Editor’s note: This article is the second installment in a series exploring Chatham County’s intricate water and sewer systems. This week, the News + Record investigates water conditions in Siler City and plans to meet projected future demand as the town aggressively pursues new enterprise.
SILER CITY — With big plans for heavy industrial development, ambitious renovation initiatives to revitalize downtown and the prospect of future real estate development, Siler City is gearing up for considerable growth — and its water systems must expand accordingly.
As explored last week, three distinct systems serve Chatham County’s rural areas. But in Siler City, the town government is exclusively responsible for water treatment and distribution.
“So we serve, of course, the city limits, but then we have some outlying areas,” says Chris McCorquodale, the town’s public works and utilities director. “We have two connections with the county that we can serve water to them like in the Silk Hope area and then down to the south side of the county.”
The town pulls its water from the Rocky River at the Charles L. Turner reservoir before processing at a dedicated treatment facility north of downtown.
“When we pick it up out of Charles Turner, it goes to our treatment plant where we pull all the dirt, nutrients and all that stuff out of it,” McCorquodale said, “and then it comes into town.”
The water can either stop at a “tank farm” for storage or funnel “straight into town,” McCorquodale said, depending on daily needs.
With its current treatment facility, Siler City can process up to 4 million gallons of water per day. Current average demand rarely exceeds 3mgd, but town staff expect that to change.
One of the primary drivers for water system expansion: the 1802-acre Chatham-Siler City Advanced Manufacturing (CAM) site which promises to introduce thousands of new jobs and increase water demands substantially as heavy industrial companies begin operations in coming years. (See our update story on the CAM site in this week’s edition.)
“And yeah, hopefully, with the development there,” said Town Manager Roy Lynch, “that will bring additional residential needs and development in the area.”
The town’s board of commissioners hopes to complement the CAM site’s attraction with a widespread revitalization campaign to make Siler City more appealing to potential new residents. If all goes according to plan, town staff expect water capacity requirements to exceed 4 mgd in the near future. Plans are thus under way to expand the facility to 6 mgd.
“And so, as we continue to grow and see the need for the 6 mgd,” Lynch said, “then we will certainly be actively working toward that, which we are doing through phased projects that we have in place already and already have the funding currently for.”
To prepare for capacity expansion needs as the town pursues new development, Siler City has launched a three-part water treatment plant upgrade project. This project will not increase water capacity to 6 mgd. Rather, it will improve efficiency at the treatment plant in preparation for future capacity expansion.
• Phase 1
Before embarking on direct expansion work, the town must upgrade its current facility. Phase 1 completed near the end 2020 and included replacement of the filtration media at the water treatment plant and rehabilitation of the filters. The media had exceeded their useful life and replacement made immediate improvement to the town’s drinking water quality.
• Phase 2
The town is now in Phase 2 — upgrading its water treatment plant’s air backwash system.
“What that does is it takes the new filter media that we put in there and we blow air through that media to pull all the contaminants back out of it that have been sucked in,” McCorquodale said.
The system extends the filters’ effective lifespans and thereby contributes to the town’s water quality. But the air backwash technology currently installed is 40 years old. It’s in desperate need of upgrade.
“So that’s the main purpose of phase 2,” McCorquodale said, “to upgrade that and bring it up to standard, the new standard, which naturally is going to work much better.”
Phase 2 is expected to conclude in Nov. 2022.
• Phase 3
In the final phase of its current plant upgrade project, the town plans to install a pretreatment unit called Actiflo, which will boost the facility’s processing capacity in anticipation of future plant expansion.
“The purpose of the tank is to pretreat raw water entering the current facility from the town’s reservoir,” Lynch wrote in a summary of the project’s scope, “ultimately reducing the sludge production at the facility, and significantly extending filter run times.”
The three-phase upgrade project should complete near the end of 2023. It will cost roughly $5 million total, about half of which will come from a state revolving fund loan. The remaining funds are guaranteed by a N.C. Dept of Commerce grant and a small local contribution.
Concurrent with its plans to enhance plant operations at the water treatment facility, the town has launched a wastewater — or sewer — treatment plant upgrade project. Proposed modifications will come in two phases.
• Phase 1
First, the town must improve nutrient removal processes to reduce total nitrogen in the town’s discharge.
“So the idea is to take those out of the water, reduce them from the levels that they are at currently,” McCorquodale said. “It’s just to make the river better, so that less contaminants are going into the rocky River.”
To accomplish that goal, the town will replace much of its equipment, modify the aeration system, upgrade process control systems and provide standby generator upgrades to improve operation during power outages.
The total estimated cost for Phase 1 is $5.1 million, all of which will be covered by secured grant funding. Work is expected to finish in Sept. 2022.
• Phase 2
The next phase will only last about a year, but will include considerably more work. To accommodate real estate growth and ensure adequate flow needs are met for the CAM site and other developing commercial areas, Phase 2 will expand the wastewater treatment plant’s capacity from 4 mgd to 6 mgd.
Despite increased flow rate, plant modifications will further reduce discharge of nitrogen and other contaminants. The project will also include a new influent pump station, UV disinfection, a solids handling facility and replacement of more than a mile of sewer main.
The upgrades are estimated to cost about $17.1 million, funds for which have not yet been secured. The town is in the process of finalizing a USDA application for loan money. Later this month or sometime in spring, Lynch expects to know the town’s chances of securing those funds.
“No,” Lynch says.
But don’t feel bad for asking.
“We get that all the time,” he said. “People ask about their property taxes ... There’s been statements about the use of water and upgrades and things and about taxes going up to sustain them.”
But that’s not how things work. Taxes have nothing to do with it. User rates fund expansion projects on the water treatment plant and sewer facility, but those aren’t likely to get more expensive either.
“We don’t anticipate costs going up,” Lynch said. “We always go through an analysis process. The engineers will sit down and analyze what the current needs are based on projected loans and things.”
From that process, the town can usually ensure rate stability, even as it plans for Siler City’s transformation.
“The town has worked hard over the past few years to be proactive in looking forward to the various types of development that we hope to see here in our city,” Lynch said. “But we have to have the infrastructure to be able to support that need.”
The next installment in this series will examine Pittsboro’s water needs and the town’s plans for water/sewer expansion to keep pace with aggressive real estate development.
Reporter D. Lars Dolder can be reached at dldolder@chathamnr.com and on Twitter @dldolder.