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Specifying STA Certified Compost


DOTs across the country have shown their confidence in the efficacy of the Seal of Testing Assurance program’s STA Certified Compost products by requiring its use on projects under their jurisdiction. We gathered case studies linked here to share with you.

The US Composting Council’s Seal of Testing Assurance Program "STA" is a compost testing, labeling and information disclosure program designed to give you the information you need to get the maximum benefit from the use of compost.

The program was created in 2000 and its method of testing and certifying compost is considered a gold standard by compost research scientists. It is the only compost testing program currently available that gives this level of labeling and information disclosure.


Landscape architect, engineer, and Department of Transportation's shared specifications will help you get started in specifying STA Certified Compost for your project.  For ease of assuring compliance, many Department of Transportations have customized lab Compost Technical Data Sheets (CTDS) through the STA Certified Compost program that show whether each parameter tested meets the specifications for that state DOT's compost use.


General Specifications

State Department of Transportation (DOT)
STA Certified Compost Landscape Specifications
Please check with the specific DOT for the most current specification as these may be revised slightly with time. For different compost applications, some states have multiple STA specifications.

Improving Roadside Revegetation and Stormwater Quality with Compost-Based BMPs

hosted by Caltrans and CalRecycle. Day 1 & 2