City examines issues with aged facility

6/26/16

As the Arcata Wastewater Treatment Facility continues to age and resulting compliance issues arise, the city is preparing for a 10- to 20-year remodeling project. The effort will take its next step Monday when Arcata’s Environmental Services Department, which manages the facility, meets with the state’s Regional Water Quality Control Board to discuss the project’s future as city officials work to have a completed plan in place by their December deadline.

“It works. It’s like an old car though,” Arcata Mayor Paul Pitino said about the system, which was originally built in 1950 and was subsequently made into the environmentally-praised system it is today in the 1980s after the city introduced a series of wetlands, ponds and marshes to help naturally treat the city’s sewage before releasing it into Humboldt Bay. While a cost estimate hasn’t been drafted, Environmental Services Department Director Mark Andre estimated that similar projects elsewhere have run in the $35 million to $40 million range. This bill would be picked up by rate payers, but the city is also looking at grants and low-interest, long-term loans, Andre said.

After receiving roughly 125 violations since 2010 — many related to treatment quality — and receiving more than $400,000 in fines from 2006 to 2007, the city will be headed to Santa Rosa on Monday to lay its plans before state officials in hopes of closing the door on years of compliance troubles.

Environmental Services Department Deputy Director Erik Lust said the scope of the improvement project has ballooned since September after the project’s engineers and consultants relayed the belief that more needed to be done than simply changing out aging infrastructure and converting to a ultraviolet treatment system. Lust added that the facility’s recent woes can be traced back to three sources, one of which is aging infrastructure.

“It has been an amazing facility. It deserves the environmental accolades. But at around the three decade mark, you’re going to need to take a look at it,” Lust said.

The facility uses gravity to pull the city’s sewage through a series of marshes and ponds to allow microorganisms to naturally treat the wastewater along with chlorine, the latter of which has been a source of many of its violations.

“Chlorine disinfection is part of it. That creates byproducts, which is a problem. We’re moving away from that,” Lust said, noting the facility will substitute in an ultraviolet treatment system to eliminate chlorine by-product levels in its discharge, which occasionally top the allowable limit.

A third source of the facility’s violations, Lust said, results from its original design — which sought to meet looser margins in its water quality discharge as well as to operate under a permit which allowed for occasional violations. The tighter margins create challenges for the facility, where performance varies widely with weather conditions, often sending water quality into the red, according to Lust.

Andre said they are taking a critical look at the facility as they continue to draft their plan.

In addition to implementing a ultraviolet treatment system and swapping out old infrastructure, Andre said they will move the discharge point, where treated water gets released into Humboldt Bay, from the Butcher’s Slough to the Mc-Daniel Slough.

“We’re aiming to improve conditions for fish and wildlife with this move,” Andre said.

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