Nitrate
Overview
Nitrate in water usually comes from fertilizer, septic systems, and animal waste. It can spike after heavy rain. It is a particular concern for very young infants.
In Florida, Nitrate was found in 838 community water systems serving about 16,948,303 people. 1 of those readings was above the federal legal limit, together serving 148 people. It was measured by 1,559 systems in all, so it was detected in 54% of the systems that tested for it.
The highest reading relative to the limit was at Ranch Oaks Estates in Hillsborough County, at 150% of it.
Where it comes from: Runoff from fertilizer; leaching from septic tanks and sewage; erosion of natural deposits.
The standards
Enforceable. A utility must stay at or under this.
Health-based, not enforceable. Often lower than the limit, sometimes zero.
California OEHHA PHG (2018), as nitrogen.
Health effects the EPA associates with it: Serious illness in infants under six months (blue-baby syndrome) if untreated.
The health goal is set on health alone. The legal limit is set as close to it as is technically and economically feasible, so treatment cost and available technology are written into the number a utility is measured against. A system at or under the limit is meeting the standard it is required to meet. Both numbers are shown so the distance between them is visible.
What removes it
Reverse osmosis or anion exchange. Nothing else at household scale removes it: carbon does not, and a softener does not. Boiling makes it worse by concentrating it, which matters because the people most at risk from nitrate are infants, whose formula is often made with boiled water.
Treatment guidance describes the methods generally used for this contaminant. What your own tap actually carries depends on your plumbing and your service line as much as on the utility, which is what a test at the house tells you and an annual report cannot.
Where in Florida
Highest reported levels
Showing the 25 highest of 838 systems that reported Nitrate.
Data Sources
These figures describe water as delivered by each utility, not what your home’s plumbing adds after it arrives. Informational; not a substitute for testing your own tap.