AURORA | Aurora is moving to create a required space and replugging standards for non-producing and “orphan” oil and gas well setbacks to ensure long-term environmental safety.
“Plugged wells are wells that are no longer producing,” said Jeffrey Moore, manager of the city’s Energy and Environment division. “All the surface equipment has been removed. There’s been some cement placed into the pipe of the well in the ground, and that has been covered up and so there’s not much left to see there.”
Orphan wells are non-producing wells with no clear ownership, often on government land.
Currently, Aurora has 68 plugged wells, but this number is expected to increase significantly, Moore said.
“We will have hundreds more in the future, because one day, decades from now, all the wells that are currently producing will be plugged,” Moore said.
Moore said that about half of Aurora’s existing wells have already been replugged, many of which were drilled in the 1970s or 1980s. Most will be replugged in the future to prevent leaking into the aquifers and to make sure they are compliant with state rules that require replugging before drilling within 1,500 feet of old wells.
Leaching oil or gas into the water or on the surface is only part of the problem with closed oil and gas wells.
According to the Environmental Protection Agency, 3.2 million abandoned oil and gas wells exist in the United States, the Associated Press reports. About a third were plugged with cement to prevent leaks. Most haven’t been plugged at all.
Many of the wells release methane, a greenhouse gas containing about 86 times the climate-warming power of carbon dioxide over two decades.
Colorado has strict regulations affecting how wells must be plugged, and replugged. The state reported as many as 47,000 unplugged wells across Colorado as of 2025, according to state environmental records.
“Fortunately, we have not had any leaks from plugged wells in Aurora,” Moore said. “But we know offsetting jurisdictions that have had that.”
Moore said he is considering a “three-pronged approach” to managing these wells, which involves using a designated setback area, a city easement and new replugging authority.
The setback area applies to the land’s owner and the developers, he said.
The setback would be 150 feet by 150 feet, which is about half an acre, with specific restrictions including no utilities within 25 feet, no buildings within 50 feet and no residences, schools or hospitals within 100 feet of the plugged well.
Utility setbacks were also reduced to 25 feet above ground and maintained at 25 feet below ground, with a possible variance. Schools and hospitals were also added to the 100-foot setback.
“The goal of the setback area is to provide that space around the well with no structures inside,” Moores said.
The land can be used for parks, open spaces and parking lots, along with agricultural livestock in rural areas.
“That space can be used by developers for a number of requirements, as long as it’s in compliance with the pros manual,” Moore said.
A limited easement granted by the property owner to the city also allows the city to test the plug, which would be reported at the county level.
“The easement is simply for the city staff to go and do a non-invasive soil test on an annual basis to make sure that there’s no leaks that are occurring,” Moore said.
City staff also proposed creating a replugging authority, which would apply to well operators or licensed rig contractors.
“The goal would be to repair a well, bring it up to modern standards if needed,” Moore said, adding that the work would require a state permit and agreement with the surface owner. “It does require the operator to reclaim the surface back to the original condition.”
Moore said the city’s collaboration with developers over the past year helped them make some of the adjustments, which included reducing the setback size from 200-by-200 feet to 150-by-150. They also allowed the authority to be shared between the city, the landowner and the state.
Developers would also no longer be responsible for determining well condition or conducting replugging. Instead, it would be oil and gas operators and licensed rig contractors with a state permit.
“We still require the developer to locate a well,” Moore said. “They need to survey it and put it on their site plan.”
The proposed ordinance was approved by city council to move forward to the meeting in July.