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Ecodur 201: Coating Concrete at a Wastewater Facility

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Hundreds of drinking water and wastewater plants in the US have either reached or long surpassed their projected service lives. In Littleton, Colorado, community demands and increasing repair costs had finally meant the death knell for its water treatment plant that was built in 1958. Construction on the new waste treatment plant is well advanced and it is expected to be fully on line in spring or early summer 2017.

Once operating, it will be able to treat four million gallons of wastewater a day. The original plant only treats 2.8 million gallons per day.

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Problem
Much of the original concrete has, with proper treatment and coating, a radically extended lifespan and its inclusion was an important factor in minimising the overall costs of the greatly more efficient and capacious plant.

The problem was to make sure that original concrete was not only repaired to a high standard, but also coated with protective material that would be equally robust and, more importantly, not contribute in any way to toxicity, either directly into the water or during application into the environment.

Solution
Ecodur contains no Volatile Organic Compounds. It is BPA-free and completely inert and non-toxic. Being made of vegetable oil and the commonly occurring gypsum mineral, it is widely regarded as a green coating, and is particularly suitable in these scenarios as it has been ANSI/NSF-61 certified as suitable for use in contact with potable water.

20-year tests in saltwater have shown no measurable degradation whatsoever. Furthermore, its widespread use as a coating in the harsh chemical environment of frac production water tanks has demonstrated how robust it is, particularly against acidic solutions which can occur in wastewater.

With approximately twice the adhesion (‘grip’) to substrates compared to conventional epoxy coatings and flexibility retained for the lifetime of the coating, it is an ideal solution for coating high flow concrete channels and spillways.

Application Results
After suitable preparation that ensured all surfaces were perfectly dry, anomalies such as cracks and gouges were filled typically by the simple process of the coating itself. There is no practical limit to the thickness that Ecodur can be applied unlike many conventional coatings. Being sprayable means that the coating can be forced deep into cracks ensuring their complete sealing off. Also, touch ups can be performed either at the time of the original work or at any time in the future as Ecodur retains a life-long ability to re-bond to itself subject to the original surface that has been cleaned and dried.

In this case study, the work was carried well within the acceptable temperature, humidity and Dew Point parameters which exceed most conventional coatings. During the spraying, the employees elsewhere on the plant carried on normal working because there were no VOCs. Similarly, because Ecodur does not contain, use, or require solvents for clean-up, the immediate work zone was the only restricted area.

At the usual 24-hour mark, final inspection was carried out and the coating project site was declared fit for normal use.