Strontium in Delaware Drinking Water
Ranked by max strontium detected (µg/L) · UCMR 3 data (2013–2015) · Data from EPA SDWIS & UCMR
Strontium in Delaware: what the data shows
Delaware has 12 cities with strontium data from the EPA's UCMR 3 program (2013–2015). Strontium was detected above the 1,500 µg/L EPA health reference level in 0 of those cities. The state average max detected level is 245.6 µg/L. Strontium occurs naturally in groundwater, particularly in areas with limestone and dolomite geology. It can also enter water from industrial waste and mining operations. There is no federal MCL for strontium, but the EPA established a health reference level (HRL) of 1,500 µg/L. Long-term exposure to strontium above the HRL may affect bone health, particularly in children, by substituting for calcium in developing bones. Reverse osmosis and ion exchange systems are effective at removing strontium from drinking water.
Cities exceeding 1,500 µg/L EPA HRL (no MCL)
Strontium data across Delaware
Each dot is a city with UCMR 3 strontium testing data. Cities where strontium exceeds the 1,500 µg/L EPA health reference level are highlighted. Size reflects population served.
Top 10 cities by strontium level in Delaware
Highest Strontium levels (µg/L)
All Delaware cities ranked by strontium level
| # | City | Level | Level | Over HRL? | Violations | Grade |
|---|---|---|---|---|---|---|
| 1 | Camden-Wyoming | 410.0 µg/L | No | 35 | B | |
| 2 | Dover | 360.0 µg/L | No | 35 | B | |
| 3 | Middletown | 330.0 µg/L | No | 17 | B+ | |
| 4 | Wilmington | 261.0 µg/L | No | 8 | B | |
| 5 | New Castle | 261.0 µg/L | No | 9 | B- | |
| 6 | Bear | 220.0 µg/L | No | 3 | B | |
| 7 | Bear | 220.0 µg/L | No | 3 | B | |
| 8 | Lewes | 210.0 µg/L | No | 20 | D+ | |
| 9 | Newark | 206.0 µg/L | No | 5 | C- | |
| 10 | Rehoboth Beach | 190.0 µg/L | No | 8 | B | |
| 11 | Smyrna | 149.4 µg/L | No | 14 | C | |
| 12 | Bethany Beach | 130.0 µg/L | No | 5 | B+ |
Frequently asked questions about strontium in Delaware
Is strontium in Delaware tap water harmful?
Strontium at low levels is not considered harmful, but the EPA set a health reference level (HRL) of 1,500 µg/L based on potential bone effects. No cities in Delaware exceed the HRL. There is currently no federal MCL for strontium. Children may be more susceptible because strontium can substitute for calcium in developing bones.
How can I remove strontium from my drinking water?
Reverse osmosis and ion exchange (water softener) systems are effective at removing strontium from drinking water. Standard carbon filters are NOT effective. If your water comes from a well in an area with limestone or dolomite geology, consider testing for strontium.