Milorganite

"Milorganite" is a portmanteau of the term Milwaukee Organic Nitrogen. It was the winning entry in a 1925 naming contest for a biosolids-based fertilizer held in National Fertilizer Magazine. Its history began with Milwaukee's goal to clean up its rivers and Lake Michigan.[6][7] Rather than land filling solids left over from wastewater treatment, the sludge was used in a pioneering effort to make, distribute and sell fertilizer.[4] as of May, 2019, 9.9 billion pounds of waste have been diverted away from landfills.[8] The resulting production is among the largest recycling programs in the world.[3][9]

Milorganite's roots began in 1911, when local socialist politicians were elected on a platform calling for construction of a wastewater treatment plant to protect against water borne pathogens.[6][10] As raising taxes for public health was relatively controversial in the early 1900s, producing an organic fertilizer as a means of partially offsetting its operating cost was proposed. With the help of researchers in the College of Agriculture at the University of Wisconsin, the use of waste solids in the form of activated sludge as a source of fertilizer had been developed in the early 20th century.[2] Experiments showed that heat-dried activated sludge pellets "compared favorably with standard organic materials such as dried blood, tankage, fish scap, and cottonseed meal."[11]

The Milwaukee Metropolitan Sewerage District's Jones Island Plant had the largest water treatment capacity of any in the world when constructed in 1925.[12] It was the first plant in the United States to succeed in using the activated sludge treatment process to produce fertilizer.[9][13][14] The Plant has been designated as a Historic Civil Engineering Landmark by the American Society of Civil Engineers.[13][15][16]

Milorganite made its debut in 1926 as the first pelletized fertilizer in the United States,[3] with sales directed at golf courses,[7] turf farms and flower growers.[17] The brand was popularized during the 1930s and 1940s before inorganic urea became available to homeowners after WWII.

Since its inception, over four million metric tons of Milorganite have been sold.[4] As of 2018, the plant produces in the range of 45,000 - 49,000 tons of Milorganite per year, which is roughly 2.4 million bags.[3] The sale of product does not generate sufficient funds to cover the costs of manufacture, but the Milwaukee Metropolitan Sewerage District states that the environmental benefits are a legitimate offsetting consideration:[4]

"Headquartered in Milwaukee, Wisconsin, Milorganite products are manufactured and marketed by the Milwaukee Metropolitan Sewerage District (MMSD), a regional government agency whose primary focus is providing water reclamation and flood management services for about 1.1 million customers in 28 communities in the Greater Milwaukee Area. Since 1926 MMSD has been a world leader in supplying Organic Nitrogen fertilizers for professional and residential use. While revenue generated through the sale of Milorganite products does not make up for the entire cost to produce and market, our belief in beneficial reuse and recycling makes producing our value added products the clear choice."[1]

Even as it balances such conflicting goals and successfully navigates the fluctuations and vagaries of a changing waste stream,[upper-alpha 1]Milorganite has been at the forefront of the sewage sludge recycling industry in the U.S.[6] Changes in the economy and the resultant sewage to be treated have had an impact on Milorganite production.[7] The process is the end point of the regional sewerage system, which includes "three thousand miles of household laterals and another 3,000 miles of sanitary sewers." Also included is the 28.5 miles (45.9 km) "deep tunnel project", which provides 521 million US gallons (1.97×10^⁶ m³; 434×10^⁶ imp gal) of overflow storage system. Two plants, one on Jones Island and the other in Oak Creek, process sewage using bacteria. Methane is recaptured and used to minimize energy costs.[18]

Heat-dried biosolids contain slow release organic nitrogen and largely water-insoluble phosphorus bound with iron and aluminum and high organic matter.[19]

Milorganite can be used without restriction on gardens growing food crops intended for human consumption under United States Environmental Protection Agency (EPA) rules.[20][21] The product is tested daily for the presence of heavy metals and weekly for waterborne pathogens. It complies with the EPA "Exceptional Quality" criteria, which establishes the strictest concentration limits in the fertilizer industry for heavy metals, allowing Milorganite to be used on food crops.[22] Milorganite has been tested for the presence of contaminants such as waste pharmaceuticals and other forms of drug pollution.[23]

According to its material safety data sheet Milorganite is "registered for sale in all 50 states and meets all federal and state requirements."[20][24] The United States Department of Agriculture (USDA) certifies it as biobased because it is derived from 85% renewable materials.[1] It is not, however, certified for use on USDA organic farms.[23]

