Well Shock-Chlorination Dose
The household bleach to shock-chlorinate a private well from the casing diameter and standing water column.
Example
You enter
- Casing inside diameter (in) 6
- Standing water column (ft) 100
- Target concentration (ppm) 100
- Bleach available chlorine (%) 6
You get
- Well water volume 147 gal
- Available (100%) chlorine 0.122 lb
- Bleach (gal) 0.245
Details, formula, and sources
Well volume, the available chlorine for the target ppm, and the bleach to pour in. The local health department governs the procedure and clearance.
well_volume_gal = 0.0408 x casing_in^2 x column_ft; bleach_gal = volume x target_ppm / (1,000,000 x (bleach% / 100)); available_cl_lb = (volume / 1,000,000) x target_ppm x 8.34.
AWWA A100 / state private-well shock-chlorination guidance (by name).
State and extension well-disinfection guides are public; bleach strength is on the label.
Estimate. AHJ and licensed professional govern.
Field names used by the API: casing_diameter_in, water_column_ft, target_ppm, bleach_pct, well_volume_gal, available_cl_lb, bleach_gal
- Target concentration default 100 ppm; a shock is commonly about 50 to 200 ppm held overnight (often 12 to 24 hours)state well guidance
- Bleach strength plain unscented household bleach, about 5 to 8.25% available chlorine; ignores the slight bleach specific gravity, so round upproduct label
- Clearance pump to waste until the chlorine clears, then retest; the health department governs the bacteriological clearancestate well code