Yeah, but to get coal ash you have to burn coal. Horrors!
Seriously, is anyone working on technology to clean up coal burning? We could sell it to China and India.
Coal burnt in its raw, or.pulverized form even with scrubbers will never be clean it’s not possible because of physics. Coal contains heavy metals that at coal combustion temperatures turns them into vapor form. No scrubber can get those vapors down to zero they struggle to get to ppt levels. There is no safe level of heavy metal exposure to humans they bioaccumulate for life. Then there is NOx and SOx here again the best scrubbers will never get that to zero. Natural gas can and does get to zero, and NG has no heavy metals so zero there as well.
The Japanese have the very best coal tech it turns coal into gas then they put that gas through six or more stages of clean up because the process to make the gas is lower in temp than coal combustion most of the metals stay in the ash along with most of the sulfur, nitrogen in the coal itself still forms NOx but at much lower levels. That coal gas is concentrated which makes analytical clean up possible down to the ppm levels this is the only way to approach the cleanliness of natural gas but it still is not as clean. The EPA is fuel and technology agnostic they simply say for X megawatt hours you can make X grams of criteria toxins how you meet that limit is up the the individual operator. Natural gas easily makes the current limits coal takes hundreds of millions of dollars in scrubbers and even then they wont meet the 2027 limits , gas is already meeting 2027 limits today. Coal is in the dust bin of history where it belongs.