Coosa Riverkeeper filed a lawsuit Tuesday against Alabama Power, alleging significant groundwater pollution violations from the utility’s Gadsden coal ash pond that has been capped in place since 2018.By Dennis PillionGADSDEN, Ala.—The coal ash lagoon at Alabama Power’s Plant Gadsden was supposed to be a model for how to close ash ponds by covering them in place, a process utilities insisted would protect human health and the environment from toxic contaminants in the ash.