Civic Lantern Ask freely. See the evidence. Think for yourself.
Issues / Wastewater & water

Issue 001 · Active research

Lebanon wastewater capacity and the proposed treatment plant

The question

Does Lebanon need a new wastewater treatment plant? How much more capacity is needed, where could a new plant go, and who would pay for it?

Plain-English answer · Evidence label: Supported

What the records show so far

Lebanon has two related wastewater problems. Some problems happen at the treatment plant. Others happen in the network of sewer pipes, manholes, and pump stations that carry sewage to the plant.

The clearest records show that rainwater and groundwater are getting into the sewer system, sewage has overflowed at several locations, some required reports contained errors, and one manhole known as MH5898 overflowed several times.

In March 2026, the Tennessee Department of Environment and Conservation, or TDEC, called MH5898 a chronic overflow point. TDEC later said two emergency-related events might be removed from the count, which could remove that label and the related pause on new flow. Civic Lantern has not found TDEC's final written decision.

Lebanon has also started building an 8-million-gallon equalization basin, which temporarily stores extra wastewater during storms. The project is expected to be mostly finished by November 18, 2027.

Current conclusion: The records support the need for major wastewater work. They do not yet prove that the current projects will fully solve the problem or show how much safe, reliable capacity remains for new development.

Research snapshot

Where this investigation stands

Research status RESEARCHING Records are still being collected and compared.
Evidence SUPPORTED The general concern is supported, but the final solution is not established.
Evidence last reviewed June 24, 2026 Page structure updated June 26, 2026.
Reading time About 10 minutes The short answer above takes about two minutes.
Source entries listed 7 Includes city materials and named TDEC records.
Records still needed 6 categories Engineering, site, cost, financing, and regulatory records remain incomplete.
Evidence access Very difficult Records are spread across several systems and viewers.
Current permit TN0028754 The permit lists a design capacity of 10 million gallons per day.

Why it matters

Wastewater capacity affects growth, cost, and public health

  • It affects whether new homes and businesses can safely connect to the sewer system.
  • It affects the risk of sewage overflows and water pollution.
  • It may affect utility bills, taxes, and public debt.
  • A new facility could affect nearby neighborhoods through odor, traffic, noise, or land use.
  • It raises the question of whether current residents or new development should pay more of the cost.

What is confirmed

Facts directly supported by the records reviewed

  • The current permit lists the treatment plant's design capacity as 10 million gallons per day.
  • A March 26, 2026 TDEC Notice of Violation found reporting errors, treatment-limit violations, sewer overflows, releases, and repeated problems at MH5898.
  • TDEC reported 20 sewer overflows and 23 releases since the prior inspection. Some had already been covered by earlier enforcement actions.
  • Lebanon received permission to begin the equalization-basin and pump-station project.
  • The city expects the project to be mostly complete by November 18, 2027.
  • On June 4, 2026, TDEC approved a revised design for an 8-million-gallon basin and transfer pump station.
  • A separate city committee is reviewing possible sites for added or replacement treatment capacity.
  • The committee can make recommendations, but City Council must approve property purchases, financing, and the final project.

What is disputed or unclear

The records do not yet answer these questions

  • Whether TDEC officially kept or removed MH5898's chronic-overflow label.
  • How much wastewater the system can reliably handle during normal weather and heavy rain.
  • How much capacity has already been promised to approved projects that are not built yet.
  • Whether the final solution will be a replacement plant, a second plant, an expansion, more pipe repairs, or a combination.
  • Why the proposed basin was reduced from 10 million gallons to 8 million gallons, beyond lowering project cost.
  • Whether the 8-million-gallon basin will provide enough protection before and after the expected 2027 completion date.
  • The full list of possible plant sites and why each site was added, ranked, removed, or rejected.
  • The full construction cost, yearly operating cost, financing cost, possible rate increases, and how much new development would pay.

Timeline

Recent regulatory and project events

  1. TDEC issued a Notice of Violation after inspecting the treatment plant and sewer system.

  2. TDEC said it might remove two emergency-related events from the MH5898 count.

  3. Lebanon held a preconstruction meeting for the new basin and pump-station project.

  4. Lebanon sent TDEC its project schedule, repair information, rainfall analysis, and flow data.

  5. TDEC approved revised plans for an 8-million-gallon basin and transfer pump station.

  6. TDEC approved a short sewer extension for Lawrence Row and warned that the new connection could not cause or add to an overflow or treatment-plant overload.

