Research
Maintenance
July 2, 2026
A peer-reviewed study of 216 households in Chennai found that 31% of post-RO water samples still contained E. coli — and the statistical reduction was not significant. The failure mode is not the membrane. Systems never maintained showed 83% E. coli positivity, equivalent to untreated source water. The implications extend to every RO system worldwide.
Nitrates
RO Systems
Legislation
June 30, 2026
After Des Moines Water Works imposed the state's first-ever lawn watering ban, Iowans began installing reverse osmosis systems at unprecedented rates. Water treatment installers are moving into larger buildings and hiring new technicians. But with the Raccoon River running at 17 mg/L nitrate — nearly double the EPA's legal limit — and the EPA having rescinded protections for seven polluted waterways without scientific justification, the filter under the sink is the last line of defense in a system that has failed at nearly every upstream point. Federal litigation is underway.
RO Filter Lab covers reverse osmosis filtration, water quality research, and drinking water contamination. Our news section tracks the policy failures, contamination events, and research findings that explain why home water filtration is growing faster than any other home improvement category.