  university  campus  by  having  the  properly  sized  unit  to  handle  the  waste  stream  from  individual  dining  facilities.  

Choosing  the  proper  composting  processing  method  requires  careful  analysis  of  feedstocks  and  the  accompanying  waste  streams  to  see  what  would  work  best.  Many  universities  begin  with  a  low-‐cost  system  involving  windrows  on  multiple  acres  of  land.  Once  the  composting  system  is  proven  effective  they  advance  to  a  higher  cost,  superior  technology  processing  method  of  in-‐vessel  or  anaerobic  digestion.  Table  2  compares  the  pros,  cons,  and  approximate  processing  time  for  each  processing  methodology.  

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Table  2:  Processing  System  Comparison  

METHOD   ADVANTAGES   DISADVANTAGES   RETENTION  TIME  

Pile  

• Low  labor  cost  • No  turning  required  • Low  cost  

• Longest  composting  time  • Requires  precise  nutrient  mixture  

• Requires  space  to  allow  piles  to  sit  for  long  time  periods  

Approximately  4-‐6  months  

Windrow  

• Faster  composting  time  • Low  cost  • Handles  large  volumes  • Remotely  located  

• Takes  up  large  land  area  • Requires  precautions  for  leachate  and  odor  

• Requires  expensive  equipment  • Labor  intensive  

Approximately  2-‐3  months  

Bins  

• Good  air  circulation  • Inexpensive  • Little  labor  • Faster  compost  production  utilizing  varying  stages  of  decomposition  

 

• Used  for  smaller  amounts  of  food  waste  

• Odor  and  leachate  control  necessary  

• More  specialized  knowledge  for  bin  transfer  

Approximately  1-‐3  months  

In-‐Vessel  

• High  degree  of  control  • Mechanical  or  Automated  • Fastest  compost  production  • Transportable  containers  effective  for  urban  areas  

• Protection  from  weather  

• High  cost  of  equipment,  buildings,  and  overhead  

Approximately  2-‐4  weeks  

   Case  Studies    

Ohio  State  

College  campuses  around  the  nation  have  begun  the  implementation  of  composting  programs  diverting  waste  and  creating  more  environmentally  conscious  campuses.  Ohio  State  University  is  leading  the  way  by  committing  to  zero  waste.  Their  program,  like  CAP,  calls  for  zero  waste  by  2030.  In  2011  they  went  one  step  further  by  committing  to  90%  diversion  of  waste  from  football  games.  Ohio  State,  like  Auburn,  attracts  over  100,000  people  to  campus  during  game  days,  and  if  these  people  can  start  the  composting  trend  then  the  students  will  follow  this  trend  on  campus  in  everyday  life.    

The  OARDC  composting  site  is  a  full-‐scale  windrow  composting  facility  with  an  aerated  concrete  composting  pad.  The  facility  is  just  over  2  acres  and  has  two  29,750  sq.  ft.  pads  one  concrete  and  one  hard  packed  soil,  Figure  13.  The  concrete  pad  is  specially  made  for  composting  with  3/8th  inch  holes  drilled  in  it.  Fans  connected  to  these  holes  allow  increased  airflow  in  the  pile.  Both  pads  are  surrounded  by  a  wood  chip  filter  berm  to  filter  out  leachate  and  runoff.  Beyond  the  filter  berm  is  a  retention  basin  that  collects  the  overflow  runoff  diverting  it  to  a  constructed  three-‐cell  wetland  to  treat  the  stormwater.  

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This  facility  uses  covers  for  the  piles  to  reduce  nitrogen  leachate.  During  covered  periods,  the  fan  and  aeration  system  in  the  concrete  pad  helps  provide  aeration.  

 

The  OARDC  composting  site  has  a  covered  barn  that  houses  all  the  equipment  needed  for  mixing  and  moving  the  materials.  The  facility  has  a  skid  steer  loader  and  an  Aeromaster  120  windrow  turner,  seen  in  Figure  14,  is  used  for  turning  the  rows.  Also  in  the  shed  is  a  feed  wagon  with  weighing  scales  to  determine  the  volume  of  materials  going  in  and  out  of  the  facility.    

Figure  14:  Aeromaster  120  Windrow  Turner  

 

 

 

 

Figure  13:  Ohio  State  composting  facilities  

Figure  13:  Ohio  State  Composting  Facility  

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Seen  in  Figure  15,  Ohio  State  has  grown  its  composting  program  to  just  over  2200  tons  of  organic  waste  in  2014.  Before  this  program,  15%  of  organic  waste  was  being  diverted  from  landfills.  After  implementation,  35%  of  organic  waste  is  being  diverted.  An  even  more  impressive  percentage  is  being  diverted  during  football  season  now  with  a  high  in  the  2014  season  of  98.8%  diverted.  Ohio  State  averaged  a  seasonal  diversion  rate  of  95.24%,  and  only  sent  1.95  tons  of  waste  to  the  landfill  compared  to  the  5.8  tons  in  2013.  

Figure  15:  Ohio  State  composting  statistics  

Ohio  State  has  shown  the  effectiveness  of  a  campus-‐wide  composting  operation,  and  even  merged  the  program  with  the  athletics  facilities.  Auburn  University  can  benefit  greatly  from  following  a  similar  model  tailored  to  a  college  campus.  Table  3  highlights  several  key  components  of  Ohio  States  successful  composting  program.  

Table  3:  Ohio  State  composting  facts  

Ohio State OARDC Composting Facility

Site Size 2 acres

Annual Organic Waste 2,200 tons

Diversion rate 35.00%

Compost value $20-$60 per ton

Landfill Tipping fees $30 per ton

22  

Cornell  

In  1992  Cornell  University's  composting  facility  began  as  a  1.4  acre  windrow  pad  and  small  retention  pond  to  compost  animal  bedding  from  the  Veterinary  school.  In  1999,  phase  two  began  by  introducing  new  feedstock  to  the  composting  facility.  With  this  increase,  they  expanded  the  pad  to  cover  1.7  acres  and  added  a  224,000-‐gallon  retention  pond.  In  2003,  Cornell  implemented  the  third  phase  of  the  composting  plan,  which  expanded  the  program  to  include  pre  and  post-‐consumer  food  scraps  from  dining  halls  on  campus.  Table  4  displays  the  major  components  of  Cornell  composting  feedstocks.  The  final  addition  to  the  facility  entailed  increasing  the  pad  to  approximately  4  acres  for  windrow  operations.    

Table  4:  Feedstock  Quantities  

Feedstocks used in Composting

Pre and Post-Consumer Food Scraps 850 tons per year

Animal Bedding 3,300 tons per year

Plant Material 300 tons per year

 

The  composting  site  is  surrounded  by  a  topsoil  berm  that  prevents  flooding  of  the  windrow  pad  and  diverts  leachate  runoff  to  a  retention  pond.  The  224,000-‐gallon  retention  pond  to  collect  rainwater  runoff  from  the  site,  and  this  water  is  used  to  irrigate  the  windrows  resulting  in  a  net-‐zero  water  facility,  seen  in  Figure  16.  The  pad  is  constructed  of  many  layers  of  geo-‐textile  cloth  and  gravel  to  increase  airflow  within  the  piles.    Cornell’s  equipment  fleet  runs  entirely  on  B20  biodiesel  to  reduce  greenhouse  gas  emissi