PUBLIC HEALTH STANDARD · EPA & CDC VERIFIED

Emergency Water Storage & Bleach Disinfection Tool

Direct Answer: How Much Water Do You Need in a Power Outage? Source: FEMA / CDC / EPA

Under CDC and FEMA guidelines, store a minimum of 1.0 gallon of water per person per day (0.5 gal drinking, 0.5 gal food prep/hygiene), increasing to 1.5–2.0 gallons/day in temperatures above 85°F or for nursing mothers. For chemical disinfection, add 8 drops of regular unscented 6% household bleach (or 6 drops of 8.25% bleach) per gallon of clear water. Stir, wait 30 minutes, and ensure a faint chlorine aroma before drinking.

1. Household Water Demand Sizing

Number of Adults (Ages 12+)

Number of Children (Under 12)

Pets (Dogs / Cats)

Planning Horizon (Duration in Days)

Climate & Environmental Temperature

Water source is cloudy, turbid, or pond/rainwater (Doubles bleach dosage)

Storage & Disinfection Allocation

Total Water Storage Volume Needed

49 Gallons

Household Daily Consumption: 3.5 gal/day

55-Gallon Food-Grade Drums: 1 Drum(s)

5-Gallon Stackable Jugs: 10 Jugs

Bleach Dosage Ratio: 8 drops/gal (6 drops if 8.25%)

Cross-section diagram of dual chamber gravity water filter showing upper reservoir and lower clean reservoir

DEADLY BLEACH PITFALLS (EPA MANDATE)

NEVER use "Splash-less", scented, or color-safe bleaches. They contain polymer thickeners (polyacrylic acid) and perfume chemicals that are toxic when ingested and fail to kill waterborne pathogens.
Check the EPA Registration Number: Ensure the label specifically states EPA registration for drinking water treatment and lists ONLY Sodium Hypochlorite (typically 6% to 8.25%) and inert ingredients.
Bleach Degrades Rapidly: Bleach loses up to 50% of its active chlorine potency after 12 months on the shelf. In an extended 90-day event, old bleach will fail to disinfect water. Rotate sealed bottles annually.