FPUD recycles sludge into high-grade fertilizer
Last updated 3/6/2008 at Noon
FALLBROOK — Flushing the toilet just took on new environmental meaning. A plan to recycle sludge into fertilizer has become a reality for the Fallbrook Public Utility District (FPUD).
The district has begun recycling its nutrient-rich, organic sludge from the wastewater treatment plant into a safe and renewable resource: organic Class A fertilizer.
The equipment that recycles the sludge is now installed, up and running at FPUD’s treatment plant off Alturas Road, and is worth more than $1 million. But the machinery will save FPUD even more than that in the long run.
FPUD is selling all the fertilizer produced to a local grower. In addition, the district no longer has to pay to have its sludge hauled away for disposal.
The district will recoup the cost of the machinery by the year 2014 from the new revenue and expenses it no longer has to pay.
The environmentally conscious decision to turn sludge into fertilizer came about as the cost of hauling the sludge out of the county has been and continues to skyrocket.
FPUD was spending $150,000 per year to haul its sludge to Riverside County, but that location is set to close and the nearest site is Kern County or out of state. But the cost of trucking the heavy, wet sludge to those sites would be significantly higher, and those costs are expected to continue rising.
Sludge is the semisolid, slushy organic material that remains after wastewater is treated.
The sludge is dehydrated first, before it is put into the dryer. Then by heating the sludge to very high temperatures – between 226 and 276 degrees – all harmful pathogens are killed. The end product is sterile granules that can be safely returned to the soil.
“This is a technology that is a glimpse into the future,” said Mike Page, engineering manager for FPUD. “Other wastewater agencies are going to move toward this because we are all looking for economic, environmentally responsible ways to dispose of our sludge. This is it. Recycling it makes perfect sense.”
And odor is not an issue. The hot air produced from the heating process is then cooled and thoroughly filtered to meet California’s strict emissions standards and prevent odor from impacting the community.
“We’re being careful to be a good neighbor to the community and especially the homes near the treatment plant, all the while keeping our costs down,” said general manager Keith Lewinger. “This is really a win-win situation. It’s good for the environment and it’s good for our ratepayers’ wallets.”