E. coli in Your Water: What a Positive Test Means & the 48-Hour Response Protocol
Quick answer: E. coli in drinking water carries a zero-tolerance MCL — it's a fecal-source pathogen, and any confirmed detection means ...
Radium in Your Water: the 5 pCi/L Limit, the $40 Screening Trick & What Genuinely Removes It
Quick answer: Radium (Ra-226 + Ra-228 combined) carries a federal limit of 5 pCi/L — and it's colorless, odorless, and tasteless, so te...
How to Test Fluoride in Water at Home: 3 Methods, What Each Costs, and the Test-Strip Trap Nobody Mentions
Testing your own water for fluoride is one of those tasks that looks like a $15 errand and isn't. Fluoride is the trickiest of the comm...
Fluoride Removal Methods Compared: RO vs Activated Alumina vs Bone Char vs Distillation
Four home methods genuinely remove fluoride from drinking water: reverse osmosis, activated alumina, bone char, and steam distillation....
Copper in Your Water: the 1.3 mg/L Action Level, Blue-Green Stains & Why pH Is the Real Culprit
Quick answer: Copper's action level is 1.3 mg/L (measured like lead's — at the 90th percentile of first-draw taps), with a 1.0 mg/L sec...
Is Fluoride in Water Bad for You? The Evidence, Both Sides (No Sides Taken)
There is no water-contaminant question in America with more heat and less light than this one — and this page is built to a specific di...
Chlorine in Your Water: MRDL 4.0, Reading Your Free Report First & the THM Side-Story
For a quick reference on chlorine, see our chlorine entry.
Quick answer: Chlorine in municipal tap water is regulated as a disinfec...
Manganese in Your Water: 0.05 mg/L, the Black Stains & the 2021 Health Advisory You Should Know About
For a quick reference on manganese, see our manganese entry.
Quick answer: Manganese carries two numbers, and most pages blur them:...
Sulfur Smell in Your Water: the Cold/Hot Split Test That Might Cost You $15 Instead of $1,500
For a quick reference on sulfur smell, see our sulfur smell entry.
Quick answer: Rotten-egg smell is hydrogen sulfide (H2S) or sulf...
Arsenic in Your Water: 10 ppb, the As(III) Trap & the Full Removal Cost Sheet
For a quick reference on arsenic, see our arsenic entry.
Quick answer: Arsenic's federal limit is 10 ppb, and long-term exposure ab...