Carson City Water Resource Recovery Facility to see $30 million in improvements
David Bruketta, Carson City utility manager, uses the word repeatedly during an hour-long tour of the city’s Water Resource Recovery Facility.
As in: “All the mixing equipment is failing. If we can’t treat solids we have a problem.”
Or, similarly, “electrical controls so outdated we can’t get parts for it,” he says, and sludge heaters that are “well beyond their useful life.”
Three years ago, the back of a sludge heater blew off. The equipment heats up solids to help break them down and uses methane gas produced in the process, which is both combustible and corrosive. The solid-pipe railing directly behind the heater is still bent out of shape from the blast.
Around the same time, the plant had what Bruketta called a catastrophic failure when pumps failed and raw sewage had to be put in a holding tank on site.
In the next couple weeks, Carson City’s nearly 50 year-old wastewater treatment facility will begin a much-needed and long-delayed makeover.
K.G. Walters Construction/Q&D Construction, under a $29,991,581 contract approved by the Carson City Board of Supervisors earlier this month, will start with the most urgently needed repairs and upgrades.
That portion of the project, known as phase 1A, is scheduled to be completed sometime in 2018.
Repairs at the plant located between Butti Way and the 5th Street and Fairview Drive roundabout have been delayed for years.
“The maintenance was deferred because there were not appropriate rates to do all the work, which was a policy decision made by public officials,” said Bruketta. “Rates were flat and for a couple years rates even went down.”
In 2013, the supervisors bit the bullet and passed new water and sewer rates to be phased in over five years that allowed the city to bond for the multimillion dollar project.
Phase 1A repairs will touch on nearly every part of the wastewater treatment process, from replacing screens at the headworks where the sewage is taken in to putting in a new bioreactor consisting of two new tanks on the east side of the facility, the costliest chunk of the $30 million project, partly because it requires all new electrical equipment from NV Energy.
In between, Bruketta says clarifiers or in-ground settling tanks where the water is pumped from the headworks is going to be rehabbed. Then the guts of the digesters, where solids are then pumped to be reduced, will be replaced. That includes the failing heating and mixing system.
The initial plan also calls for six bid alternates, an additional $2 million in work that’s the next priority if there’s any money left over to do it. The first of those secondary priorities is fixing the screw pumps in the headworks.
Replacing the whole headworks comprises the project’s so-called phase 1B, which will be planned and bonds issued for in 2017-2018.
That should help with the odor emanating from the facility, said Bruketta, because modern plants are built with covered headworks, reducing the problem.
To define the project’s parameters, Carollo Engineers was brought in a few years ago to help the department set priorities.
“We did a risk assessment and looked at the risk and danger of everything,” said Bruketta, prioritizing upgrades based on both the likelihood and danger level of each possible failure.
Bruketta said the plant will need ongoing upgrades for the next 30 years.
“The Board of Supervisors at one point asked for the cost of building a new plant,” he said. “It was in the ballpark of well over $100 million.”
The facility is permitted to handle 6.9 million gallons of wastewater a day and currently handles 4.2 million gallons, Bruketta said during the March 3 supervisors meeting at which the contract was approved.
At the meeting, the board asked about the impact of city growth on the plant.
Daniel Rotter, engineering manager, said the Nevada Department of Environmental Protection permit requires the plant to build out when it reaches 85 percent of capacity.
“We could add 4,000 equivalent residential units before needing to expand,” he told the board.
“Five hundred in a year is the highest we’ve had,” said Supervisor Brad Bonkowski. “So we’re nowhere close to that yet.”