Evidence reviewed

Records behind this page

Most TDEC records do not have simple permanent links. Use the official viewer, search permit TN0028754, and match the document title and date listed below.

State records and approvals

Open TDEC's official data viewers · Read TDEC's public-record guide

  • March 26, 2026: Notice of Violation. Search TN0028754 and “2026 NOV for CEI & SSO.”
  • May 11, 2026: Letter about possibly removing MH5898's chronic-overflow label. Search “Field Office Reply to 2026 NOV Response.”
  • June 2, 2026: Lebanon's MH5898 response, project schedule, and sewer-repair information. Search “2026 Chronic Overflow Point Response Letter.”
  • June 4, 2026: Approval for the revised 8-million-gallon basin and pump station. Search project number 25.0688R.
  • June 22, 2026: Approval for the Lawrence Row sewer extension. Search project number 26.0321.
City records and meeting materials
Why access is rated very difficult: A resident must search city agendas, TDEC databases, permit numbers, engineering approvals, meeting videos, and separate public-record systems. A record can be public and still be difficult to find or understand.

Field notes

What required closer comparison

Field note 1 · MH5898 status

The March notice called MH5898 a chronic overflow point. A May letter said TDEC was considering removing two emergency-related events, which would lower the count and remove the label. Civic Lantern has not found the final written decision.

Assessment: UNCLEAR.

Field note 2 · Basin size changed

Earlier records described a 10-million-gallon basin. TDEC's June 4 approval describes an 8-million-gallon basin and says the size was reduced to lower project costs. The engineering explanation for why 8 million gallons is sufficient has not been found.

Assessment: CONFIRMED CHANGE; ENGINEERING BASIS UNCLEAR.

Field note 3 · Reported repair results

Lebanon said it inspected about 82,300 feet of sewer pipe and reported about 59 million gallons less flow in one repaired area during the first 145 days of 2026 compared with the same period in 2025. The city described this as a 38 percent drop.

Assessment: SUPPORTED. The figures appear in the city's report, but Civic Lantern has not found a separate review confirming them.

Field note 4 · Design capacity is not available capacity

A 10-million-gallon-per-day permit does not mean 10 million gallons per day remain available for new development. Current use, rain-driven flow, collection-system limits, and capacity already promised to approved projects must also be considered.

Assessment: AVAILABLE CAPACITY REMAINS UNCLEAR.

Outstanding questions

Records still needed for a final conclusion

  • TDEC's final written decision about MH5898.
  • The city record explaining and approving the change from a 10-million-gallon basin to an 8-million-gallon basin.
  • Current engineering numbers showing how much reliable capacity remains.
  • The amount of sewer capacity already promised to approved but unbuilt development.
  • The complete site list, score sheets, rankings, and reasons sites were removed.
  • Project cost estimates, financing plans, possible rate changes, and the proposed division of costs.

What would change the conclusion

The current answer is not permanent

Our conclusion could change if newer engineering records show that the current system has enough reliable capacity, if repairs and the new basin greatly reduce overflow risk, if a less expensive solution meets the same needs, or if new TDEC records change the status of MH5898 or other system limits.

Civic learning note

Design capacity does not equal unused capacity

Design capacity is the amount a treatment plant was built and permitted to treat under normal design conditions. It does not tell residents how much capacity is currently unused or safely available for new connections.

More helpful wastewater terms
  • Collection system: Pipes, manholes, and pump stations that move wastewater to the plant.
  • Infiltration and inflow: Rainwater or groundwater that enters sewer pipes and adds extra flow.
  • Sanitary sewer overflow: Sewage that escapes before reaching the treatment plant.
  • Equalization basin: Temporary storage for high wastewater flows, especially during storms.

Revision history

How this page has changed

  1. Reorganized the page into Civic Lantern's standard investigation format. The evidence label and substantive conclusion did not change.
  2. Evidence and source list last reviewed.

Help improve this page

Found a public record, correction, or missing context?

Every submission is reviewed before the page is changed. Do not include private or identifying information about another person.

Submit a question or source Email Civic Lantern

← Back to all issues