Water system
Norwalk City
EPA ID OH3901111 · Huron County · 17,466 people served · owned by a local government
Norwalk City treats its own water from Huron River / East Branch Huron River (via Upper, Memorial, and Lower Reservoirs).
The system's record
- Water bodies
- Huron River, East Branch Huron River, Upper Reservoir, Memorial Reservoir, Lower Reservoir
- Raw intakes
- Huron River
Memorial Reservoir
Reservoir
Reservoir Spillway
E Branch Huron River - Serves
- 17,466 people · Huron County
- EPA ID
- OH3901111
About this area's water
Did you know
- Norwalk's municipal water system dates to 1871, when fewer than 20 towns in the entire state of Ohio had one.
- The reservoirs were nicknamed Laning's Lakes after the city councilman who spent six years pushing the project through before construction began in 1896.
- In 1969 the Lower Reservoir dam failed after nine inches of rain fell on Norwalk in nine hours.
- Norwalk buys supplemental water almost every day of the year: over 54 million gallons came through the Northern Ohio Rural Water connection on 350 days in 2025, and the city says that connection is used about 355 days a…
- The 1927 filtration plant building is still the working water plant, upgraded rather than replaced.
History6
- 1871First water plant built on the East Branch of the Huron River near the current river pump station, at a time when fewer than 20 towns in Ohio had municipal water systems.
- 1896After roughly six years of debate, construction begins on the Upper and Lower reservoirs and an adjacent pump station; the site was chosen partly for its abundant springs. The reservoirs were…
- 1898First water pumped from Lower Reservoir with no additional treatment; a tall standpipe is erected next to the pump station to improve pressure.
- 1924Norwalk begins chlorinating its water at the urging of the Ohio Department of Health.
- 1927Water filtration plant, at Old State Road and Woodlawn Avenue, put into service and still the plant building in use.
- 1952750,000-gallon water tower built near Maple and Chestnut streets, replacing the tower at the plant; high service pumps installed to feed it.
Treatment & pressure
How it is treated
The plant draws surface water directly from an intake in Lower Reservoir, immediately next to the treatment plant at Old State Road and Woodlawn Avenue (Water Treatment Department, 201 Woodlawn Avenue). Upper, Memorial and Lower Reservoirs form a three-reservoir system holding nearly 700 million…
Source: norwalkoh.comnorwalkoh.comnorwalkoh.com
Water pressure
No psi figure is published. The city states that two water towers maintain system pressure and supply: a 750,000-gallon tower built in 1952 near Maple and Chestnut streets and a…
Source: norwalkoh.comnorwalkoh.com
What it costs
$9.00 per 1,000 gallons
Typical household bill about $32 a month for water.
Inside city limits: minimum charge $4.50/month for 1,000 gallons or less, then $0.90 per 100 gallons, which is $9.00 per 1,000 gallons. Outside city limits is exactly double…
Water quality & impurities10
| Contaminant | Level | Limit | Year |
|---|---|---|---|
| Total trihalomethanes (TTHM) Locational running average; no violation, but individual detections ran above the 80 ppb MCL and this is the… | 59.6 (range of… ppb | MCL 80 | 2025 |
| Haloacetic acids (HAA5) Locational running average; no violation. | 35.5 (range… ppb | MCL 60 | 2025 |
| Total chlorine Residual disinfectant. | 1.57 (range… ppm | MRDL 4 | 2025 |
| Total organic carbon Value is the ratio of TOC actually removed to TOC required to be removed; above 1.0 means compliance. | 1.45 (range -1… removal… | treatment… | 2025 |
| Turbidity Filtration performance indicator. | 0.26 highest… NTU | treatment… | 2025 |
| Fluoride No violation. | 0.94 (range… ppm | MCL 4 | 2025 |
| Barium No violation. | 0.019 (range… ppm | MCL 2 | 2025 |
| Nitrate The CCR prints a level found of 0.8 ppm alongside a detection range of 0.12-0.57 ppm, which is internally inconsistent… | 0.8 ppm | MCL 10 | 2025 |
| Lead 0 of 30 samples above the 15 ppb action level. | 0 (90th… ppb | AL 15 | 2025 |
| Copper 0 of 30 samples above the 1.3 ppm action level. | 0.2 (90th… ppm | AL 1.3 | 2025 |
Source: norwalkoh.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.
4 violations of any kind logged since 2020: 4 for required testing that was missed or reported late.
