When overflows increase and a wastewater treatment plant nears its operating capacity, there has historically been one logical solution: expand the treatment plant.
“If the only tool you have is a hammer, you tend to see every problem as a nail.” Abraham Maslow said it. Veterans of our industry understand what he meant. When overflows increase and a wastewater treatment plant nears its operating capacity, there has historically been one logical solution: expand the treatment plant. Today that may no longer be the case. If we can reduce the need for additional capacity by targeting the problem at its source, we will do so. That is what happened in 2010 in the Coldwater Creek Watershed in north St. Louis County, where an innovative approach to reducing overflows has eliminated the need for a $50 million wastewater treatment plant expansion. The idea is simple: we will temporarily store wet weather in two huge 6 million gallon storage tanks in the hours and days following rainfall. As normal conditions return, we will slowly release the stormwater back into the system, being careful not to overtax the treatment plant. The first tank is currently being built in S t. Ann near Lambert St. Louis International Airport. The $25 million cost for both tanks means that funds originally planned for the Coldwater Creek Wastewater Treatment Plant expansion can now be put to beneficial use addressing other needs. Our approach to the Coldwater Creek Watershed is emblematic of the more strategic approach we are taking to project planning, design and construction. Human intuition has been replaced with statistical analysis to quantify risk, prioritize projects and conduct cost-benefit analyses. The bottom line: we make better decisions, with the goal of delivering the low-cost, high-value alternative.