Water system

Delphos City

EPA ID OH0200412 · Allen County · 7,101 people served · owned by a local government

Little Auglaize River, stored in city reservoir
Inland river

Delphos City treats its own water from Little Auglaize River, stored in city reservoir.

The system's record

Little Auglaize River, stored in city reservoir
Inland river
Water bodies
Little Auglaize River
Raw intakes
Little Auglaize River
Reservoir
Serves
7,101 people · Allen County
EPA ID
OH0200412

About this area's water

U.S. Route 30 crossing the Little Auglaize River, Delphos's water source
U.S. Route 30 crossing the Little Auglaize River, Delphos's water sourcePhoto: Chris Light, CC BY-SA 4.0 · Wikimedia Commons
Did you know
  • 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

History4
  • 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

Treatment & pressure

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

What it costs

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

Water quality & impurities10
ContaminantLevelLimitYear
Total trihalomethanes (TTHM)
Range 42.80-93.9 ppb — individual results ran above the 80 ppb MCL, though the running annual average stayed compliant…
62.00 ppb80 (MCL)2025
Nitrate
Range 1.91-5.71 ppm, over half the MCL. Runoff from fertilizer use, leaching from septic tanks and sewage, erosion of…
5.71 ppm10 (MCL)2025
HAA5 (haloacetic acids)
Range 14.7-20.8 ppb.
18.53 ppb60 (MCL)2025
Total chlorine
Range 1.34-2.16 ppm.
1.77 ppm4 (MRDL)2025
Fluoride1.09 ppm4.0 (MCL)2025
Atrazine
Range 0.33-0.55 ppb — detected in every sample, not just occasionally. Runoff from herbicide used on row crops.
0.41 ppb3 (MCL)2025
Total organic carbon (TOC)
Range 1.9-3.7. TOC has no direct health effect but is the feedstock for trihalomethane and haloacetic acid formation…
2.4 removal…Treatment…2025
Turbidity
Range 0.04-0.15 NTU; 100% of monthly samples met the turbidity limits.
0.15 NTU…Treatment…2025
Lead
20 samples taken 9 July and 23 July 2025; 0 exceeded the action level, range 0 to 0.
0 ppb15 (action…2025
Copper
Range 0-0.053 ppm; 0 of 20 samples over the action level.
0 ppm1.3 (action…2025

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 for a report, record or notice that was missing, late or incomplete (the yearly water quality report, a public notice, lead line records).

Projects & plans8

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

Supply stress

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

Sewers

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

Sourcesverified

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

Main supplier in 1 ZIP code

Serves

Main water supplier in 1 ZIP code

Population-weighted resident shares; a ZIP code can have more than one system on record. Recomputed from each ZIP's own system list, not from the map's cached footprint.

Buys from · Sells to

Delphos City does not buy water from another system on record; it treats its own source water.

No other system is on record buying water from Delphos City.

What the records show about Delphos City

Who runs it

EPA's record describes Delphos City as owned by a local government. It has 2,750 service connections and serves 7,101 people.

EPA classes it as a community water system, one that serves the same residents all year.

Its office telephone on EPA's record is 419-695-4010.

Source: EPA Safe Drinking Water Information System (SDWIS), water system record.

How the water is treated

EPA's treatment table registers these steps for Delphos City: corrosion control, coagulation and settling, chlorine disinfection, iron and manganese removal, fluoridation, granular activated carbon, lime softening, sand or media filtration, and ultraviolet disinfection.

The list is what each system registered with EPA for treatment plants EPA still shows as active, and it can lag a plant upgrade.

Source: EPA Safe Drinking Water Information System (SDWIS) treatment table (EPA Envirofacts, pulled September 2026).

Violations

EPA's record shows no health-based violations for Delphos City since 2015.

EPA logs 1 violation of any kind since 2020: 1 for a report, record or notice that was missing, late or incomplete (the yearly water quality report, a public notice, lead line records).

Source: EPA Safe Drinking Water Information System (SDWIS) violation records: health-based violations with compliance periods beginning in 2015 or later, all violations from 2020 or later (EPA Envirofacts, pulled September 2026).

