Frequently Asked Questions

What is Bloom®?

Bloom is a fertilizer and soil conditioner made from EPA approved Exceptional Quality Class A biosolids. Bloom provides essential plant nutrients, including slow-release nitrogen, and organic matter, which is key to building healthy soil. Slow-release fertilizers like Bloom slowly add nutrients to the soil by naturally breaking down and decomposing into a plant-available form. Research has shown Bloom provides improved drought resistance and water holding capacity among other benefits. Bloom is great for improving and establishing lawns, remediating poor soils, planting trees and shrubs, and establishing flower and vegetable gardens, among other applications.

DC Water produces Bloom at its Blue Plains Advanced Wastewater Treatment Plant using an advanced process that uses high heat, high pressure and biology to produce a soil amendment similar to compost. Bloom meets all U.S. Environmental Protection Agency (EPA) standards for use in homes and gardens. Learn more.

Are there environmental benefits to using Bloom?

There are multiple benefits for using Bloom. Applying biosolids to the land helps capture carbon and prevents it from being released to the atmosphere. Using Bloom also reduces demand for commercial petroleum-based fertilizers and the energy used to manufacture it. Using biosolids locally reduces emissions and the carbon footprint created by hauling this valuable product far from its source. Learn more with this factsheet.

Oversight from EPA means that biosolids-based soil amendments are more regulated and studied than other fertilizer and soil amendment alternatives. Bloom goes beyond these standards to produce EPA-certified Exceptional Quality biosolids, the EPA’s highest rating.

I’ve been hearing about PFAS. What are they and are they found in Bloom?

PFAS are a group of more than 3,000 manmade chemicals that are fire, oil, grease, water and stain resistant, and are found in a wide array of consumer and industrial products, including non-stick cookware, food packaging, dental floss, cleaning products, and cosmetics. Exposure to humans can occur through a number of pathways, including ingestion and inhalation. At high concentrations, PFAS compounds have been linked to negative health consequences. We share the growing public concern over the presence of these chemicals in our society, and strongly believe that source control is the solution.

Recent measurements of Bloom have shown concentrations of PFOS and PFOA, which are among the most studied PFAS compounds and have the largest data sets to support risk assessment, to be many thousands of times lower than in food packaging materials, hundreds of times lower than in products like ketchup and cosmetics, and ten times lower than the levels measured in household dust. Learn more about PFAS and biosolids.

What does Bloom® smell like?

Bloom’s products are low in odor and often described as earthy or musty. After it is applied and mixed with soil, odors are even further reduced. It can take up to a week to 10 days for any odor of Bloom to completely disappear, however. For large-scale orders, we can provide free samples of material for you to get a better sense of the texture, odor and other properties.

How is Bloom made?

DC Water has the largest advanced wastewater treatment plant in the world. Our wastewater goes through a very sophisticated, tightly controlled process to transform our waste into a precious resource. DC Water has invested in advanced processing called thermal hydrolysis that treats materials at extremely high heat and pressure to kill pathogens and then takes it through anaerobic digesters, which convert some of the solids into renewable natural gas. The final product, Bloom, is sold in bulk to commercial farmers, soil blenders and construction companies, and is also blended on site into our Sandy and Woody Blends.

Which product should I use for my project, how much do I need and how should I apply it?

The short answer is it depends on what you’re looking to accomplish, how you are applying the product (topdressing versus incorporation), the quality of your soil, and many other factors. This page provides a table of usage by product and includes a calculator where you can calculate how much material you need. Our team is available to help you figure out what product and quantity is best; email us for a consultation at bloom@bloomsoil.com.

Where can I purchase Bloom?

Bloom’s blends can be purchased in bulk directly from Blue Plains for orders as small as a few cubic yards or from a host of retailers in Maryland, DC and Virginia. This page has a dynamic map where you can enter your zip code to sort by the nearest retailer to you. Fresh Bloom is available only directly from Blue Plains, for commercial use such as farming and construction.

Do other cities use biosolids soil amendments?

Yes. Cities like Milwaukee, Seattle, Tacoma, Austin, Houston, Boston, and Baltimore use and sell their high quality biosolids soil amendment products. Milorganite, for example, has been produced for a century and can be found in most home and garden centers nationwide. Click here for a comprehensive list.

Where can I learn more about the science and research behind the product?

Bloom regularly partners with independent researchers at area universities and institutions on research projects to test the efficacy of different applications. Click here for a page summarizing some of the recent research. Bloom also undergoes regular testing by independent labs; sample analyses for each of our products can be found on this page.

What about other toxins like trace metals and pharmaceuticals?

Toxins are something we monitor both as prescribed by EPA and beyond mere regulatory compliance to ensure that we are not harming the environment or putting public health at risk. There are minute trace amounts of pharmaceuticals and other compounds but in concentrations many orders of magnitude below what is found in products on our shelves and in therapeutic doses of the pharmaceuticals.

