Tennessee county well guide

Well Water in Williamson County, TN: Testing, Contractors and Rules

About 1,071 households in Williamson County, 1% of the county, rely on a private well. Nobody tests that water unless the owner does.

Labs within 40 milesLicensed contractors
1%of households on a private well
Share on wells, county vs state
Williamson County1%
Tennessee average9%
15licensed contractors serve the county
16 mito the nearest certified lab, Tennessee Department of Health Laboratory Services (Nashville)
Nostatewide test required when a home is sold

Wells are the exception in Williamson County: about 1,071 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 Williamson County

The rules that apply in Williamson County are set at the state level in Tennessee. The state does not require a test on a new well, 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 wellNot required statewide

No statewide water test and no state permit for a household well. The Water Well Act requires the well to be drilled by a TDEC-licensed water well driller to the rule 0400-45-09 construction standards (steel casing at least 19 ft deep or into bedrock, grouted, ending 6 in above grade with a sanitary seal; 50 ft from septic tanks and drainfields, 10 ft from property lines), and the driller must file a well report with TDEC within 30 days. A few counties permit wells through the county health department, Shelby County most notably, and lenders usually want a bacteria test on a new well.

Water test when a home is soldNot required statewide

No statewide requirement. The Tennessee Residential Property Condition Disclosure asks only whether the water supply is a 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

TDEC and the Department of Health recommend testing a private well for coliform bacteria every year, and for nitrate, pH, hardness, iron, manganese, lead and copper at least once and again every few years. Add radon and uranium in East Tennessee bedrock wells, arsenic on the Highland Rim and in West Tennessee sands, pesticides in shallow Coastal Plain wells, and test again after flooding, well work or a change in taste, color or smell. Karst wells in Middle and East Tennessee should be retested after heavy rain, when bacteria and turbidity spike.

Free or low-cost testingAvailable

No statewide free program. The Department of Health laboratory in Nashville (and the Knoxville regional laboratory for East Tennessee) tests private well and spring samples for bacteria, nitrate and metals for a modest fee; bottles and forms come through the county health department or the laboratory (615-262-6337). Some county health departments and UT Extension offices run periodic screening days.

Getting your water tested near Williamson County

The nearest certified lab is Tennessee Department of Health Laboratory Services (Nashville) in Nashville, about 16 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 Williamson County

Licensed help in Williamson County includes Amos Todd Neel and Carter Services and 13 others. Every listing was matched to the Tennessee license list; the "verify" link on each profile opens the state lookup.

Well depth and water chemistry

Well depth and water chemistry in Williamson County follow the rock underneath it. Typical wells here run 160 to 300 feet; the median of 1,429 residential and farm wells reported to TDEC since 2000 is 220 feet. Contaminants worth testing for in this part of Tennessee include coliform bacteria (the most common failure statewide, worst in karst limestone wells that draw surface water after rain), nitrate (farm counties and shallow west tennessee wells), hardness (limestone across middle and east tennessee).

Typical well depth

160 to 300 feet; the median of 1,429 residential and farm wells reported to TDEC since 2000 is 220 feet

Contaminants to test for
  • Coliform bacteria (the most common failure statewide
  • Worst in karst limestone wells that draw surface water after rain)
  • Nitrate (farm counties and shallow West Tennessee wells)
  • Hardness (limestone across Middle and East Tennessee)
  • Iron and manganese (West Tennessee sands
  • The Cumberland Plateau and shale wells)
  • Hydrogen sulfide (shale and deeper limestone wells)
  • Turbidity after storms (karst wells)
  • Acidic corrosive water that pulls lead and copper from plumbing (Plateau sandstone and Blue Ridge wells)
  • Radon and uranium (East Tennessee crystalline rock and black shale)
  • Arsenic (locally on the Highland Rim and in West Tennessee)
  • PFAS near airfields and industrial sites

Neighboring counties: Davidson County, Rutherford County, Maury County, Cheatham County.

What well work costs in Williamson County

Bacteria test (coliform and E. coli)$40published Tennessee lab fees
Nitrate test$10 to $80varies by lab; ask when you order
Broad panel (metals and minerals)$125published Tennessee lab fees
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

Tennessee Tech Water Center: $40 bacteria, $125 basic package with bacteria, minerals and nitrate. Installed costs are national 2026 ranges; local quotes vary with depth, access and materials. Sources, checked September 2026: Tennessee Tech Water Center lab, HomeGuide cost guides, Angi: cost to shock a well.

Questions Williamson County well owners ask

How many homes in Williamson County are on a well?

About 1,071, 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 Williamson County?

Tennessee Department of Health Laboratory Services (Nashville) in Nashville, about 16 miles away. It accepts homeowner samples.

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

No statewide water test and no state permit for a household well. The Water Well Act requires the well to be drilled by a TDEC-licensed water well driller to the rule 0400-45-09 construction standards (steel casing at least 19 ft deep or into bedrock, grouted, ending 6 in above grade with a sanitary seal; 50 ft from septic tanks and drainfields, 10 ft from property lines), and the driller must file a well report with TDEC within 30 days. A few counties permit wells through the county health department, Shelby County most notably, and lenders usually want a bacteria test on a new well.

What does a well test cost near Williamson County?

Published lab fees in Tennessee: $40 for a bacteria test. Tennessee Tech Water Center: $40 bacteria, $125 basic package with bacteria, minerals and nitrate. Mail-in kits cost about the same as walking in.