CHICAGO — Bags of the earthy muck are labeled organic or natural. Sometimes it is billed as exceptional quality compost. Industry held a nationwide contest years ago and decided to call it biosolids, a euphemism that beat out black gold, geoslime and humanure. No matter how it is described, the humuslike material distributed to gardeners, neighborhood groups and landscapers by the Metropolitan Water Reclamation District is still sewage sludge — a byproduct of human excrement and industrial waste from Chicago and the Cook County suburbs. Gardeners are encouraged to grow vegetables and leafy gre…
