In the world of industrial construction, nothing begets business like experience, and this is especially true when it comes to building water and wastewater treatment facilities. With fourteen water treatment projects to its credit over roughly five years, Guarantee Electrical Company (GECO) has built a portfolio second to none as a provider of electrical and systems construction of large, complex water treatment facilities. Located as we are at the confluence of the largest river system in North America, there are few places in the world where water and wastewater treatment projects are more important, more visible or more demanding in terms of scale and the need for quality, given a large urban population and the incredible diversity of industrial and commercial consumers in the St. Louis region.
Two significant water infrastructure projects spanning the length of Missouri happen to be reaching conclusion as this calendar year comes to a close. They are: MSD’s Missouri River Wastewater Treatment Plant in Maryland Heights MO, completing its second and final phase at $90 million, and the new $55.6 million municipal wastewater treatment plant on the Mississippi River at Cape Girardeau, MO. Both projects represent breakthrough examples of the advancing state of wastewater treatment. Both plants deliver significantly “greener” improvements in water treatment technology, including microwave ultraviolet disinfection and new methods of managing massive volumes of storm water that have historically overwhelmed municipal sewerage management systems and now are included in federal and state water quality regulations.
Bringing State of the Science Wastewater Treatment to Cape Girardeau
As a brand new “standalone” wastewater treatment facility, the Cape Girardeau plant features the latest in wastewater treatment technologies and will handle 11 million gallons per day (MGD) with a peak capacity of 50 million gallons. The plant brings significant automation to both plant operations and emergency management. The latter features 
radio telemetry supporting a system of wireless alarms tying the plant’s advanced SCADA (Supervisory Control And Data Acquisition) communications network into the wireless telephone networks, bringing new levels of emergency access and flexibility. Among the new treatment capabilities are a two channel microwave ultraviolet (UV) disinfection system and a bubble diffusion system designed to deliver aerated, continuous flow treatment through all four of the plant’s concrete basins simultaneously.
The Cape plant also features the latest in microwave UV radiation systems using low-pressure, high-output electrode-free lamps, capable of delivering disinfection within 12 seconds compared to 20 seconds for the traditional UV lamp. In addition to a faster, more lethal dose of UV radiation, an additional advantage of the new electrode-free system is a tripling of the UV lamp-life. In addition, the units offer a significantly improved warm up and shutoff response capability which facilitates managing wastewater flow pacing in real time. Their simpler electronics also reduce overall energy consumption including less heat which further contributes to prolonged lamp life.
Cape Girardeau’s new, high performance facility uses a1200 amp electrical service, backed up by three 1500 kW Cummins generators, and features two transformers of 2000 KVA and 2500 KVA respectively, the latter stepping power down from 12470 to the lower voltages needed to power UV disinfection and a range of treatment control systems. The electrical system at Cape is controlled via two switchboards, of 3200 and 5000 amps respectively. Guarantee also installed a total of seven (7) motor control centers across the facility, two for the plant’s sequence batch reactors (SBR), three for managing bio solids, one for the ultraviolet system and one serving the Administration Building. Distribution of power was achieved throughout the Cape Girardeau campus via a roughly 4,000 foot underground duct-bank system encased in protective concrete.
MO River’s Expansion to 190 Million Gallons Can Handle Peak Storm-Water
While it’s rare to build a brand new “stand-alone” wastewater treatment plant such as the new facility in Cape Girardeau, additions and upgrades to existing facilities have been critical to the growth of the St. Louis region. The secondary expansion of the Missouri River plant in Maryland Heights MO is a case in point. Designed to expand treatment to a maximum of 190 million GPD, which more than doubles the typical daily capacity of 80 million gallons. This final phase of construction adds a heap of additional infrastructure, including new peak flow storage basins that can hold up to 30 million additional gallons of 
wastewater during high flows. In all, the final phase adds to the existing plant a Low Lift Pump Station, six Aeration Basins, a Blower Building, six 125’ diameter Final Clarifiers, a Sludge Pumping Station, a Solids Handling Building, along with a new ultraviolet disinfection facility, a Primary Digester, and two Splitter Structures. The MO River plant illustrates the physical and technical challenges for which GECO’s expertise in value engineering, control systems installation and prefabrication have all proved indispensable. The enormous scale of the $90 million secondary expansion was matched by the ongoing need to keep the existing facility running as closely as possible to full capacity while construction was under way. Scheduled outages and construction process management were almost daily challenges, and exacting timelines have defined the project throughout. In addition, capping a great effort, schedule performance on the MO River project has been achieved without a single lost time accident or injury.