Are they taking into account what many of those regulations will save?
For example, they say regulations of lead in drinking water cost $43 billion. That regulation required water systems to replace lead pipes over the next 10 years. So...about $4 billion/year for 10 years.
Various studies put the economic damage in the US due to lead pipes in water systems at about $50 billion per year so this regulation looks like a net win.
Around $1.1 trillion of their claimed $1.8 trillion is from increased fuel efficiency and decreased emissions requirements for cars and trucks.
US economic loses due to air pollution range from around $500 billion to $1 trillion per year. Even a modest reduction in air pollution will save a lot (and increase fuel efficiency can save consumers quit a bit of money), so it seems likely that over 10-20 years these regulations would be a net win. A study in 2011 that analyzed the Clean Air Act found that every $1 spent on air pollution control results in about $30 of economic benefits.
Other things in their lists are PFAS drinking water regulation, and Medicare and Medicaid improvements to long term care facilities and children's health. These two are things that I would expect to have some long term benefit that really should be taken into account.
This 1.8 T was calculated by the AAF a republican right wing group that once asserted that it is proven that in medicine market forces work. So take that absurd amount with a grain of salt.
How about the OMB under Biden, which estimated "information collection" alone takes the government 10.3 billion hours in FY2022? At $50/hour, that's already $500B. If you factor in everything other than "information collection", as well as the cost of compliance from private companies, $1.8T doesn't seem implausible.