Lead and copper at the tap

In the sampling period ending December 2025, the 90th-percentile lead result at Delphos City was 0 ppb, under both the current 15 ppb action level and the 10 ppb level that applies from 2027. A result of 0 means at least nine in ten of the homes sampled had no lead detected.

The highest result on file is 5.3 ppb, in the period ending December 2022.

EPA has 7 sampling periods on file for Delphos City since 2016, the first ending in 2017; no period was above 10 ppb.

Every water system has to inventory its service lines, the pipes from the main to each building. In the inventory Delphos City sent EPA, 2,892 lines are counted.

Service lines in the inventory
MaterialLines
Lead1,938
Galvanized, needing replacement2
Unknown material46
Not lead906
All lines2,892

Systems sample taps in the homes most likely to have lead pipes or solder. The 90th-percentile result is the level nine in ten of the sampled homes were at or below. Lead comes mostly from service lines and house plumbing, not the source water, so a low result for the system does not clear an old house.

EPA's dashboard status for this inventory: reported all required service line types.

Source: EPA Safe Drinking Water Information System (SDWIS) lead and copper 90th-percentile results (EPA Envirofacts), sampling periods ending 2016 or later; EPA's service line inventory dashboard, Ohio's 2026 Q2 submission.

PFAS

EPA's fifth national round of testing (UCMR 5) took 4 samples of the water entering the pipes of Delphos City in 2024 and measured 29 PFAS. No PFAS was detected, PFOA and PFOS (federal limit 4 ng/L each) among them.

Ohio EPA's own statewide sampling tested 1 plant of Delphos City (latest sample September 2020). Not one of the six PFAS tested (PFOA, PFOS, PFHxS, PFNA, GenX and PFBS) was detected.

PFAS are the 'forever chemicals' from firefighting foam, plating shops and non-stick coatings. Results are for water leaving the plant, not your tap.

Source: EPA UCMR 5 occurrence data (final release, August 2026); Ohio EPA statewide PFAS sampling, 2019 to 2021, and its sampling status map.

Disinfection byproducts

Chlorine that disinfects water also reacts with organic matter to form byproducts. Two groups have federal limits: total trihalomethanes (TTHM, 80 µg/L) and five haloacetic acids (HAA5, 60 µg/L), judged on running yearly averages at each sampling site.

For TTHM, the average of Delphos City's samples in 2019, the last year it was sampled, was 48.4 µg/L. The worst yearly average was 58.3 µg/L and the highest single sample was 82.8 µg/L, from 60 samples taken from 2012 to 2019.

For HAA5, the average in the last year sampled was 22 µg/L. The worst yearly average was 22.7 µg/L and the highest single sample was 33 µg/L, from 60 samples.

Disinfection byproducts in the distribution system
ByproductLimitLatest yearly averageWorst yearly averageHighest sampleSamples
TTHM80 µg/L48.4 µg/L (2019)58.3 µg/L82.8 µg/L60
HAA560 µg/L22 µg/L22.7 µg/L33 µg/L60

A yearly average of 0 means nothing was detected in that year's samples. EPA's file stops at 2019; Ohio EPA's Drinking Water Watch has newer results.

Source: EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, distribution-system samples (non-detects counted as zero).

Nitrate, arsenic and radioactivity

Nitrate: the highest of 96 samples was 3.62 mg/L (as nitrogen) in 2017; in 2019, the last year sampled, the highest was 1.5 mg/L. No sample was over the limit of 10 mg/L. Nitrate above 10 is unsafe for infants.

Arsenic was not detected in 8 samples (limit 10 µg/L).

Nitrate, arsenic and radioactivity in finished water, 2012 to 2019
ContaminantSamplesHighest resultLimitSamples over limit
Nitrate (as nitrogen)963.62 mg/L10 mg/L0
Arsenic8not detected10 µg/L0

Measured in finished water: at the plant's entry points and in the distribution system; raw well and intake samples are left out. Non-detects count as zero.

Source: EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, finished water.

Solvents and fuels

EPA's file holds results for all six solvent and fuel compounds it checked. Benzene, carbon tetrachloride, 1,2-dichloroethane, trichloroethylene, tetrachloroethylene, and vinyl chloride were not detected in 9 samples each.

