Pennsylvania – Composting Rules

On-farm, Small-scale Composting

Pennsylvania’s General Permit WMGM017 pertains to on-farm composting of residual and municipal waste, whereas the WMGM042 permit is for anaerobic digestion of animal manures and food waste. The WMGM017 permit allows farmers to compost materials including: yard waste, untreated wood waste, paper, cardboard, agricultural wastes (except for mortalities), and food processing waste (whether pre-consumer and post-consumer food residuals). After these materials have been composted, the resulting product is no longer considered waste and the farmer can sell or distribute it as desired.

In order to qualify for a general permit, the compost facility’s total storage space for all its waste materials, composting areas, and finished product cannot exceed 15 acres. (Storage areas for bagged retail products are not included in the 15 acre maximum.) In addition, a financial bond for a sum that “guarantees the removal and proper management of any feedstocks, compost, and finished products, is required for facilities larger than five acres and for facilities less than five acres if the total volume managed at the facility exceeds 6,000 cubic yards per acre.”


Other provisions stipulated by the latest version (2020) of the WMGM017 permit include, but are not limited to:

A site plan of the compost facility along with a description of the procedures used to assure compost quality, as well as a plan for nuisance minimization so that activities do not negatively impact the quality of air, water, or public health.
Composting methods must be via windrows, aerated static piles, or in-vessel. Windrows must maintain a minimum temperature of 55 degrees C for 15 days and turned in consistency with currently accepted science-based composting technology. Aerated static piles and in-vessel systems must maintain that same temperature for 72 consecutive hours.
Incoming food scrap must be incorporated into the composting processes within 24 hours. Incorporation of all other materials must occur within one week of receipt.
The compost pad options include “a compacted mixture of select granular material with adequate fine-grained particles to bind it together and reduce permeability,” lime-stabilized soil blends, or paving with concrete, asphalt, or geosynthetics. All compost pads much be sloped at 2-4% to prevent ponding of liquids and storm water should be diverted away from the composting area.
The permit also requires that the compost operation cannot be within a 100 year floodplain, 300 feet of an “exceptional value wetland,” within 100 feet of a wetland other than an exceptional value wetland, within 300 feet from an occupied dwelling, within 50 feet of a property line, within 300 feet of a water source, within 3.3 feet of a ground water table, or within 100 feet of a perennial stream.


As stated in the Pennsylvania Code § 287.101, parties are exempt from obtaining a permit if materials are generated as part of “normal farming operations”–which includes food processing waste or sludge that were generated as part of the farm’s operations–and are not hazardous. Forms of material management on a farm that overstep or violate the law’s stated conditions may result in the Dept. of Environmental Protection (DEP) requiring the facility operator to obtain a solid waste permit (or take other action deemed appropriate) if the composting activity poses “a threat of harm to the health, safety or welfare of the people or the environment of this Commonwealth.” Of note is that, while mushroom composters may qualify to be exempt from obtaining a permit, they must follow best management practices (Document 254-5401-001) laid out by the DEP.


Disposal Ban on Yard Trimmings

Pennsylvania, like many other states, has regulations that prohibit yard trimmings in landfills. The state has prohibited yard trimmings in landfills since 1990. However, because the applicability of the law banning green waste from landfills does not extend to grass clippings, Pennsylvania’s ban is less encompassing than many states, including Massachusetts and Minnesota, which ban yard trimmings in landfills regardless of their source of origin. Below is a list of the sections of Pennsylvania’s Code pertaining to the leaf waste disposal ban.

Chapter 271.1 — Definition of “leaf waste”

Section 272.422 — Municipal ordinance requiring separation of leaf waste at residential, commercial, municipal, or institutional establishments

Section 273.201 (j) — Loads composed primarily of leaf waste may not be disposed at a municipal waste landfill

Section 277.201 (j) — Loads composed primarily of leaf waste may not be disposed at a construction/demolition waste landfill

Section 283.201 (g) — On and after September 26, 1990, loads composed primarily of leaf waste may not be processed at a municipal waste processing facility [which includes resource recovery facilities and incinerators but not transfer, composting facilities nor incinerators operating under permit-by-rule] except for purposes of composting.



Original post from July 30, 2012
Updated July 26, 2021