Projects & plans3
Recent and current work
- Water plant rebuild and expansion · 1992 · completed
Raised plant capacity from 2.85 to 4.0 MGD. No cost figure is published by the city. - Northern Ohio Rural Water interconnection · 2010 · completed
Supplemental supply connection now used roughly 355 days a year. No cost published. - Source Water Protection Plan for the Norwalk Creek watershed · 2025 · completed
Developed with the Ohio Rural Water Association and Ohio EPA and endorsed by Ohio EPA in 2025; calls for the city to work with watershed property owners to…
Source: norwalkoh.comnorwalkoh.com
Supply stress
Norwalk's own supply depends entirely on a small, roughly 8-square-mile Norwalk Creek watershed feeding three shallow reservoirs, and the city already covers the gap by buying supplemental water from Northern Ohio Rural Water on about 355 days a year. During drought it also pumps from the East Branch of the Huron River into Memorial…
Source: norwalkoh.comnorwalkoh.com
Sewers
Sanitary
The City of Norwalk operates its own wastewater treatment plant at 201 Plank Road, designed for an average flow of 3.5 million gallons per day with a peak of 8.2 MGD; actual 2024 average daily flow was 2.45 MGD. Flow reaches the plant through two 24-inch interceptor sewers. Treated effluent discharges to the west branch of Rattlesnake…
Storm
Norwalk has COMBINED sewers, not separate ones: the city publishes combined sewer overflow (CSO) explainers, annual CSO reports and event notifications, with 25 separate four-hour CSO events and matching seven-day notifications logged for 2024 alone. A…
Source: norwalkoh.comnorwalkoh.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
- 44857 · Norwalk73% of residents
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
Norwalk 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 Norwalk City.
What the records show about Norwalk City
Who runs it
EPA's record describes Norwalk City as owned by a local government. It has 7,130 service connections and serves 17,466 people.
EPA classes it as a community water system, one that serves the same residents all year.
EPA's record says it has substantially implemented source water protection under Ohio's program, dating the program from 2023. Its office telephone on EPA's record is 419-663-6736.
Source: EPA Safe Drinking Water Information System (SDWIS), water system record.
How the water is treated
EPA's treatment table registers these steps for Norwalk City: corrosion control, coagulation and settling, chlorine disinfection, iron and manganese removal, fluoridation, powdered activated carbon, and sand or media filtration.
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 Norwalk City since 2015.
EPA logs 4 violations of any kind since 2020: 4 for required testing that was missed or reported late.
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 Norwalk 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 2.9 ppb, in the period ending December 2022.
EPA has 4 sampling periods on file for Norwalk City since 2016, the first ending in 2016; 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 Norwalk City sent EPA, 6,566 lines are counted.
| Material | Lines |
|---|---|
| Lead | 156 |
| Galvanized, needing replacement | 53 |
| Unknown material | 3,236 |
| Not lead | 3,121 |
| All lines | 6,566 |
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 Norwalk City in 2023 and measured 29 PFAS.
PFOA and PFOS were not detected, against a federal limit of 4 ng/L each.
The highest PFAS result was PFBA 10.2 ng/L.
Ohio EPA's own statewide sampling tested 1 plant of Norwalk City (latest sample September 2020). Not one of the six PFAS tested (PFOA, PFOS, PFHxS, PFNA, GenX and PFBS) was detected.
Ohio EPA's current sampling status map lists 1 plant of Norwalk City as sampled, most recently October 2023.
| Compound | Highest result | Federal limit |
|---|---|---|
| PFOA | not detected | 4 ng/L |
| PFOS | not detected | 4 ng/L |
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 Norwalk City's samples in 2019, the last year it was sampled, was 53 µg/L. The worst yearly average was 53 µg/L and the highest single sample was 92.2 µg/L, from 128 samples taken from 2012 to 2019.
For HAA5, the average in the last year sampled was 32.1 µg/L. The worst yearly average was 32.1 µg/L and the highest single sample was 65.3 µg/L, from 127 samples.
| Byproduct | Limit | Latest yearly average | Worst yearly average | Highest sample | Samples |
|---|---|---|---|---|---|
| TTHM | 80 µg/L | 53 µg/L (2019) | 53 µg/L | 92.2 µg/L | 128 |
| HAA5 | 60 µg/L | 32.1 µg/L | 32.1 µg/L | 65.3 µg/L | 127 |
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 97 samples was 1.12 mg/L (as nitrogen) in 2015; in 2019, the last year sampled, the highest was 0.82 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).
