Ohio county well guide

Well Water in Seneca County, OH: Testing, Contractors and Rules

About 7,739 households in Seneca County, 35% of the county, rely on a private well. Nobody tests that water unless the owner does.

Labs within 40 milesLicensed contractors
35%of households on a private well
Share on wells, county vs state
Seneca County35%
Ohio average18%
6licensed contractors serve the county
11 mito the nearest certified lab, BoJhun Environmental Services
Nostatewide test required when a home is sold

About one in 3 households in Seneca County relies on a private well, around 7,739 homes. Outside the towns with public water, wells are the norm here.

Local rules for wells in Seneca County

The rules that apply in Seneca County are set at the state level in Ohio. New wells must be tested before use, and nothing is required at sale. Some counties and townships add permits or setbacks of their own, so check locally before drilling. The state's own recommendations are below.

At a glance

Water test for a new wellRequired

Under OAC 3701-28 a permit from the local health district is required before a well is drilled or altered. When the work is done, the owner asks the health district for the final inspection, and a sanitarian collects the water sample: total coliform, E. coli and nitrate. The system is approved only when the sample passes (4 or fewer total coliform per 100 mL and no E. coli for a well without continuous disinfection).

Water test when a home is soldNot required statewide

No statewide requirement. Most local health districts offer a real-estate evaluation of the well on request (a visual inspection plus a bacteria and nitrate sample), and some lenders ask for one. Ask the county health district for its fee and turnaround.

What the state recommends

ODH recommends a total coliform and nitrate test every year, and every time the water changes in taste, color or smell, after flooding, or after any work on the well or pump. Add arsenic, iron and manganese, hardness and sulfate at least once, and PFAS or methane where local conditions call for it.

Free or low-cost testingAvailable

No statewide free program. Several county health districts run their own labs (Erie, Logan, Mahoning, Canton City among them) and sell bacteria and nitrate tests at cost; others sell bottles from a certified lab. OSU Extension fact sheet AEX-315 lists labs that accept samples from homeowners.

Getting your water tested near Seneca County

The nearest certified lab is BoJhun Environmental Services in Fostoria, about 11 miles from the county center, and it accepts samples from homeowners. There are 3 more within 40 miles, listed below with what each tests for.

4 certified labs within 40 miles

Licensed well contractors serving Seneca County

Licensed help in Seneca County includes A & D Excavating, LLC and Bishop’s Plumbing & Heating of Tiffin Inc and 4 others. Every listing was matched to the Ohio license list; the "verify" link on each profile opens the state lookup.

Well depth and water chemistry

Well depth and water chemistry in Seneca County follow the rock underneath it. Typical wells here run 50 to 200 ft in glacial sand and gravel; 100 to 400 ft in bedrock in the east and south feet. Contaminants worth testing for in this part of Ohio include coliform bacteria, nitrate (northwest and central farm counties), arsenic (glacial aquifers in northwest and central ohio), iron.

Typical well depth

Varies by location. Check the state well record search for logs of nearby wells.

Contaminants to test for
  • Coliform bacteria
  • Nitrate (northwest and central farm counties)
  • Arsenic (glacial aquifers in northwest and central Ohio)
  • Iron
  • Manganese
  • Hardness
  • Sulfate and hydrogen sulfide (eastern shale and coal country)
  • Radium and uranium (some sandstone and shale wells)
  • Methane (near oil and gas fields)

Neighboring counties: Sandusky County, Wyandot County, Hancock County, Ottawa County.

What well work costs in Seneca County

Basic bacteria and nitrate test$25 to $75lab fee, homeowner sample
Full panel lab test$150 to $400metals, VOCs, radiologicals
Well inspection$250 to $550flow, pressure, visual, water test
Submersible pump replacement$1,200 to $4,500parts and labor
Pressure tank replacement$400 to $1,200installed
Whole-house treatment system$800 to $6,000softener, iron filter, UV, RO
New well drilled$5,500 to $25,000about $25 to $65 per foot
Shock chlorination$80 to $300or about $20 as a DIY job

National ranges from published 2025 to 2026 contractor pricing. Local quotes vary with depth, access and materials.

Questions Seneca County well owners ask

How many homes in Seneca County are on a well?

About 7,739, or 35% of households, based on Census housing data and state well surveys. The share is highest outside the towns with public water.

Where is the closest certified lab to Seneca County?

BoJhun Environmental Services in Fostoria, about 11 miles away. It accepts homeowner samples.

Do I need a permit to drill a well in Seneca County?

Under OAC 3701-28 a permit from the local health district is required before a well is drilled or altered. When the work is done, the owner asks the health district for the final inspection, and a sanitarian collects the water sample: total coliform, E. coli and nitrate. The system is approved only when the sample passes (4 or fewer total coliform per 100 mL and no E. coli for a well without continuous disinfection).

What does a well test cost near Seneca County?

A bacteria and nitrate test runs $25 to $75 at most certified labs; a full panel with metals is $150 to $400. Mail-in kits cost about the same as walking in.