A St. Petersburg waste-to-energy plant now under construction has been billed for years as an environmentally friendly money saver. Now it looks more like a boondoggle, with the cost and mission changing on the fly. Itís yet another example of a city project that seemed worthwhile at the start but spiraled out of control for lack of discipline and oversight.The city began exploring the cost of a renewable energy plant in 2011, during former Mayor Bill Fosterís term. The plant, now being built at the southwest wastewater treatment facility near Eckerd College, would convert methane gas from sewage into energy that could power the plant itself and provide fuel for the cityís sanitation vehicles. Mike Connors, the now-retired public works administrator, told the City Council that the project would lower maintenance and equipment costs at other plants and reduce the cityís use of diesel fuel by 1,600 gallons a day. There was even the chance the plant would generate excess power that the city could sell, and "biosolids" left over from the process could be dried and sold as fertilizer. Altogether, Connors claimed, the city would save about $30 million over 20 years. That was then.Now public works administrator Claude Tankersley paints a less rosy picture. His update to the council last week showed a project priced at $42 million in 2011 has ballooned to $84 million. Rising construction and engineering costs, plus administrative expenses that werenít previously taken into account drove the increase, Tankersley said. He also said the plant will generate gas to cover 75 percent of its power needs ó but was corrected within minutes by his own staff. In fact, the city will still need to purchase gas for the plant, which would generate 75 percent of its own electricity. And there wonít be any surplus fuel to sell. Will fuel consumption still go down by 1,600 gallons a day? "I do not know," Tankersley said. Will the city still save $30 million over 20 years? "I cannot say that." (Although he did say it in 2016, during another project update for the council.) Thereís simply no excuse for such substantial changes to be realized this far into such a costly project. Council member Ed Montanari summed up the outrage: "I wouldnít have voted for this if I would have known that the savings werenít going to materialize."Undisciplined spending has become all too common during Mayor Rick Krisemanís era. Among the other projects the mayor inherited whose costs have exploded on his watch are the police headquarters, which was first envisioned as a $50 million undertaking. Kriseman added a secure parking garage, shooting range and energy-saving features, and the budget now sits at $85 million. The new St. Pete Pier, replacing the old inverted pyramid, began with a $50 million budget. Kriseman added $20 million to construct an approach linking the project to downtown and later requested several million more for enhanced features for a current total of $76 million.The Pier didnít have to be built, but it could be a marketable asset and point of pride in the city for decades. The police station is an overdue need, replacing the departmentís cramped, crumbling headquarters. But the biosolids plant is neither a tourist draw nor a must-have. With the savings it was expected to yield quickly dwindling under the mounting costs, the necessity and usefulness of the project are now in question. Itís too bad the City Council and residents didnít know that before now.