Trace metals are present in Bloom at a level that is detectable but not deemed by the EPA to be a risk to human health and are in most cases an order of magnitude below the EPA’s Class A Exceptional Quality standards. Many of the metals found in biosolids are also present at higher concentrations in popular multi-vitamins and consumer products that we use every day. In addition, heavy metals typically enter the water system from industrial sources (only around 3% of total flow to Blue Plains). DC Water has an aggressive pre-treatment program that requires these users to remove these compounds before they reach Blue Plains. To put it in context, it’s estimated that a healthy adult would have to eat 38 cups of biosolids per year to reach the FDA’s recommended daily value of copper.

Another family of compounds are antibacterials like triclosan, which are used in antimicrobial soaps and hand sanitizers. DC Water monitors and has invested in research related to these compounds. However, triclosan can be found at much higher levels in products we use every day. There are 4,000 parts per million of triclosan present in a single use of common toothpaste. DC Water’s biosolids contain only 15-20 parts per million of triclosan.

This summary of a report conducted by King County Washington provides more detail on the relative risk of pharmaceuticals and other compounds. It looks at four potential pathways to human exposure, including a child eating a spoonful of soil amended with biosolids every day. The calculations show that it takes many years of this level of exposure (sometimes thousands of years) to consume enough soil to get a single therapeutic dose of the compound.

Is Bloom organic?

“Organic” in the context of a soil conditioner refers to it being derived from carbon-based material that was previously alive. Generally speaking, organic soil conditioners will improve any kind of soil in a number of ways. Bloom provides both the carbon-based organic matter as well as an organic form of nitrogen, versus the inorganic nitrogen of traditional chemical fertilizers. Learn more about organic versus inorganic soil conditioners here.

Despite their organic components, biosolids products (like Bloom) are not permitted for use for Certified Organic products by the USDA National Organics Program.

Is Bloom the same product as ComPRO?

Bloom was created in 2017, after DC Water upgraded its systems to a combination of thermal hydrolysis and anaerobic digestion, resulting in an EPA Class A Exceptional Quality product. Decades before Bloom, Maryland Environmental Services (MES) and Washington Suburban Sanitary Commission (WSSC) produced a popular bagged fertilizer called ComPRO, which went through a very different process than Bloom. That product was discontinued in 1999, although you may occasionally see “ComPRO substitute” still in the market today as a way to capitalize on its previous fandom.

Is Bloom a good source of nitrogen for my soil?

Many farm customers seek out Bloom specifically as a sustainable, affordable, organic form of nitrogen. Nitrogen is one of the three primary plant nutrients (along with phosphorus and potassium), which simply means that they are required by plants in greater quantities than other nutrients. Indeed, nitrogen is probably the most important for plant growth. Farmers, turf managers, landscapers and gardeners alike understand that when plant foliage starts turning yellow and their growth stunted, additional nitrogen is probably required. You can learn more here.

Is Bloom the same as Milorganite?

Like Bloom, Milorganite is a Class A biosolids fertilizer popular for lawns, gardens, golf courses and more. Milorganite has been produced by the Milwaukee Metropolitan Sewerage District for a century, and is sold in bag by big box retailers like Home Depot nationwide. There are a few key differences between the products, particularly the nutrient concentrations. Milorganite is heat dried, leading to an NPK ratio of 6-4-0, whereas Bloom is de-watered via belt presses, a less energy intensive process that leaves more moisture in the end product and therefore a literally more watered down nutrient content (NPK of 1.5-1.5-0 for Fresh Bloom). Bloom also is currently only sold in bulk in the DMV area. While the application rates differ, both products offer a similar array of benefits, including slow-release nitrogen that is less likely to run off or burn plants and iron for dark, lush leafy growth.

Now that I have Bloom, how do I spread it?

If you have one of our blended products (Woody or Sandy Blend), methods for spreading it depend on the amount you have and the size of the area you’re covering. It can be as simple as using a shovel and rake or involve more specialized spreading equipment.

For just a few cubic yards of Bloom, a shovel, wheelbarrow, and bow rake (or something similar) may be all you need to distribute the material evenly and break up any clumps.

For larger projects, spreading equipment can complete the job faster and more efficiently. On the less expensive end, you can rent a soil and compost spreader from a hardware or equipment rental store. These spreaders can cover an area more quickly, but generally provide less control over the exact application rate.

For a step up from a basic roller spreader, tow-behind top dressers can be attached to a lawn mower, tractor, or ATV and are good option for larger properties, landscapers, or anyone who spreads Bloom regularly but doesn’t need a dedicated self-propelled machine.

For the top tier, professional option, self-propelled top dressers can spread Bloom even faster and more consistently while providing greater control over the application rate.

If you are a farm customer and have our Fresh Bloom, a manure spreader is advised. Watch our webinar for more on how to spread Bloom. For larger orders, a manure spreader can be loaned at no cost. Reach out to bloom@bloomsoil.com to learn more about this program.