| Contaminant | Samples | Highest result | Limit | Samples over limit |
|---|---|---|---|---|
| Nitrate (as nitrogen) | 97 | 1.12 mg/L | 10 mg/L | 0 |
| Arsenic | 8 | not detected | 10 µg/L | 0 |
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 8 samples each.
| Compound | Limit | Samples | Detected in | Highest result | Samples over limit |
|---|---|---|---|---|---|
| Benzene | 5 µg/L | 8 | 0 of 8 | not detected | 0 |
| Carbon tetrachloride | 5 µg/L | 8 | 0 of 8 | not detected | 0 |
| 1,2-dichloroethane | 5 µg/L | 8 | 0 of 8 | not detected | 0 |
| Trichloroethylene (TCE) | 5 µg/L | 8 | 0 of 8 | not detected | 0 |
| Tetrachloroethylene (PCE) | 5 µg/L | 8 | 0 of 8 | not detected | 0 |
| Vinyl chloride | 2 µg/L | 8 | 0 of 8 | not detected | 0 |
"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 8 of the nine herbicides and metals it checked. Detected: atrazine in 3 of 23 samples, highest 0.4 µg/L (limit 3); barium in 8 of 8 samples, highest 22 µg/L (limit 2,000). Not detected: alachlor in 23 samples, chromium in 8 samples, cadmium in 8 samples, mercury in 8 samples, selenium in 8 samples, thallium in 8 samples.
| Substance | Kind | Limit | Samples | Detected in | Highest result | Samples over limit |
|---|---|---|---|---|---|---|
| Atrazine | Farm chemical | 3 µg/L | 23 | 3 of 23 | 0.4 µg/L | 0 |
| Alachlor | Farm chemical | 2 µg/L | 23 | 0 of 23 | not detected | 0 |
| Chromium | Metal | 100 µg/L | 8 | 0 of 8 | not detected | 0 |
| Cadmium | Metal | 5 µg/L | 8 | 0 of 8 | not detected | 0 |
| Barium | Metal | 2,000 µg/L | 8 | 8 of 8 | 22 µg/L | 0 |
| Mercury | Metal | 2 µg/L | 8 | 0 of 8 | not detected | 0 |
| Selenium | Metal | 50 µg/L | 8 | 0 of 8 | not detected | 0 |
| Thallium | Metal | 2 µg/L | 8 | 0 of 8 | not detected | 0 |
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, 2 of 2,358 routine total coliform samples taken in the distribution system at Norwalk City tested positive (0.08%); in 2019, the last year on file, 0 of 180 did. E. coli was never found in the 2 samples 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 Norwalk City adjusts the fluoride level to the recommended level for preventing tooth decay.
EPA's treatment table lists fluoridation among the steps at Norwalk City.
Measured fluoride: 0.99 mg/L on average at the plant's entry points in 2019 (in the range dentists aim for); samples ran from 0.84 to 1.06 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 Norwalk City, last sampled in 2023 (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 1 time in 224 raw-water samples, across 1 bloom season (2025); the highest raw-water result was 0.289 µg/L on September 22, 2025. The highest raw-water result since 2024 was 0.289 µg/L.
In treated water, microcystin was detected 1 time; the highest result was 0.167 µg/L (December 2022), below the 0.3 µg/L advisory level.
In all, 305 samples from 2016 to 2026, the latest on August 24, 2026.
| Water | Samples | Detections | Highest result |
|---|---|---|---|
| Raw water, at the intake | 224 | 1 | 0.289 µg/L |
| Treated water | 81 | 1 | 0.167 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).
How well the service area is mapped
EPA estimated the service area of Norwalk City with a computer model rather than drawing it from the utility's map, so its edges are approximate.
Counting the people who live in the ZIP codes it overlaps, this atlas estimates 17,239 residents are inside the boundary, 99% of the 17,466 people Norwalk 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
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 OH3901111 (EPA ECHO).
Norwalk City's own pages: en.wikipedia.org
Notable facts: norwalkoh.com, norwalkoh.com, norwalkoh.com
History: norwalkoh.com, norwalkoh.com, norwalkoh.com
Water quality: norwalkoh.com
Water pressure: norwalkoh.com, norwalkoh.com
Capital projects: norwalkoh.com, norwalkoh.com
Rates: norwalkoh.com, norwalkreflector.com
Sewers: norwalkoh.com, norwalkoh.com
Treatment: norwalkoh.com, norwalkoh.com, norwalkoh.com
Supply stress: norwalkoh.com, norwalkoh.com
