2005-07-26_PWETC_AgendaPacket - Laserfiche WebLink

Home

As discussed in Appendix G, Beck/Krivit reviewed literature regarding processing residuals. In addition, WM/RAA did provide the results of an internal study at the Minneapolis MRF in 2003 of single-stream residuals (Appendix F). Key items regarding residuals and contamination issues: WM/RAA Studv . The WM/RAA study was internal, and the information that was provided was in summary form; thus no critical review was possible. . The study was performed for materials collected only from single-stream routes in the Twin Cities area (normally this MRF processes material from non-single-stream sources as well), and it showed that 5.95% of total inputs became residuals. These materials included. both contamination by residents at the curb (non-targeted materials) and residuals from facility operations (processing residuals, such as dirt and very small pieces of material). . Note that this 5.95% number is actually below or at the low~rid of the. confidence intervals for contaminants found in the single-stream pilot study areas, which onlyillclude contamination at the curb (see Appendix D, Tables 4 and 5), not processing,esiduals from MRFoperations. . Beck/Krivit note that the WM/RAA study consider~dboth the 2% of colorcs()rted glass and II % of color-mixed, broken glass to be defined as a product;. Were the II % of colorcmixed, broken glass not considered to be a marketed, recycled commodity, the.residuaFrate would be about 17% for this facility. . No comparison of dual-stream versus single-stream residuals is available for this facility. . The study cited its production standard of an average of 1.5% or)ess for total contamination (outthrows and prohibitives) for its newspajJergrade with an actionJimit of2%. The study stated that sample bales pulled at random met this standard. Other Studies . An R.W. Beck study f()fthe Amerisan Forest aIldPaper Association (AFPA) showed significantly higher "prohibitives" in n~""spaperand mixed paPRffrom single-stream versus dual-stream sources. Another consulting study (Jaakkol'oyry Consultillg and Skumatz Economic Research) for the AFP A showed an incre.ase in net recycled tOllllagefrom single-stream. . The EurekaRecyclirigpilot studyjIl2001-2, which used data from single-stream programs elsewhere in the S()l)l)try, showed allayeragere~iql)al rate of about 16% when mixed glass is considered to be recycled,atl<l27% when itisnot considered recycled. Bale Audit Bale audits are conductedtoassess the quality and composition of processed recyclable material. Four metro area recycling coordinators were invited to witness a paper bale audit at the Waste Management/Recycle America Alliance (WM/RAA)MRF in the fall of2004. A crew took a finished bale of Number 8 News, broke it open, removed non-targeted material and weighed the non-targeted material- primarily other types of paper such as boxboard, although there were a few containers. In consultation with its paper mill customers, Waste Management set a standard of 1.5% (average) of non-targeted material- also called prohibitives and outthrows. (Note: the Institute of Scrap Recycling Industry 2004 standard for unwanted material in a bale of Number 8 News is Y. of 1 %). The weight of the prohibitives and outthrows in the bale was approximately 1.5%. This did not include fine particles of glass visible on some of the paper. The exact percentage of bale material collected through a single-stream process was unknown because the recycling coordinators were not able to witness the paper being processed before it was baled. And 21