Biosolids and Septage

Weld County has more than 20 wastewater treatment agencies treating millions of gallons of wastewater each day. Treatment results in the production of 10 dry tons of biosolids each day. In addition, individual sewage disposal systems (septic tanks) are a source of solids when they are periodically pumped and those wastes are discharged at a publicly owned treatment facility. Disposal of these biosolids is a significant issue facing this region.

The only options for reuse/disposal of biosolids that meet Environmental Protection Agency (EPA) and Colorado Department of Public Health and Environment (CDPHE) criteria are incineration, landfill disposal, or recycling as soil amendments. Incineration is not practiced because of air quality problems, and landfill space is limited. Recycling biosolids as soil amendments and fertilizers is the best use for this material. Recycling biosolids is increasingly being adopted by cities across the country. More than 80% of biosolids produced in Colorado are recycled by land application.

Industrial pre-treatment programs are in place for controlling industrial wastes from larger wastewater treatment facilities and for smaller facilities with significant industrial flows. These industrial pre-treatment programs reduce discharges of pollutants from commercial and industrial sources to municipal sewer systems, and the effectiveness of these programs are the major reasons wastewater treatment facilities can produce biosolids that meet the strict metals content restrictions in state and federal regulations. Weld County also has regulations for land application sites, and county permits must be renewed annually.