by Casey Furlong, MSW Professional
As long as municipalities have been treating wastewater, they’ve had to manage the remaining biosolids. This typically means paying to send it to a landfill or incineration – or where possible — giving it away for land spreading on a farm field.
But why not sell it instead? After all, it has nutrient properties similar to petroleum-based fertilizers.
Cities like Tacoma, Milwaukee and Austin – and their residents –recognize that their plants’ biosolids product has value worth paying for, and these cities have been able to distribute it through garden stores or sell it in bulk.
Marketing is not generally within a wastewater treatment plant’s core competencies but the two steps that these cities have figured out is 1.) Telling a prospective buyer what the product is, and 2.) Emphasizing what it will do for the purchaser of it. “Sell the sizzle not the steak” is an old idiom on the idea.
That may sound utterly simple but a whole industry has grown up around those two tasks. So if your facility is interested in generating revenue from something that is now an expense item, you might want to check with a local ad agency for assistance. Given the general public’s lack of awareness, don’t be surprised if the response is something like, “You want me to help you promote what?”
Casey Furlong is an Environmental Specialist for InSinkErator. With an extensive background in landfill engineering, Casey designed, permitted, constructed and operated municipal solid waste landfills and large-scale food and landscape waste compost facilities. He is a certified landfill manager in Wisconsin and registered professional engineer in the states of WI, IL and IN.
When I speak about food waste disposers to wastewater professionals that oversee or manage sewage collection systems, one concern I hear is that food waste will settle out and even clog pipes. Previously, I’ve written about ground food waste becoming a slurry that it is efficiently transported in plumbing and sewers. See “The Voice Over.”
The misconception persists that disposer discharge contains food chunks, and that the use of disposers will lead to sedimentation problems. This further suggests that municipalities will have to pay for additional cleaning and maintenance of sewers because of disposers.
To which I say, it’s time that inspectors pull their head out of the sewer and read the research!
A recent study from Lulea University in Sweden looked at the long-term impacts of residential disposers on sewers to understand if pipe blockages are real or just perceived. The researchers focused on understanding the implications of disposer use, based on the ratio of their presence with the extent and distribution of deposits. Closed circuit television inspection of the sewers serving single family homes was conducted on 181 sewer pipes with a diameter of 225 mm (~9”). Using the videos taken during low flow conditions, the researchers classified deposits observed in the sewers on a score from one to four. They also included an evaluation of pipe slope and sags.
Based on statistical analysis of the scores tallied for the deposits found in the sewer, the researchers concluded that the use of food waste disposers has minimal impact on sewers. The study was funded by the Swedish Water and Wastewater Association and the Swedish Agency for Economic and Regional Growth. In recent years municipal leaders in Sweden have proposed the use of disposers to increase biogas production and decrease vehicle transportation of solid waste, and so the research was sponsored to address concerns raised with regard to potential sewer impacts.
To my wastewater and conveyance friends — I’m interested in knowing what else it will take to convince you… do you still need more?
Why is it taking so long for the hundreds of wastewater treatment plants with anaerobic digesters to become net energy producers?
Reducing energy demand and costs through codigestion, as well as generating revenue from tip fees, enables a facility to improve the balance sheet. So why don’t more treatment plants consider alternative feedstocks for codigestion? One reason is that operators are concerned contaminants could be introduced into their digesters. This means more maintenance to clear the buildup of inert material and clogs in pumps and piping.
But the leaders in codigestion – East Bay Municipal Utility District, Sheboygan, Gloversville Johnstown, and Des Moines, among others – didn’t let maintenance stand in the way. Why not?