INTERNATIONALBIOCYCLE

INTENSIVE source sep-aration of organics(ISSO) represents astrategic decision, and isItaly’s key factor forreaching an overall highperformance of residen-tial source separationschemes. It has the dualpurpose of maximizingorganics diversion fromlandfills and reducingthe amount of putresci-ble materials in residualwaste to less than 10 per-cent. This allows residu-al waste collection fre-quency to be drasticallyreduced, making theoverall scheme economi-cally viable.

ISSO started in the northern part ofItaly in the mid-1990s, with two drivingforces: lack of space in landfills and (con-sequently) increasing tipping fees. Com-pared to the traditional scheme still in usein many parts of Italy, which is based on

large centralized con-tainers placed on theroads (“bring” schemes),ISSO is a “fetch” schemeand has some distinctivefeatures that boost thequality and diversionrate of recyclable frac-tions. All of the wastefractions (organics, dryrecyclables and residualwaste) are collected atthe curbside.

Several characteristicsof ISSO make it highlysuccessful. Food wasteis set out in small, certi-fied compostable bagswhile curbside collec-tion of yard trimmings

is discouraged to address waste mini-mization. Yard trimmings collection islimited to seasonal services linked toPAYT (pay as you throw) systems, andvia promotion of backyard compostingwhen possible (the general rule is:“when there is a courtyard that pro-

duces green waste there is also an areato do home composting”). In any col-lection scheme (bring or fetch), citizenshave the option of taking materials suchas yard trimmings to drop-off locations(recycling facilities or waste transferstations).

A major benefit of ISSO is an overalldecrease in residential waste genera-tion, due to limits on curbside setouts.Nonresidential waste is also reduced be-cause it can no longer be dropped offanonymously in centralized roadsidecontainers. The integration approachcalls for high frequency collections offood waste, in order to keep organicslow in the residual waste stream. Or-ganics collection typically ranges fromtwo to three times a week, depending onthe Mediterranean/Continental climateand season. This enables use of smaller(4 to 6 cy capacity) collection truckswithout compaction. Single familyhomes are given 8- or 10-gallon curbsidebins, which can be manually tipped, re-ducing collection time; condos are pro-vided 32- to 64-gallon carts (mechanical-ly tipped), serving 10 to 20 householdseach. Two-gallon vented kitchen pailsand yearly supplies of compostable bagsare given to each household (bags arecertified according to European com-postability standard EN 13432). Residu-al waste typically is collected weekly.

Positive EconomicsAfter 15 years of experience in the

field, estimates from 2009 show thatmore than 1,800 municipalities in Italyare source separating according to theISSO model. Additionally, another 700are using the “bring” scheme with cen-tralized carts (100 to 250 gallons) for or-ganics collection, placed on the roadsand serving many households at thesame time. The differences in capturerates and purity of the collected materi-als are striking: Participation rates are 80percent or greater and impurities areless than four percent in most situations.

A key aspect of ISSO is its economicviability. A survey completed in March2010 focused on the economics of collec-tion schemes in the Region of Lom-bardy, in northern Italy. Milan is the

BIOCYCLE APRIL 2010

The Italian model of intensive residential food wastecollection achieves impressive diversion rates withouthigher costs, and is catching on in Spain andthe United Kingdom.

Michele Giavini and Christian Garaffa

Italy

Intensive SourceSeparated Organics

Single family homes aregiven 8- or 10-galloncurbside bins to set out foodwaste.

capital of Lombardy, and the regioncontains one-sixth of Italy’s population.The survey was based on detailed eco-nomic data reported by all 1,546 munic-ipalities in the region (including Milan),which shows that door-to-door collec-tions with the ISSO model are highly ef-fective when looking at overall costs.

All municipalities in Lombardy arerequired to enter detailed data aboutwaste collection in a web-based applica-tion approved by the Regional Environ-mental Agency (ARPA). According tothis database, about 850 municipalitiesin the region are collecting with the ISSOmodel, about 300 municipalities collectfood waste using centralized road con-tainers and the remaining communitiesdo not collect food waste at all. An eco-nomic evaluation of the data finds thataverage overall costs (including collec-tion, disposal and recycling) for munic-ipalities with the ISSO model are ap-proximately 10 percent lower than theother sample (road containers), but withalmost twice the diversion rate (averag-ing 53.2 percent compared to 30.5 per-cent). Among the municipalities follow-ing the ISSO model, 192 show adiversion rate of 60 percent or greater,yet bear the same average costs as thosediverting less than 40 percent.

Some unexpected outcomes were un-covered by the survey, based on use of anew indicator for evaluating economicefficiency. This indicator expresses nor-malized overall costs for waste collec-tion and treatment per equivalent in-habitant, per year (i.e. accounting fornonresident citizens and nondomesticactivities), and excludes costs not direct-ly related to waste collection such asroad cleaning (Figure 1). One of theseoutcomes is lack of a strong relationshipbetween overall costs and geographic ordemographic parameters, meaning thatwaste management costs don’t changemuch between densely and sparselypopulated areas. This is because everymunicipality succeeded in fitting thegeneral collection model to its specificcircumstances.

