Behind the Lake Waco dam is a public-works project with an ambitious mission to provide the Greater Waco, Texas with plentiful, tasteless water for decades to come. When it starts operation in June, the $50 million dissolved air flotation water plant will shoot tiny bubbles through lake water to remove algae that make Waco water have an unpleasant taste. An ozone disinfection process will be added in the fall. The construction project is 76 percent complete.
These processes will remove all detectable traces of geosmin, the natural compound that occasionally gives Waco water its earthy taste. Water quality may be the most noticeable improvement, but the plant also will vastly expand its potential quantity. The plant will send pretreated water to Waco’s two existing water treatment plants — Riverside and Mount Carmel — where it will be prepared for public consumption.
The pretreatment eases the burden on the existing plants. The result will be a 36 percent increase in overall treatment capacity, from 66 million gallons to 90 million gallons per day. That will be enough to meet water-supply projections to about 2030. There is room for a second phase that would expand capacity to more than 130 million gallons.
The Lake Waco algae secrete the most geosmin when they are under stress and begin to die in the long journey to the treatment plant. He said that by removing the organisms just hundreds of feet from the lake intake, the plant is able to eliminate the problem. The algae cells are removed through a series of baffles in huge concrete “cells,” where jets of bubbles force them to the top of the water column and skimmers remove them. The water will then run into stainless steel chambers, where it will be mixed with ozone, a disinfectant that will be manufactured on site using pure oxygen.