Anaerobic Digestion, that is.
Last Tuesday (March 12) I had the opportunity to visit the Monterey Regional Waste Management District’s brand new AD facility that is in the process of becoming operational. In point of fact, as I toured the plant, a starter batch of digestate was being pumped into underground tanks, awaiting its introduction to a mixture of food- and greenwastes.
The AD process goes through several stages, commencing with that of bacterial hydrolysis, in which such organic materials as carbohydrates are converted to sugars and amino acids, following which acidogenic bacteria convert them into CO2, hydrogen, ammonia, and a variety of organic acids. Next, acetogenic bacteria converts these acids into acetic acid, after which methanogens convert the vetch into methane and CO2…pretty much the same process that takes place in a landfill or your gastric system. Pretty nifty insofar as the production of methane and compost is concerned, but there’s another situation in California that needs to be considered.
First, a little background on the status of AD as a diversion practice in the state of California as presented by the analysis of a proposed amendment to AB 997:
The California Integrated Waste Management Act of 1989 establishes an integrated waste management program administered by the Department of Resources Recovery and Recycling that requires each city, county, and regional agency, if any, to develop a source reduction and recycling element of an integrated waste management plan. The element is required to divert 50% of the solid waste subject to the element through source reduction, recycling, and composting activities. The act allows the source reduction and recycling element to include not more than 10% diversion through transformation, which is defined as excluding, among other things, composting. The act defines the term “composting” for the purposes of the act as the controlled or uncontrolled biological decomposition of organic wastes. The act also defines the term “solid waste facility,” for purposes of the permitting requirements of the act, as a composting facility.
This bill would define the term “anaerobic digestion,” for purposes of the act, as a process using the bacterial breakdown of compostable organic material in a controlled environment that meets the parameters that may be established by the department, and would revise the definition of the term “composting” to include anaerobic digestion
It is this interpretation that has separated AD from other conversion technologies (CTs), allowing them to receive full diversion credit relative to the state’s 50% (soon to be pushed to 75%) diversion mandate. Effectively, this has given the green light to AD investment, while other CTs, stuck with minimum—and soon to become even more minimum—access to materials and diversion credits, will likely find themselves locked out of the state’s waste management business.
As much as I like what’s happening with AD in California, I am seriously concerned by the state’s continued opposition to other CT opportunities. What appears to be happening between the lines is that the amendment, rather than allowing innovation, will stifle it. Present California law does not provide any diversion credit to CTs or new WTE facilities. Moreover, as the state’s mandated diversion rate moves up the scale, little is likely to be left beyond inert materials to work with…a situation in which no investment is remotely possible.