On the afternoon of Thursday, June 9, Eric Walter of Black Bear Composting took a dozen of us associated with the Market Compost Drop-off project on a tour of his facility off highway 340 in Crimora. Started in October of 2011, the business currently occupies just a few of Eric’s 47 acres allowing most of the property to be a natural buffer.
First steps in the composting process involve emptying the 65 gallon bins collected throughout the Black Bear Composting service area which includes Charlottesville, Waynesboro, Staunton, Harrisonburg and Shenandoah National Park. This day’s route happened to pick up from Shenandoah National Park. This step includes one of several efforts to pick out non-organic contaminants to the composting process. Common contaminants include non-compostable plastic bags and wrappers, plastic bottles and utensils.
Green wastes are mixed with about four times their volume of equal parts dried leaves and wood chips. The leaves are delivered each fall from curbside collections in the Waynesboro area. Wood chips come from local landscapers. The water from bin washing is added to this mix which is arranged in long windrows and covered with a special black fabric which allows moisture to escape but sheds rain water. It is also very effective at keeping down odors and keeping out hungry wildlife.
The freshly assembled piles must be turned five times in the next 15 days to assure a ready supply of oxygen for the busy microbes breaking down the organic wastes. After the frequent turning phase, the piles stay covered for another two months and are monitored to verify they are reaching temperatures of at least 130 ° F but not more than 170°, the range within which pathogens and weed seeds are effectively killed without killing off the helpful microbes. Samples are sent to the Virginia Department of Environmental Quality to test for Salmonella and a pathogenic roundworm egg.
The piles then continue to cure uncovered for about four months after which they may be sifted through a 1/2 inch screen for the final end product. About 40% of the material from any one “finished” pile successfully makes it to this end stage with the remaining “overs” going back into the beginning of the composting process.
A newer, less labor intensive method of composting has been undergoing a trial period at Black Bear Composting since late last fall. Large concrete pads are overlaid with a grid of 4-6″ perforated PVC piping connected to a blower similar to those used to blow up bounce houses. The PVC piping is covered with wood chips and/or “overs” on which the incoming green waste mixed with leaves and/or wood chips is piled and then capped with 8-12″ of wood chips and/or “overs.” The blower is rigged to a timer to fire up for 5 minutes out of every 15 minutes 24 hours a day, effectively aerating the pile without mechanical turning. This process brings the pile to the required temperatures faster and more evenly and is proving a time, space and labor saving alternative.
Our tour ended with Eric helping us shovel up some finished compost for our home gardens.
Many thanks to Eric for the inspiring tour and offering such a great service for our valley! Black Bear Composting is an impressively low-tech, productive and scenic operation fighting environmental degradation with each binful of compostable material diverted from the landfill.
Thanks to Kate Guenther, Art Fovargue and Carl Droms for their photos!