Section 287.657. Anaerobic digestion.

Rule 7. (1)    Unless otherwise approved by the director, anaerobic digestion methods shall accommodate either of the following:

(a)     Normal daily natural mortality under common ownership.

(b)     Dead animals under the management of licensed dead animal dealers.

(2)        Anaerobic digestion technologies suitable for mortalities include plug flow and complete mix digester operating in the mesophilic and  thermophilic temperature ranges.

(3)     Anaerobic digestion systems shall consist of all of the following:

(a)     Controlled input of organic digester feedstock.

(b)     Controlled heating of digester feedstock, also known as digester contents.

(c)     Control of digester vessel atmosphere.   The  headspace   shall  contain less than 5% oxygen.

(d)    Biogas and digestate production.

(e)     Biogas destruction.

(f)    Digestate management in accordance with federal and state regulations.

(4)       Digester feedstock is commonly referred to as influent or substrate. Acceptable digester feedstocks for anaerobic digesters in this state include the following:

(a)     Livestock manure.

(b)     Waste animal feed.

(c)     Dead animals.

(d)    Yard waste or grass clippings.

(e)     Organic food processing waste.

(f)    Waste grease/trap grease.

(g)     Food waste intended for human consumption.

(h)     By-products from ethanol, biodiesel, and algal production.

(i)       Other digester feedstocks may be   approved   by   the   director   of    the Michigan department of  environmental  quality operating under a national

pollutant discharge elimination system permit.

(5)     Facilities operating under a national pollutant discharge elimination system permit shall comply with the terms and conditions of the permit when utilizing non-farm digester feedstocks for anaerobic digestion.

(6)      A person shall manage an  anaerobic  digestion  system  treating  dead animals in compliance with the guidelines described in the  Michigan  on-farm anaerobic digester

operational  handbook,  as  adopted  by   reference  in  R 287.651a, and in accordance with MCL 287.665.

(7)     A qualified anaerobic digester operator. The operator of an anaerobic digester shall meet all of the following requirements:

(a)        Possess the skills necessary to start, maintain, and troubleshoot an anaerobic digester.

(b)     Complete the Michigan-on-farm anaerobic digester operator certification course.

(c)         Obtain certification by the Michigan department of agriculture and rural development as an anaerobic digester operator. The Michigan on-farm anaerobic digester operator certification course provides instruction for persons seeking to obtain the skills and knowledge necessary to meet the Michigan department of agriculture and rural development's requirements for qualified digester operator certification. Information on  course  enrollment may  be   obtained   from   Michigan  State University         extension, (https://researchgroups.msu.edu/adrec) or the Michigan Department of Agriculture and Rural Development, P.O. Box 30017, Lansing, Michigan 48909.

(8)     One or both of the following methods of anaerobic digestion shall be used:

(a)     Plug flow anaerobic digester. A plug flow anaerobic digester is a long, narrow tank with a rigid or flexible cover. The tank is heated and often built partially underground to reduce heat loss.  Use of plug-flow digesters is limited to higher solids feedstocks. Plug flow digesters are generally not mixed, however, in some cases mixing is used to facilitate the process.

(b)         Complete mix anaerobic digester. A complete mix anaerobic digester is an enclosed heated tank with a mechanical, hydraulic, or gas mixing system. Complete anaerobic mix digesters are intended for slurry  or  liquid feedstocks.  Mixing ranges from intermittent to continuous.

(9)         Anaerobic digestion systems processing dead animals shall operate within the following parameters:

(a)     Temperature: 95 degrees Fahrenheit to 145 degrees Fahrenheit.

(b)     Hydraulic retention time: greater than 20 days. (c)  pH: 6.8 to 7.5.

(d)    Volatile solids loading: in the range of 0.02 to 0.25 pounds of volatile solids per cubic foot.

(e)     Total solids of the digester contents: not to exceed 20% (200,000 ppm).

