The following article is from the Summer 2011 edition of the Iowa Septic Newsletter.
In 2007, Polk County authorities discontinued permits for land application of septage. That’s when Jody Forest of Forest Septic Tank Service started looking for alternatives for central Iowa’s septic tank service companies.
As a state-licensed land-applicator of septage, Forest says, “My back was against the wall, but I wasn’t the only one facing this regional problem.” What he created to meet the needs of his company and those of his industry peers in Polk County was Accurate Dewatering Services Inc, Iowa’s first and only privately owned septage dewatering facility.
Dan Olson of the Iowa Department of Natural Resources says Polk is the only Iowa county he is aware of that has banned land-application. “The county is simply too urban,” says Olson. “DNR is happy that we have a facility such as Accurate Dewatering available, because getting rid of septage is becoming more and more difficult. In the future we’re going to see more of these facilities around the state, especially with smaller community wastewater treatment systems. They have difficulty taking the waste.”
Forest and his friend Jerry Heckman attended the 2007 NAWT Waste Treatment Symposium in Pennsylvania to learn about building and operating dewatering systems. Heckman, whose mechanical skills and ability to communicate regarding machinery and equipment is tops, said he found himself “absorbing information like a sponge.” As soon as he had a grasp of the industry acronyms being used, Heckman was sharing ideas with Forest regarding how the facility would work in central Iowa. Also attending the conference was Therese Wheaton of Crystal Environmental, a consultant in creating, maintaining and optimizing dewatering facilities. Her feasibility analysis—which revealed that about one million gallons of septage annually is the breakeven point—made the $500,000 venture a reality. Jerry Heckman came on board to run the facility and remains its superintendent and sole employee.
Accurate Dewatering opened with three contracted septic waste haulers on August 18, 2008 at 3201 East Granger Avenue in Des Moines. The company operates from 8 a.m. to 4 p.m., Monday through Saturday. For an additional 1 cent per gallon, disposal at Accurate Dewatering is available on Sunday and after regular business hours. The facility, which will soon begin its third year of operation, receives 5,000 to 25,000 gallons of septic waste a day. In 2010 nearly 2 million gallons were converted to “cake,” a biosolid that is land-applied outside of Polk County under Chapter 67 of the Iowa Code.
Two things are key to the successful, non-municipal dewatering operation in Des Moines. The first is maintaining a “fair and level competitive marketplace” for all central Iowa liquid waste haulers; the second is keeping the consumers’ costs for pumping septic tanks at a rate that would enable them to properly maintain their systems. “We all have to watch the bottom line,” said Forest. “If the cost of pumping a septic tank is too high, we all lose, including the environment.”
Accurate Dewatering is sized to process up to 40,000 gallons per day, and its receiving station can offload two trucks at a time. Heckman samples each load to assure that it is septic waste. “Our firm accepts septic waste only,” said Heckman. “Portable toilet waste, restaurant grease waste and car wash pit waste must all be taken to the Des Moines WRA.”
The offloaded septage flows through a grit tank and an auger removes any plastics, hair, hygienic materials, rocks and other debris. As the water is squeezed out, that debris is deposited into a trash bag. “The system could create two garbage bags a week or two bags from just one load,” says Heckman. “It all depends on the amount of debris in each load. The garbage bags are then taken to the metro east landfill.”
After debris removal, the remaining sludge is discharged into two 25,000-gallon underground tanks where large paddles mix it for approximately 20 minutes to create a consistency in the septic waste. Heckman then introduces a polymer into the mix, and the resulting solid product is pumped into a 30-cubic-yard dewatering box capable of holding 14 tons of “cake.” Screens in the box assist in the removal of the remaining moisture, which flows from the box into the tank filtering system. That liquid output, which will enter the city sewer system, is metered and sampled regularly, with quarterly lab analysis for pH, CBOD, COD, TSS, oil, grease and nitrogen.
“Without Accurate Dewatering Services, the only option for my Polk County peers and me was really the Des Moines Wastewater Reclamation Authority (WRA),” said Forest. “Nationally, our local WRA is at the high end of disposal costs. Today’s fee for offloading at Accurate is $75 per 1,000 gallons or 7.5 cents per gallon,” said Forest. “WRA’s fee is 17 cents.”
The door at Accurate Dewatering Services is open to anyone interested in using the septic disposal facility or in building a similar facility. Call Jerry Heckman (515-447-7474 or 515-265-4039) to visit or learn more about the septic acceptance facility. The operation, which continues to meet its expenses and keep costs low, is designed for additional growth should that option become feasible for the central Iowa business.