Virginia has established site-specific biosolids management practices that go above and beyond the EPA’s Part 503 Rule. These include:
- Agronomic rate application (fertilizer application that matches the crop needs) only once every three years, or annually only at less than agronomic rates. These practices control the buildup of soil phosphorus and residual nitrogen.
- Soil pH requirements based on regional soil types.
- No application to slopes over 15 percent and specified best management practices (BMPs) and restrictions on applications to slopes over five percent.
- Additional restrictions on winter operations.
Site physical characteristics that influence the land application of biosolids include:
- Geology (limestone or other fractured bedrock beneath the surface)
- The ability of soil to absorb water and drainage patterns
- Depth of the soil to groundwater
- Soil conditions (rocky, shallow or saturated)
- Proximity to ponds, lakes, rivers and streams