PROP's Compost Directory Welcome to PROP's compost directory home page. Clicking on a county will open a page for that county which will have a list of composting sites, or composting operations in that county. Online Certification Course Sponsor If the county is not colored we either have no listing of composting sites within that county, or have not received information back from that county about any composting operations. If you know of a site, either owned privately, by the township, or by a municipality that is not listed on the county's page, or if the information we have is incorrect, please email PROP and place {Compost Directory} in the subject line of the email so we can make the changes as soon as possible. For a more comprehensive look at composting within the commonwealth, you can view the PA DEP's Composting Location Reports found on the PA DEP's website.