Continuous chlorination is the answer for wells that ultraviolet cannot serve well: water carrying iron, manganese, sulfur smell or iron bacteria alongside a microbiological problem. It does two jobs at once, disinfecting and oxidizing, and in exchange it is more equipment, more maintenance and more attention than a lamp.
Why difficult wells choose it
Chlorine oxidizes as well as disinfects. Dissolved iron and manganese become particles a downstream filter can catch. Hydrogen sulfide and its rotten egg smell are dealt with. Iron and sulfur bacteria, which form slime that shields organisms from ultraviolet light and foul filters, are attacked rather than passed through. And a residual carries into the household plumbing, so contamination entering downstream is still addressed, which no lamp can offer. On a well with several problems, one system handles them together.
What the installation consists of
A solution tank holding the chlorine mixture. A metering pump injecting it into the line, triggered by the well pump or a flow switch so dosing tracks water use rather than running continuously. A static mixer, because an injected stream does not blend on its own at household flow rates. A contact tank giving the chlorine time to work, which is the component most often undersized. And an activated carbon filter at the end removing the residual and its taste before the water reaches the taps.
Shock chlorination is a different thing
Shocking a well is a one off disinfection of the well and plumbing, used after a positive test or after work that opened the system. It clears what is there and does nothing about how organisms are getting in, so a well that needs repeated shocks has a physical defect: a cracked casing, a failed sanitary cap, a flooding well pit or surface water tracking down the outside of the casing. Continuous chlorination is what you fit when the entry route cannot be found or cannot be sealed.
Running it
Solution weakens in storage, so mix fresh and keep the tank out of heat and sunlight. The injection point and check valve block, because the reaction happens exactly where the chemical enters, and a blocked injector stops dosing with no obvious symptom. The carbon filter exhausts and is replaced on schedule. Check for a residual at a tap upstream of the carbon periodically, since that is the only proof it is dosing. The EPA notes private wells are not federally regulated, so this monitoring is the owner's. Our well filtration guide covers the ordering.
Questions people ask about chlorination system for well water
Why choose chlorination over ultraviolet?
Because it also oxidizes iron, manganese and sulfide, deals with iron bacteria, and leaves a residual in the plumbing that ultraviolet cannot.
Will the household taste chlorine?
Not if the carbon filter at the end of the system is sized and maintained. That stage exists to remove the residual before the taps.
Is shock chlorination the same thing?
No. Shocking is a one off disinfection. Repeated need for it means a physical defect letting organisms in, which continuous dosing then manages.
How do I know it is still dosing?
Test for a residual at a tap upstream of the carbon filter. A blocked injection point stops dosing without any visible symptom.