There is unfortunately a lot of propaganda on this subject, and it's quite aggravating how much of the public has just bought into these ideas. A data center is no less "ecologically destructive" than any other large building project, like a meat processing plant or chemical plant, except they don't even have to worry about food safety or chemical pollution. The only novel things about a data center are:
- Servers need a lot of electricity
- Servers need cooling
- Data centers can generate noise pollution
Does that need some level of mitigation? Of course. But, the current attitude makes people believe that they are on the level of some nuclear waste processing facility.
purify wastewater and generate their own clean energy
These are jobs for other facilities. A data center, just like 99.999% of the other buildings, are just going to buy whatever electricity is already on the grid.
If you want clean energy, promote more alternatives on the grid. Electricity is only as clean as whatever your local power plant provides.