NEWPORT — On Monday, the Newport City Council voted to rescind the water emergency in effect since June 24, which came with water curtailments that cost commercial customers more than $2 million.
Fouling of the filters at the Newport water treatment plant were first detected in May. When the problem persisted into late June, it coincided with peak season for the city’s seafood processing facilities — the biggest consumers of municipal water — and the combination of reduced production and increased demand dropped water storage to critical levels.
In response, the acting city manager declared an emergency, later ratified by city council, and implemented restrictions on residential use. Additionally, the city curtailed use for some commercial customers entirely, largely pausing the local fishing industry for several days. To supplement capacity, the city brought in mobile sand filters. Plant operators also tested and refined filter cleaning processes, eventually implementing a system of more frequent and longer cleanings in a sequence that allowed all filter racks to be cleaned before the first became too fouled to operate. This required maintenance around the clock but allowed plant operators to increase production sufficient to meet demand and lift curtailments.
In the meantime, the city worked with HDR Engineering, the water plant’s designer, and Pall Water Corp., manufacturer of the filters, to determine the cause of the fouling. The problem, according to a report delivered to the city on Sept. 3, was dissolved iron, manganese and organics in raw water. The source of the increased level of dissolved minerals and organics is not yet known — it has since resolved as mysteriously as it appeared — and a new testing regimen has been implemented to analyze long-term trends, which could help predict when those dissolved constituents will again become problematic.
According to a report to the council Monday from Public Works Director Tim Gross, a survey conducted by Dig Deep Research found the 10-day use curtailment hit the local fishing industry to the tune off $3.3 million, with $2,431,000 in losses reported by fish processors and $848,200 in losses reported by independent fishing vessels.
The city’s costs responding to the fouling and subsequent shortage exceeded $350,000, including $148,393 paid to HDR for technical assistance and operation of sand filters; $75,574 to Suez Corp. for sand filter rental, start up, take down and shipping; $29,930 to Pall for water and membrane testing and technical assistance; $29,228 to Rain for Rent for pump and pipe rentals and shipping; $11,512 to Above Board Electric for installation of electrical service for sand filters; and $67,604 in other professional services and materials.
Permanently correcting the problem could cost upwards of $1 million. According to Gross’s report to council, HDR recommended three actions to prevent future fouling, one of which, the collection of more water quality data, has already been implemented. The step most likely to next be taken by the council would be the addition of a fifth filter rack for increased redundancy, which had been planned at the time of the plant’s design but was eliminated as a cost-saving measure.
The new rack would be an estimated $626,000 expense, and the council will need to move relatively quickly to have it in place in time. According to Gross’s report, “historical trends show raw water quality worsening each year between May and July. Therefore if the city chooses to modify the plant to address the identified water quality issues, the deadline to have the recommendations constructed and operational at the treatment plant is approximately May 1, 2021.” Fabrication of the new rack will take 18 weeks, and with shipping, installation and re-programming, it would need to be ordered by November for operation by next summer.
HDR also recommended retrofitting existing filters, which would allow for both more chemical treatment of water to precipitate fouling constituents, as well as simpler cleaning. The retrofitting would likely not be completed in time for next year, even if design had begun last month, so the report recommended the estimated $430,000 project be undertaken during the next fiscal year, in time for May 2022.
Council took no action Monday regarding those recommendations. They did approve an unrelated water treatment plant expenditure — an $87,559 agreement with Murraysmith for design, fitting and construction review to replace the existing biosolids conveyor, which is at the end of its useful life. A total of $510,000 has been appropriated to that project.
In other water-related business, the council approved a $594,368 task order with HDR Engineering for the first phase of final design of a new dam at Big Creek. The city had anticipated receiving $4 million from the state for dam design and permitting, but the lottery bonds from which those funds were expected were not issued this year due to anticipated revenue shortfalls. Those state funds required a 25 percent city match, so Newport had already dedicated $647,843 to the Big Creek Dam account, from which it will pay for the task order.
Replacement of the two existing dams at Big Creek has been deemed a critical task — they’re highly vulnerable to failure during a seismic event as low as 3.0 on the Richter scale, experiencing “advanced seepage,” and cannot meet the city’s anticipated future water needs. The half-million-dollar expenditure approved Monday is a fraction of the total cost for a new concrete dam to replace the two earthen dams constructed in 1958, which is estimated at $70-80 million.
Editor's note: A previous version of this article referred to the new Big Creek dam as "earthen." The new dam will be concrete.