City of Raymore
The City of Raymore has a history of odor and corrosion in their gravity system to which the Owen Good force main discharges. Low velocities in the oversized force main result in long retention times and anaerobic conditions, under which sulfides are formed.
With no chemcial feed, the H2S concentrations have been peaking at 600-900ppm daily, causing not only corrosion and odor issues, but also workers’ safety concerns.
Owen Good Pump Station
The Owen Good Pump Station collects flow from 7 sub-areas. It is designed for a 7.78 MGD capacity, but currently pumps on average 0.7 MGD, resulting in up to.
17 Hours Hydraulic Retention Time
In the 17,000ft long 24″ force main, which discharges at a manhole in the parking lot of a bank near city hall.
As many other cities around the country, the City of Raymore designed their force mains for future growth. The Owen Good Pump Station has a capacity of over 7 MGD, but pumps less than 1 MGD, resulting in less than optimum velocities in the force main and hydraulic retention times of up to 17 hours. Sewage goes septic after approx. 1 hour in a force main, at which point the sulﬁde formation begins. City staff measured H2S concentrations of 123 ppm avg. with daily spikes of up to 600-900 ppm at the discharge of the over 3 mile long 24’’ force main.
The City realized that these H2S concentrations go beyond the odor complaints they’ve been receiving in the downtown area and the accelerated corrosion they’ve been experiencing. The data indicates that at times the City staff maybe exposed to a severe health risk when working in their gravity system.
Innovative and highly effective, SuperOxygenation technology is an eco friendly alternative to traditional chemical treatments for water and wastewater. Focusing on odor and corrosion prevention, ECO2 has helped cities across the country solve their needs in both municipal and industrial applications.
Odor Control for Primary Clarifiers
HDR prepared an odor evaluation for the City of Raymore, comparing the ECO2 Technology to two other oxygen injection methods, as well as traditional chemical feed alternatives, such as calcium nitrate, ferrous chloride, hydrogen peroxide, potassium permanganate and sodium hypochlorite.
Oxygen addition is less expensive than any of the chemicals. Operating the ECO2 Equipment is also less expensive than any other pressurized side stream oxygenation system, due to lower pump horse power and lower maintenance requirements.
While a direct oxygen addition with a sparger would be less capital intensive, the risk for rags and debris getting caught on it is signiﬁcant. Furthermore, non-dissolved oxygen will build up to form a headspace in the pipe, which will affect the pump operation.
The City chose the ECO2 Equipment not only for the lowest operating and capital cost, but also for the most reliable system with the highest proven oxygen transfer efﬁciency.
Results from the Start-Up can be seen on the reverse OdaLog Graph. As soon as the ECO2 System is turned on and maintaining aerobic conditions in the force main, the H2S concentrations drop to near 0 ppm.
Become a leader in water treatment.
ECO2 SuperOxygenation systems for water and wastewater treatment are designed and produced by Eco-Oxygen Technologies, LLC headquartered in Indianapolis, Indiana. The technology is the pioneering effort of Dr. Richard Speece, Centennial Professor Emeritus of Civil and Environmental Engineering at Vanderbilt University.
The ECO2 oxygenation method is a simple process based upon the scientific principle of Henry’s Law. No chemicals and no moving parts other than standard industrial water pumps are used. The result is a robust, reliable, economically competitive and environmentally friendly technology.
In municipal applications, ECO2 technology eliminates hydrogen sulfide odor and corrosion by dissolving pure oxygen in wastewater at high concentrations (50-75 mg/l) which prevents the formation of hydrogen sulfide and the associated “rotten-egg” odor. This approach saves money on alternative chemicals, provides pretreatment and does not increase total dissolved solids. ECO2 engineers are presently focused on wastewater projects in Maine, Indiana, California, Kentucky and Texas.