Solvents and fuels in finished water, 2012 to 2019
CompoundLimitSamplesDetected inHighest resultSamples over limit
Benzene5 µg/L90 of 9not detected0
Carbon tetrachloride5 µg/L90 of 9not detected0
1,2-dichloroethane5 µg/L90 of 9not detected0
Trichloroethylene (TCE)5 µg/L90 of 9not detected0
Tetrachloroethylene (PCE)5 µg/L90 of 9not detected0
Vinyl chloride2 µg/L90 of 9not detected0

"Not detected" means the lab's result was below what its method can measure, not that the compound is absent. Non-detects count as zero in the highest-result column.

Source: EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, finished water.

Farm chemicals and metals

EPA's file holds results for all nine herbicides and metals it checked. Detected: atrazine in 22 of 25 samples, highest 0.69 µg/L (limit 3); barium in 5 of 8 samples, highest 12 µg/L (limit 2,000). Not detected: alachlor in 25 samples, 2,4-D in 1 sample, chromium in 8 samples, cadmium in 8 samples, mercury in 8 samples, selenium in 8 samples, thallium in 8 samples.

Herbicides and metals in finished water, 2012 to 2019
SubstanceKindLimitSamplesDetected inHighest resultSamples over limit
AtrazineFarm chemical3 µg/L2522 of 250.69 µg/L0
AlachlorFarm chemical2 µg/L250 of 25not detected0
2,4-DFarm chemical70 µg/L10 of 1not detected0
ChromiumMetal100 µg/L80 of 8not detected0
CadmiumMetal5 µg/L80 of 8not detected0
BariumMetal2,000 µg/L85 of 812 µg/L0
MercuryMetal2 µg/L80 of 8not detected0
SeleniumMetal50 µg/L80 of 8not detected0
ThalliumMetal2 µg/L80 of 8not detected0

Non-detects count as zero in the highest-result column.

Source: EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, finished water.

Bacteria in the pipes

From 2012 to 2019, 1 of 768 routine total coliform samples taken in the distribution system at Delphos City tested positive (0.13%); in 2019, the last year on file, 0 of 96 did. E. coli was never found in the 1 sample tested for it.

A positive coliform test is a warning sign, not a violation by itself. E. coli is a sign that human or animal waste may have reached the water. Coliform counts are routine samples only; E. coli counts include repeat samples.

Source: EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, distribution-system presence/absence tests for total coliform and E. coli.

Fluoride

The Ohio Department of Health's report to the CDC (My Water's Fluoride) says Delphos City adjusts the fluoride level to the recommended level for preventing tooth decay.

EPA's treatment table lists fluoridation among the steps at Delphos City.

Measured fluoride: 1.05 mg/L on average at the plant's entry points in 2019 (in the range dentists aim for); samples ran from 0.86 to 1.08 mg/L across 8 samples in 2012 to 2019.

The recommended level for preventing tooth decay is 0.7 mg/L; the federal limit is 4 mg/L. The treatment list is what each system registered with EPA and can lag a plant upgrade.

Source: CDC My Water's Fluoride (fluoridation status as reported by the Ohio Department of Health, fetched September 2026); EPA Safe Drinking Water Information System (SDWIS) treatment table; EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, entry-point fluoride samples.

Lithium

Lithium was not detected in 4 UCMR 5 samples at Delphos City, last sampled in 2024 (the method reports from 9 µg/L).

Lithium is not regulated. EPA's draft health reference level is 10 µg/L, and it occurs naturally in deep groundwater, so well systems in the northwest run highest.

Source: EPA UCMR 5 occurrence data (final release, August 2026), samples from 2023 to 2025.

Algal toxins

Ohio EPA tests for microcystin, a toxin that harmful algal blooms can release, in raw water at the intake and in treated water.

At the intake, microcystin was detected 78 times in 287 raw-water samples, across 4 bloom seasons (2016 to 2019); the highest raw-water result was 19.2 µg/L on December 24, 2018. There has been no raw-water detection since 2024.

In treated water, microcystin was detected 2 times; the highest result was 0.25 µg/L (December 2025), below the 0.3 µg/L advisory level.

