PITTSFIELD — A $100,000 engineering assessment of the city's water treatment plant operations, future requirements and upgrade options is expected to begin soon and be completed by November.
Commissioner of Public Utilities Bruce Collingwood said the assessment follows up on an evaluation that was part of a 20-year water master plan effort in 2010, and several smaller studies of such treatment aspects as aluminum-reduction options and equipment corrosion control throughout the water system.
Essentially, he said, the goal now is to decide whether to retain and upgrade the Krofta water filtration systems that were installed at the city's Ashley and Cleveland water treatment plants during the 1980s or install a different filtration system.
The current evaluation is expected to provide information to help make that determination and provide an indication of costs, Collingwood said, as well as allow the city to begin the design phase for a new treatment system next year.
When the project might go to the construction phase is listed as "to be decided" in the city's multi-year capital projects plan, he said.
Of the Krofta treatment systems, Collingwood said, "They are in good condition overall, but we are at the end of the service life of the equipment."
The systems have been well maintained over the years, he said, adding, "We've done a lot of TLC."
The evaluation will look at whether "to keep the Krofta system, all the pluses and minuses, and alternative systems, and the pluses and minuses," the commissioner said.
"This is like a mini-master plan," he said, "and we are looking at both [treatment plants], and the way we operate."
Linked to the water system assessment is the impact the plants will have on the city's wastewater treatment plant, which also is scheduled for a major upgrade in order to treat waste water to current federal Environmental Protection Agency requirements. The requirements are focused on the level of phosphorus and other material remaining at the end of the process, when water is discharged into the Housatonic River.
The water treatment facilities use aluminum chloride and similar materials in treating drinking water, Collingwood said, and this produces a sludge material that either must be treated at the wastewater treatment plant — as it is currently — or treated in smaller facilities at the water plant sites. Those are the types of determinations that will go into design of the new or upgraded water plants, he said.
Current and future state Department of Environmental Protection drinking water standards also will be considered during the planning stages, along with the chemistry of the city's water and its effects on equipment and the treatment processes.
In a project narrative Collingwood submitted to the City Council during recent budget sessions, he stated that the Krofta system "has performed adequately, and the analysis showed [in 2010] that a feasible and cost-effective alternative for potential future upgrades could involve a newer version of the Krofta process in place of the existing."
But he notes that "some aspects of the recent [studies and upgrade projects] have exposed the drawbacks of the Krofta process, such as the high volume of treatment residuals, lack of robustness when used on more challenging source waters or with alternative coagulants, and lack of conventional mixing (coagulation and flocculation) that could otherwise be used to optimize pre-treatment."
The commissioner adds, "There also continue to be concerns about the long-term viability of the Krofta process as the sole technology for the city's water supply. Compared to other water treatment equipment manufacturers, the Krofta technology is supported by an unusually small staff with very limited resources, which could undermine future technical support, parts replacement availability, and ability to adapt to ever-changing regulations."
In recent years, he said, "the aluminum load to the city's wastewater treatment plant has put a burden on the operating budget and the ability to meet compliance. This aluminum originates from the water treatment operations."
Collecting and recycling the waste products at the water plant sites would alleviate that problem, he writes, but "given the arrangement of the Krofta process and the sensitivity to high raw solids, this would be a costly and complex propositions. A process with the ability to handle recycle water and to minimize sludge load would be beneficial."
The city concurrently has been upgrading its water lines and water storage tank systems. Upgrades and repairs to the city's reservoir dams also is continuing, such as at the Upper Sackett Reservoir in Hinsdale, which was found to have deficiencies during a 2014 inspection.
The Krofta systems were installed at the water plants in Pittsfield during the 1980s and were developed by the Lenox-based firm led by the late Milos Krofta, who died in 2002. The system, with a then-innovative filtration technology, was credited with saving the city millions over other treatment options being considered at the time.
Collingwood said the companies now operates as Krofta Technologies.
The city water system includes six reservoirs: Cleveland and Sackett reservoirs in Hinsdale; Ashley Lake, Lower Ashley, Farnham and Sandwash reservoirs in the town of Washington.
There are two water treatment plants, the Ashley Water Treatment Plant in Dalton and the Cleveland Water Treatment Plant in Hinsdale. Treatment at the plants includes removal of particulate matter, chlorination and use of additives to make the water less corrosive to water pipes.
Contact Jim Therrien at 413-496-6247.