In the United States, 50% of homes had disposal units as of 2009,[12] compared with only 6% in the United Kingdom[13] and 3% in Canada.[14]
In Sweden, some municipalities encourage the installation of disposers in order to increase the production of biogas.[15]
In Britain, Worcestershire County Council and Herefordshire Council started to subsidize the purchase of garbage disposal units in 2005, in order to reduce the amount of waste going to landfill and the carbon footprint of garbage runs.[16] However, the use of macerators was banned in Scotland in 2016[17] in non-rural areas where food waste collection is available, and banned in Northern Ireland in 2017. They are expected to be banned for businesses in England and Wales in 2023.[18][needs update] The intention is to reduce water use.
Many other countries in Europe have banned or intend to ban macerators. The intention is to realise the resource value of food waste, and reduce sewer blockages.
In the United States, 50% of homes had disposal units as of 2009,[12] compared with only 6% in the United Kingdom[13] and 3% in Canada.[14]
In Sweden, some municipalities encourage the installation of disposers in order to increase the production of biogas.[15]
In Britain, Worcestershire County Council and Herefordshire Council started to subsidize the purchase of garbage disposal units in 2005, in order to reduce the amount of waste going to landfill and the carbon footprint of garbage runs.[16] However, the use of macerators was banned in Scotland in 2016[17] in non-rural areas where food waste collection is available, and banned in Northern Ireland in 2017. They are expected to be banned for businesses in England and Wales in 2023.[18][needs update] The intention is to reduce water use.
Many other countries in Europe have banned or intend to ban macerators. The intention is to realise the resource value of food waste, and reduce sewer blockages.
In the United States, 50% of homes had disposal units as of 2009,[12] compared with only 6% in the United Kingdom[13] and 3% in Canada.[14]
In Sweden, some municipalities encourage the installation of disposers in order to increase the production of biogas.[15]
In Britain, Worcestershire County Council and Herefordshire Council started to subsidize the purchase of garbage disposal units in 2005, in order to reduce the amount of waste going to landfill and the carbon footprint of garbage runs.[16] However, the use of macerators was banned in Scotland in 2016[17] in non-rural areas where food waste collection is available, and banned in Northern Ireland in 2017. They are expected to be banned for businesses in England and Wales in 2023.[18][needs update] The intention is to reduce water use.
Many other countries in Europe have banned or intend to ban macerators. The intention is to realise the resource value of food waste, and reduce sewer blockages.
The garbage disposal unit was invented in 1927 by John W. Hammes, an architect working in Racine, Wisconsin.[1] He applied for a patent in 1933 that was issued in 1935.[2] His InSinkErator company put his disposer on the market in 1940.[citation needed]
Hammes' claim is disputed, as General Electric introduced a garbage disposal unit in 1935,[3][4] known as the Disposall.
In many cities in the United States in the 1930s and the 1940s, the municipal sewage system had regulations prohibiting placing food waste (garbage) into the system.[5] InSinkErator spent considerable effort, and was highly successful in convincing many localities to rescind these prohibitions.[6]
Many localities in the United States prohibited the use of disposers.[7] For many years, garbage disposers were illegal in New York City because of a perceived threat of damage to the city's sewer system. After a 21-month study with the NYC Department of Environmental Protection,[8] the ban was rescinded in 1997 by local law 1997/071, which amended section 24-518.1, NYC Administrative Code.[9]
In 2008, the city of Raleigh, North Carolina attempted a ban on the replacement and installation of garbage disposers, which also extended to outlying towns sharing the city's municipal sewage system, but rescinded the ban one month later.[10][11]
In the United States, 50% of homes had disposal units as of 2009,[12] compared with only 6% in the United Kingdom[13] and 3% in Canada.[14]
In Sweden, some municipalities encourage the installation of disposers in order to increase the production of biogas.[15]
In Britain, Worcestershire County Council and Herefordshire Council started to subsidize the purchase of garbage disposal units in 2005, in order to reduce the amount of waste going to landfill and the carbon footprint of garbage runs.[16] However, the use of macerators was banned in Scotland in 2016[17] in non-rural areas where food waste collection is available, and banned in Northern Ireland in 2017. They are expected to be banned for businesses in England and Wales in 2023.[18][needs update] The intention is to reduce water use.
Many other countries in Europe have banned or intend to ban macerators. The intention is to realise the resource value of food waste, and reduce sewer blockages.
Rationale
Food scraps range from 10% to 20% of household waste,[20] and are a problematic component of municipal waste, creating public health, sanitation and environmental problems at each step, beginning with internal storage and followed by truck-based collection. Burned in waste-to-energy facilities, the high water-content of food scraps means that their heating and burning consumes more energy than it generates; buried in landfills, food scraps decompose and generate methane gas, a greenhouse gas that contributes to climate change.[21]
The premise behind the proper use of a disposer is to effectively regard food scraps as liquid (averaging 70% water, like human waste), and use existing infrastructure (underground sewers and wastewater treatment plants) for its management. Modern wastewater plants are effective at processing organic solids into fertilizer products (known as biosolids), with advanced facilities also capturing methane (biogas) for energy production.[22][23]
Kitchen waste disposal units increase the load of organic matter that reaches the water treatment plant, which in turn increases the consumption of oxygen.[30] Metcalf and Eddy quantified this impact as 0.04 pounds (18 g) of biochemical oxygen demand per person per day where disposers are used.[31] An Australian study that compared in-sink food processing to composting alternatives via a life-cycle assessment found that while the in-sink disposer performed well with respect to climate change, acidification, and energy usage, it did contribute to eutrophication and toxicity potentials.[32]
This may result in higher costs for energy needed to supply oxygen in secondary operations. However, if the waste water treatment is finely controlled, the organic carbon in the food may help to keep the bacterial decomposition running, as carbon may be deficient in that process. This increased carbon serves as an inexpensive and continuous source of carbon necessary for biologic nutrient removal.[33]
One result is larger amounts of solid residue from the waste-water treatment process. According to a study at the East Bay Municipal Utility District's wastewater treatment plant funded by the EPA, food waste produces three times the biogas as compared to municipal sewage sludge.[34] The value of the biogas produced from anaerobic digestion of food waste appears to exceed the cost of processing the food waste and disposing of the residual biosolids (based on a LAX Airport proposal to divert 8,000 tons/year of bulk food waste).[35]
In a study at the Hyperion sewage treatment plant in Los Angeles, disposer use showed minimal to no impact on the total biosolids byproduct from sewage treatment and similarly minimal impact on handling processes as the high volatile solids destruction (VSD) from food waste yield a minimum amount of solids in residue.[35]
Power usage is typically 500?1,500 W, comparable to an electric iron, but only for a very short time, totaling approximately 3?4 kWh of electricity per household per year.[36] Daily water usage varies, but is typically 1 US gallon (3.8 L) of water per person per day,[37] comparable to an additional toilet flush.[38] One survey of these food processing units found a slight increase in household water use.[39]