In all, 448 samples from 2016 to 2026, the latest on August 25, 2026.

Microcystin results
WaterSamplesDetectionsHighest result
Raw water, at the intake2877819.2 µg/L
Treated water16120.25 µg/L

The ten-day advisory levels for treated water are 0.3 µg/L for children under six and 1.6 µg/L for everyone else. Any detection at the intake triggers more frequent testing until two clean weeks.

Source: Ohio EPA public water system harmful algal bloom monitoring, 2016 to present (HAB data, fetched September 2026).

Water and sewer bills

Ohio EPA's 2023 rate survey puts the water bill at Delphos City for a household using 5,000 gallons a month at $907 a year, about $76 a month.

The sewer bill in the same survey is $951 a year at 5,000 gallons a month.

Annual bills, 2023
UseWater, per yearSewer, per year
2,500 gallons a month$534$529
5,000 gallons a month$907$951
8,000 gallons a month$1,356$1,457

The survey lists it as “Delphos”. These are inside-city rates and annual bills at the use shown.

Source: Ohio EPA 2023 Sewer and Water Rate Survey (Ohio State University, May 2025).

How well the service area is mapped

The service area drawn on the map for Delphos City comes from the utility's own map.

Counting the people who live in the ZIP codes it overlaps, this atlas estimates 6,802 residents are inside the boundary, 96% of the 7,101 people Delphos City reports serving.

The resident count is an estimate from 2020 Census ZIP-code populations, not a count of customers.

Source: EPA Service Area Boundaries; resident estimate by this atlas from ZIP-code overlap.

Photograph

U.S. Route 30 crossing the Little Auglaize River, Delphos's water source
U.S. Route 30 crossing the Little Auglaize River, Delphos's water sourcePhoto: Chris Light · CC BY-SA 4.0 · Wikimedia Commons

On the map

Show this system's territory on the map — 1 ZIP code in all.

Sources

U.S. EPA SDWIS and Community Water System Service Area Boundaries (v3, 2026), Ohio EPA primacy data, 2020 census blocks: the system serving most residents, traced through purchases to the treating utility; Ohio EPA 2023 Sewer and Water Rate Survey (Ohio State, May 2025) for household bills; Ohio EPA DEFA loan awards since 2016 for the loans paragraph · EPA SDWIS · EPA service area boundaries · Ohio EPA drinking water · Ohio EPA rate survey

EPA's own record for this system: Enforcement and Compliance History report for OH0200412 (EPA ECHO).

Delphos City's own pages: en.wikipedia.org, vanwert.org

Notable facts: cityofdelphos.com, cityofdelphos.com, codelibrary.amlegal.com

History: cityofdelphos.com, cityofdelphos.com, cityofdelphos.com

Water quality: cityofdelphos.com, cityofdelphos.com

Planned work: cityofdelphos.com, cityofdelphos.com

Water pressure: cityofdelphos.com, cityofdelphos.com

Capital projects: cityofdelphos.com, cityofdelphos.com, cityofdelphos.com

Rates: cityofdelphos.com, codelibrary.amlegal.com

Sewers: cityofdelphos.com, cityofdelphos.com, cityofdelphos.com

Treatment: cityofdelphos.com, codelibrary.amlegal.com

Supply stress: cityofdelphos.com, cityofdelphos.com

Quick answers

Where does Delphos City get its water?

Delphos City treats its own water from Little Auglaize River, stored in city reservoir.

How many people does Delphos City serve?

Delphos City serves about 7,101 people, and is the main water system for 1 ZIP code.

Who owns Delphos City?

Delphos City is owned by a local government.

Is there lead in Delphos City water?

In 2025 testing, Delphos City's 90th-percentile lead level in tap samples was 0 ppb (the federal action level is 15 ppb). 20 samples taken 9 July and 23 July 2025; 0 exceeded the action level, range 0 to 0.

How much fluoride is in Delphos City water?

Delphos City reported fluoride at 1.09 ppm in 2025.

Cite this page

Cite this page as:

Cracked Buckeye, "Delphos City · OH0200412", https://crackedbuckeye.com/water/OH0200412/, built 2026-10-31, accessed [date].

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