What is Louisville Green?

Louisville Green is an organic-based fertilizer suitable for many uses.  This fertilizer provides slow-release nitrogen and is made of organic, nutrient rich and highly treated solids left over after municipal wastewater treatment.  It is useful as a fertilizer to improve and maintain productive soils and stimulate plant growth.

“Slow-release fertilizers provide a steady supply of plant nutrients over an extended period of time. They require fewer applications because the materials are held in the soil and gradually release the nutrients” [per Healthy Lawn and Garden Technical Advisory Committee] Most fertilizers are designed to dissolve quickly by rain. Heavy rains can leach the nitrogen into streams, causing too much algae and robbing oxygen from fish. Louisville Green instead breaks down slowly, keeping nutrients in the soil and available to the plants. The slow release allows the plants to get the nutrients they need and greatly reduces negative impacts to streams.

One of the major benefits of organic fertilizers is they add to the composition of the soil which is a benefit to gardeners. They help to hold in moisture, promote healthier root growth, and naturally help to maintain the pH balance in the soil.

Where can I use Louisville Green?
Louisville Green fertilizer has been used effectively for lawns, gardens, agricultural crops, and for landscaping.  For more information on specific applications, refer to either the homeowner page or the agricultural page.  (Louisville Green is not approved for use in organic farming.)

What does the 5-3-0 mean?
Important nutrients for plants (referred to as macro-nutrients) are nitrogen, phosphorous and potash (N-P-K).  The specific guaranteed analysis follows:

Guaranteed Analysis
Total Nitrogen (N) 5 %
Water Insoluble Nitrogen 4.5%
Water Soluble Nitrogen 0.5%
Available Phosphate (P2O5) 3 %

The three big numbers on fertilizer labels show how much macro-nutrients  are contained in the fertilizer. Louisville Green is guaranteed to contain a minimum of 5% Nitrogen and 3% Phosphorous and 0% (no) potash.

Is it safe for pets and children?
Yes, Louisville Green meets the US EPA’s most stringent requirements for fertilizers. The product is subjected to high temperatures to eliminate any harmful pathogens. The end result is a pathogen free, earthy smelling product, which is non-toxic.

We do recommend that you store the fertilizer in an area away from pets and children as with any other fertilizer or garden products.

Are there concerns regarding heavy metals?
What nutritionists call “minerals” and farmers call “micro-nutrients,” chemists call “heavy metals” in biosolids. Humans need certain nutrients in various amounts.

Louisville Green is regularly tested for metals and other components. It meets the U.S. Environmental Protection Agency (EPA) "Exceptional Quality" criteria which establishes the strictest concentration limits in the fertilizer industry for heavy metals.  

How is Louisville Green produced?
Louisville’s wastewater is cleaned and disinfected at MSD’s Morris Forman Water Quality Treatment Center before being discharged to the Ohio River. The solids removed in the wastewater process (biosolids) are digested in anaerobic (oxygen free) digesters, dewatered in centrifuges and then dried in rotary drum dryers. The dryers are fueled with natural gas, or a mixture of digester gas (a natural byproduct of anaerobic digestion) and natural gas. The final product is stored in silos and loaded onto trucks for either bulk sales to farmers and fertilizer blenders or for filling bags for sale to homeowners.

Louisville Green pellets are being loaded into truck from the storage silo.

Louisville Green meets the requirements of an exceptional quality, Class A biosolids according to the USEPA and State of Kentucky:

  • Class A pathogen reduction requirements: The material temperature during the drying process reaches 195°F, effectively sterilizing the product.  Therefore, Louisville Green biosolids contain no detectable levels of pathogens.
  • Metals: Louisville Green meets the most stringent metals pollutant concentration limits established by EPA.  (For metals data, click here.)
  • Vector attraction reduction:  Vectors (flies, rodents, birds, etc.) can transmit diseases directly to humans or play a specific role in the life cycle of a pathogen as a host. Vector attraction reduction refers to processing which makes the biosolids less attractive to vectors thereby reducing the potential for transmitting diseases. Louisville Green meets the criteria by continually exceeding 90% dry solids in the final product.  Exceptional Quality biosolids products are as safe as other agricultural and horticultural products and may be used without site restrictions.

Intense dryer heat kills all germs (bacteria, viruses and molds) in biosolids pellets.

What does it mean for MSD to agree to follow an Environmental Management System (EMS) for Biosolids?
The biosolids EMS is a management tool used by Louisville Green to document regulatory compliance requirements, best management practices for biosolids, promote continuous improvement in operations, and to gain public confidence and acceptance in its biosolids beneficial use program.

Facilities who pledge to follow the EMS are agreeing to follow community-friendly practices in addition to being in compliance with applicable state and Federal regulations. Community friendly practices refer to the control of odor, traffic, noise, and dust as well as the management of nutrients.

The Louisville Green production facility began to aggressively pursue development and implementation of a Biosolids EMS in April 2006. One year and nine months later, an internal audit was conducted in December 2007. In May 2008, the facility was audited by a third party with a follow up audit conducted in July 2008 to verify the findings. The Biosolids EMS was certified on July 31, 2008 as having met the requirements of the National Biosolids Partnership.

Our EMS Coordinator works in the field as he trains the staff.

How is the quality of Louisville Green controlled?
Quality is controlled in many ways:

  • Samples are collected and analyzed for many parameters including metals, ammonia, nitrates, PCB’s to ensure that the product meets the strictest requirements of the EPA and State of Kentucky. The lab analysis also provides fecal coliform results as an indication of pathogen reduction.

Laboratory staff analyze Louisville Green pellets.

  • The density of the product is also closely monitored. By the federal regulations, 90% dry solids is exceptional quality; however, our experience has led us to produce Louisville Green that is 94% dry solids as a transportation and storage safety measure. These tighter specifications and better quality control equipment for measuring percent dry solids has made the product density more consistent. 
  • The size of the pellets are checked several times per day. Customer feedback allowed us to learn that the product must be large enough to spread but small enough to break down appropriately once applied to the soil. Therefore, we maintain tight specifications on the product’s size distribution by using a sieve capture test.

Maintenance staff change the screens in the shakers.

Product size is checked and recorded several times each day.

How can I learn more?
To take a tour of the facility that produces Louisville Green, contact:
Robert Bates at (502) 540-6733.

The following references can provide useful information about fertilization and biosolids management:

Want more information?
To view the LG Brochure, click here.