KNOW THE FACTS!

Cistern Disinfection

A cistern should be cleaned & disinfected after installation, repairs or receipt of hauled water to guarantee a safe drinking water supply.

 

When to clean and disinfect

A cistern should be cleaned & disinfected after installation, repairs or receipt of hauled water to guarantee a safe drinking water supply.

 

To clean…

Remove debris. Scrub the interior of the cistern with a stiff brush or broom and a solution of 1/4 cup of 5.25 percent unscented chlorine bleach in 10 gallons of water. Mix solution thoroughly.

 

To disinfect…

Place as much potable water as possible in the cistern. Add 2 gallons of 5.25 percent chlorine bleach to every 1000 gallons of water. Mix thoroughly. Use only regular chlorine bleach. Scented bleaches leave a powder residue. Run all taps (inside and outside) until a distinct chlorine odor is present at each spigot. Retain chlorine solution in cistern for at least 24 hours. After 24 hours check for chlorine odor. If odor is present, flush system with potable water until chlorine odor disappears. Once no odor is present repeat disinfection process. Clean and disinfect system every three to six months depending on household water usage.

Maintenance Tips

Replace roof washers and floating filter cartridges on a regular basis (every three months). Visually inspect filters monthly and replace as needed. To inspect the retention tank, purchase a chlorine residual testing kit. A residual of 2/10 parts per million (ppm) is desirable after a 20 minute period.

Questions

For more information, contact the Water Quality Division, 513-946-7966.

 

Download a printable version of this fact sheet here.

 

250 William Howard Taft Road
2nd Floor, Cincinnati, OH 45219
Phone 513.946.7800 Fax 513.946.7890
hamiltoncountyhealth.org