· Michael Blair
Outside Metro’s service area, private wells are common across Middle Tennessee. They are not regulated or monitored, so testing and treatment are entirely the owner’s responsibility.
What to test for
Bacteria annually at minimum. Then nitrates, hardness, iron, manganese, pH and total dissolved solids. On limestone geology, hardness is close to guaranteed.
A test after any flooding, after work on the well, and whenever taste, smell or appearance changes.
The common results and what they need
Bacteria: shock chlorination and then continuous disinfection, commonly ultraviolet. Iron and manganese: oxidising filtration, which addresses the orange and black staining.
Hydrogen sulphide, the rotten egg smell, needs oxidation and filtration. Hardness needs softening. Low pH needs a neutralising filter, and it is worth addressing because acidic water corrodes plumbing.
- Test for bacteria annually, more after flooding
- Iron and manganese cause orange and black staining
- Rotten egg smell is hydrogen sulphide
- Low pH corrodes plumbing and needs neutralising
- Sediment pre-filtration protects everything downstream
Order of treatment matters
Treatment components go in a specific sequence — sediment, then oxidation and filtration, then softening, then disinfection. Out of order, each stage fouls the next.
This is where a designed system differs from a collection of purchased units.
Maintaining the well itself
The cap should be sealed and above grade, the surrounding ground should slope away, and there should be no septic or livestock too close.
Most bacterial contamination in Middle Tennessee wells is surface water entering at the head rather than anything in the aquifer.