Now that you’ve implemented your process (perhaps the Bioset Process?) for turning sludge into Class A biosolids, you’re probably faced with a new concern: what to do with all this high-quality fertilizer? If you’re providing it to farmers or citizens for land application, it might go out fast enough during some seasons of the year, but municipalities are generating wastewater year-round, even if the ground is frozen or fallow. The EPA provides guidelines for biosolid storage. Some of the primary concerns are:
- Site Selection Considerations
- Field Storage: Stockpiles
- Field Storage: Constructed Facilities
- Odor Prevention and Mitigation
- Spill Prevention and Response
For site selection, you’ll want to consider some key factors:
- Climate: How will weather affect the location? Do the prevailing winds blow odor toward a community? In many areas of the United States, land application of biosolids is severely limited from November through March.
- Topography: Is the location regularly inundated by water or in a wetlands? Is it fairly level? Stockpiles should be near the top of slopes to minimize exposure to up-slope runoff. Storm water controls may be necessary. Storage locations should be in areas with adequate buffers.
- Soil/Geology: Sites should not be located on excessively moist or wetland soils that regularly have standing water or excessive runoff after storms, or areas with loose soils (gravel or sand) that permit excessive infiltration.
- Buffer Zones: Sites must comply with any federal (10 meters by the 503 rule), state, or local regulations regarding minimum buffer distances to waterways, homes, wells, property lines, roads, etc.
- Odor Prevention/Aesthetics: Try to minimize visual and odor impact on residential areas. Storage during the summer poses a greater potential for development of unacceptable odors and requires a higher level of management.
- Accessibility and Hauling Distance: How far do you have to haul sludge and/or biosolids? What’s the accessibility of the site during bad weather, or heavy traffic? Take note of weight restriction and other roadway limits along the haul route. Consider the traffic impact as well.
- Property Issues: Ensure local zoning requirements and ordinances are met, and consider the relative security and liability associated with leasing versus ownership of the land. Any leases should extend for several years and preferably over the expected life of the facility.