Suggestions that Milorganite deters deer are unsubstantiated, and the reputed costs[upper-alpha 2] of having it certified as a repellent are greater than its potential return.[14][23][25][26] The Environmental Protection Agency denied the application to permit its use as a deer repellant because of a lack of supporting studies showing its environmental impact.[7]

"Milorganite Weed and Feed”, combining Milorganite with 2,4-D, in a partnership with Parker Fertilizer was considered in 1971. Seeking to associate itself with the “ecology kick”, Milorganite’s marketing staff considered the implications of “Milorganite-cide blends.” Critics said that the invention of such a product was a repudiation of the sewage district’s history, in the first place. It was eventually rejected, and was never marketed to the public.[7] Claims that it was a “natural, organic and/or safe” product came into focus in 1992, when the Federal Trade Commission began an investigation saying the claim was deceptive. By 2000, the United States Department of Agriculture banned the application of all biosolids to any crops bearing the label “organic.”[7]

The EPA and others have shown that biosolids can contain measurable levels of synthetic organic compounds, radionuclides and heavy metals.[27][28][29] USEPA has set numeric limits for arsenic, cadmium, copper, lead, mercury, molybdenum, nickel, selenium, and zinc.[30]

The presence of heavy metals is a source of concern. The facility reports that they have been substantially reduced over the years.[31] Milorganite contains metals at levels found safe by EPA when Milorganite is used as directed.[32]

The EPA has not regulated levels of environmentally toxic manmade dioxins.[30] Polybrominated diphenyl ethers, a type of "persistent, bioaccumulative and toxic" (PBT) contaminant, were detected in biosolids in 2001.[33] PCBS are occasionally detected despite production being banned since the 1970s. In 2007, unusually high levels of toxic polychlorinated biphenyls (PCBs) were detected in Milorganite that was donated to the City of Milwaukee and Milwaukee County and subsequently applied on parkland.[34] The cost to the Milwaukee Metropolitan Sewerage District and tax payers was estimated as $4.7 million.[35] PCBs were banned from commerce in the US in the mid-1970s. The source of the PCB contamination was later determined to be a shuttered die-casting facility. The PCBs made their way to the treatment plant when sewer lines were cleaned years after the facility stopped operation.

Milorganite holds itself to an even higher standard than the EPA requirement on polychlorinated biphenyl (PCBs), testing for an amount less than one part per million, a third less than the government requirement for a safe product. Many household foods and products include very low levels of PCB’s, such as milk which the FDA regulates PCB’s levels at two part per million and red meat at three parts per million.[36]

The United States Geological Survey analyzed in 2014 nine different consumer products containing biosolids as a main ingredient for 87 organic chemicals found in cleaners, personal care products, pharmaceuticals, and other products. These analysis detected 55 of the 87 organic chemicals measured in at least one of the nine biosolid samples, with 45 chemicals found in Milorganite.[37]

The incidence and effects of PFOs and PFAs in Milorganite, and municipal waste in general—as a part of the waste stream, and as a source of water and environmental contamination—has been a subject of study, controversy and concern.[38][39]

• Water resource management

Notes

Further reading

• Alvord, John W.; Whipple, George C.; Eddy, Harrison P. (April 25, 1911). A Report to the Common Council upon the Disposal of the Sewage and the Protection of the Water Supply of the City of Milwaukee. Unpublished. Milwaukee Metropolitan Sewerage District.
• Eddy, Harrison (April 17, 1924). "Sewerage and sewage disposal". Engineering News-Record. 92 (16). pp. 693–695.
• Gurda, John (May 1978). Change at the River Mouth: Ethnic. Succession on Milwaukee's Jones Island, 1700 to 1922 (Unpublished master's thesis). Milwaukee, Wisconsin: University of Wisconsin–Milwaukee.
• Horvath, R. Dennis (May 1964). The Sewage Disposal Controversy: A Study in Milwaukee Area Politics (Unpublished master's thesis). Milwaukee, Wisconsin: University of Wisconsin–Milwaukee.
• Leary, Raymond D.; Peot, Werner A. (1973). Development of a Wastewater Treatment System for the Milwaukee Metropolitan Sewerage District.
• National Register of Historic Places nomination form for the Jones Island Wastewater Treatment Plant.[9]

Citations

• Official website of milorganite
• Washington State Department of Agriculture Fertilizer and Pesticide Database — "M"
• USDA Bio-Preferred Program