TAGRO Safety

TAGRO Safety - Rated "Class A" by EPA

You may wonder how anything that’s made out of treated sewage can be safe, and good, to use in gardening and landscaping. In fact, TAGRO products are packed with nutrients that plants need and thrive on. Safety is always our number-one concern as we make products out of biosolids. In fact, it’s the law. Today, modern treatment processes and strict controls on what is discharged into sewers contribute to high quality, recyclable and safe biosolids.


With the passage of the Clean Water Act of 1972, municipalities instituted programs to control the quality of wastewater discharged to the wastewater treatment system. Called pretreatment or source control programs, they have significantly improved the quality of our recycled water and biosolids. Businesses now recycle or use fewer hazardous products as a result of pretreatment programs.

You may have heard news stories about public outcry against the land application of biosolids on farmland. That type of biosolids is called Class B. Although this level of treatment is generally safe, Tacoma chose a different and more strenuous process for its biosolids to ensure that our products would be completely pathogen free.

Our biosolids are so safe the U.S. Environmental Protection Agency calls them “Class A-Exceptional Quality,” the agency’s highest rating. But we had to wait to earn this rating. As one of the pioneers of Class A biosolids treatment and product innovation, Tacoma’s treatment program preceded the EPA’s very definition for the process.

 

We’ve had great results from our efforts. In addition to our satisfied customers and hundreds of blue ribbons from the Puyallup Fair for vegetables grown in TAGRO, Tacoma has won awards from the EPA for its odor-free TAGRO Potting Soil product and for the best biosolids recycling program in the country.

Chances are, you contribute to the biosolids production process. Businesses and households, whether connected to sewer systems or on septic tanks, generate waste solids. And, the average person in Tacoma produces enough “raw material” to make about 40 dry pounds of processed biosolids a year.

TAGRO is recycling at its very best; creating something truly useful and beneficial out of what goes down the drain.   

 

What's in TAGRO

TAGRO products are loaded with elements that are good for your grass and plants, all at a price that’s good for your wallet, too.
 

Made of a blend of City of Tacoma Class A Biosolids, the EPA’s highest rating, highly screened sawdust and other gardening elements, TAGRO products offer you an attractive medium for all of your gardening needs.

 

Here are just some of the benefits:

  • TAGRO provides plenty of nutrients for your plants such as phosphorus, nitrogen, magnesium, potassium and sulfur. A chemical fertilizer would provide some but not all of these nutrients. 
  • TAGRO is ideal in low-water landscaping conditions because it conditions soil to provide more moisture holding capacity. 
  • TAGRO has a low ammonia content and a high amount of organic nitrogen that’s released slowly, so you stretch out the benefits. The slow-release feature of the nitrogen, even during rainstorms, helps TAGRO to last for an entire season.
  • Research at both Washington State University and the University of Washington show that things planted in TAGRO grow taller, greener and produce more blooms than those grown in commercial or chemical products.
  • TAGRO helps the environment and greens our community.

 

How Are TAGRO Products Made?

Made from what we call biosolids, which are highly treated or pasteurizedwastewater byproducts as well as combinations of sand, sawdust, bark and other ingredients, TAGRO allows you to reuse our community’s resources to the benefit of your lawn and garden. And, because of improvements to the process that Tacoma uses to create its biosolids, the material that goes into TAGRO Potting Soil is virtually odor-free.

Here’s a little about how the wastewater treatment process works, and how we reuse biosolids to make TAGRO products:

The Wastewater Treatment Process    

Water that goes down our sink and toilet drains every day in our homes and businesses becomes wastewater. The City of Tacoma treats wastewater to separate and process the liquids and solids, then we return them to the environment. Because wastewater treatment destroys disease-causing organisms that may be in the wastewater, it protects public health and safeguards water quality, preventing pollution in our lakes, rivers and oceans.

 

Pretreatment

With the passage of the Clean Water Act of 1972, municipalities instituted programs to control the quality of wastewater discharged to the wastewater treatment system. Called pretreatment or source control programs, they have significantly improved the quality of our recycled water and biosolids. Businesses now recycle or use fewer hazardous products as a result of pretreatment programs. Before business and industry can send wastewater through the public sewer system, they have to “pretreat” it to clean contaminants.

Grit Chamber    

Once wastewater comes to a treatment facility, machines remove “grit” materials such as sticks, rags and pebbles.

The wastewater then slowly flows through large sedimentation tanks, where gravity physically separates solids from liquids. In secondary treatment the liquids go through aeration where the biological action of beneficial microorganisms removes additional organic matter.

From here, the final process disinfects the cleaned water, which is now ready to return to Commencement Bay.

Solids Treatment

The City of Tacoma uses what’s called Class A biosolids, EPA’s highest rating, so that our products are completely pathogen free. This way, we make sure that our biosolids are safe, and what’s more, they help us produce a product that consumers use in their very own yards.

In our dual digestion process, we actually cook our biosolids to kill pathogens and make our product safe to use in your home garden. Beneficial microorganisms decompose—or digest—the solids. This biological stabilization process destroys the potentially harmful pathogens contained in the solids—and reduces odors.

These stabilized solids are now called biosolids and are mostly organic matter, rich in essential plant nutrients. We can return biosolids in liquid or de-watered form to the environment as a soil conditioner, recycling them directly onto soils in the forest, on agricultural land or use them in landscaping and gardening.

We use a three temperature phase process during the anaerobic phase of our dual digestion to kill odors. At the three temperature levels, different populations of organisms do their jobs then die off, and a different population that does not generate the same smelly gases takes over. It’s almost like ecological succession in a 21-day period.

Getting rid of the odor means the City of Tacoma can make more products that more consumers will enjoy using in their yards—and even indoor container gardens.

Read more about the solids treatment process and odor control in the article, Biosolids That Don't Stink (Honest!).