Follow a water testing schedule
Water quality changes with seasons, floods and repairs. Regular testing catches problems before people get ill.
How
- Wells: test at least once a year for total coliform bacteria, nitrates, total dissolved solids and pH (CDC, US EPA).
- Rainwater for drinking: the Texas manual advises testing for pathogens at least quarterly.
- Chlorinated supplies: check free chlorine at the tap with a DPD kit and write it down. Aim for 0.2 to 0.5 mg/L (Sphere, WHO Technical Note 11).
- Springs: test before and after heavy rains each year (NC State).
- Test again after floods, nearby ground works, well repairs, or any change in taste, colour or smell, and when someone becomes pregnant or a child joins the household (CDC).
- Inspect the wellhead every spring for mechanical problems (CDC) and check cap, casing and seals (US EPA).
- Note that standard bacteria tests do not detect Giardia or Cryptosporidium; test for these if illness is suspected (NC State).
Sources
- The Texas Manual on Rainwater Harvesting, 3rd edition. Texas Water Development Board, accessed 2026-11
- Guidelines for Testing Well Water. US Centers for Disease Control and Prevention (CDC), accessed 2026-11
- Protect Your Home's Water. US EPA, accessed 2026-11
- Protecting Water Supply Springs. NC State Extension, accessed 2026-11
- Sphere Handbook, Water supply standard 1: access and water quantity (interactive edition). Sphere Association, accessed 2026-11
- Technical Note 11: Measuring chlorine levels in water supplies. World Health Organization and WEDC, Loughborough University, accessed 2026-11