Missouri county well guide

Well Water in Linn County, MO: Testing, Contractors and Rules

About 24 households in Linn County, 1% of the county, rely on a private well. Nobody tests that water unless the owner does.

1%of households on a private well
Share on wells, county vs state
Linn County1%
Missouri average14%
1licensed contractors serve the county
40+ mito a certified lab; mail-in kits recommended
Nostatewide test required when a home is sold

Wells are the exception in Linn County: about 24 households, under 1% of the county, are on a private well. Being in the minority means less local help, so this page gathers what applies.

Local rules for wells in Linn County

The rules that apply in Linn County are set at the state level in Missouri. 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

No permit for the owner, but the well must be built by a Missouri permitted well installation contractor to the 10 CSR 23-3 standards for its drilling area (Missouri has 13 drilling areas with different minimum casing depths, grouted casing, 50 ft from a septic tank and 100 ft from a lagoon or drainfield), and the contractor must disinfect the well, take a water sample for bacteria after construction and file a well certification report with the Missouri Geological Survey within 60 days. The State Public Health Laboratory's New Well Series (pH, fluoride, chloride, nitrate, sulfate, iron, manganese and lead) is the usual chemistry check on a new well.

Water test when a home is soldNot required statewide

No statewide requirement. The Missouri seller's disclosure asks only whether the water supply is a private well and whether the seller knows of problems. FHA, VA and USDA loans normally require a bacteria, nitrate and lead sample from a certified lab before closing.

What the state recommends

The Department of Health and Senior Services recommends testing a private well every year for coliform bacteria, and every few years for nitrate, pH, hardness, iron, manganese, lead and copper (the State Public Health Laboratory's minerals, nutrients and metals panel covers all of these plus arsenic and uranium). Add radon and radium in the Ozarks, lead and cadmium in the Old Lead Belt and Viburnum Trend mining districts, sulfate and chloride in deep northern wells, pesticides in shallow Bootheel wells, and test again after flooding, well work or a change in taste, color or smell. Karst wells and springs in the Ozarks should be retested after heavy rain.

Free or low-cost testingAvailable

No free program, but the cheapest state lab in the country: the State Public Health Laboratory tests a private well or cistern sample for total coliform and E. coli for a $10 handling fee. Pick up the kit from your local public health agency or district health office, collect the sample and hand it back for the lab's free statewide overnight courier. Chemistry panels cost more and are ordered through the same agency or the Bureau of Environmental Epidemiology (573-751-6102).

Getting your water tested near Linn County

Linn County has no certified lab within 40 miles, so most owners here test by mail. Order bottles from a certified lab, sample from the cold tap before any treatment, and ship the same day with an ice pack.

Licensed well contractors serving Linn County

Licensed help in Linn County includes Northway Well & Pump Co. Every listing was matched to the Missouri license list; the "verify" link on each profile opens the state lookup.

Well depth and water chemistry

Well depth and water chemistry in Linn County follow the rock underneath it. Typical wells here run 300 to 800 ft in the Ozark dolomite of southern and central Missouri, the deepest domestic wells in the Midwest; 400 to 700 ft around St. Louis and in the counties along the Missouri River; 100 to 300 ft on the Springfield Plateau; 30 to 100 ft in the glacial till of northern Missouri, where yields are small and water is poor enough that most homes are on rural water districts; 60 to 200 ft in the alluvium of the Bootheel and the Missouri River bottoms. Contaminants worth testing for in this part of Missouri include coliform bacteria (the most common failure statewide, worst in ozark karst wells and springs after rain), nitrate (shallow wells in farm country, the bootheel and northern missouri).

Typical well depth

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

Contaminants to test for
  • Coliform bacteria (the most common failure statewide
  • Worst in Ozark karst wells and springs after rain)
  • Nitrate (shallow wells in farm country
  • The Bootheel and northern Missouri)
  • Hardness (dolomite across the Ozarks)
  • Iron and manganese (glacial till
  • Alluvium and Bootheel sands)
  • Radon and radium (locally in the Ozark aquifer)
  • Lead
  • Cadmium and zinc (Old Lead Belt
  • Viburnum Trend and Tri-State mining districts)
  • Sulfate
  • Chloride and sodium (deep bedrock wells in northern and western Missouri)
  • Arsenic (locally)
  • Pesticides (shallow Bootheel and river-bottom wells)
  • PFAS near airfields and industrial sites

Neighboring counties: Chariton County, Livingston County, Sullivan County, Macon County.

What well work costs in Linn County

Bacteria test (coliform and E. coli)$10published Missouri lab fees
Nitrate test$10 to $80varies by lab; ask when you order
Broad panel (metals and minerals)$85 to $450state and university lab packages
Well inspection$250 to $550$350 to $900 with water testing
Submersible pump replacement$1,000 to $2,500installed; deep wells cost more
Pressure tank replacement$800 to $1,500installed
One treatment unit$700 to $3,500softener, iron filter or UV, installed
Multi-stage whole-house treatment$2,500 to $10,000+several units or whole-house RO, installed
New well, complete$6,000 to $16,000typical 200 ft well with pump; drilling alone about $20 to $30 per foot; deeper wells cost more
Shock chlorination$80 to $200by a contractor; under $30 to do yourself

State Public Health Laboratory bacteria kit from any local health department ($10 handling fee). Installed costs are national 2026 ranges; local quotes vary with depth, access and materials. Sources, checked September 2026: Missouri State Public Health Laboratory, HomeGuide cost guides, Angi: cost to shock a well.

Questions Linn County well owners ask

How many homes in Linn County are on a well?

About 24, or 1% 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 Linn County?

There is no certified lab within 40 miles. Use a mail-in kit from a Missouri certified lab, or the county health department if it collects samples.

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

No permit for the owner, but the well must be built by a Missouri permitted well installation contractor to the 10 CSR 23-3 standards for its drilling area (Missouri has 13 drilling areas with different minimum casing depths, grouted casing, 50 ft from a septic tank and 100 ft from a lagoon or drainfield), and the contractor must disinfect the well, take a water sample for bacteria after construction and file a well certification report with the Missouri Geological Survey within 60 days. The State Public Health Laboratory's New Well Series (pH, fluoride, chloride, nitrate, sulfate, iron, manganese and lead) is the usual chemistry check on a new well.

What does a well test cost near Linn County?

Published lab fees in Missouri: $10 for a bacteria test. State Public Health Laboratory bacteria kit from any local health department ($10 handling fee). Mail-in kits cost about the same as walking in.