Minn. R. agency 167, ch. 7020, STANDARDS FOR DISCHARGE, DESIGN, CONSTRUCTION, OPERATION, AND CLOSURE, pt. 7020.2150

Current through Register Vol. 49, No. 19, November 4, 2024

Part 7020.2150 - MANURE COMPOST SITES

Subpart 1.General.

An owner composting only manure at a manure compost site shall comply with subparts 2 and 3. An owner composting manure and solid wastes shall comply with part 7035.2836, subparts 4 to 7. An owner composting dead animals shall comply with part 1721.0740.

Subp. 2.Operational requirements.

An owner of a manure compost site meeting the requirements of subpart 1 shall comply with items A to C.

A. The owner shall comply with part 7020.2125.

B. If operating a compost site under part 7020.2125, subparts 1 to 3, the owner shall comply with part 7020.2125, subpart 4, item C.

C. The owner shall produce finished compost by a process to further reduce pathogens (PFRP). The temperature and retention time for the material being composted must be monitored and recorded each day. The owner shall comply with one of the PFRP methods in subitems (1) to (3).

(1) The windrow method for reducing pathogens consists of an unconfined composting process involving periodic aeration and mixing. Aerobic conditions must be maintained during the compost process. A temperature of 55 degrees Celsius must be maintained in the windrow for at least three weeks. The windrow must be turned at least once every three to five days.

(2) The static aerated pile method for reducing pathogens consists of an unconfined composting process involving mechanical aeration of insulated compost piles. Aerobic conditions must be maintained during the compost process. The temperature of the compost pile must be maintained at 55 degrees Celsius for at least seven days.

(3) The enclosed vessel method for reducing pathogens consists of a confined compost process involving mechanical mixing of compost under controlled environmental conditions. The retention time in the vessel must be at least 24 hours with the temperature maintained at 55 degrees Celsius. A stabilization period of at least seven days must follow the enclosed vessel retention period. Temperature in the compost pile must be maintained at least at 55 degrees Celsius for three days during the stabilization period.

Subp. 3.Record keeping and reporting requirements.

An owner of a manure compost site that is required to apply for and obtain a permit under part 7020.0405, subpart 1, item A or B, must:

A. analyze mature manure compost and maintain records of the results for:

(1) pH;

(2) moisture content;

(3) particle size;

(4) NPK ratio; and

(5) soluble salt content; and

B. if the owner's NPDES or SDS permit requires submittal of an annual report, include the following information in the annual report:

(1) the quantities and sources of manure and bulking agents delivered to the facility;

(2) temperature and retention time data for all compost produced; and

(3) the information recorded under item A.

Minn. R. agency 167, ch. 7020, STANDARDS FOR DISCHARGE, DESIGN, CONSTRUCTION, OPERATION, AND CLOSURE, pt. 7020.2150

25 SR 834; 37 SR 1396

Statutory Authority: MS s 115.03; 116.07; 122.23