D33/100
Arco Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 1,080 residents · Idaho
What's In Arco's Tap Water?
1
Contaminants Tested
0
Exceed EPA Limits
1
Above EPA Goals
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Lead (90th percentile) | 0.002 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
2
Violations (last 5yr)
1
Unresolved
1
Health-Related
TIER 3Unresolved
Violation related to E. coli (RTCR)
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: July 1, 2025 – July 31, 2025Rule: Consumer Confidence RuleEnforcement: Informal — resolved cooperativelyVerify on EPA.gov
TIER 1 — URGENTResolved
Maximum Contaminant Level Violation
When: August 1, 2022 – August 31, 2022Rule: Total Coliform RuleEnforcement: Resolving — corrective action underway
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Water Utility Details
ARCO CITY OF
Population Served
1,080
Water Source
Groundwater
System ID
ID6120001
Frequently Asked Questions About Arco Water
Is Arco tap water safe to drink?
Arco, Idaho tap water receives a grade of D (33/100), which is considered poor. 0 contaminant(s) exceed EPA maximum contaminant levels and 36 violation(s) are on record. Residents should consider using an NSF-certified water filter to reduce contaminant exposure.
What contaminants are in Arco's water?
Of the 1 contaminants tested in Arco's water supply, the most notable include Lead (90th percentile). No contaminants exceed EPA legal limits. 1 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.
Does Arco have any water quality violations?
Yes, Arco has 36 EPA violation(s) on record, with the most recent in 2025. Violation types include MR, MCL. 7 of these are health-based violations, which are the most serious category.
Do I need a water filter in Arco?
Arco water meets EPA standards, so a filter is not strictly necessary. However, some residents prefer the added security of a water filter. EPA health goals (MCLGs) are stricter than legal limits and are set at levels with zero expected health risk. 1 contaminant(s) exceed these stricter goals.
Where does Arco's tap water come from?
Arco's drinking water is sourced from groundwater and supplied by ARCO CITY OF. The system serves approximately 1,080 people. Groundwater is pumped from underground aquifers, which often provides natural filtration.
How often is Arco's water tested?
Under the Safe Drinking Water Act (SDWA), water utilities are required to regularly test for over 90 contaminants. Testing frequency varies by contaminant — some are tested monthly, others quarterly or annually. Arco's water systems must report results to the EPA and publish an annual Consumer Confidence Report (CCR). The data on this page reflects the latest available EPA testing data.
How does Arco's water compare to other cities in Idaho?
Arco's water quality score of 33/100 earns a grade of D, which is considered poor. This is a concerning score that suggests significant water quality issues. Visit our Idaho state page to see how all cities in the state compare.
What should I do if I'm concerned about Arco's water quality?
If you have concerns about Arco's tap water, consider these steps: (1) Request your utility's annual Consumer Confidence Report for detailed local data. (2) Get your water independently tested through a state-certified laboratory. (3) Consider an NSF-certified water filter rated for the contaminants found in your area. (4) Contact your water utility (ARCO CITY OF) with specific questions. (5) Report water quality issues to your state drinking water program or the EPA Safe Drinking Water Hotline at 800-426-4791.