Biosolids are nutrient-rich organic matter resulting from the treatment of wastewater. This by-product can be recycled by uses that include application to agriculture, forest, rangeland, and reclamation area soils to improve soil condition and stimulate plant growth.

The Metro District markets its biosolids Cake product under the trade name of METROGRO™.

Since Biosolids are treated sewage solids they can have an odor. Typically the odor is a musty-like earthy smell. Normally it does not pose any problem because the odor quickly dissipates into the atmosphere.

Absolutely. Sewage sludge encompasses untreated solids from wastewater that remain after being processed at a wastewater treatment facility. Regulation dictates that biosolids are to be processed and treated to remove pathogens found in sewage sludge.

• Biosolids are nutrient rich and are a good source of organic matter
• Water-holding capacity of the soil will improve
• Soil porosity will improve
• Timing of fertilizer uptake by plant (slow-release)
• Biosolids are rich in Nitrogen, Phosphorous, and Potassium
• Biosolids are also a good source of micronutrients such as Zinc and Copper
• Soil tilth improvement
• Decrease soil erosion potential
• Decrease need for pesticide use
• Decreased fertilizer/operating costs

Biosolids typically are land applied once per cropping cycle, or once per year. Keep in mind biosolids can only be land applied if the soil is showing nutrient deficiencies for the crop to be grown.

The Metro District’s biosolids are transported to each site in semi-trucks. The biosolids are transferred from the truck to the applicator, a modified side-discharge manure spreader. The amount of biosolids applied to each site (agronomic loading rate) is calculated using the following factors:

• Crop to be grown
• Yield goal for that crop
• Nutrient requirement for that crop
• Nutrients presently available in the soil
• Nutrients presently available in the biosolids

With these factors an agronomic rate is calculated and the amount of biosolids to be applied to each site is then determined.

The Metro District charges a fee of $8.00 per acre for 75lbs. or less of Nitrogen applied per acre and $12.00 per acre for 76lbs. or more of Nitrogen applied per acre. A fuel surcharge of 2% of the District’s current fuel price per gallon multiplied by the total number of miles traveled to the land application site is also charged. This fee includes soil sampling, transportation, field application, and if required, incorporation of the biosolids into the soil.

Biosolids are regulated by the Environmental Protection Agency (EPA) through 40 CFR Part 503 and by the Colorado Department of Public Health and Environment Water Quality Control Commission Biosolids Regulation No. 64. Under these regulations there are a few portions that pertain to Farmer/Rancher responsibility:

• Food crops, feed-crops, and non-food crops shall not be harvested 30 days after application of biosolids.
• Animals shall not be allowed to graze on the land for 30 days after application of biosolids.
• Public access shall be restricted for one year after the application of biosolids.

*Certain County or Local Agencies may have additional rules/restrictions that apply.

The permit process takes about 4-6 months, and all proper permits must be issued prior to land application. The earlier you contact us, the earlier we can start planning for application of biosolids to your farm or ranch.