2011:
The Streets Division is planning a pilot collection program for collecting household organics from a select group of households. The number of households will be determined by the funding available in the 2011 Operating Budget. The funding will also determine the start date.
The goal is to have at least 500 households in two different refuse collection district, one east and one west.
Material collected will include food waste, pet waste, contaminated paper, waxed cardboard and possibly diapers.
In addition to the collection pilot, the program will also include a mail survey of 1000 Madison households and a later internet survey.
The 2012 City Operating Budget includes funding for a feasibility study on an anaerobic digester. The intent is to hire an experienced consultant to conduct the study.;
The Engineering Division conducted a wetlands mapping survey of potential digester sites located near the Dane County Landfill. Other City owned parcels may also be considered for a digester. Those sites are yet to be determined.
City staff is also looking at the various technologies that could be employed for a digester.
2012:
For the first six months of the pilot program we collected 13.8 pounds per household per week. That would translate into 21-25,000 tons of material per year, which is more than our waste sort indicated was in the waste stream. Staff believes that the volunteers are very committed to the program which accounts for the higher than anticipated diversion.
Data was collected from our volunteers for Mater B, the plastic resin producer that provided us with bags for the first six months of the program. They were quite pleased with the response and the information will be presented at a Bio Cycle conference in Portland, OR in April
March, 2012:
City staff has determined that the best location for a digester will be near the Rodefeld landfill. Staff will begin discussions with Dane County on how best to locate the facility and develop a plan for facility sharing where feasible.
Staff has narrowed down possible consultants to four and will be conducting interviews. We hope to be able to report on a selection at the April 5th Solid Waste Advisory Committee meeting.
The plan is to expand the pilot program by adding 100 households on the west side in late spring. We currently have 300 households plus the Madison Children's Museum on the east side routes and 185 households on the west side.
2013
Some households were added to the west side pilot area but it fell short of the goal of adding 100. A few more households were put in on the east side as staff felt they could hadle the added workload. There are now just over 500 households participating in the program.
2014
The Streets Division has received funds in the budget to expand the pilot project by adding 1,600 households and 25 to 30 commercial establishments to the budget. The plan is to do the expansion in July. Recruitment will begin in May.
May, 2014
The pilot expansion program has been put on hold. The digester at UW Oshkosh has been informed by the composter Zilgas, that there is too much non compostable plastic material in the digestate when it comes form the digester. The Wisconsin DNR also has issues with the presence of pet waste in the material coming form Madison. The pet waste issue can be overcome easily. The contamination requires the Streets Division to screen the material. We will be testing several screens to see what might work.
July, 2014
Pilot participants were advised that we can no longer accept pet waste. The DNR is satisfied that this notification will assure that only incidental amounts of pet waste will come into the colelction program so they will allow us to proceed.
August, 2014
It was determined that a screen adequate for our purposes would cost $120,000. At this time there is no funding in the budget for the screen. A decision was made as part of the capital budget process to postpone the digester construction by one year to 2017. Based upon this decision and the lack of funds for the screen, the Streets Division has determined that the pilot will come to an end in September.
September, 2014
The Council has voted to allow the Streets Division to use $120,000 from the Sustainability Fund for the purchase of a screen. The Streets Division will continue the pilot program while conducting more screen testing. The expansion of the pilot to commercial facilities will go forward ASAP. The expansion to the 1,600 households has been put on hold because it will not be possible to get the households recruited and carts distributed before the start of leaf collection. At that time, the Division will not have staff to take on the distribution of carts for the start up of the expansion. The household expansion will be put on hold until spring, 2015.
2015
The problem with contamination continues to put our expansion plans on hold. The amount of contamination is relatively small. However, since the composter who is processing the digestate from the Oshkosh digester generates its revenue by selling high end compost, the contamination is enough to jeopardize revenue.
February, 2015
After continued study staff has determined that additional screening of our material prior to sending it to Oshkosh will not resolve the contamation problem. At the root of the problem is that fact that we must use existing equipment to shred the material after collection. (Shredding is necessary in order to break open the compostable bags and expose the material inside to the digester's bacteria.) We use our Peterson Pacific shredder to process the organics and this shredder has a screen that reduces the material to a one inch size. This means that any contaminants in the material are reduced to a size too small to screen out later.
April, 2015
Working with staff at Oshkosh we have come up with a plan to keep our material seperate when it is loaded into the digester and when it is removed. Streets staff will haul the digestate from our material back to Madison when we make deliveries to Oshkosh. The digestate will then be mixed with elaves and yard waste at Circle B and composted. We will test this system out for 60 days. If it works, we will proceed with our plans to expand the project.