Across the water systems that serve Marysville, Washington, Nitrate has appeared in EPA compliance samples — standard municipal treatment targets this contaminant, though detections in the compliance record indicate it has reached household taps at measurable levels.

Data: EPA SDWIS, CCR Reports, ECHO Last verified: 2026-04-05

Nitrate in Marysville Tap Water

Nitrate has been detected in Marysville, Washington drinking water at a maximum level of 6.1 ppb — below the EPA MCL of 10 mg/L (as nitrogen).

This analysis covers 84,305 residents across 2 ZIP codes in Marysville.

Marysville's overall water quality grade is A (92/100).

Is Nitrate in Marysville Water Safe?

Nitrate was detected in Marysville water but currently falls within EPA limits. However, some health organizations argue the EPA MCL may not be protective enough.

If you are concerned, a reverse osmosis or ion exchange filter can reduce nitrate levels further.

Nitrate Levels by ZIP Code

Average nitrate level across Marysville: 6.1 ppb

Health Effects of Nitrate

• Methemoglobinemia ("blue baby syndrome") in infants under 6 months
• Increased risk of colorectal and bladder cancer (long-term)
• Thyroid disease from chronic exposure
• Possible reproductive effects

Health risk severity: High. Governed by the National Primary Drinking Water Regulations.

How Nitrate Gets Into Drinking Water

• Agricultural fertilizer runoff
• Animal feedlot operations and manure
• Septic system leachate
• Urban stormwater and wastewater discharge

What to Do About Nitrate in Marysville Water

1. Reverse osmosis is the most effective method for nitrate removal
2. Ion exchange systems designed for nitrate can also work
3. Standard carbon filters do NOT remove nitrate
4. Boiling water increases nitrate concentration — never boil for nitrate

Look for filters certified under NSF 53 / NSF 58 for nitrate removal.

Related

• Nitrate — National Overview
• Washington Water Quality
• Marysville Water Quality
• Check Your ZIP Code