Another impressive outcome, shownin Figure 2, illustrates the different costsfor collection and treatment/disposal,using subsets of municipalities with thesame recyclables diversion rate. It isclear that overall treatment costs de-crease with higher diversion rates, be-cause of the lower tipping fees for mostrecyclables. Collection costs tend to

slightly increase (especially with over 60percent diversion), but not as much aswas commonly thought before thisstudy. This is the result of collection fre-quency optimization performed by mu-nicipalities after years of experiencewith the first pilot areas.

Education Is Key Education campaigns are crucial for

the success of ISSO collection, as citi-zens must believe in what they arepushed or required to do. These cam-paigns also need to be repeated, per-haps every other year. For instance,ETRA SpA, an Italian company, man-ages the integrated water and munici-pal solid waste treatment service in theVeneto Region. A recent study by ETRAof 170 municipalities doing ISSO foundthat when there is a “not monitored”situation (i.e. without sensitization/ed-ucation campaigns), impurities in foodwaste increase to seven to eight percent,

compared to the standard of two tothree percent in a well-managed situa-tion. For reference, when residential or-ganics are collected with big road con-tainers, impurities can get up to 10 to 20percent. ETRA started a communicationcampaign called “umido pulito” (“cleanfood waste”) which helped in reducingcontamination back to the 2 to 3 percentlevel, resulting in savings of about 1a/inhabitant/year. The contaminationlevel is particularly important becauseit leads to extra costs at organic recov-ery facilities.

Another very important issue is whatmethod is used to deliver compostablebags to citizens for the collection of or-ganics. Where they are provided for“free” (the cost is charged on the wastetax fees), the collection works perfectly.Another option is free (but controlled)distribution of bags through a local re-tail network, or via prepaid cards usedat vending machines that sell bags(charged directly to the waste tax). Col-lection quality and participation de-creases when citizens are not directlysupplied with compostable bags. Al-though some will purchase the bags atretail stores, others will tend to use non-compostable bags or won’t participatein the SSO scheme at all.

The remaining challenge to address iswhen municipalities still allow foodwaste collection in polyethylene bags,thinking only of the short-term costs be-ing cheaper than biodegradable/com-postable bags. This initial price doesn’tfactor in higher overall costs due tomore intensive and expensive pretreat-ment and screening systems to handleplastic contamination at organic recov-ery facilities, disposal of plasticresidues, and risks of producing a lowerquality compost.

Another important strategy withISSO — to ensure high diversion rateswhile controlling overall cost — is to op-timize collection frequencies. This mustbe done when the municipality firststarts the new curbside collectionscheme. Occasionally local govern-ments are afraid that citizens will rejecta lower frequency collection schemeand try setting an experimental transi-tion period to ease into the new pro-gram. However, this endangers the via-bility of the whole program, because it’svery difficult to then implement astricter program once citizens get usedto an “easy” model. Instead, the desired

BIOCYCLE APRIL 2010

BIOCYCLE INTERNATIONAL

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FIGURE 1. Overall standardized costsfor subsets of municipalities inLombardy with the same percentdiversion rate of recyclables.

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BIOCYCLE APRIL 2010

INTERNATIONALBIOCYCLE

collection frequency should be imple-mented from the beginning, using theaforementioned household tools to easethe transition: two bins (kitchen andcurbside), as well as a supply of com-postable bags.

Overall, ISSO schemes in northernItaly have been widely successful, andcontinue to influence trends in othercountries. The model is spreading to Eu-ropean countries such as Spain and theUnited Kingdom, particularly in areaswhere some concurrent elements arepresent: lack of landfill space and in-creasing tipping fees, available orplanned composting or anaerobic diges-

tion capacity, regional regulations man-dating separate organics collection andadoption of the diversion targets givenby the European Union Landfill Direc-tive 99/31/EC. �

Michele Giavini runs Ars Ambiente Srl, aconsultancy for waste management focusingon source separation and planning of com-posting facilities. (giavini@arsambiente.it).Christian Garaffa is Marketing Manager forsource separation & recycling at NovamontSpA, producers of compostable polymers. Hechairs the working group for waste & recov-ery of the European Bioplastics Association(christian.garaffa@novamont.com).

Organics collection ranges from two tothree times a week, enabling use ofsmaller (4-6 cy capacity) collectiontrucks without compaction.

ADVANCING COMPOSTING, ORGANICS RECYCLINGAND RENEWABLE ENERGY

419 State Avenue, Emmaus, PA 18049-3097610-967-4135 • http://www.biocycle.net

Reprinted From:April, 2010