Board considers wastewater treatment system expansion

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PITTSBORO — The town’s board of commissioners dedicated most of its Monday meeting to a public hearing on suggested wastewater treatment system improvements from Raleigh’s The Wooten Company, which the board had commissioned to compile an engineering report and environmental information document.

The project will be part of Pittsboro’s larger effort to expand infrastructure in anticipation of a swelling population as Chatham Park and other builders pursue aggressive development across town.

Pittsboro, the population of which is now shy of 5,000, will expand many times over in the next 20 years, even by conservative estimates.

Carl Scharfe, P.E., a project manager and process engineer, represented the Wooten Company on Monday to share its evaluation.

“Even without Chatham Park,” Scharfe said, “a 20-year projection in Pittsboro anticipates population growth to reach 16,345.”

A more realistic estimate, accounting for Chatham Park’s certain contribution to a population spike, puts the town at 47,642 in 20 years with continued growth likely.

To accommodate such growth, the town must expand its wastewater flow capacity to almost 5 million gallons per day. The existing wastewater treatment plant handles .75 mgd and “cannot meet future flows,” Scharfe said.

According to Scharfe, were the town to decline any wastewater flow expansion efforts, Pittsboro would exceed its flow capacity in 2030 when discharge is likely to reach 3.22 mgd. Chatham Park alone is anticipated to eventually produce .499 mgd.

Scharfe outlined several options to address the need, but his company strongly recommended a two-phase plan to mitigate one-time cost of expansion.

In phase one, Pittsboro would construct a new pump station at the existing Pittsboro water treatment plant and modify its equalization tank. This would permit the town to pump up to 2 mgd of wastewater to Sanford’s Big Buffalo wastewater treatment plant.

“We project the 2 mgd capacity to last an estimated eight to 10 years,” Scharfe said.

Phase two would involve construction of a second wastewater treatment plant with a 1.91 mgd capacity to discharge to the Haw River.

The Wooten Company estimated the project, which Scharfe emphasized only accounts for phase one at this point, would cost about $19.7 million. That figure is variable, however, pending constructor bids.

The town is eligible for a loan administered by the N.C. Dept. of Water Infrastructure having been issued an “intent to fund” letter back in 2016. The loan would come with a 1.84% interest rate and a 2% origination fee to be paid by the town. The town is not obligated to the accept the loan until after the bidding process begins.

Chatham Park, as the major contributor to wastewater flow expansion need, has agreed to pay 62.5% of the loan cost, up to $13.5 million, leaving 37.5% for the town.

Chatham Park would also contribute 25% to the Sanford agreement capacity reserve fee along with a provision to cover shortfalls.

Following construction, one or two years after the loan agreement would begin, Pittsboro would owe its first payment. Considering Chatham Park’s contribution, The Wooten Company estimated that Pittsboro would owe about $686,000 annually — the equivalent of 1,400 new water customers.

It would likely take two or three years to reach this customer threshold, Scharfe said, so the town would have to front the cost in the meantime.

“But I understand from your town manager,” Scharfe said, “that the town has about $2 million in retained sewer fund earnings that could be used for the initial loan payments versus increasing rates.”

The commissioners, in general, expressed approval of the recommendation but anxiety over the timeline.

Commissioners Kyle Shipp and Michael Fiocco pointed out there was a reason the town pursued a loan four years ago. Already then, a need had been identified. Construction in Chatham Park is under way and population growth estimates seem reasonable and on track.

Following Monday’s meeting, Scharfe said, he would add a summary of the public hearing to the engineering report as an appendix after which a 30-day public comment period could begin.

Pending no serious objections from the public, the commissioners could pursue approval of the report and design proposal and open for bids. The Dept. of Water Infrastructure has the right to approve bids and the final loan amount.

Should all go well, construction would begin immediately thereafter to last approximately 15 months.

Reporter D. Lars Dolder can be reached at dldolder@chathamnr.com and on Twitter @dldolder.