BY CINDY TOOPES COURIER STAFF WRITER
March 13, 2008 10:43 am
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OTTUMWA — Grit. Bob Bruett sees too much of it at the city’s Water Pollution Control Facility, also known as the sewage treatment plant.
But the current Ottumwa City Council and future councils may need plenty of “true grit” to fix the city’s infrastructure problems.
Bruett, WPCF’s superintendent, said the grit — which is sand or other tiny, hard particles — gets past the plant’s first screen, which keeps larger items from entering all of the plant’s systems.
“The first screen has never worked right,” he said.
The WPCF is supposed to have a second screen but doesn’t. That’s only one of the items that has to change to make the facility compliant with Iowa Department of Natural Resources regulations for clean water.
At this week’s council meeting, Bruett and Jim Rasmussen, a project engineer and senior project manager with Howard R. Green & Co., Des Moines, presented a 20-year plan for improvements at the facility.
Rasmussen said the study began two years ago.
“We took a thorough look at the plant so the city didn’t have to just jump in,” he said. “We have prepared a long-term plan for the facility.”
Rasmussen and the council had copies of the plan and the spiral-bound document was nearly two inches thick. He said both Howard R. Green staff members and the WPCF staff prepared three tiers of improvements.
Each tier lists what needs to be done, the cost, funding sources and a target implementation date. The improvements are spread over a 20-year period.
“The first tier of recommended improvements focuses on safety and other improvements needed to meet the regulatory requirements,” Rasmussen said.
In the first tier, grit-handling improvements were estimated at $935,000 and the cost will be paid through sewer funds and the State Revolving Fund Program, he said.
Items targeted for completion in 2008, the estimated cost and funding source are: Installing brownwater pumps, $10,000, sewer funds; primary clarifier sludge pumping, $30,000, sewer funds; and WPCF air system and aerobic digester improvements, $1.2 million, sewer funds and SRFP.
Clarifiers, air system and aerobic digester improvements refer to the “bugs” that break down sewage and the system that keeps them “happy” so they’ll continue to feed.
The second tier of recommended improvements relates to those needed to improve operational reliability and reduce critical maintenance.
“The largest single project, the Elm Street pump station replacement project, was put in this category but could be moved to the first tier due to its important effect on elimination of combined sewer overflows,” Rasmussen said.
The third tier relates to existing treatment infrastructure in need of repair and for peak flow treatment, he added.
Rasmussen said the city has a “fairly low projected population growth” but a higher commercial/industrial growth for the 20-year planning period.
ABC Bottling, one of the city’s current industries, consumes nearly 65 percent of the wastewater treatment plant’s capacity. Pretreatment for this industrial load is needed to relieve the potential plant overload and provide capacity for other residential, commercial and industrial flows.
Pretreating the industrial load means building a treatment plant at the airport, Rasmussen added.
Bruett is looking forward to the day when he has an overhead door for the building that houses the plant’s only screen, which has its own special room. The overhead door is part of the second tier of improvements.
The screen’s process of filtering the sewage is very controlled because an explosion could result.
“The air in here changes 11 times in 30 minutes,” Bruett said.
The screen is a large piece of equipment. Years ago, they constructed the building around the equipment, he added.
Although no agenda has been posted yet, the council seemed to accept the proposed plan and most likely will vote to approve it at next week’s council meeting.
Cindy Toopes can be reached at (641) 683-5376 or via e-mail at cindy@ottumwacourier.com.
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