These standards were based on years of field research results. In fact, because of the Clean Water Act, Loop is far more regulated and studied than all other soil amendments on the market. While some industries eschew such restrictions, we think it’s a good thing to be held accountable to standards. The quality of Loop is well documented, even beyond required parameters, largely out of respect for public safety concerns. We stand behind Loop with firm conviction as to its safety.
No one is denying that Loop contains traces of organic chemicals from things like pharmaceuticals and personal care products. The important thing is that they are present in such tiny amounts, it would take many, many lifetimes of working or playing around biosolids products to get just one dose of these pharmaceuticals and personal care products.
The unfortunate truth of the matter is that many organic compounds are so widely used, it would be impossible to find a place on Earth where they don’t appear. But if there’s anywhere on Earth that’s a good place for these chemicals to end up, it’s in the soil where they remain safely bound to particles of organic matter and soil while soil microorganisms and other natural processes quickly break them down.
Great strides in biosolids quality have been made in the decades since “source control” programs began regulating the release of industrial chemicals into wastewater. And more folks are turning to consumer education programs to identify non-toxic alternatives to common household and personal care products. These efforts have drastically reduced the amount of these chemicals found in Loop and other biosolids products to near the lowest detectable traces.
EPA found that super low concentrations of trace organic chemicals, as found in biosolids, pose negligible risk to public health and the environment. For this reason, EPA has not included them in biosolids regulations. Still, King County regularly monitors Loop and has consistently confirmed that the chemicals identified by EPA as priority pollutants exist at extremely low concentrations.
Although EPA and university research shows that biosolids are safe, there still questions about these trace amounts of chemicals from pharmaceuticals and personal care products that wind up at treatment plants. These are great questions – King County had the same ones. To help answer these questions and put this in perspective, King County used a risk analysis to calculate how biosolids use compares to the amount of these chemicals we deliberately use or encounter in our everyday lives.
Click on the infographic above to view at full size.
For more detailed information about trace organic chemicals visit Evaluating Exposure Risk to Trace Organic Chemicals in Biosolids.
Loop contains small amounts of metals, as do all soils, manures, composts, and synthetic fertilizers. Some metals are micronutrients required for healthy plant and animal growth. Other metals, sometimes called “heavy metals,” provide no benefit to plants or animals. In Loop, these particular metals are only found in tiny, nontoxic amounts. EPA and the Washington State Department of Ecology regulate the metals content of biosolids based on amounts deemed safe according to extensive risk assessment research. The amounts of metals in Loop fall far below the most stringent regulatory limits.
|2014 AVERAGE METAL CONTENT IN LOOP COMPARED TO REGULATORY LIMITS
(in parts per million on a dry weight basis)
|West Point Treatment
State Regulatory Standards
Microorganisms such as bacteria and fungi are vital components of the natural world. Most perform essential functions such as breaking down organic matter during digestion and decomposition. Some microorganisms, called pathogens, can cause disease. The wastewater treatment processes uses anaerobic digestion, where beneficial microorganisms break down wastewater solids and pathogens into simple organic matter, killing 95 to 99 percent of the pathogens.
Because some pathogens survive the treatment process, straight-up Loop biosolids (not composted) is classified as Class B biosolids. Fortunately, the remaining pathogens aren’t around for very long. Soon after Loop biosolids is applied to farms and forests as a soil conditioner and fertilizer replacement, these pathogens are killed by harsh environmental conditions such as temperature changes, sunlight, drying, and competing soil organisms.
Some Loop is composted with sawdust or woody plant debris to become an “exceptional quality”, pathogen-free compost made biosolids compost called GroCo. ”Exceptional quality” biosolids products can be used without restrictions just like any other compost, fertilizer or soil conditioner. GroCo made with Loop is available to the public for use in home gardens, parks, and landscaping.