Delphos City

• When it opened in 2006, Delphos's sewage plant was the largest flat plate membrane bioreactor facility in the world — and the only membrane plant anywhere running Autothermal Thermophilic Aerobic Digestion on its solids.
• A town of about 7,000 people built a wastewater plant sized for the organic load of 70,000, because its industries put out that much.
• The plant's solids are cooked by their own bacteria: the ATAD reactors hold about 140°F with no external heat, producing a Class A biosolid that gets pressed to roughly 22% solids and spread in city parks or handed to…
• There are 52,000 individual membrane plates in the bioreactor, stacked into 130 double units across five trains — and in a storm the fifth train stops thickening sludge and starts treating sewage.
• The reservoir has its own chapter of city law: Chapter 931 of the Delphos codified ordinances is the Delphos-Gillmor Reservoir.

Source: cityofdelphos.comcityofdelphos.comcodelibrary.amlegal.com

• 2005The city began a wastewater treatment improvement project to handle its unusually high industrial organic loadings, improve effluent quality discharged to Jennings Creek, and meet coming Total…
• 2006The new wastewater plant came online — at the time the largest flat plate membrane bioreactor facility in the world, and the only membrane treatment facility operating with an Autothermal…
• 2025Ohio EPA issued the Delphos Water Plant a warning for failure to meet the requirements for service line notifications; the city posted a lead service line replacement program policy and a service…
• 2026Council authorized a run of wastewater headworks work: new screens from SAVECO North America installed by Peterson Construction (O2026-11, O2026-18, O2026-21), a COG bar screen from Du Peron…

Source: cityofdelphos.comcityofdelphos.comcityofdelphos.com

How it is treated

The Delphos Water System takes its raw water from the Little Auglaize River via the Delphos Gilmore Reservoir northwest of the city — the river is impounded first rather than pumped straight to the plant, and the reservoir has its own chapter in the codified ordinances (Chapter 931, Delphos-Gillmor…

Source: cityofdelphos.comcodelibrary.amlegal.com

Water pressure

Not published. Neither the 2025 consumer confidence report nor the Water Department page gives a distribution system pressure figure.

Source: cityofdelphos.comcityofdelphos.com

Not published online. Delphos bills water and sewer through Muni-Link with payment via AuthorityPay, and the city's Documents & Forms library has a dedicated 'Water Sewer'…

Source: cityofdelphos.comcodelibrary.amlegal.com

Source: cityofdelphos.comcityofdelphos.com

EPA compliance record

Lead at the tap: 90th-percentile result 0 ppb in 2025 (action level 15 ppb).

EPA record: no health-based violations since 2015.

1 violation of any kind logged since 2020, 1 of them paperwork (monitoring, reporting, public notice or consumer report).

Recent and current work

• Wastewater treatment plant replacement (membrane bioreactor facility) · 2005-2006 · completed
  Begun 2005, online 2006. Designed for the organic loading of a community of 70,000 despite a population near 7,000, with a 12 MGD design peak flow. The largest…
• Storm holding pond expansion · 2005-2006 · completed
  Enlarged an existing pond to bring the city's storm holding capacity to 12 million gallons, part of the same wastewater project. Cost not published.
• Project No. 2025-100 S. Main Street Storm Sewer Project · 2025 · under construction
  New storm sewer running from W. Clime Street, begun 15 August 2025 and listed 'In Progress' on the city's projects page as of September 2026. Cost not…
• Wastewater plant headworks screen replacement · 2026 · under construction
  Screens purchased from SAVECO North America (O2026-11, amended by O2026-18) with removal and installation by Peterson Construction (O2026-21). Costs are in the…
• Wastewater plant COG (bar) screen · 2026 · under construction
  Screen purchased from Du Peron Corporation (O2026-22) and installed by Peterson Construction (O2026-23). Cost not published on the ordinance index.
• 7th Street lift station repair and renovation · 2026 · under construction
  Contract with All Purpose Contracting, Inc. (O2026-24). Cost not published on the ordinance index.
• Sewer inspection trailer and camera · 2026 · completed
  Purchase of a 2023 Envirosight inspection trailer and sewer camera from Best Equipment Company (O2026-25). Cost not published on the ordinance index.

Source: cityofdelphos.comcityofdelphos.comcityofdelphos.com

Planned or needed

• Lead service line replacement program · planned
  The city adopted a lead service line replacement program policy and published a service line inventory survey after Ohio EPA warned it in 2025 for failure to…

Source: cityofdelphos.comcityofdelphos.com

Not documented as quantity-stressed. Delphos banks Little Auglaize River water in the Delphos Gilmore Reservoir rather than pumping the river directly, which buffers it against low flow, and it maintains a published Surface Water Assessment Plan. The visible pressure is on quality, and it is the classic farm-country surface water…

Source: cityofdelphos.comcityofdelphos.com

Sanitary

A 2006 membrane bioreactor plant discharging to Jennings Creek, built from 2005 to treat industrial organic loadings equivalent to a community of 70,000 in a city of about 7,000. Average dry weather flow is roughly 1.5 MGD; design peak flow is 12 MGD. Wastewater enters an influent pump station on the old plant site through a 48-inch and…

Storm

Delphos runs a combined sewer system, so storm flow goes to the wastewater plant rather than to a separate outfall network — when it rains the plant sees flows in excess of eight times the 1.5 MGD dry weather average, which is why it was built for a 12 MGD…

Source: cityofdelphos.comcityofdelphos.comcityofdelphos.com

Compiled from the utility's own reports and public records, then independently re-checked against primary sources.