(f)     Modifications to the operating parameters require approval from the director and may occur when the director has sufficient evidence that the modifications will allow the process to work effectively without causing harm to humans or the environment.

(g)       Processing is recommended to reduce dead animals prior to introduction into the anaerobic digesters. Particle size reduction to less than 2 inches in size improves heat transfer and exposes additional  surface area for biological activity.

(h)      All water used for or generated during particle size reduction must be put directly into digester or stored according to state regulations.

(i)       Dead animals shall be added to the anaerobic digester within 24 hours following death.

(j)      Afterbirth may be stored in closed impervious containers and shall be added to the anaerobic digester within 3 days of initiating container use.

(k)       The anaerobic digestion systems site shall maintain the following minimum isolation distances:

(i)        Two hundred  feet  from  waters   of  the  state   as  defined  in  R 287.651(1)(u)(i) to (viii).

(ii)       Two feet above the seasonal high water table, as defined by NRCS 313 Waste Storage Facility Conservation Practice Standard, and adopted by reference in R 287.651a.

(iii)     Not within a 10-year time-of-travel zone designated as a  wellhead protection area as recognized by the Michigan department of environmental quality, pursuant to the program established under the Michigan safe drinking water act, PA 399 of 1976, MCL 325.1001 to 325.1023, unless approved by the local unit of government administering the wellhead protection program. Where no designated wellhead protection area has been established, construction shall not be closer than the minimum isolation distance as stated on the well permit for a Type I or Type IIa public water supply. Facilities shall not be constructed closer than 800 feet to a Type IIb or Type III public water supply unless the structure is located in accordance with Table 1 of the Natural Resources Conservation Service Technical Guide Waste Storage Facility (No) 313.

(iv)     Two hundred feet from nearest non-farm residence.

(l)      The disposition of digestate may be by direct application to soils, sale, or other transfer of ownership. Application to soils shall be done in accordance with the recommendations within the Generally Accepted Agricultural and Management Practices for Nutrient Utilization, January 2010,

as      specified      in      1981       PA      93,      MCL      286.471,      and      published      at http://michigan.gov/mda/0,1607,7-125-1567_1599_1605-70361--,00.html.

(m)     In the interest of public health or animal health, the director may require that any digestate be tested at a laboratory approved by the director for certain pathogenic organisms or  any  contaminant  at  any  time before the digestate is land applied.

(n)        The owner or operator of the anaerobic digester shall keep records for 5 years containing the following information and shall make the  records available to the director immediately upon request:

(i)       The approximate weight, maturity, and species of dead animals or afterbirth added each time an addition is made and the dates the tissue is added to new batches.

(ii)     The daily input mass or volume of all digester feedstocks.

(iii)     The daily temperature digester contents.

(iv)     Daily biogas production information.

(v)     Quarterly biogas composition information.

(vi)     System maintenance and operation logs.

(vii)          Design and construction documents showing the as-built capacity of the anaerobic digester

(viii)        The final disposition  of   digestate,  including   the  method, destination, date, and volume for the batch.

(ix)      A contingency plan to remedy problems and ensure the proper disposal of dead animals by anaerobic digestion. The contingency plan shall include all of the following information:

(A)       A contingency plan shall be prepared to describe how digester contents will be managed in the event of a biological failure. The contingency plan shall identify at a minimum how to restart the digester,  and   how  state regulations will be followed  in the event that the digester cannot be restarted. The plan shall include management of dead animals and digester contents if operation of anaerobic digestion is interrupted or terminated.

(B)    A list of both of the following:

(1)     The location of telephone numbers for and emergency  numbers  for  the police, the fire department, and medical aid.

(2)     The person or persons  responsible for operation of the anaerobic digester.

(C)    An action plan for all of the following emergencies:

(1)     Fire.

(2)     Wind.

(3)     Flood.

(4)     Other mechanical failures.

History: 2011 AACS.