STA stands for the U.S. Composting Council's Seal of Testing Assurance. It is designed to let the consumer know that the compost they are buying is tested at regular intervals by a permitted facility and tested for EPA 503 pathogen reduction and metal limits.

​

In the early days of composting, everyone had their way of producing this wonderful soil amendment. Some used organic food scraps or landscaping waste, while others might add manure. Whatever the method, in the year 2000, it was decided that a standard should be adopted so homeowners and landscapers could rely on safe compost, with testing results available to the consumer.

​

While the industry helped design a testing program that included physical, chemical and biological tests, it was decided that outside independent labs would provide analysis. This way, users of compost could be assured that the compost they were buying would be scientifically analyzed, free of outside bias, so when it was STA Certified they knew it was tested by a reputable, independent lab (CAP proficiency tested labs with TMECC).

​

In addition, the program testing frequency was designed to correlate with the raw tonnage of compost produced by a manufacturer. At St. Louis Composting, as one of the Midwest's largest compost producers, we test monthly, the highest level of frequency the program requires.

​

So what does the laboratory test for you ask? In addition to rules which require us to be fully compliant with all Federal and State mandates to assure public health/safety and environmental protection, our compost is evaluated on the following properties:

​

• pH

• soluble salts

• nutrient content (total N, P2O5, K2O, Ca, Mg)

• moisture content

• organic matter content

• bioassay (maturity)

• stability (respirometry)

• particle size (report only)

• pathogen (Fecal Coliform or Salmonella)

• trace metals

​

What does STA Certified mean to you? All of our compost is tested at regular monthly intervals to make sure we satisfy our benchmark for consistent results and safety. If you see an STA logo on your compost, you can be confident you're buying a product that will deliver the wonderful benefits of compost in your yard or garden, manufactured and tested regularly to company and government standards by a properly permitted facility (required for STA certification).

 

In addition, as part of the program, all STA Certified manufacturers are required to provide a Compost Technical Data Sheet (CTDS) on request, ensuring transparency and accountability to the markets they serve.

​

It should be noted that participation in this program is voluntary and is not required by law. We participate in U.S. Composting Council's STA Certification to demonstrate commitment to our customers that we strive to operate in a manner consistent with the requirements defined by the program's guidelines and industry standards.