The plan to overhaul Pima County’s main sewage treatment facilities has three “major components,” according to Jackson Jenkins, deputy director of the county’s treatment division.
Work already has begun building a 5-mile “interconnect” (or pipe) that would divert sewage from the aging Roger Road treatment plant to the newer facility off Ina Road, Jenkins said.
The Ina plant “has all the extra capacity,” he said, explaining the rationale for diverting sewage from the Roger Road facility.
Built in 1951, the Roger Road plant is essentially “three different plants pulled into one, with different eras of technology,” Jenkins explained.
County officials decided it would be “cheaper to build a new plant” than to remodel the Roger Road facility, Jenkins explained.
The new Roger Road plant would accommodate 32 million gallons of sewage per day, slightly smaller than the current facility’s payload.
The Ina campus basically includes two facilities — a late-1970s unit that can treat up to 25 million gallons of sewage per day and a more recently built facility that treats 12.5 million gallons per day.
But, the county plans to expand the Ina Road campus to a capacity of 50 million gallons per day, Jenkins said.
All the work is part of a major plan by the county to bring its major treatment facilities into compliance with federal environmental standards for lower levels of toxins, mainly nitrogen.
The county has until 2014 to upgrade and expand its Ina Road plant and until 2015 to build a new Roger Road plant.
“The ratepayers are going to have to bear those costs,” Jenkins explained.
The county has 260,000 sewer service customers, who pay an average of $23.62 per month. That monthly bill will almost double to help pay for the work, Jenkins said.
The county, however, will have to seek voter approval in the coming years for several bonds to finance the construction costs, which likely will top $1 billion.
But, county officials this month asked for a five-year extension to meet regulatory requirements for the treatment of effluent.
“The more time we have, we can minimize the cost,” Jenkins said. “We don’t have very much fluff in the schedule.”