Through a covert tip in a community where inhabitants were exposed to poisonous vapors, a gang made half a million pounds.
Shredded garbage was "regularly" transported in lorry loads to the Long Bennington, Lincs, location, where it was burned and interred every day.
Over the course of seven months, an estimated 11,000 tonnes were dumped, bringing in about £500,000 for the company.
Officials believe it will cost £1.2 million to clean up the site, which is the size of a football pitch.
Ten people pleaded guilty and the remaining three defendants were found guilty following an eight-week trial at Nottingham Crown Court.
During sentencing on Oct 18, the gang received a collective 11 years in prison.
Environment Agency officers spent months gathering intelligence about the site and eventually conducted a raid in April 2020 alongside Lincolnshire Police.
At the time of the raid, an excavator and a lorry were actively depositing more waste at the site - leading to two arrests.
Overall, 12 people and one company were charged with either knowingly causing the operation of the illegal waste site or knowingly causing the deposit of waste.
His Honour Judge Coupland said the offending caused harm of the “highest level” and condemned the defendants for putting locals at risk from toxic fumes.
He deemed the offences had been “deliberately concealed” through the use of falsified paperwork and said their repeated nature, alongside the financial gain obtained, were aggravating factors.
Leigh Edlin, the Environment Agency’s area director for Lincolnshire and Northamptonshire, said: “This was a serious illegal waste site which was highly organised and involved multiple offenders.
“Those involved sought to profit from Covid restrictions at the cost of the environment and by inflicting misery on the local community.
“The site and its operators had a major impact on legitimate businesses and our regulatory work.
“Our enforcement teams will continue to tackle serious illegal waste crime by working with partners such as Lincolnshire Police, fire services and councils, as we did in this case to hold those responsible to account.”
The Canner family trio of father Paul, 53, mother Judith, 55, and son Joshua, 29, who ran the illegal waste site, were sentenced to 26 months, 16 months, and 16 months respectively.
Sonia Surpal, 52, and Luke Woodward, 37, who pleaded guilty to depositing waste at the site, were sentenced to 13 and 11 months imprisonment.
Peter Wainwright, 32, and Nathan Jones, 43, were both sentenced to 16 months in prison for disposing of the waste at the site.
Marcus Chapman, 39, and Daniel Lippitt, 55, were sentenced to 12 months and 9 months imprisonment - both suspended for 18 months.
Landowners James Baggaley, 38 and Marc Greenfield, 46, who both “knowingly permitted the operation of the illegal waste site”, will be sentenced on December 16.
Robert Malone, 41, and Fletcher Plant Limited, who were found guilty of failing to comply with the waste duty of care, will both be sentenced at a later date.