Radium is regulated under the Safe Drinking Water Act because of its potential health effects at elevated concentrations; for residents of Knob Lick, Missouri, the relevant fact is that it has shown up in recent EPA compliance samples — point-of-use filtration is one option residents research, alongside reviewing the utility's published treatment data.

Data: EPA SDWIS, CCR Reports, ECHO Last verified: 2026-05-14

Radium in Knob Lick Tap Water

Radium has been detected in Knob Lick, Missouri drinking water at a maximum level of 16.9 pCi/L — 3.38x the EPA MCL.

This analysis covers 18,217 residents across 1 ZIP code in Knob Lick.

Knob Lick's overall water quality grade is D (53/100).

Is Radium in Knob Lick Water Safe?

If you live in an affected ZIP code, consider installing a reverse osmosis or ion exchange filter certified under NSF 58 and testing your water independently.

Radium Levels by ZIP Code

Average radium level across Knob Lick: 16.9 pCi/L

Health Effects of Radium

• Increased risk of bone cancer (radium accumulates in bones)
• The body treats radium like calcium, storing it in bones
• Lifetime cancer risk of ~1 in 10,000 at 5 pCi/L
• No safe threshold for radioactive contamination

Health risk severity: High. Governed by the Radionuclides Rule.

How Radium Gets Into Drinking Water

• Natural radioactive decay in underground rock formations
• Groundwater sources (especially deep wells)
• Mining and industrial waste
• Higher in regions with specific geology (Midwest, parts of South)

What to Do About Radium in Knob Lick Water

1. Reverse osmosis (NSF 58 certified) removes 90%+ of radium
2. Ion exchange (water softeners) can reduce radium
3. Point-of-use RO at kitchen tap is most cost-effective
4. GAC filters alone are NOT effective for radium

Look for filters certified under NSF 58 for radium removal.

Related

• Radium — National Overview
• Radium in Missouri
• Missouri Water Quality
• Knob Lick Water Quality
• Check Your ZIP Code