It's been a perfect storm for Western Butler County Authority's wastewater treatment facilities.

The authority, known as the WBCA, is working with decades-old infrastructure, with sewage lines in Harmony and Zelienople — two of its four member municipalities — dating back to the 1920s and 1930s. The other two municipalities — Jackson and Lancaster townships — are experiencing rapid growth, adding more wastewater to what the authority must clean and return to the watershed.

With design changes in the 1950s, 1978 and 1999 — the latter two of which were “poor design,” according to WBCA administrator Autumn Crawford — engineer Chad Hanley described the authority's current system as a “piecemeal plan that has reached the end of its useful life.”

Within five years, the authority projects, its water pollution control plant will be unable to handle the loads required of it; the time frame for the overload of the Harmony Pump Station is within five to 10 years; and the Harmony Junction Pump Station has a remaining 20 to 30 years of useful life.

In comes a hefty proposal from the authority: It wishes to rehabilitate and upgrade the Harmony Pump Station to increase capacity and address other issues at a cost of about $10.6 million. Additionally, the authority wishes to build a new water pollution control plant to meet Department of Environmental Protection limits and projected flows at a cost of about $64 million.

The impact on ratepayers would be 50 cents per 1,000 gallons each year for four years, and $1 per 1,000 gallons in 2030, 2035 and 2040, increasing rates from $16 to $21 per 1,000 gallons by 2040. Residential charges for Pennsylvania American Water wastewater customers, for comparison, are $16.47 per 1,000 gallons in 2021 and $19.49 in 2022.

It's an expensive project. But, Crawford said, a significant amount of the issues stem from rain-derived inflow and infiltration, and “a lot of it's not on the public sewer side.” Crawford said to address the inflow and infiltration problem via pipes would cost $66 million for the public sewer lines and an additional $41 million on repairs and upgrades to landowners' sewer connections — a total cost of $107 million.

“We're trying to be proactive and avoid a situation like ALCOSAN in Pittsburgh (which was) placed under consent decree” by the DEP, Crawford said. “We vetted all the different alternatives and said, 'Here's what we can do.'”

On top of that, Hanley said the cost estimates for the Harmony station and the pollution control plant are probably higher than they will end up being. Hanley said he used fewer new customers — and, therefore, less money in tap fees — than is being projected, and added an additional 15% of contingency to the estimate to account for unexpected expenses.

“The authority board provided direction to me on being very conservative,” Hanley said. “We were very conservative with all that.”

Crawford said Harmony and Zelienople were somewhat apprehensive about the plan at first, in part because they thought their ratepayers would pay for the development in the townships; conversely, she said, Jackson and Lancaster townships were initially apprehensive in part because they believed their ratepayers would subsidize the boroughs' old sewage lines.

Despite that, both Harmony and Jackson Township approved the authority's proposal to submit to DEP a new Act 537 plan, which details WBCA's current issues and proposed solutions. The matter is still pending in Lancaster Township and Zelienople.