Four men have been sentenced after illegally dumping waste at six sites across London.
CCTV footage shows the men breaking into the areas and directing tipper trucks loaded with rubbish for dumping.
Patrick Doherty was jailed for 28 months and Martin Ward was jailed for 18 months.
Michael Ward, also known as Martin McCann, and Simon O’Donnell both received 14-month prison sentences suspended for two years.
It came after the men were found guilty at Kingston-upon-Thames Crown Court of conspiracy to illegally dump controlled waste following a pattern of offending that spanned a year.
The criminal operation involved repeatedly dumping rubbish, such as tyres and waste, from house clearances and construction at different sites over a year, the Environment Agency said.
As part of its investigation, the agency obtained CCTV footage showing the men taking control of sites and directing tipper trucks.
It also shows them interfering with CCTV cameras, frequently hiding their own faces, and removing or covering vehicle registration plates as part of efforts to conceal their identities.
The Environment Agency said the landowner of one site – at Imperial Way in Croydon – was left with a clean-up bill of £300,000 after security cameras were smashed and a company representative was threatened and refused entry.
At Station Road in Colliers Wood, the group told a site worker that they had to either pay £5,000 or the unit would be filled up with waste, the Environment Agency said.
With the money not paid, rubbish was piled five feet high, costing £15,000 to clear, the watchdog said.
Despite attempting to hide their identities, the Environment Agency said its investigators were able to identify the four men after nearby cameras, council CCTV and police-body worn footage captured their activities.
Waste crime in the UK has escalated in recent years, with high-profile illegal tips provoking public outrage, including the 150-metre-long dump near the River Cherwell in Oxfordshire and a 30,000-tonne heap in the protected area of Hoads Wood in Kent.
Officials have also warned that around a fifth of all rubbish is illegally managed, with gangs behind it becoming increasingly sophisticated.
In response, the government unveiled a “zero-tolerance” new action plan to tackle the £1bn problem.
Environment secretary Emma Reynolds said: “The actions of these shameless waste criminals are unacceptable and have rightly been punished.
“My message is simple – break the law by dumping waste and we will come after you.
“This government is stepping up action, through our waste crime action plan, with new powers and more funding for the authorities and tougher punishments for criminals.”
Matt Higginson, environment manager for the Environment Agency, said: “This verdict is justice for residents who have had to endure misery and environmental damage at the hand of this gang.
“We are laser-focused on tackling illegal waste crime and are stepping up action with better intelligence, faster interventions and naming and shaming rogue operators.
“I would urge anyone who suspects illegal waste activity to report it anonymously so we can tackle these crimes head-on.”
Under the plans, the Environment Agency will step up enforcement and intervene earlier, backed by an additional £45m from the government over the next three years.
The agency plans to make greater use of powers that can shut down an illegal waste operation immediately, with up to 51 weeks in prison for an operator who ignores the restriction.
It said it will also suspend or revoke permits for rubbish handling where there is evidence of criminal activity, and create a new “intelligence unit” to hunt down criminals using tools ranging from aerial surveillance to financial data.
The government is also looking to give the agency “police-style” powers so that officers could search premises, seize assets and arrest people suspected of waste crime without a warrant.
