Angola City Council weighs legal route over five-year compliance plan for wastewater chloride limits

Craig Williams, a former superintendent of the Angola Wastewater Treatment Plant, told the Angola City Council that meeting numeric chloride limits in the plant's discharge permit would require costly, technically difficult steps that still might not achieve long-term compliance.

Williams summarized nearly two decades of work, saying the plant has long operated under a National Pollutant Discharge Elimination System permit administered by the Indiana Department of Environmental Management and that Angola is currently the only Indiana permit holder with an individual chloride variance. He told the council that engineering studies and outreach efforts have not produced a reliable path to meet the water-quality-based effluent limit IDEM calculates for the plant.

The issue matters because IDEM has signaled that EPA Region 5 is unlikely to approve future variance renewals, and Angola's current variance and permit cycle approach renewal in May. Council members said the potential capital and operating costs could impose a significant burden on residents and local businesses if the city is required to build and operate energy- and chemical-intensive treatment such as full reverse-osmosis filtration.

Williams described the technical challenge: wastewater treatment does not remove chlorides, and roughly half the chloride load to Angola's system comes from water-softening processes, he said. He summarized other source estimates he reported to the council: about 20% from residential wastewater, about 15% from industrial or commercial processes and the remainder from other sources. He said three study pathways presented by GEI Consultants were vetted with IDEM in 2023 and were not accepted as likely to be approved by EPA.

On costs, Williams cited a 2019 engineering estimate of about $12 million for some treatment options (he said that figure had only a national inflation adjustment applied and could be meaningfully higher now) and pointed to engineering estimates that annual operation-and-maintenance costs for a reverse-osmosis system could be roughly $1.3 million a year. He said those O&M costs alone would be a very large portion of the plant's current annual O&M budget.

Williams outlined four broad pathways the city could pursue: (1) reduce chloride sources (including municipal and private water softeners), (2) change municipal water-softening processes, (3) capture and treat softener brines separately, or (4) install reverse-osmosis or electrodialysis at the wastewater facility. He told the council none of the first three options guarantees continuous compliance because the city cannot control all private and industrial sources, and the fourth option would be capital- and energy-intensive and create additional waste streams.

He also described a potential regulatory path used elsewhere: a focused Use Attainability Analysis (UAA) or limited-use designation for the specific 2.9-mile stretch of the HD Wood Ditch downstream of the plant. That path would seek to recognize stream characteristics that limit the ability to meet statewide water-quality criteria. Williams said the city previously proposed similar approaches and that IDEM did not accept the options in 2023, but he and staff think there may be new opportunities through continued technical and legal engagement.

After discussion and questions from Mayor Martin and council members, the council gave a consensus direction to the administration to begin consultation with environmental counsel to explore legal options, rather than immediately committing to a five-year compliance plan that would include capital expenditures. Council Member Dunne explicitly recommended against entering a five-year compliance plan; Council Member McNeriff also favored pursuing the legal route; Council Member Coffey signaled agreement with those positions. Administration staff said they already have a relationship with GEI Consultants and can arrange an initial attorney consultation quickly.

Next steps: staff said they will obtain a budget and scope estimate from environmental counsel and report back at the next council meeting so the council can decide whether to formally pursue a regulatory appeal or to accept a permit-based compliance plan. The permit renewal process and the city's variance timing make a decision time-sensitive, the administration said.